Progress 10/01/98 to 09/30/04
Outputs
Regulatory restrictions imposed by the US Food Quality Protection Act of 1996 and the development of insecticide resistance have led to a renewed search for alternative control methods. Boric acid dust has long served as an insecticide in urban pest management and may be an effective alternative for use in sensitive environments such as swine production. The purpose of this study was to evaluate the efficacy of liquid baits containing boric acid for the control of German cockroaches in a commercial swine nursery. Bait, consisting of 1 or 2% boric acid and sucrose, was deployed in 21 bait delivery tubes per room. Study results indicate significant reductions in cockroach populations. When baits were withdrawn in the summer, the cockroach population increased significantly faster than when the baits were removed during the winter. Liquid formulations of boric acid effectively reduced the burden of cockroach infestation in swine production. Mortality of German cockroaches
caused by the insect pathogen, Metarhizium anisopliae alone and in combination with different formulations of boric acid was evaluated in laboratory bioassays. Injection of the low dose of M. anisopliae (causing 30% mortality) together with the sublethal concentration of boric acid directly to cockroach hemocoel resulted in a great mortality increase (65%). Topical application of M. anisopliae in combination with boric acid (topically in the dust form or in drinking water) resulted in significantly shorter lethal time than when applied separately. Lethal time of cockroaches from M. anisopliae conidial dust with addition of either 12.5% boric acid dust or 0.1% boric acid in drinking water was shortened to 8 days without compromising the fungus re-emergence from cadavers. In contrast, 28 days were required to cause high (>92.0 %) cockroach mortality from M. anisopliae alone. Lesser mealworm, Alphitobius diaperinus (Panzer) emergence from North Carolina field soils was evaluated in field
studies. In seasonal field studies, lesser mealworm emergence from clay soil with poultry litter incorporated by disk, mulch and plow was compared with emergence from plots with no incorporation. Incorporation significantly reduced beetle emergence when poultry litter containing large numbers of beetles was applied to clay field soils during the summer. Although mechanical incorporation of poultry litter reduced beetle emergence relative to the control, greatest reductions were seen in plowed treatments. The use of resistant cattle breeds was investigated. Senepol cross cattle had significantly fewer horn flies than Angus cattle for both 2001 and 2002 season, respectively. Mean number of horn flies on Angus cattle during 2001 fly breeding season was 324, and the Senepol-Angus cross cattle mean was 64. Horn fly densities on Senepol crossbred cattle exceeded the 200 flies per animal threshold twice, weeks 11 and 12. Purebred Angus cattle exceeded the fly threshold 15 of 21 weeks. In
2002, the mean number of horn flies counted from Angus cattle was 263 while the Senepol-Angus cross cattle horn fly densities were 62.
Impacts
Components of integrated pest management include cultural, mechanical, biological and chemical control. Under this CRIS we have focused on specific components and evaluated their merit in IPM programs. The cultural practice of incorporating litter and manure into field soil to help reduce poultry pests could be a valuable tool in the IPM plan. Additional studies proved the use of insect pathogens as a means of killing cockroaches and flies in livestock facilities. We demonstrated the use of insect pathogens in combination with boric acid to increase efficacy for managing cockroaches in hog houses. Inclusion of boric acid bait stations provided effective cockroach control and the utility of bait stations in poultry houses is under investigation. Lastly, the use of resistant varieties is a recognized component of crop IPM but receive little attention in livestock systems. Our data confirm the Senepol breeding lines contribute to horn fly resistance. Each of the studies
presented may be used effectively in IPM programs for livestock and poultry.
Publications
- Zurek, L., J. C. Gore, S. M. Stringham, D. W. Watson, M. G. Waldvogel and C. Schal. 2003. Boric acid dust as a component of an integrated cockroach management system in confined swine production. J. Econ. Entomol. 96: 1362-1366.
