Progress 10/01/04 to 09/30/10
Outputs
OUTPUTS: Study results are primarily being disseminated to the scientific community in Arkansas via publications and presentation at scientific meetings. In addition, a final report (thesis) was presented to Arkansas Post National Memorial, and a set of high quality digital pictures of the ants collected was delivered to the park for their visitor educational programs. Titles and locations of professional presentations follow. -- Effects of bottomland hardwood silvicultural operations on Brachinus ground beetles. 2005. 13th Biennial Southern Silvicultural Research Conference, Memphis, TN. -- Ants collected from bait stations at Arkansas Post National Memorial in SE Arkansas. 2005. Southeastern Branch Meeting, Entomology Society of America, Tunica, MS. -- Updated list of the ants of Arkansas. 2006. Arkansas Academy Science, Batesville, AR. -- Ant diversity of Arkansas Post National Memorial. 2007. The Wildlife Society, Monticello, AR. --New distributional records of ants in Arkansas. 2007. Arkansas Entomological Society, Hot Springs, AR. --Ant collecting at Arkansas Post National Memorial. 2007. Arkansas Academy Science, Russellville, AR. -- Effects of harvesting treatments on ant assemblages in a Mississippi River bottomland hardwood forest in west-central Mississippi. 2007. 14th Biennial Southern Silvicultural Research Conference, Athens, GA; AND Arkansas Academy Science, Russellville, AR. -- Effects of harvesting treatments on ants in a Mississippi River bottomland hardwood forest in west-central Mississippi. 2008. Symposium, Integrating Science into the Restoration and Management of Floodplain Ecosystems of the Southeast. Little Rock, AR. -- Ants of Arkansas Post National Memorial: how and where collected; AND -- New distributional records of ants in Arkansas. 2008. Arkansas Academy Science. Arkadelphia, AR. -- Residual effects on the ant community of 2 harvesting treatments applied 12-years-earlier in a pine-hardwood forest in southeastern Arkansas. 2008. 15th Biennial Southern Silvicultural Research Conference. Hot Spring, AR. -- Forest disturbance and its effects on ants in the mid South - 2 studies. 2009. School of Forest Resources Graduate Seminar Series, Monticello, AR. -- New state distributional records of ants collected in 2008. 2009. Arkansas Academy Science, Clarksville, AR, AND Arkansas Entomological Society, Little Rock, AR. -- Residual effects on the ant community of 2 harvesting treatments applied 12-years-earlier in a pine forest in southeastern Arkansas. 2009. Arkansas Academy Science, Clarksville, AR, AND Arkansas Entomological Society, Little Rock, AR. -- Pogos in Arkansas--what do we know 2009. Arkansas Entomological Society. Little Rock, AR. -- Rare Comanche harvester ant in Arkansas--what do we know; AND -- Survey of ants in selected prairies in Arkansas. 2010. Arkansas Academy Science, Little Rock, AR. -- A robust population of the rare Arkansas ant, Pogonomyrmex comanche, in Nevada County, Arkansas. 2010. Arkansas Entomological Society. Fayetteville, AR. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
One objective was to understand human disturbance effects on ant communities; accomplished with several studies. First--harvesting in bottomland hardwoods. The forest received 3 treatments, including selection, clearcut, and undisturbed forest (checks). Analysis showed 8 ants dominated, and these species were influenced differently by treatments. As expected, species preferring undisturbed sites did poorly in clearcuts, and species preferring disturbed sites flourished in clearcuts. Interestingly, numerous species preferring undisturbed forests liked selection harvests almost as well. This demonstrated that selection harvests provided the habitat needs of these ants. Second--residual effects on the ant community of harvesting done 12-years-earlier in pine-hardwoods. The experiment received treatments, including selection, clearcut, and uncut checks. Faunal analysis over 6 years showed 18 species were ubiquitous and dominated the site, comprising 93% of community abundance. Most common species were found in all treatments, but 6 were more abundant in undisturbed checks. Check communities were found to be different from disturbed treatments. We suspect that species more plentiful in checks were there because of the hardwoods, which were