Progress 10/01/07 to 09/30/12
Outputs
OUTPUTS: Activities that have been conducted this year include conducting and analyzing experiments related to the sanitation of food processing facilities, the effect of sanitation post fumigation with food processing facilities, the efficacy of fumigants in a real world situation, a survey of food processing facilities on their ideas about the relationship between sanitation and pest management. Results from these concepts have been used in the classroom at Purdue University in teaching students about research, pest management and insect biology. They have also been reported at several national and regional extension meetings including the Purdue Pest Control Conference, the University of Kentucky Short Course, the University of Maryland Tri-State Pest Management Conference and the Purdue University Post Harvest Education and Recertification Workshop. Information was also presented as such scientific meetings as the National Entomological Society of America meeting, Ohio Valley Entomology Association and the North Central Branch of the Entomological Society of America. PARTICIPANTS: Purdue University Mahsa Fardisi Klien Ileleji Scott Williams Muhammad Zia ul Haq Yanlin Tian Marissa McDonough C.P. Woloshuk WanTien Tsai Outside Purdue C. A. Campabadal D. E. Maier A. Denvir W. Chayaprasert Medizone Inc TARGET AUDIENCES: pest managers grain managers post harvest researchers extension educators and specialists home owners PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Research this year has focused on three major projects, cigarette beetle flight initiation, influence of DDGS on insect development, and ozone efficacy on urban pests. The DDGS research focused on the influence of two samples of corn DDGS obtained from an "old" generation dry-grind fuel ethanol plant as a food and oviposition resource for red flour beetle, in contrast with traditional flour (90%)/yeast (10%) diet. Larval development was significantly faster on a flour/yeast diet compared to the DDGS samples while mortality was higher on DDGS (38.7%) compared with flour/yeast (4.4%). Additionally, fecundity was significantly lower on DDGS compared to the flour/yeast diet. These results indicate that this type of DDGS is not as suitable a developmental diet compared to the standard laboratory diet and that the addition of this type of DDGS to animal feeds should not increase feed vulnerability to flour beetle infestation. The objective our ozone work was to determine the concentration-time (CT) relationship of ozone needed to achieve 100% mortality for various life stages (adult, nymph and egg case) of german cockroaches and provide baseline information needed to develop ozone technology for German cockroach management. The most ozone-tolerant stage were eggs, followed by the adults and nymphs with CT's ranging from 4800-5700. Lastly, flight is an important factor in spread of cigarette beetle infestation and can be affected by internal and external factors. Temperature within a facility not only influences the rate of pest population growth within the stored product, but it can influence the timing of management programs. If the facility is warm enough for the cigarette beetles to live and grow inside the food stuff, but not enough to permit flight then insects will not be captured in traps. Thus, a trap catch of zero might not reflect a zero population presence. The influence of temperature in combination with age, gender, and mating status was examined to determine minimum temperature and percent of flight initiation of cigarette beetle. We found that flight activity of cigarette beetles is highly dependent on environmental temperature, gender, age and mating status of individuals. The minimum predicted temperatures at which different categories of males (virgin young, virgin old, mated young and mated old ) initiated flight were 22.6 C, 19.7, 23.3, and 22.4C, while virgin young, virgin old, mated young and mated old females were predicted to initiate flight at 24.5, 22.9, 22.1, and 23.5C respectively. Young virgin males had the highest percentage flight initiation and thus the greatest probability of being caught in the monitoring traps. Thus, environmental temperature must be above 19.7C when interpreting sex pheromone traps in food storage facilities since they attract mostly males.
Publications
- McDonough, M. X., L. J. Mason, and C.P. Woloshuk. 2011. Susceptibility of stored product insects to high concentrations of ozone at different exposure intervals J. Stored Prod. Res. 47: 306-310
- McDonough, M. X., C. A. Campabadal, L. J. Mason, D. E. Maier, A. Denvir, C.P. Woloshuk. 2011. Ozone application in a modified screw conveyor to treat grain for insect pests, fungal contaminants, and mycotoxins. J. Stored Prod. Res. 47:49-245.
- Tsai, W.T., L. J. Mason, W. Chayaprasert, K. E. Ileleji and D. E. Maier. 2011. Investigation of fumigant efficacy under real-world fumigation conditions. J. Stored Prod. Res. 47: 179-184.
- Fardisi,M., L.J.Mason, and K. E. Ileleji. 2013. Development and Fecundity Rate of Tribolium castaneum (Herbst) on Distillers Dried Grains with Solubles. Journal of Stored Product Research. In revision 2012
- Fardisi, M. and L.J Mason. 2013. Influence of Lure (Food/Sex Pheromone) on Young Mated Cigarette Beetle (Lasioderma serricorne (F.)) (Coleoptera: Anobiidae) Flight Initiation Journal of Stored Products Research. In revision. 2012.
|
Progress 10/01/10 to 09/30/11
Outputs
OUTPUTS: This past year we completed the fumigation evaluation of methyl bromide and sulfuryl fluoride in flour mills. This work has allowed us to determine the appropriate dosages to assure equivalent fumigation efficacy and to provide the information to flour millers through extension meetings, professional meetings, and consulations and demonstrations needed to make pest management decisions. PARTICIPANTS: Kansas State University Department of Grain Science, Entomology Department Oklahoma State University, Entomology Department TARGET AUDIENCES: Flour Millers Fumigators Grain Managers Pest Managers PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Food processing plants often conduct thorough cleanings prior to fumigation, but sanitation practices post fumigation are quite variable. In field studies we found that although facility age, construction material and door policy were important, the most important factor was facility sanitation. Regardless of fumigant type, or time of year the fumigation that occurred in the facilities that maintain the highest sanitation levels, achieved the longest rebound time and that received in the maximum fumigation benefit. Those facilities that had poor sanitation practices, rebounded very quickly, sometimes within months, to pre-fumigation levels. Our findings support the use of sanitation as a pest management tool in flour mills and points out the importance of an IPM program. Another project that we have completed is the study of high concentrations of ozone and stored product, specifically all life stages of red flour beetle and Indianmeal moth, adult maize weevil and adult rice weevil. Insects were treated with six ozone concentrations between 50-1800 ppm. The specific objective was to determine minimal time needed to attain 100% mortality. The most ozone-tolerant stages of red flour beetle were pupae and eggs, which required a treatment of 180 min at 1800 ppm ozone to reach 100% mortality. Eggs of Indianmeal moth also required 180 min at 1800 ppm ozone to reach 100% mortality. Ozone treatments of 1800 ppm for 120 min and 1800 ppm for 60 min were required to kill all adult maize and adult rice weevil, respectively. The results indicate that high ozone concentrations reduce the treatment times significantly over previously described results. Our results also provide new baseline information about insect tolerance to ozone treatment. Lastly we studied the application of ozone in the field. This study evaluated the efficacy of a modified screw conveyor to treat grain with ozone in a continuous-flow system. The ozone concentration delivered into the screw conveyor was 47,800 ppm and the average retention time for a corn kernel moving through the system was 1.8 min. Under these conditions, 100% mortality of adult red flour beetle (Tribolium castaneum (Herbst)) and adult maize weevil (Sitophilus zeamais (Motsch.)) was achieved after three passes through the screw conveyor, which equated to a concentration (by) time (CT) product value of 258,120 ppm-min. The potential effectiveness of the continuous treatment to reduce mold on the surface of corn kernels was also explored. Aspergillus flavus counts were reduced by 96% in a single pass through the screw conveyor. Three passes through the screw conveyor reduced the mold count by more than 2-log units. Ozone treatment also reduced aflatoxin applied to the grain; however, the reduction was not sufficient enough to be of commercial value. The results of this study provide valuable information for estimating the parameters needed for effectively treating grain in a commercial scale continuous-flow treatment system.