- Watson, D. W. , M. H. Poore, S. P. Washburn, M. A. Bertone, and S. S. Denning 2003. Cattle Breed Differences in Horn Fly (Diptera: Muscidae) Populations. CEFS Field Day, Sept 15, Center for Environmental Farming Systems. Goldsboro, NC
- Calibeo-Hayes, D., S. S. Denning, S. M. Stringham, and D. W. Watson. 2004. Lesser mealworm (Panzer) Coleoptera: Tenebronidae) emergence after mechanical incorporation of poultry litter into field soils. J. Econ. Entomol. In Press 2004
- Gore, J. C., L. Zurek, R. G. Santangelo, S. M. Stringham, D. W. Watson, and C. Schal. 2004. Water solutions of boric acid and sugar for management of German cockroach populations in livestock production systems. J. Econ. Entomol. 97:715-720
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Progress 10/01/02 to 09/30/03
Outputs
Objective. Evaluate Cattle Breed Differences in Horn Fly (Diptera: Muscidae) Populations. The horn fly is a persistent and severe pest of pastured cattle. Recently IPM programs have taken interest in developing parasite resistant breeds. Brahman cattle and Brahman cross cattle have significantly fewer horn flies than European cattle. Similar breed differences were observed in Iberian Criolla heifers. Factors contributing to the apparent resistance include size of the animal, sebaceous secretions, hair coat, hair density and hair color. Color has not been found to be a significant factor. Differences in animal size may be directly related to hair coat and density, and selecting breeds of cattle, e.g. Brahman and Chianina, with dense hair follicles and short flat hair coats contribute significantly to horn fly resistance. Senepol cattle were developed on the island of St. Croix by cross breeding Senegalese N'Dama cattle with Red Poll. Breed for heat tolerance, Senepol
cattle grazed significantly longer than Hereford, or Angus breeds. Senepol and Senepol-Angus cross cattle were included in the Angus cattle herd to evaluate the breed for heat tolerance in Eastern North Carolina. Our objective was to compare differences in horn fly densities on Senepol-Angus cross cattle and purebred Angus. Horn fly densities were monitored weekly from May until October over two seasons. Horn fly densities were determined by counting the number of flies on the entire animal. Flies were counted on ten animals of each breed randomly selected from the herd for each sampling date. General linear model (GLM) ANOVA was used to determine statistical differences between horn fly means for treatment and control groups. Senepol cross cattle had significantly fewer horn flies than Angus cattle, P < 0.0001, F = 26.68, df = 40; P < 0.006, F = 8.95, df = 25, respectively. Mean number of horn flies on Angus cattle during first fly breeding season was 324 + 49.5, and the
Senepol-Angus cross cattle mean was 64 + 13.8. Horn fly densities on Senepol crossbred cattle exceeded the 200 flies per animal threshold twice in late summer. Purebred Angus cattle exceeded the fly threshold 15 of 21 weeks. During the second season the mean number of horn flies counted from Angus cattle was 263 + 65.3 while the Senepol-Angus cross cattle horn fly densities were 62 + 16.5. Cattle were treated during week 6 of the study. Horn fly densities on Senepol cross cattle exceeded economic thresholds twice, weeks 15 and 16 of the study, while Angus cattle exceeded the threshold 10 of the 17-week study. Interestingly, the treatment of the cattle during week 6 provided relief to the Angus cattle during peak horn fly activity and may be recommended when fly densities exceed 800-1000 flies per animal.
Impacts
These data confirm the Senepol breeding in these cattle contribute to horn fly resistance. Specific factors contributing to this perceived resistance are unknown. Performance and mechanisms of resistance of Senepol crossbred cattle and Angus are being investigated. Further studies of the impact of inheritable characteristics are under consideration.
Publications
- Zurek, L., J. C. Gore, S. M. Stringham, D. W. Watson, M. G. Waldvogel and C. Schal. 2003. Boric acid dust as a component of an integrated cockroach management system in confined swine production. J. Econ. Entomol. 96: 1362-1366.