missing from most treated stands dominated by pines. This showed that some ant species remained sensitive to old harvesting treatments. Third--assessing ant communities in remnant habitats at Arkansas Post National Memorial. Habitats included: open mowed grass, mowed grass under scattered hardwoods, unmowed bahiagrass with blackberry/weeds, and numerous forest types, including mixed oak and hardwoods, pine, juniper, black locust, and old and young sweetgum. Analysis showed no difference in species richness among habitats, except in one site of mowed grass without trees, showing ants in forest stands were foraging into mowed areas. Mowed areas with some overstory trees harbored many forest ants, indicating the importance of a few large overstory trees in mowed areas. Shared species among forested stands was high, indicating that more than half the ant species perceive little difference in forest types. Another objective was to evaluate effects of non-native invasive species (specifically red imported fire ant RIFA) on native ants. We concurrently sampled infested and uninfested prairies. Three infested prairies were sampled in southern Arkansas where RIFA has been in the ant community for some 30 years, and in 4 uninfested prairies in east-central Arkansas where RIFA range expansion is heading. Cluster analysis classified prairies into 2 distinct groups, RIFA infested and uninfested. RIFA was one of 3 species identified by Indicator Species Analysis as affected by prairie location. RIFA was absent from the central prairies but made up more than 78% of ants collected on the 3 infested prairies. Other significant species were Pheidole dentata (PD) and Temnothorax pergandei (TP), both at very low abundance in RIFA infested prairies. PD was the dominant species in uninfested prairies, and TP was the 7th most common species. So, RIFA affected the ant community by decimating populations of 2 common species.
Publications
- Thompson, L.C., and Lockhart, B.R. 2006. Effects of bottomland hardwood silvicultural operations on Brachinus ground beetles. Pp 459-463. Proceedings, 13th Biennial Southern Silvicultural Research Conference, Memphis, TN. Gen. Tech. Rep. SRS-92, Asheville, NC: U.S. Forest Service, Southern Research Station.
- General, D.M., and Thompson, L.C. 2007. Ants (Hymenoptera: Formicidae) of Arkansas Post National Memorial. Journal Arkansas Academy Science. 61: 59-64.
- General, D.M., and Thompson, L.C. 2008. Ants of Arkansas Post National Memorial: how and where collected. Journal Arkansas Academy Science. 62: 52-60.
- General, D.M., and Thompson, L.C. 2008. New distributional records of ants in Arkansas. Journal Arkansas Academy Science. 62: 148-150.
- General, D.M., and Thompson, L.C. 2009. New distributional records of ants in Arkansas for 2008. Journal Arkansas Academy Science. 63: 182-184.
- Thompson, L.C., General, D.M., and Lockhart, B.R. 2010. Effects of harvesting treatments on the ant community in a Mississippi River bottomland hardwood forest in west-central Mississippi. Pp 591-599. Proceedings, 14th Biennial Southern Silvicultural Research Conference. Gen Tech Rept SRS-121. Asheville, NC: USDA, Forest Service, Southern Research Station.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Study results are being primarily disseminated to the scientific community via publications and presentations at scientific meetings. Titles and locations of presentations follow. --Forest disturbance and its effects on ants in the mid South - 2 studies. School of Forest Resources Graduate Seminar Series, Monticello, AR. --New state distributional records of ants collected in 2008. Arkansas Academy of Science, Clarksville, AR, AND Arkansas Entomological Society, Little Rock, AR. --Residual effects on the ant community of 2 harvesting treatments applied 12-years-earlier in a pine forest in southeastern Arkansas. Arkansas Academy of Science, Clarksville, AR, AND Arkansas Entomological Society, Little Rock, AR. --Using pitfalls to collect ants. EAST lab of Lonoak HS. Hazen, AR. --Pogos in Arkansas--what do we know Arkansas Entomological Society. Little Rock, AR. PARTICIPANTS: Arkansas Natural Heritage Commission, Arkansas Game and Fish Commission, and U.S. Fish and Wildlife Service, landowners; David General - Program Technician; and Harvard University for help with ant ID. TARGET AUDIENCES: Study results are primarily being disseminated to the scientific community in Arkansas via publications and presentations at meetings, and to government agencies so they may better understand how their land management decisions impact native ants. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