Publications
- Marissa X. McDonough, Linda J. Mason, Charles P. Woloshuk. 2011. Susceptibility of stored product insects to high concentrations of ozone at different exposure intervals. J. Stored Prod. Res. 47, 306-310
- Tsai, W.T., L. J. Mason, Wat Chayaprasert, Klein E. Ileleji and Dirk E. Maier. Investigation of fumigant efficiency in flour mills under real-world fumigation conditions. 2011. J. Stored Prod. Res. Volume 47, Issue 3, July 2011, Pages 179-184
- Marissa X. McDonough, Carlos A. Campabadal, Linda J. Mason, Dirk E. Maier, Adrian Denvir, Charles Woloshuk. 2011. Ozone application in a modified screw conveyor to treat grain for insect pests, fungal contaminants, and mycotoxins J. Stored Prod. Res., 47: 249-254.
|
Progress 10/01/09 to 09/30/10
Outputs
OUTPUTS: This past year we have been concluding experiments on the influence of Dried Distillers Grains with Solubles (DDGS) (a byproduct when corn or other distiller grains are dry milled) on insect growth and development, and the use of high concentrations of ozone on insect mortality. The results of these works were presented at the 10th International Conference of Stored Product Protection in Portugal and in symposium proceedings. They have also been presented at 6 PAT presentations in Illinois, 2 in Michigan, and 2 in Indiana. This information has also been included in numerous extension trainings, field days and workshops throughout the Midwest Region. Material is currently being incorporated into extension material for specific targeted groups. As a result of this research 1 PhD student has graduated. Results have also been used as examples in the teaching of an undergraduate class in insect behavior and a senior level capstone class at Purdue University. PARTICIPANTS: M. Fardisi, M. McDonough, S. Williams, W.T. Tsai, K. Ileleji, C. Campabadal, C. Woloshuk, Purdue University, West Lafayette, IN USA; D.E. Maier, Kansas State University, Manhattan KS USA TARGET AUDIENCES: Pest Control Managers, Technicians, and Operators; Stored Grain Managers, Technicians, and Operators; Food Processors, Producers, and Retailers; Educational Institutions; Homeowners PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Dried Distillers Grains with Solubles (DDGS) is a byproduct when corn or other distiller grains are dry milled. Our research determined the vulnerability of old generation DDGS to insect infestation. We found that the larval stage, in contrast with other stages of development, was significantly elongated when fed a diet of DDGS. Development on flour/yeast diet averaged 19.15d compared to 45.44d when fed a diet of DDGS. As expected there was no effect of diet on the length of the egg or pupal stages since these stages are non-feeding. We also found that twenty-six of the 70 red flour beetle females on the DDGS diet laid no eggs, and in 12 instances one of the pair died with no oviposition occurring compared to the flour/yeast dishes, in which all females laid eggs and none died. The number of eggs that hatched and survived two weeks was significantly lower (P<0.05) on DDGS (17.37+1.22 eggs per female (n=32)) compared to a flour/yeast diet (204.7+10.99 eggs per female (n=32)). The DDGS rate decreased to an average of 9.59+1.33 eggs per female (n=58) when females that survived but did not lay eggs is included. Thus, oviposition rate in the control diet was 12-21 times higher than the DDGS diet. This elongated development period for larvae and reduced oviposition rate on DDGS is good news for those who store DDGS, especially during the warmer storage periods. Infestations by storage insects may grow significantly slower, resulting in less damage over the vulnerable storage period.Combined with the developmental data, this indicates that even if eggs are laid on DDGS, the resulting larvae will develop very slowly, resulting in a greatly extended life cycle. It is evident that the development and oviposition rate of red flour beetle is significantly reduced on "old" generation DDGS compared to the standard flour/yeast diet. Results showed that there were significant differences in larval development period and fecundity between the two diets, but the egg and pupal periods were not influence by diet. As a result, this type of DDGS is less vulnerable to red flour beetle infestation. We are currently testing other types of DDGS. Another project we are currently research is the use of high concentrations of ozone to generate the parameters needed for treating a moving stream of grain. The efficacy of short periods of exposure to high ozone concentrations was determined for all life stages of red flour beetle, and Indianmeal moth, adult maize weevil and rice weevil. Our results indicate the increasing ozone concentration reduces the treatment time required to kill stored grain insects. However, the maximum ozone concentration (1800 ppm) tested is far below what is required to effectively treat a moving streams of grain under real-world conditions. However, these reduced treatment times are feasible for other treatment scenarios and show promise for reducing the current recommended treatment time of 3 d.
Publications
- Alexander, C., Y.A. Yigezu, D.E. Maier, L.J. Mason, and C.P. Woloshuk. Cost of Good Sanitation Practices for On-Farm Grain Storage. Purdue University, GQ-50-W, March 2008, pages 1-5.