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Progress 10/01/01 to 09/30/02
Outputs
Manure management is a key component in Integrated Pest Management Programs for poultry. Flies and litter beetles are extremely difficult to control during and after storage and subsequent to land application of litter. Fly and beetle nuisance complaints often result in litigation, impacting both the farm and the farming community. Legal cases concerning nuisance flies and beetles often occur following the land application of poultry litter. Rich in nitrogen (N), phosphorous (P), and potassium (K), litter is often applied to field soils as an organic fertilizer. Over use of organic fertilizers has resulted in state and federal regulation through animal waste management plans. The fate of N, P, and K of manure applied to field soils is a concern in concentrated production areas as there may not be enough cropland within economical hauling distance to properly use the manure. The development alternative systems that reduce manure nutrients through management, and reduce
the insects associated with poultry waste will lead to better efficient utilization of these materials. Objective: Evaluate conventional and experimental poultry manure management systems as they influence production of house flies and litter beetles. Within this objective, we will evaluate the insects commonly associated with poultry litter as impacted by manure handling, i.e., covering, tarping and composting. Litter treatments included; roof covered pile (control), piled and tarped, Ag-bagged composted, and bin-composted. In covered pile treatments, litter was stored in a building. Piled litter covered with plastic tarps and staked tight. Litter was placed in large plastic bags currently designed to hold silage (i.e. Ag-Bags) but modified to provide air necessary for composting in the third treatment. Litter was placed in a conventional compost bin for the 4th treatment. Water (100 liters) was sprayed onto each treatment during preparation. The control did not receive additional
water. Data loggers recorded manure and ambient temperatures hourly for one month. Temperatures in tarped and bin-composted treatments were lethal for fly and darkling beetles in the litter. Temperatures in the Ag-bag treatments only exceeded 50 degrees C temporarily and some surviving insects were observed in these treatments. Live insects were observed in the roof-covered treatment at the surface level only. Chemical analysis of roof covered litter was 23.28, 22.16 and 22.16 ppm for elemental nitrogen, phosphate and potassium, respectively. Covering moistened litter with a tarp reduced N and K to 10.08 and 17.26 ppm, respectively. Similarly moistened Ag-bag treatments reduced N and K to 8.9 and 13.86 ppm, respectively. Bin-composting reduced N and K to 16.3 and 16.34 ppm, respectively. In contrast, phosphate increased in all treatments, 25.38, 25.44, and 30.02 ppm for tarp, Ag-bag and bin treatments.
Impacts
Composting on farm mortality has been readily adopted as a convenient method of destroying animal carcasses as well as effectively reducing the spread of disease organisms. Composting litter for insect management has not been readily adopted. Potentially such treatments could greatly reduce nuisance insect outbreaks, a much desired goal of the public health departments and the poultry industry. The added benefits of reduced nutrient loading following land application of composted litter are viewed favorably by the Environmental Protection Agency. We anticipate repeating these experiments in 2003.
Publications
- No publications reported this period
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Progress 10/01/00 to 09/30/01
Outputs
Objective 1. Role of arthropods in the transmission of disease. Coronavirus (TCV) has been a persistent disease of turkeys in North Carolina. Darkling beetle transmission of TCV appears to be time limited as the virus is inactivated in the gut of the beetle within an hour. The potential of the house fly to transmit TCV is significant. We have isolated viable TCV from the crop of the house fly for up to 1,3,6,and 9 hours but not 12 and 24 hours following initial feeding. Studies on direct transmission to turkey poults were conducted at fly to bird ratios of 1 to 1, 10 to 1 and 100 to 1. Transmission of TCV was density dependent. Fifty percent of the birds became infected with TCV at densities as low as 1 fly per bird. Objective 2: Mechanical control of horse flies. We have completed a two-year evaluation of trapping technology for the management of horse and deer flies on horse farms. Three trap designs were evaluated 1) Epps trap, 2) Horse Pal, and 3) Sticky Williams
trap. The Epps and Horse Pal traps are currently commercially available. Placement of these traps reduced biting fly densities in pastures. We captured 24 species of Tabanidae. The Epps captured 1340 flies, however Horse Pal was effective for a longer period, capturing 2566. Although Sticky Williams traps were effective, bird captures precluded their use in pastures. Objective 3: Biological control of cockroaches in swine production. Mortality of german cockroaches caused by Metarhizium anisopliae alone and in combination with boric acid killed cockroaches significantly faster than boric acid alone. Fungal conidia, 8.96x10E8 with 12.5% boric acid killed cockroaches in 8 days without adverse effects on conidiophore production. Dust placebo did not have the same effects. Low dose of fungal conidia alone killed 30% of the cockroaches but increased to 60% in combination with boric acid demonstrating synergy between both agents.