It has been suggested that the exotic and invasive Red Imported Fire Ant (RIFA) negatively influences the native ants where it has colonized. The logic is that RIFA are excellent recruiters to food and their large colonies are excellent at eliminating other species through combat. Most studies showing negative effects have followed invasion of new lands as RIFA have increased their range. However, others have suggested that RIFA do not impact native ants that much. Their evidence comes from studies conducted many years after RIFA have colonized an area, and show that native communities at pre-invasion levels. Our objective was to assess the influences of RIFA on native ants in space, sampling ant communities concurrently in infested and uninfested areas. Three infested prairies were sampled in extreme southern Arkansas where RIFA has been part of the ant community for some 30 years, and 4 uninfested prairies were sampled in east-central Arkansas where RIFA range expansion is heading. Ants were sampled using small pitfall traps. Ant species list by prairie were assembled using the quantitative measure total number of pitfalls that collected a species over the entire summer. The total number of ants collected was not used because ants are colonial animals and some pitfall traps would collect hundreds of ants because they were close to a colony. One measure of community diversity is the number of species collected. Species richness over all prairies was 34, with 10 species being rare. For the treatments (infested vs uninfested), species richness was generally lower in the infested prairies (mean 8.7, std 5.2). The uninfested prairies had more consistent species counts (mean 10.6, std 2.3). Although the number of species collected is important, species relative abundance and presence or absence are also important metrics. To analyze ant communities over all sites multivariate statistics, specifically hierarchical cluster analysis, and indicator species analysis (ISA) were used. Cluster analysis identified the overall differences in prairie communities and the ISA identified specific species significantly affected by RIFA. The cluster analysis classified prairies into 2 distinct groups, RIFA infested and uninfested. Of course, it is surmised that RIFA caused this outcome. In fact, RIFA was one of the 3 species identified by the ISA as being significantly affected by prairie location. RIFA was absent from the central prairies but RIFA made up more than 78% of the ants collected on each of the 3 infested prairies (78, 91, and 94%). The other significant species were Pheidole dentata and Temnothorax pergandei, all collected at very low abundance (only once or never, respectively) in RIFA infested prairies. Pheidole dentata was the dominant species in uninfested prairies averaging 134 collections, and Temnothorax pergandei was the 7th most common species averaging 27. So, RIFA has affected the ant community in prairies by decimating populations of one dominant species, Pheidole dentata, and limiting those of another, Temnothorax pergandei.
Publications
- General, D.M., and L.C. Thompson. 2009. New distributional records of ants in Arkansas for 2008. Journal Arkansas Academy of Science. In Press
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Study results are being primarily disseminated to the scientific community via publications and presentation at scientific meetings. Titles and locations of professional presentations follow. - Effects of harvesting treatments on ants in a Mississippi River bottomland hardwood forest in west-central Mississippi. Symposium entitled Integrating Science into the Restoration and Management of Floodplain Ecosystems of the Southeast. Little Rock, AR. - Ants of Arkansas Post National Memorial: how and where collected. Arkansas Academy of Science annual meeting. Arkadelphia, AR. - New distributional records of ants in Arkansas. Arkansas Academy of Science annual meeting. Arkadelphia, AR. - Residual effects on the ant community of 2 harvesting treatments applied 12-years-earlier in a pine-hardwood forest in southeastern Arkansas. 