- M. Fardisi, L. J. Mason, K. Ileleji. 2009. The influence of a DDGS diet on the development and oviposition rate of Tribolium castaneum (Herbst). Proc. 10th International Working Conference on Stored Product Protection. Eds. M. O. Carvalho, P. G. Fields, C. S. Adler, F. H. Arthur, C. G. Athanassiou, J. F. Campbell, F. Fleurat-Lessard, P. W. Flinn, R. J. Hodges, A. A. Isikber, S. Navarro, R. T. Noyes, J. Riudavets, K. K. Sinha, G. R. Thorpe, B. H. Timlick, P. Trematerra, N. D. G. White. Estoril, Portugal. Julius Kuhn-Archiv. pgs 156-159.
- L. Mason, W. Tsai, K. Ileleji. 2009. Influence of Sanitation on Post-Fumigation Pest Rebound. Proc. 10th International Working Conference on Stored Product Protection. Eds. M. O. Carvalho, P. G. Fields, C. S. Adler, F. H. Arthur, C. G. Athanassiou, J. F. Campbell, F. Fleurat-Lessard, P. W. Flinn, R. J. Hodges, A. A. Isikber, S. Navarro, R. T. Noyes, J. Riudavets, K. K. Sinha, G. R. Thorpe, B. H. Timlick, P. Trematerra, N. D. G. White. Estoril, Portugal. Julius Kuhn-Archiv. pg 983.
- D. E. Maier, C. A. Campabadal, C. P. Woloshuk, L. Mason. 2009. Continuous ozonation treatment systems as other alternative more efficient grain protection technologies Proc. 10th International Working Conference on Stored Product Protection. Eds. M. O. Carvalho, P. G. Fields, C. S. Adler, F. H. Arthur, C. G. Athanassiou, J. F. Campbell, F. Fleurat-Lessard, P. W. Flinn, R. J. Hodges, A. A. Isikber, S. Navarro, R. T. Noyes, J. Riudavets, K. K. Sinha, G. R. Thorpe, B. H. Timlick, P. Trematerra, N. D. G. White. Estoril, Portugal. Julius Kuhn-Archiv. pgs. 346-351.
- M. X. McDonough, L. J. Mason, C. Woloshuk, C. Campabadal. 2009. Ozone technology in the post-harvest storage environment- a comparison of efficacy of high doses of ozone to insects treated under laboratory conditions and field conditions. Proc. 10th International Working Conference on Stored Product Protection. Eds. M. O. Carvalho, P. G. Fields, C. S. Adler, F. H. Arthur, C. G. Athanassiou, J. F. Campbell, F. Fleurat-Lessard, P. W. Flinn, R. J. Hodges, A. A. Isikber, S. Navarro, R. T. Noyes, J. Riudavets, K. K. Sinha, G. R. Thorpe, B. H. Timlick, P. Trematerra, N. D. G. White. Estoril, Portugal. Julius Kuhn-Archiv. pgs. 386-388.
|
Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: Currently we recommend that raw grain be treated with 50 ppm for 3 d for management of most stored grain pests. This is acceptable when grain is to remain in storage for a long period of time, but will not be effective for trt of large quantities of moving grain. Treatment with the initial parameters (50-1800 ppm for 30-60m) did not result in 100% mortality of maize weevil (MW) although 93.3% mortality was achieved at 1800 ppm for 60m. Mortality increased to 97.7% at 90m and 100% mortality was finally achieved at 120m (1800 ppm). This was a longer time than originally desired and would require excessive grain holding times to achieve this level of control. The biological consequences of achieving 93.3% rather than 100 % mortality are unknown at this time. Maximum mortality for adult rice weevils (RW) at the 30m trt was 90%. Mortality (100%) of adult RW was only achieved at a treatment ct of 1800ppm for 60m. At 60m treatment time, no significant difference was found between the trt at 1800 & 1500ppm nor 1000 & 500ppm. It appears that RW adults are more sensitive to high concentrations of ozone and would be easier to control compared to MW. A 60m treatment time is acceptable for a semi-continuous trt system. In a field trial evaluating the efficacy of extremely high doses of ozone on insects in a continuous flow auger, there were no significant differences in insect mortality found between the 3-run wet and dry ozone trt. Insect mortality (100%) was achieved for adult MW and red flour beetle (RFB) in the 3-run dry treatment. For MW, significant differences were found between each of the dry trt (1-run, 2-run & 3-run). Significant differences were found between the 1-run and 2-run treatments as well as the 2-run & 3-run treatments with RFB. However, no significant differences were found between the 1-run & 3-run trts. These data show that high doses of ozone have an increased effect on insect mortality and in the future, may prove to be useful as a means to control insects in storage grain This information had been transferred to end users during several extension and PAT workshops, including: 4 PAT fumigation workshops in Illinois; 4 extension grain meetings in Indiana; an all day fumigation workshop at Purdue, and 2 food processing meetings in Minnesota. PARTICIPANTS: Yigezu A. Yigezu, Corinne E. Alexander, and Paul V. Preckel, Department of Agricultural Economics, Purdue University, 403 West State Street, West Lafayette, IN 47907, USA D.E. Maier, Department of Grain Science and Industry, Kansas State University, 201 Shellenberger Hall, Manhattan, KS 66506, USA C.P. Woloshuk, Department of Botany and Plant Pathology, Purdue University, 915 West State Street, West Lafayette, IN 47907, USA J. Lawrence, Carlos Campabadal and D.J. Moog, Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, IN 47907, USA Marissa McDonough, WanTien Tsai, Department of Entomology, Purdue University, 901 West State Street, West Lafayette, IN 47907, USA TARGET AUDIENCES: Grain managers; food processors; pest control managers; organic food producers; scientists PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
This research provides critical data in the development of ozone as a control strategy especially against two important pest species of weevil using reduced trt times. It is important to keep in mind that although these two species look and act very similar, they behave differently under similar conditions. Results showed that there was no significant difference between the treatments of 1800ppm for 90 & 120m in the MW. However, a treatment of 1800ppm for 120m is needed to achieve maximum control. RW required half the time than MW at the same ozone concentration to achieve 100% control. If ozone is to be used in these shorter treatment times compared to the currently recommended dose-time of 50 ppm for 3 d, the desired holding time will need to be increased to probably 120m for complete elimination of RW and MW adults. As a result of this we have adjusted our research methodologies and recommendations to account for species specific dosage. Having proved that high dosages are effective against insects and are feasible in the field we are currently targeting mold control to assist farmers with this difficult storage year.