Impacts
Coronavirus is a presistent disease of turkeys in NC. Biosecurity reduces the rate of spread of disease, but does not prevent it. The importance of arthropods particularly the house fly may play an important role in the management of this disease. Chemical control of horse flies is difficult. We have demonstrated that mechanical trapping relieves horses of the persistant biting of horse flies. Combinations of entompathogenic fungi and boric acid to manage cockroaches reduces insecticides in our foods and the environment.
Publications
- Zurek, L., D. W. Watson, and C. Schal. 2002. Synergism between Metarhizium anisopliae (Deuteromycota: Hyphomycetes) and Boric Acid against the German Cockroach (Dictyoptera: Blattellidae). Biological Control. Accepted
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Progress 10/01/99 to 09/30/00
Outputs
Horse IPM Objective 1: Evaluate the Epps, Williams sticky traps and Manitoba traps (Horse Pal) for inclusion in Horse IPM programs. The experimental portion of this study was conducted on 4 farms. Two farms functioned as a control receiving no traps. The two remaining farms were treatment farms. There was a significant difference in the size of the traps. A single Epps and a Horse Pal were placed at each farm. Eight sticky Williams traps were placed at a single site on treatment farms. Site selection was based on where Tabanids were reported to be a pasture problem and placed between the larval breeding sites and daily resting sites of the flies. Traps were placed approximately 50 meters apart. The traps were examined twice weekly during peak season and weekly thereafter and the trapped flies removed. Twenty-two species of Tabanidae were captured using these devices. Total trap catch for Epps, Horse Pal and Williams traps were 1477, 1405, and 464, respectively.
Williams sticky traps were highly effective for the capture of Deer flies. The Williams traps were removed for the study after 36 days because birds frequently became caught in the traps. Number of captured tabanids by the Horse Pal and Williams sticky traps were similar from June 22 to July 26. The Epps trap caught more flies from June to August than either the Horse Pal or the Sticky Williams traps. Densities of tabanids on the farms declined after August. During this period of low fly densities, the Horse Pal caught more flies when compared to the Epps trap. Further evaluation is anticipated for 2001. Cattle IPM Objective 2. Develop preliminary data on the use of walk through flytraps for horn fly and face fly management under field conditions. A walk through fly trap prototype was purchased from FlyOff Inc. The trap was placed in the walkway leading to the milking parlor. Cows passed through the device twice/day. Preliminary data suggest that the walk through flytrap may provide
an alternative to conventional insecticide use for the management of pasture flies. Horn fly densities were determined by counting the number of horn flies on the both sides of the body of ten animals randomly selected from the herd. Horn flies were counted on the control herd in a similar manner. During the pre-treatment period mean horn fly densities on the CEFS dairy and the control herd were1418 and 532 flies/animal, respectively. Within two weeks of placing the trap horn fly densities on the CEFS dairy herd had declined to below threshold levels (200 flies/animal) and remained below threshold for eight weeks. Full evaluation of the walk through flytrap on dairy and beef cattle production systems is anticipated. Further study on the ecology of dung beetles is planned, including beetle diversity, prevalence and seasonality, developmental time and impact on fly populations.
Impacts
These data suggest that tabanid traps and walk through fly traps may provide an alternative to traditional insecticide based pasture fly management. A diverse population of dung beetles exists in the state of North Carolina. Little is known of the diversity and importance of these insects in the decomposition of dung and the potential impact on pasture pests in North Carolina. These management principles contribute to program goals of developing environmentally, economically, and socially sustainable agriculture. Our study goals are to evaluate alternatives to traditional insecticide based pasture fly management, including an evaluation of recent innovations in trapping technology and biological control.
Publications
- Watson, D. W. (2001). Swine Pest Management. In: Encyclopedia of Pest Management. David Pimentel (Ed). Marcel Dekker Publishing. NY.