15th Biennial Southern Silvicultural Research Conference. Hot Spring, AR. PARTICIPANTS: Georgia Pacific Corporation and International Paper Company, landowners; David General - Program Technician; and Harvard University for help with ant ID. TARGET AUDIENCES: Study results are primarily being disseminated to the scientific community via publications and presentations at scientific meetings. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The residual effects on the ant community of 2 harvesting treatments done 12-years-earlier in pine-hardwood forests in southeastern Arkansas were assessed. Ants were collected weekly using pitfall traps, from July through October in 1994, 1996, 1998, and 2000 in Drew County. The experiment received 2 replicated harvesting treatments in 1981, including: 1) selection treatments where about 50% of trees were removed, leaving the remaining pines to grow, 2) clearcut treatments where all trees were harvested, with felled noncommercial trees and tops windrowed and burned, and 3) uncut controls (checks). Disturbed stands regenerated naturally. A total of 7 subfamilies, 30 genera, 51 species, and 39,000 individuals were collected. Faunal analysis showed 18 species (38%) were almost ubiquitous and dominated the site, comprising 93% of the community abundance. Treatment effects on common species were analyzed with ANOVA. Most common species were found in all treatments, but 6 were more abundant in the undisturbed checks. However, 1 species showed more abundance in selection harvests (Aphaenogaster fulva), and 2 others for the disturbed clearcuts and selection cuts (Myrmicina americana and Pheidole dentata). Two-way cluster analysis classified treatment effects using ant species occurrence and presence/absence. The ant community in the undisturbed checks were found to be different from those in the disturbed treatments 18 years after disturbance. In summary, 9 members of the ant community remained sensitive to these old harvesting disturbances. We suspect that the species more plentiful in the undisturbed checks are there because of the hardwood component, which was missing from many of the treated stands dominated by pines. This study shows that some ant species remain sensitive to old harvesting treatments. However the study also showed that the ant community in the disturbed stands appeared to be moving toward that in the undisturbed checks. Perhaps they will be similar sometime in the near future as stand composition continues to change in the disturbed treatments.
Publications
- General, David M., and Lynne C. Thompson. 2009. Ants of Arkansas Post National Memorial: how and where collected. Journal Arkansas Academy of Science. In Press
- General, David M., and Lynne C. Thompson. 2009. New distributional records of ants in Arkansas. Journal Arkansas Academy of Science. In press
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: Study results are primarily being disseminated to the scientific community via publications and presentations at scientific meetings. In addition, a final report (thesis) was presented to Arkansas Post National Memorial, and a boxed display of ants collected and high quality digital pictures of same will soon be delivered to the park for their visitor educational programs. Titles and locations of professional presentations follow. -Ant diversity of Arkansas Post National Memorial. The Wildlife Society, Monticello, AR. -New distributional records of ants in Arkansas. Arkansas Entomological Society, Hot Springs, AR. -Ants of Arkansas Post. Arkansas Academy of Science, Russellville, AR. -Ant collecting at Arkansas Post National Memorial. Arkansas Academy of Science, Russellville, AR. -Effects of harvesting treatments on ant assemblages in a Mississippi River bottomland hardwood forest in west-central Mississippi. Arkansas Academy of Science, Russellville, AR. -Effects of
harvesting treatments on ant assemblages in a Mississippi River bottomland hardwood forest in west-central Mississippi. 14th Biennial Southern Silvicultural Research Conference, Athens, GA.
PARTICIPANTS: Arkansas Post National Memorial, David General - graduate student, Harvard University - help with ant ID
TARGET AUDIENCES: Study results are primarily being disseminated to the scientific community via publications and presentations at scientific meetings.