Publications
- Y. A. Yigezu, C. E. Alexander, P. V. Preckela, D.E. Maier, C.P. Woloshuk, L.J. Mason, J. Lawrence and D.J. Moog. 2008. Optimal management of molds in stored corn. Agricultural Systems, Volume 98, Issue 3, Pages 220-227
|
Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: Activities including - mentoring 2 graduate students (MS and PhD) and 1 undergraduate and analyzing data from the past year's field studies in processing plants and grain bins. Information from the first year of research has been reported at various extension meeting around the region including the annual Post Harvest Research and Education, Ohio State and Illinois PAT trainings, as well as society meetings (International Congress of Entomology, Grain Elevator and Processing Society Meetings and Entomology Society of America (national and regional) meetings. PARTICIPANTS: Charles Woloshuk, Purdue University; Klein Ileleji, Purdue University; Dirk Maier, Kansas State University; O3Co, Aberdeen, ID; Fumigation Service & Supply Inc., Indianapolis, Indiana; Graduate and Post Graduate Training, W. Chayaprasert, W. Tsai, M. McDonough and C. Campabadal TARGET AUDIENCES: The following groups have been served by the research/extension efforts listed previously: Food processing facilities, Grain handling facilities, Pest management professionals, Flour mills, and Fumigators PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Currently the lab is focused on the influence of high dose/short resident times of ozone on mortality of stored product insects. Previous research indicated that 3 days at 50 ppm was effective in controlling most stored product insects. However, this long treatment time is not practical for moving streams of grain nor treatment during busy handling times of the year. Thus, additional efficacy data of ozone is needed to broaden the applicability of ozonation. The need to treat moving streams of grain for very short periods of time (resident times of less than 1 hour) necessitates generating efficacy data on stored product pests at considerably higher concentrations (>500ppm to 1800ppm). It appears that we can achieve 100% for many insect pests in less than 1 h at the high end of the range. However there will be survivors under the current practical application of this technique. Thus we are currently examining the influence of sublethal dosages on reproduction and development and the issue of repellency during treatment. Preliminary data indicate that there is a significant influence on reproduction, especially when the insects are treated multiple times, over a short period of time. This preliminary data are encouraging that a counterflow or semi-continuious flow rapid treatment system is possible. Our research on pest monitoring, sanitation and rebound rates in working flour mills fumigated with either sulfuryl fluoride or mthyl bromide indicates that red flour beetle post fumigation daily capture rates were significantly lower than pre-fumigation level and remained low at least 3 months post fumigations with exceptions of one sulfuryl fluoride and one methyl bromide fumigation. Indoor Indianmeal moth pre-fumigation populations were not significant with extremely low daily average capture. Post fumigation daily average captured moth varies and was not significantly influenced by either fumigant. Linear and Loglinear models were both used to evaluate the effect of fumigants on the rebound rate of both species. For the current standard in controlling red flour beetles, sulfuryl fluoride is as effective as methyl bromide and there was no significant influence of both fumigants to the Indianmeal moth populations. Pest populations took longer to rebound to pre-fumigation level in mills that practice better sanitation. Residual pesticide application also influenced pest rebound, however, the major factor that influences the pest level is the sanitation level of the mill. Mills with a better sanitation ranking had better long-term control over pests.
Publications
- Taylor, A.M., L.J. Mason and J.J. Morrell. 2007. Effect of ozone treatment on survival of termites and wood decay fungi. 38th Annual International Research Group on Wood Preservation. Jackson, Wyoming.
- Tsai, W.T. 2008. Examination of insect mangement practices in food processing plants prior to, during, and post sulfuryl fluoride or methyl bromide fumigation. Disseration. Dept. of Entomology. Purdue University
|
Progress 10/01/06 to 09/30/07
Outputs
OUTPUTS: This past year we conducted experiments to determined if various aspects of hairy fungus beetle development are affected by three fungal species commonly found in stored grains. The effect of aflatoxin in the diet was also examined. This information was included in our post harvest recertification workshop held in December, the Illinois PAT stored grain workshops, and to the various food production client with which I consult.
PARTICIPANTS: C.P Woloshuk, Purdue University W.T. Tsai, Purdue University - graduate student on the project
TARGET AUDIENCES: Stored grain producers and processors
Impacts
We recently examined development times and ovipositional preference of hairy fungus beetle (Typhaea stercorea (L.) Col: Mycetophagidae), when reared on pure cultures of Aspergillus flavus, Eurotium rubrum, and Penicillium purpurogenum, and the ability of hairy fungus beetle to develop in the presence of high levels of aflatoxin when fed A. flavus grown on coconut agar medium. Results indicate that hairy fungus beetle can complete its life cycle when fed these mold species grown on a defined medium in pure culture. Developmental times were shortest on A. flavus and longest on P. purpurogenum. Females appeared to prefer A. flavus as an ovipositional site resulting in more egg laying on cultures of A. flavus than on the other two species. Lastly, hairy fungus beetle can complete their life cycle in the presence of high levels of aflatoxin. The results suggested that the species of mold degrading grain can influence insect developmental rates and thus population growth
rates. We are continuing this work to determine the relationship between mold feeding insects and the mycotoxins found in grain.
Publications
- Tsai, W.T., L.J. Mason & C.P. Woloshuk. 2007. Effect of three stored grain fungi on the development of Typhaea stercorea. J. Stored Prod. Res. 43: 129-133.
|
Progress 10/01/05 to 09/30/06
Outputs
Insects and fungi (molds) contribute to quality deterioration of stored grains and food and thus it is essential for the food storage and production industry to have effective pest management programs to protect against contamination by insects, molds and mycotoxins. This past year we have addressed this problem three different ways; sanitation influences on trap catch, ozone as a grain protectant, and a comparison of two fumigants used for structural and commodity pest treatment. The first project examined the influence of sanitation on red flour beetle trap catch. We found that the distance the insect will travel to a trap decreases as the level of sanitation decreases and that within a sanitation level (high, med or low) as the distance to a trap increases, the percent capture decreases. Thus, trapping efficiency increases as the sanitation level increases within a facility. The second approach, ozone, has been examined in the field against stored grain pests and
in the lab against other urban pests. Our field research indicates that ozone can be an effective management tool for the food industry in the grain trade. It also shows great promise as a control strategy for other urban pests. To date high dose efficacy trials have been conducted against termites and cockroaches and high mortality rates were achieved in very short periods of time (less than 1 hour) The third approach is part of a multi year project developing a better way to deliver fumigants to eliminate structural food pests. In 2005 and early 2006, two SF and two MB fumigations have been completed in four different flour mills. Additional fumigations are currently underway in 2006. All life stages (eggs, larvae, pupae, and adults) of two major pest species, Indianmeal moth, Plodia interpunctella (L) and red flour beetle, Tribolium castaneum (Herbst) were used in bioassays exposed during fumigations. Insect monitoring (moth flight and beetle dome traps) was conducted before and
after the fumigations to determine the existing pests population and rebound rates. Current results indicate 100% mortality of larval and adult stages of both species for both fumigants. In addition, sulfuryl fluoride had 100% mortality of the pupal stage, but low initial survivorship of the egg stage. The majority (99.3%) of RFB larvae from treated eggs died before the adult stage. Methyl bromide had 100% mortality of IMM pupae. However, there was extremely low RFB survivorship (0.4%) in one facility and 95.4% mortality of IMM eggs in the other. Thus, it appears that SF will be a viable replacement for MB but that dosage rates may need adjustment to kill all life stages. This work is continuing in several additional mills and includes an additional objective of examining the influence on sanitation on insect rebound rates.