- Watson, D. W. (2001). Integrated pest management for livestock. CAST Integrated Pest Management Report. Ken Barker Ed.
- Baker, J. R., C. S. Apperson, M. S. Stringham, M. Waldvogel, and D. W. Watson. 2000. Insect and other pests of man and animals. NC Agricultural Extension Service Publication. AG-369, Revised.
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Progress 10/01/98 to 09/30/99
Outputs
We examined the role of Alphitobius diaperinus Panzer in the transmission of an enteric disease of turkeys caused by a coronavirus. Turkey coronavirus (TCV) from two sources was studied, one isolate (NC95) was embryo propagated, the second was TCV infected material from turkeys diagnosed with Poult Enteritis Mortality Syndrome (PEMS). Beetles were fed virus-infected feces mixed with chicken feed. Transmission of virus was effectively halted by surface sterilization of the beetles. Turkey poults administered beetle homogenates infected with TCV+ PEMS that had not been surface sterilized had reduced weight gains and 50% mortality. Mortality and weight gains were not effected in the NC95 group. Virus isolation procedures were performed to determine NC95 viability at varying time intervals. Beetles were dissected and the guts removed 1, 12, and 24 hr following the initial viral feeding. Whole beetles were also examined for comparison. Whole beetles and beetle guts were
homogenized and injected into turkey eggs for embryo propagation. Direct immunofluorescence was used to determine the presence of TCV. Alphitobius diaperinus were capable of mechanical transmission of TCV. However only turkey embryos receiving whole beetle and beetle gut homogenates within one hour of feeding on the virus were positive for TCV. Laboratory studies demonstrating PEMS transmission by A. diaperinus are continuing. Objective 2: Canvas the horse enthusiasts at the Horse Management Field Days to determine receptiveness to IPM and Biological Control for the management of fly pests. Pest and Pesticide Use Survey was conducted among horse owners in North Carolina. Horse owners ranked house flies, stable flies and horse flies as their most important pests. Horse owners generally use low residual insecticides and repellants to manage flies on horses. To manage house flies in the barn, some horse owners are using over-head spray systems and apply permethrin mist up to 7 times per
day. Few recognize that this practice will lead to insecticide resistance. Most horse owners do little to control pests in the barn other than frequent removal of bedding and manure. Most horse owners are receptive to biological control and integrated pest management on the farm. Objective 3. Evaluate releases of the parasitoid Muscidifurax raptorellus as a biological component of a Horse IPM program. M. raptorellus is a gregarious pupal parasitoid that has received significant interest in recent years. Three control farms received no parasitoid releases, and three farms received parasitoids released at a rate of 10,000 parasitized fly pupae every two weeks. Sentinel fly pupae were used to monitor the distribution of M. raptorellus inside and outside the barns. Emerging parasitoids were identified to species, number of progeny, and sex. Ten sentinel bags were used on each farm. When possible, wild fly pupae were collected to determine if the parasitoids were finding the wild
populations. Analysis to be completed.
Impacts
Darkling beetles have a limited capacity for the mechanical transmission of TCV, which may be important during outbreaks. Results of the horse IPM studies will provide essential information on the pest and pesticide uses in North Carolina, the importance of indigenous parasitoids associated with flies on the control farms, and to what extent they help control fly population. Furthermore, the efficacy of M. raptorellus as a biological control agent is unknown in this setting and may be a valued tool in the future of horse IPM in North Carolina.
Publications
- Watson, D. W., J. S. Guy, and S. M. Stringham. 2000. Limited Transmission of Turkey Coronavirus (TCV) in Young Turkeys by Adult Lesser Mealworm, Alphitobius diaperinus (Coleoptera: Tenebrionidae). Journal of Medical Entomology. In Press.
- Watson, D. W., P. E. Kaufman, D. A. Rutz, and C. S. Glenister. 2000. Impact of the darkling beetle, Alphitobius diaperinus Panzer on the establishment of the predaceous beetle, Carcinops pumilio Erichson for the control of house fly, Musca domestica in caged-layer poultry houses. Biological Control. In Press.
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