Impacts
In a faunal study, ants were collected from 10 habitat pairs at Arkansas Post National Memorial (APNM) in southeastern Arkansas. Intensive sampling techniques were used, including: leaf litter sifting with Berlese extraction; breaking into ground twigs, branches, and coarse woody debris; baiting trees with peanut butter; general hand collecting, and pitfall trapping. The habitat types included: open mowed-bermudagrass, mowed-bermudagrass under scattered hardwood trees, unmowed bahiagrass with blackberry and weeds, and numerous forest types, including: burned and unburned mixed oak and hardwoods, pine, juniper, black locust, and old and young sweetgum. A total of 46 species in 25 genera and 6 subfamilies were identified. Species richness and species composition of each stand was analyzed. Chi-square analysis showed that there was no significant difference in species richness among the stands or ecotones, except in one set of mowed grass without trees that was paired
with mixed sweetgum. Evidently, ants in the forest stands are foraging into the mowed areas. The mowed areas with trees harbored many forest ants, indicating the importance of the few large overstory trees in these areas. Shared species among forested stands was high, indicating that more than half the ant species perceive little difference in forest types. Hierarchical cluster analysis was performed to discover how the ant community related to the stands, and it showed no clear stand preferences for common, uncommon, or rare species. Even the unique stands, such as the pine, juniper, and black locust types, did not harbor unique species. The exotic and invasive red imported fire ant (RIFA - Solenopsis invicta) continues to make inroads into the disturbed areas of the park, with the potential for displacing native species. This study identified some of the native ants vulnerable to the RIFA and highlighted species able to negatively impact RIFA colonization at APNM. Suggestions for
better management of ant habitats were offered to APNM. First, instead of managing the different forested stands individually, it may be better to manage them as a single forest. This can simplify the management of these forested stands. Second, to expand sites for ant nesting it is suggested to increase the amount of downed woody debris in the forest by throwing any downed wood occurring in the mowed areas into the adjacent forest stands, and planting a few trees, pecan or sweetgum for example, in the low-traffic mowed areas. Finally, controlling RIFA by spot treatment of individual colonies (mounds) (rather than broadcast application of insecticides) should minimize impacts on the common and ubiquitous native ant species (like Solenopsis molesta and Monomorium minimum) that adversely affect colonization by the invasive RIFA.
Publications
- General, D.M., and Thompson, L.C. 2007. Ants (Hymenoptera: Formicidae) of Arkansas Post National Memorial. Journal Arkansas Academy of Science. Vol. 61: IN PRESS.
- Thompson, L.C., General, D.M. and Lockhart, B.R. 2007. Effects of harvesting treatments on the ant community in a Mississippi River bottomland hardwood forest in west-central Mississippi. Proceedings of the 14th Biennial Southern Silvicultural Research Conference. Gen Tech Rept SRS-XX. Asheville, NC: USDA, Forest Service, Southern Research Station. IN PRESS.
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Progress 01/01/06 to 12/31/06
Outputs
In a faunal study, ants were collected from 10 habitat pairs in the spring, summer, and fall of 2006 at Arkansas Post National Memorial (APNM) in southeastern Arkansas. In late spring and early summer, intensive techniques were used, including: leaf litter sifting with Berlese extraction; breaking into ground twigs, branches, and coarse woody debris; baiting trees with peanut butter; and general hand collecting. Additionally, pitfall traps were run every other month. The habitat types included: open mowed-grass, mowed-grass under hardwood trees, unmowed tall-grass and weeds, and numerous forest types, including: burned and unburned mixed oak and hardwoods, pine, juniper, black locust, and old and young sweetgum. A total of 46 species in 25 genera and 6 subfamilies were identified. Interesting discoveries include 6 new distributional state records: Crematogaster atkinsoni, Discothyrea testacea, Pheidole dentigula, P. pilifera, Proceratium pergandei, and Protomognathus
americanus. Several new generic/species records for Arkansas County (location of APNM) include: Proceratium pergandei, Pyramica clypeata, P. ornata, Strumigenys louisianae, and Temnothorax schaumii. The different techniques were not all effective in collecting ant species: leaf litter collected 29, wood breaking 30, tree baiting 10, general collecting 26, and pitfalls 38. Seven species were collected using only pitfalls: Aphaenogaster fulva, Crematogaster atkinsoni, Forelius pruinosus, Pheidole pilifera, Tapinoma sessile, Temnothorax schaumii, and Trachymyrmex septentrionalis. Two species were collected using only litter sampling (Crematogaster missuriensis and Discothyrea testacea), 1 species was collected using only wood breaking (Protomognathus americanus, although lots of important information on the colonies of many species was collected), and Pseudomyrmex pallidus was found only by general collecting. Tree baiting did not collect any new species. Research efforts continue to
relate the species collected to habitat variables in hopes of providing APNM with suggestions for managing its interesting ant fauna. The red imported fire ant (Solenopsis invicta) continues to make inroads into the disturbed areas of the park, with the potential for displacing native species. This study should identify some of the native ants vulnerable to this exotic invasive species.