Impacts
In the United States more than 15 billion bushels of grain are stored every year. Total annual storage losses are estimated at more than $500 million. Therefore, preventing the deterioration of quality and nutritional value during storage is critical. As a result of the Montreal Protocol, methyl bromide (MB), a major fumigant for the food industry, is facing a mandatory 100 % production and importation phase out. Millers, food processors and fumigators are looking for replacements. Sulfuryl fluoride (SF) is one replacement strategy that was recently labeled for the food market. Since 2005 two SF and two MB fumigations have been completed in four different flour mills. Additional fumigations are currently underway in 2006 but will not be included in this summary. All life stages (eggs, larvae, pupae, and adults) of two major pest species, Indianmeal moth (IMM) and red flour beetle (RFB) were used in bioassays exposed during fumigations. Insect monitoring was conducted
before and after the fumigations to determine the existing pest population and rebound rates. Results indicate 100% mortality of larval and adult stages of both species for both fumigants. In addition, sulfuryl fluoride had 100% mortality of the pupal stage, but low initial survivorship of the egg stage. The majority (99.3%) of RFB larvae from treated eggs died before the adult stage. Methyl bromide had 100% mortality of IMM pupae. However, there was extremely low RFB survivorship (0.4%) in one facility and 95.4% mortality of IMM eggs in the other.
Publications
- Bruesch, J. & L.J.Mason. 2006. Role of the Pest Management Professional in Food-Processing In: Insect Management for Food Storage and Processing 2nd Edition, J. Heaps (Ed) American Association of Cereal Chemists, Inc. Chapter 2 pgs 11-18.-Product Insects. Environmental Entomology. In Press
|
Progress 10/01/04 to 09/30/05
Outputs
Our research focuses on evaluating the efficacy of ozone as a new tool for the management of stored food grains. Our previous work has shown that ozone treatment can kill stored grain insects without affecting quality important to end-users. The goal of the current research is to test this technology under field conditions in farm-scale bins for two food grains (food corn, popcorn) at two locations (Indiana, Illinois) during two consecutive storage seasons (2005, 2006). This study is being conducted by a multidisciplinary team at Purdue University in collaboration with a corporate sponsor which manufactures large-scale ozone generators. This year's research indicates that insect mortality is very high (92-100% mortality) when fumigated with 50 ppm ozone for three days. Field studies will continue next summer. Another area of research involves the comparison of a newly labeled fumigant versus one that is being phased out. As a result of the Montreal Protocol, methyl
bromide, a major fumigant for the food industry, is facing a mandatory 100 percent production and import phase out. Millers, food processors and fumigators are looking for replacements. Sulfuryl fluoride, is one replacement strategy that was recently labeled for the food market. This study is being conducted to examine the effectiveness of sulfuryl fluoride under real world conditions. To date, two fumigations have been conducted in two separate flour mills. Two pest species, Indianmeal moth, Plodia interpunctella (L) and red flour beetle, Tribolium castaneum (Herbst) and all life stages were used in bioassays during the 24 hour fumigations. Trapping (pheromone and dome traps) was conducted before and after the fumigations to determine the existing pest population and rebound. Preliminary results indicated 100% mortality of larval, pupal and adult stages of both species. Mortality of egg stage is still under observation.
Impacts
In the United States more than 15 billion bushels of grain are stored every year. Total annual storage losses assuming a conservative 1% dry matter loss due to insects and fungi is estimated at more than $500 million. Therefore, preventing the deterioration of quality and nutritional value during storage is critical. Insects and fungi (molds) contribute to quality deterioration of stored grains. Also, mycotoxins produced by fungi are toxic to humans and livestock. Therefore, it is essential for the food grain industry to have effective pest management programs to protect against contamination by insects, molds and mycotoxins. Currently, there is an interest in the application of ozone in this industry for several reasons: (a) ozone has regulatory acceptance; (b) ozone is effective in controlling stored product insects without any adverse effects on end use quality which were validated by small scale field research trials with organic rice and barley (c) ozone is
effective in sterilizing food grain surfaces, which eliminates odor volatiles and fungal spores; and (d) ozone satisfies consumer demand for post-harvest chemical-free as well as for organic food products of highest quality, nutritional value, safety and biosecurity. Our research indicates that ozone can be an effective management tool for the food industry.
Publications
- No publications reported this period
|
Progress 10/01/03 to 09/29/04
Outputs
As noted in last year's update, we continue to test ozone as alternative to traditional fumigation in commercial size grain holding facilities. The ozone generator continues to perform effectively and every time we upscale the size of the trial, the generator meets or exceeds expectations. We continue to pursue external funding to take this project to the final commercialization phase. We have recently received funding to continue our investigations of another stored grain / food facility alternative to methyl bromide, sulfuryl fluoride. In this proposal we will be modeling and monitoring fumigation in flour mills and food processing structures in order to get a better model of how the gas moves and distributes itself through out the structure. The results will be used to draft a Precision Fumigation Manual. Another project that we are involved with is the influence of fungal diet on the development and oviposition preference of hairy fungus beetle Typhea stercorea
(Linn) (Col: Mycetophagidae). Hairy fungus beetles, Typhea stercorea (Linn) (Col: Mycetophagidae), are a pest of stored grain throughout the Midwest. It is thought that they are primary mycetophores, preferring moldy grains to grains of better quality. While little is known about the effect of various mold species on the growth rates or ovipositional preference of grain insects, published research has suggested that some mold species might create an environment that is unsuitable for development. Our study examined development times and ovipositional preference of hairy fungus beetle when exposed to pure cultures of Aspergillus flavus, Eurotium rubrum and Penicillium spp. And the study indicated that hairy fungus beetle can complete its life cycle when fed these mold species grown on agar that was qualitatively similar. Developmental times were shortest on A. flavus and longest on Penicillium spp. Females appeared to prefer A. flavus as an ovipositional site resulting in more egg
laying on cultures of A. flavus than on the other two species. Thus ii appears that the species of mold degrading grain can influence insect development.
Impacts
Insects cause significant damage to both raw grains and processed foods annually. Current control strategies are not effective for organic products and limited in scope for non-organic grains. Ozone appears to fill many of the current gaps in pest management for the grain industry. The food industry however not only has to manage pests in raw ingredients but also the structure and equipment. These often require special measures to manage pests. The recently funded project will address this issue by determining the influence of facility conditions on gas flow. This will permit the fumigation to occur under the most efficacious and cost effective combination.
Publications
- Mason, L.J. Insects and Mites. 2002. In: Food Plant Sanitation. Richard Gorham, (Ed.) Marcel Dekker, Inc. Chapter 19: 293-315.
- Mason, L.J. and C.L. Storey. 2003. Effect and control of insects affecting corn quality. In: Corn: Chemistry and Technology 2nd edition. P. White (ed). American Association of Cereal Chemists, Inc. pg 221-240.
|
Progress 10/01/02 to 09/30/03
Outputs
This year we made additional progress on the implementation of ozone in commercial grain facilities. Although we have made great strides in determining the efficacy of ozone as a post harvest pest management tool, we had not found a commercial ozone generator company that could generate the level ozone needed for large scale ozonation. After a university press release, hundreds of companies made contact and we found one that appeared to have the ability to generate the needed levels of ozone. A field test of their equipment at PHERC indicated that the generator would meet our needs. This partnership resulted in contact with one of the largest organic rice producers in the country and the first field test of the technology on a realistic bin size under field conditions. This trial was completed in September and was successful enough to warrant further testing. We have now sought additional funding to build the generator commercially and implement further laboratory
research on a new set of pests. We have also started investigating the influence of sanitation practices on efficacy of pheromone traps in food processing facilities. These traps utilize an aggregation pheromone and are attractive to red and confused flour beetles. Often visual inspections reveal infestations before trap records. This work is examining the influence of flour spills and trap placement on efficacy. To date it would appear that unless facilities are extremely clean, trap efficacy is greatly reduced and that percent capture declines dramatically when the distance travel increases from 1.5 m to 3 m. Little difference was found from 0.9 m to 1.5 m .
Impacts
Insects cause significant damage to both raw grains and processed foods annually. Current control strategies are not effective for organic products and limited in scope for non-organic grains. Ozone appears to fill many of the current gaps in pest management options for the grain industry. Further commercial tests should clarify the economics of doing this treatment on larger facilities. Trap efficacy is critical to maintaining the strictest of GMPs in food processing facilities. If populations of insects can not be monitored, then control procedures cannot be timed correctly. The impact of improper or poorly timed control strategies can be financially devastating when pest problems become public. Food that is already processed in either at distribution warehouses or retail stores has a very high value and infestations within final product results in total loss of the product and a loss of consumer confidence in the product, manufacture and retailer. It is believed
that improving the efficacy of monitoring tools will significantly improve food safety and reduce product loss.
Publications
- No publications reported this period
|
Progress 10/01/01 to 09/30/02
Outputs
We have evaluated the efficacy of ozone as a fumigant to control pests of stored grain. Ozone is attractive because its breaks-down product is oxygen, thus leaving no undesirable residue, and ozone can be generated on-site eliminating the need to store or dispose chemical containers.The highly reactive nature of ozone poses some unique challenges to achieve affective movement of ozone through a grain mass. Two distinct phases of ozone movement have been described in maize. When grain is treated with ozone for the first time (Phase 1), a concentration of ozone is reduced as it moves through the grain because interaction with matter on and around the grain surface rapidly degrades the ozone. Once these reactive sites are eliminated, the ozone moves freely through the maize with little degradation caused by the grain mass. The grain is then considered to be in the Phase 2 state. Our previous study on the flow of ozone through a column of maize indicated that an apparent
velocity of 0.03 m/s was optimal for achieving 85% of the ozone concentration from the ozone generator to a 2.7 m depth in 0.8 d during Phase 1. Once Phase 2 was reached, 90% of the ozone concentration was reached in less than 0.5 d with an apparent velocity 0.02 m/s. These velocities are within the capability of standard aeration fan suggesting that ozone fumigations are achievable in maize. Another phase of the project examined the influence of low concentrations of ozone on the flight behavior of Indian meal moths. Ozone was forced through one leg of a y-olfactometer while the other leg contained room air. Insects were given a choice of just air, air or ozone and just ozone. Insects readily traveled up the leg containing ozone while rejecting the ozone leg 82-96% of time depending on dose. When presented with no choice, insects would enter the ozone environment, however their behavior changed and attempts were made to change direction. Additional studies are needed to determine the
depth of ozone needed to make a moth not enter a grain bin to deposit eggs. The last phase of the project investigated the flow characteristics of ozone through a less porous grain such as wheat and the effects long exposure to a high ozone concentration (50 ppm) have on grain quality for end-users of the grain. The flow of ozone through a 3 m-column of wheat was similar to that previously observed for maize having a Phase 1 in which the ozone rapidly degraded as the ozone front moved through the grain and a Phase 2 in which the ozone moved freely through the grain with little degradation. Also, increasing the velocity of the ozone from 0.02 to 0.04 m/s facilitated deeper penetration of wheat in a Phase 1 state. Treatment of grains with 50 ppm ozone for 30 days had no detrimental effect on popping volume of popcorn, fatty acid and amino acid composition of soybean, wheat, and maize, milling characteristics of wheat and maize, baking characteristics of wheat, and stickiness of rice.
These data indicate that if repeated ozone fumigations are needed, such treatment should not decrease the quality of grain for end-users.
Impacts
Once laboratory trials can be confirmed in the field, the behavior of Indian meal moth and native populations of beetles can be tested to determine if ozone can not only be used as a fumigant but also as a deterrent. Research completed to date provides information for grain handlers and food processors that will ultimately use ozone-treated grain. All grains tested suggest that grain can be repeatedly fumigated with ozone without detrimental effects.