Impacts
Studies like this help land managers to better interpret the effects that human disturbances have on native animals like ants. The studies also help land managers to better appreciate and understand that when environmental conditions drastically change due to human activities, or exotic plants or animals invade sites, coping by specific native species becomes more troublesome.
Publications
- No publications reported this period
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Progress 01/01/05 to 12/31/05
Outputs
Ants (Formicidae) were collected monthly in the spring, summer, and fall of 2005 from 10 habitat types (open mowed grass, mowed grass under hardwood trees, unmowed tall grass and weeds, and numerous forest types, including: burned and unburned oak, pine, juniper, black locust, and old and young sweetgum) at Arkansas Post National Memorial (APNM) in southeastern Arkansas. A total of 27 species were identified in 15 genera. Interesting discoveries from these APNM collections include records of 3 possible new species: Crematogaster near ashmeadi, Stenamma cf. meridionale, and Brachymyrmex cf. obscurior (possibly a parasitic species). Several new species records for APNM include the tiny Pheidole tysoni, and Strumigenys louisianae (a leaf litter species). Sampling continues into 2006 and analysis of habitat preferences will be assessed by species. In addition, as the exotic red imported fire ant invades APNM the impacts of this species on the native ant fauna will be
assessed. Ants were also collected using pitfall traps in a bottomland hardwood forest on Pittman Island, along the Mississippi River in west-central Mississippi, from July to November in 1996, 1997, and 2000. The forest received three replicated harvesting treatments in 1995, including: 1) undisturbed treatments, 2) selection treatments where about 50% of trees were removed, leaving the most desirable commercial species to grow and the felled noncommercial trees and tops left on the site, and 3) clearcut treatments where all trees were harvested, with felled noncommercial trees and tops left on the site. Year 1996 was the first growing season following harvest. Total ant species collected was 36. Analysis of the fauna showed 8 species dominated the site, and these 8 species were influenced differently by the treatments. As expected, species that prefer undisturbed sites did poorly in clearcuts, and species that prefer disturbed sites flourished in clearcuts. Interestingly, numerous
species that prefer undisturbed forests liked the selection harvests almost as well. The occurrence of red imported fire ants increased substantially in all treatments by 2000. An interesting feature of the ant community was the tenacity of those species preferring undisturbed forests in surviving in the heavily disturbed clearcut treatments during 1996. However, by 1997 considerably fewer of these species were collected in the clearcuts. Also of note is the effect of total flooding of the site in the spring of 1997 on the ant community. There was a 28% reduction in the number of species collected in 1997, compared with 27 and 26 species collected in 1996 and 2000, respectively. In addition, an extended drought in the fall of 2000 revealed few changes in the ant community, but the numbers of ants using the selection harvests dropped off substantially. This study demonstrates that the selection harvests continued to provide the habitat needs of these ants, and the clearcuts continued
to provide less suitable habitat, despite a lush growth of plants in 2000. Evidently, the presence of overstory of trees provides the necessary environmental conditions for many of these ant species.
Impacts
These studies should help us to better understand the effects that human disturbances have on native ants. The studies should also help us to better understand that when environmental conditions change drastically due to human activities, or exotics invade sites, coping by specific native species becomes more troublesome.
Publications
- Thompson, L.C., and Lockhart, B.R. 2005. Effects of bottomland hardwood silvicultural operations on Brachinus ground beetles. In: Connor, Kristina F., ed. Proceedings, 13th Biennial Southern Silvicultural Research Conference, Memphis, TN. Gen. Tech. Rep. SRS-xx, Asheville, NC: U.S. Forest Service, Southern Research Station. In Press.