Publications
- Mendez, F., Maier, D.E., Mason, L.J., Woloshuk, C.P. 2002. Penetration of ozone into columns of stored grains and effects on chemical composition and processing performance. J. Stored Prod. Res. 9:33-44
|
Progress 10/01/00 to 09/30/01
Outputs
We are currently evaluating the efficacy of ozone as a fumigant to disinfest stored corn. Treatment of large quantities (350 bu) of corn with high doses of ozone for 3 days resulted in 92-100% mortality of adult red flour beetles, adult maize weevils, and larval Indianmeal moths and reduced the contamination level of Aspergillus fungi by 63%. Ozone fumigation was determined to have to have two distinct phases: phase one is characterized by a rapid degradation of the ozone and slow movement through the grain; during phase two the ozone flows freely with little degradation. We have also determined the optimum flow rate for ozone through a grain mass. To achieve deep penetration the apparent velocity should be 0.03m/s, which is easily achievable in a typical grain storage structure. Work continues on determining the influence of ozone on insect behavior and the influence of high concentrations on end-use qualities.
Impacts
Insects eat up $12 million worth of stored grain in Indiana each year, and pesticides have been the onlytool that grain handlers had to stop them. Ozone fumigation is a potential alternative to traditional control methods. In initial tests, ozone fumigation killed more than 90 percent of major insect pests and cut Aspergillus fungus infections by more than half. It leaves no residue in grain, does not escape into the environment, and appears to be economically competitive.
Publications
- Kells, S.A. Mason, L.J., Maier, D.E., Woloshuk, C.P. 2001. Efficacy and Fumigation characteristics of ozone in stored maize. J. Stored Prod. Res. 37 (2001) 371-382.
|
Progress 10/01/97 to 09/30/98
Outputs
Research under this project at Purdue University focuses on the pest management of cereals and oilseeds during handling, storage and transport (pre and post processing) by assessing the effects of traditional and new post-harvest practices on microbial growth, insect infestation, and chemical usage. Progress made on two specific projects this year includes testing of ozone under both lab and field conditions and evaluation of vikane against post harvest pests. Ozonation of stored grains has been researched for the past three years. Fumigation with ozone was effective at controlling active stages tested of stored product insects (adult confused flour beetles (CFB), adult red flour beetle (RFB), adult maize weevil (MW), and late instar Indianmeal moth (IMM)) within a grain mass. Mortality was observed much faster at the high dosage (all dosges were less than 75 ppm) rather than the low dosage, with 100% mortality achieved after 3 d at the high dosage for CFB, RFB, and
MW, and 6 d at the high dosage for IMM. At the low dosage 100% mortality was not observed until day 12 for CFB, day 9 for adult RFB and larval IMM, and day 4 for adult MW. Delayed mortality effects were seen, as adult CFB exposed for only 1 d at the high dosage, or for 4 d the low dosage, exhibited 63.3% and 34.0% mortality, respectively. Only 13.3% of IMM larvae exposed for only 1 d at the high dosage, or 6.7% of larvae exposed for 4 d at the low dosage, were able to complete development. In these laboratory experiments, ozone had no economically significant effect on fungi in stored grain, and did not affect intrinsic grain properties or seed germination. Additionally, the ozonation technology was scaled up this summer utilizing 3 of our 16 pilot bins filled with corn. Flow rates required for achieving insect kill were determined in the field as well as preliminary trials using ozone as a insect repellent in the headspace of the bins. Tests are continuing in the laboratory to
determine the effectiveness of ozone as a headspace repellent. Results indicate the ozone shows great potential for as both a preventative and pest management tool. Plans for the construction of a commercial unit are ready to proceed. Sulfuryl flouride, currently used for residential and commercial structure fumigation for termites, is under investigation for determining rates that might be effective for controlling stored product insects. To date the results of these trials indicate that 100% mortality of IMM egg stage can be achieved with reasonable dosages. Results were variable at the three other concentrations tested. At intermediate dosages, mortality was highest in the youngest age group (0-1 day old eggs), 100% for both intermediate dosages; and lowest in the oldest age group (3-4 day old eggs) 41.9 - 80.9%. Test results at low dosages did not follow this trend as mortality in the youngest age group was 96.7% and 98.8% in the oldest age group. Work is continuing on other
species and life stages.
Impacts
(N/A)
Publications
- Mason, L.J. and C.A. Strait. 1998. Stored product pest management with extreme temperatures. In: G.J. Hallman and D.L. Denlinger (eds.) 141-177 pgs. Temperature Sensitivity in Insects and Application in Integrated Pest Management. Westview Press.
|
Progress 10/01/96 to 09/30/97
Outputs
We are currently investigating several new control strategies for control of stored product pests. One of the most promising is the use of ozone for insects and mold management. While ozone technology is currently being used as a disinfectant of microorganisms and viruses, as a means of reducing odor, and for removing taste, color, and environmental pollutants, it has not been used for insect control. Our current research suggests that the application of ozone in a stored grain facility may be a feasible alternative to the fumigant methyl bromide. The project has been divided into three phases. In Phase 1, we demonstrated under laboratory conditions that 5 ppm ozone exposure for 3 to 5 days killed adult flour beetles and saw-toothed grain beetles. We also observed that ozone at 1 ppm inhibited all surface growth and sporulation of two mycotoxin-producing fungi (Aspergillus flavus and Fusarium moniliforme). In phase 2, we used a laboratory-scale design to determine the
physical properties of moving ozone through grain. Using 5 gallon simulation bins the data indicated that ozone movement is similar to a cooling front. This will allow us to use existing aeration fronts models to predict ozone movement. Finally, in Phase 3, we have demonstrated that the primary stored product insects are can be killed under simulated field conditions with dosages between 10 and 50 ppm. Fumigation times were within the 3-4 day time frame and thus should be able to compete with currently available fumigants.
Impacts
(N/A)
Publications
- L.J. Mason. 1997. Alternative methods for suppression of pantry pests. J. Agri. Entomol. 14: 323-332
- Mason, L.J. & C.A. Strait. 1997. Stored Product Integrated Pest Management with Extreme Temperatures. In: Lethal Temperatures in Integrated Pest Managemen. G. Hallman & D. Denlinger (Eds). Westview Press, Denver, CO. (In Press)
- Mason, L.J., C.P. Woloshuk, & D.E. Maier. 1997. Efficacy of ozone to control insects, molds, and mycotoxins in stored grain facilities. In: Proc. Inter. Conf. Cntr. Atm. Fum. Stored Prod. (Eds.) S. Navarro & J. Donahaye (In press).
|
Progress 10/01/95 to 09/30/96
Outputs
With the reduce availability of traditional pesticides in the post harvest storage environment, safe alternatives are desperately needed. The long range goal of this research is to find new technologies that control insects and mold growth in stored grain and decrease the likelihood of mycotoxin contamination. Toward attaining this goal, this research project focused on the use of ozone technology as a means of controlling insects, molds, and mycotoxins in post harvest grain storage. The specific objectives were to determine the effect of ozone on insect (T. confusum & O. surinamensis) and mold (Aspergillus flavus & Fusarium moniliforme) survival, and mycotoxin production in stored corn. Ozone atmospheres (5 ppm) were compared to air environments (controls) for effects on insect mortality and mold radial growth, sporulation and aflatoxin production. One hundred percent mortality was found in 5 days for T. confusum and 3 days for O. surinamensis. Radial growth of both
A. flavus and F. moniliforme was inhibit for the first two days. After three days in the ozone atmosphere the growth paralleled that of the control. Sporulation and hyphal growth above the surface of the agar were completely inhibited by the ozone. Aflatoxin production was also reduce by greater than 99 % in the A. flavus cultures exposed to ozone.
Impacts
(N/A)
Publications
- MASON, L.J. 1996. Sweet potato - A strong case for integrated pest management. J. Okinawa Agric. 31: 97-105.
- MAIER, D.E., ADAMS, W. H., THRONE, J. E.,and L.J. MASON. 1996. Temperature management of the maize weevil, Sitophilus zeamais Motsch.(Coleoptera: Curculionidae), in three locations in the U.S. J. Stored Prod. Res. 32(3): (In press).
- MAIER, D. E., RULON,R.A. and L.J. MASON. 1996. Chilled aeration of stored popcorn- Part 1: Temperature Management. J. Stored Prod. Res. (In press).
- MASON, L. J., RULON, R. A. and D.E. MAIER. 1996. Chilled aeration of stored popcorn - Part 2: Pest Management. J. Stored Prod. Res. (In press).
- MASON, L. J., WOLOSHUK,C.P. and D.E. MAIER. 1997. Efficacy of ozone to control insects, molds, and mycotoxins in stored grain facilities. In: Proc. Inter. Conf. Cntr. Atm. Fum. Stored Prod. (Eds.) S. Navarro & J. Donahaye (In press).
|
Progress 10/01/94 to 09/30/95
Outputs
OBJECTIVE ONE: (Examine the biology of stored product insect pests): Studies examining the oviposition behavior of the rice (Sitophilus oryzae) and maize weevil (Sitophilus zeamais) have been initiated. Differences have been found in the time required for mating to occur as well as differences in the behavioral sequences that lead to mating. OBJECTIVE TWO: (Influence of temperature on population growth, mating, development) Studies were undertaken to determine the mortality rate as a function of temperature for various life stages of several stored product insects. Temperatures tested included 36#, 38#, 41#, 43#, and 46#C. The range of susceptibility to temperature was as follows: Adults: Plodia interpunctella >Sitophilus zeamais > Oryzaephilus surinamensis > Tribolium. castaneum >T. confusum > Rhyzopertha dominica; Pupae T. castaneum >T. confusum > P. interpunctella; Larvae T. castaneum =T. confusum > Oryzaephilus surinamensis = P. interpunctella; OBJECTIVE
THREE/FOUR: (Verify the results of objectives 2&3 in field studies at commercial facilities). Field trials were completed at a commercial popcorn facility. Significant differences were found in the number of Indianmeal moths (Plodia interpuctella) that were captured in pheromone baited sticky traps. Fewer moths were captured in the bins that were chilled to 15#C than bins that were maintained at ambient temperatures (30# to 38#C).
Impacts
(N/A)
Publications
- NO PUBLICATIONS REPORTED THIS PERIOD.
|
Progress 10/01/93 to 09/30/94
Outputs
OBJECTIVE ONE: (Examine the biology of stored product insect pests). Several experiments have been initiated to address this objective. A graduate student has been identified that is examining the mating and oviposition behavior of the rice weevil. Video tape equipment has been obtained to facilitate this project. In addition, we have initiated a closely related project that also falls under the guidelines of OBJECTIVE TWO (Influence of temperature on population growth, mating, development). In this allied study, the attraction of Indianmeal moths to pheromone traps is being examined based on variable temperatures. Research this summer at a commercial popcorn facility indicated that cool grain was less attractive to moths than conventionally stored grain. Laboratory studies have been initiated that will elucidate the mechanisms involved in the reduced response of males to pheromone traps. Other studies that examine the influence of temperature are also underway. The
first is determining the influence of extreme temperatures on the survivorship and development of several post-harvest insects. All adult stages, and half of the larval stages, are completed for the seven species.
Impacts
(N/A)
Publications
- No publications reported this period.
|
Progress 10/01/92 to 09/30/93
Outputs
The project "Chemical Ecology and Behavior of Tribolium confusium" (IND058065) has been rewritten and was replaced this fall with a new project, "Biology and Non-chemical Management of Stored Insect Pests". The new project is waiting for final approval. Objective one and three are in the early phases of development and consequently no data is available to report. In the first objective we are examining the mating behavior of the rice weevil (Sitophilus oryzae) using close action video recording. In the third objective we have just completed our first harvest of the two hybrids of corn (one hard and one soft) and are preparing to initiate an examination of airflow rates and hybrid resistance on insect development. The second objective will not be initiated till year two. Progress has been made on the influence of chilled aeration on insect development (Objective 4). Four (250bu) bins were intentionally infested with insects during the fall of 1992. Population growth
rates are being followed in each of the bins, while comparing the influence of chilled aeration, conventional aeration, no aeration, and fumigation on grain quality. During the fall and winter of 92-93, insect populations did not become established. However, encouraged by warmer temperatures and a second inoculation on insects this summer, populations rapidly began to grow. Trap counts in excess of 10,570 insects/trap/week were experienced. All treatments were stressed to the maximum due to the high population pressure.
Impacts
(N/A)
Publications
- No publications reported this period.
|
Progress 10/01/91 to 09/30/92
Outputs
Project description was written prior to PI's arrival on campus. PI's work has taken another direction and new AD-417 and 416 forms have been initiated.
Impacts
(N/A)
Publications
- NO PUBLICATIONS REPORTED THIS PERIOD.
|
|