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Progress 01/01/04 to 12/30/04
Outputs
Ants (Formicidae) were collected monthly using sugar-based baits in the spring, summer, and fall of 2003 and 2004 from 4 habitat types (open mowed-grass, mowed-grass under hardwood trees, unmowed tall-grass and weeds, and old oak forest) at Arkansas Post National Memorial in southeastern Arkansas. A total of 26 species were identified in 14 genera. Common species in the subfamily Myrmicinae included: Aphenogaster (rudis group), Monomorium viridum and M. minimum, Pheidole dentata and P. bicarinata, Solenopsis molesta, Temnothorax curvispinosus and T. pergandei; and in the subfamily Formicinae: Formica pallidefulva and F. incerta, and Lasius neoniger. One probable new species of Crematogaster (near ashmeadi) was discovered. Sampling continues into 2005 and analysis of habitat preferences will be assessed by species. In addition, as the exotic red imported fire ant (Solenopsis invicta) invades the site the impacts of this species on the native ant fauna will be assessed.
Ground beetles (Carabidae) were collected from a bottomland hardwood forest in the Mississippi River floodplain that received three harvesting treatments in 1995 (3 replicates each of clearcut, selectioncut, and check) to assess the effects of forest disturbance on beetles over time. Four species in the genus Brachinus accounted for about 80% of all specimens collected. Brachinus larvae are ectoparasites on the pupae of water beetles, and the adults prefer moist habitats. In 1996, the year after applying treatments, the selectioncuts yielded almost 3 times as many Brachinus (57% of 6,067 total) as the check (23%) and clearcut (20%) treatments. One year later, in 1997, both the check (45% of 2,572 total) and selectioncuts (44%) yielded almost 3 times the number of Brachinus than the clearcuts (14%). In 2000 (an exceptionally dry summer), both the check (44% of 465 total) and selectioncuts (45%) yielded 4 times the number of Brachinus than the clearcuts (11%). The steady loss of beetles
during the study is believed to be due to several summer floods followed by several summer droughts. Nonetheless, this study demonstrates that the selectioncuts continued to provide the habitat needs of these beetles, and the clearcuts continued to provide less suitable habitat, despite a lush growth of plants in 2000. Evidently, the presence of overstory of trees provides the necessary environmental conditions for these beetles.
Impacts
These studies should help us better understand the effects that human disturbances have the native insects. These studies should also help us to better understand that when environmental conditions worsen, or exotics invade sites, coping by native species becomes more troublesome.
Publications
- Lane, M., Weih, R, and Thompson, L. 2004. Measuring the Earths Surface Temperatures with Landsat 7. Pages xx to xx. In proceedings, Arkansas Forest Resources Center Symposium, Little Rock, Arkansas, May 26, 2004. In press.
- Zeide, B, and Thompson, L.C. 2005. Impact of spring sawfly defoliation on growth of loblolly pine stands. Southern Journal of Applied Forestry. Vol. 29: In press.
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Progress 01/01/03 to 12/31/03
Outputs
Pine stands throughout the southeastern U.S. are managed using prescribed fire. Concerns regarding the impacts of prescribed fires on faunal communities have led to numerous studies. One soil/litter insect that may be influenced by fire is springtails, an important member of the forest floor community. To better understand long-term effects of fire on springtails, a study was conducted in burned and unburned loblolly/shortleaf pine stands in southeastern Arkansas. The study examined whether springtail abundance, composition, and diversity were different between areas burned every 2-3 years over the past 20 years, and areas not burned at all. Litterbags were used to collect springtails periodically over a 10-month period. Comparisons of springtail populations for the two treatments were analyzed by abundance, diversity, and similarity. A total of 5,528 individuals were collected; identified specimens represented 24 genera and 10 families. The prescribed fires
significantly affected only one genus, Orchesella, which occurred in burned areas more frequently than in unburned areas. Springtail diversity was not affected by burning. Dendrograms based on Jaccard and Sorenson (Bray-Curtis) similarity indices showed no distinct grouping of treatments. These results indicate that springtail populations are influenced more by other environmental factors than by prescribed fire. In another study, temperatures were measured at 13 sites typical of grassy fields in northwestern Arkansas from 1998 to 2001. Electronic temp loggers simultaneously measured hourly temps at 10 cm above soil surface and 10 and 50 cm below soil surface. Regression analysis defined the relationships between surface temps and those at -10 and -50 cm. The best model for 10 cm below soil surface was a second order polynomial: 10cmBelow = 2.2026 + 0.4977(10cmAbove) + 0.0048(10cmAbove*10cmAbove). This model represented 82% of the variation, had a standard error of 3.4 degrees C, and
tended to over predict values. The best model for 50 cm below soil surface was another second order polynomial: 50cmBelow = 5.4954 + 0.3516(10cmAbove) + 0.0056(10cmAbove*10cmAbove). This model represented 75% of the variation, had a standard error of 3.5 degrees C, and tended to over predict values. Using this research, one can, with reasonable accuracy, predict below ground temps in grass-covered areas at -10 and -50 cm using surface temps at +10 cm.
Impacts
Our study shows that the long term impacts of prescribed fires on springtail (Insecta: Collembola) communities in the pine forests of southern Arkansas are nonexistent. However, Collembola are evidently sensitive to environmental factors what we did not measure.
Publications
- Renschin, Michele; Thompson, Lynne; Shelton, Michael G. 2003. Springtail populations in frequently burned and unburned areas of uneven-aged loblolly pine stands in southeastern Arkansas. Proceedings, Twelfth Biennial Southern Silvicultural Research Conference. Connor, Kristina, F. (ed.). USDA Forest Service Gen. Tech. Rep. SRS-[xx]. February 24-26: Biloxi, MS. Asheville, NC: Southern Research Station.
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Progress 01/01/02 to 12/31/02
Outputs
We used our red imported fire ant (RIFA), Solenopsis invicta, colony development model and max/min weather and precip data from across the globe to predict potential range of RIFA in other nations. Go to the following web site for maps of the results: [http://cmave.usda.ufl.edu/ifahi/ifarange_global.html] In short, the ant could become a pest in much of the warm-moist temperate and tropical areas of the world. We continued development of a procedure to use Landsat 7 satellite thermal imagery to estimate soil temperatures for RIFA model input, rather than using max/min air temperatures from weather stations. Objectives included creating regression models; the 1st to predict air temps at +10 cm above the soil surface in open fields, the 2nd to predict soil temps at -10 and -50 cm below the surface using predicted air temp. With these models one would have the ability to obtain surface and subsurface temps from a single satellite scene without in-situ temp recorders.
Data were obtained from an experimental database, and Landsat 7 images were purchased from EROS Data Center. The high-gain thermal band (#7) of Landsat 7's ETM+ provided the best means of detecting surface temp. This regression model accounted for 78% of all variation with Fit Standard Error of 2.1C. Surface to sub-surface models created using recorded temps over a 3 year period that correspond with the satellite's imaging time did not perform as well as models created using hourly temps over that three year period. Polynomial regression predicted temps at -10cm from +10cm temps at times corresponding to the satellite image. This equation accounted for 82% of all variation with Fit Standard Error of 3.4C. Correspondingly, predicting temps at -50cm from +10cm temps accounted for 75% of all variation with a Fit Standard Error of 3.5C. We used computer simulations of RIFA population dynamics to determine the best timing of applications of the commonly used hydramethylnon (Amdro) bait for
RIFA suppression throughout its range in the southern U.S. Results showed that at the northern limits of its range (OK, northern AR, TN and NC) 1 bait application per year is probably needed to maintain control and September is the best time to make 1 application. However, when 2 applications are needed, July and October are the best times. Ground beetles collected from a bottomland hardwood forest in the Mississippi River floodplain that received three harvesting treatments in 1995 (3 replicates each of clearcut, selectioncut, and check) are being analyzed to assess the effects of forest disturbance on beetles over time. Five species of beetles in the genus Brachinus accounted for about 80% of all specimens collected. In 1996, the year after applying treatments, the selectioncuts yielded almost 3 times as many Brachinus as did the check and clearcut treatments. Five years later, in 2000, the check and selectioncuts caught 3 times the number of Brachinus than the clearcuts,
demonstrating that the selectioncuts continue to provide the habitat needs of these beetles. Clearcuts continue to produce 1/3 the numbers of Brachinus.
Impacts
The range of the red imported fire ant continues to expand, and densities remain high in disturbed areas within its current range. Thus, optimizing the frequency and timing of pesticide applications for its control will minimize both the damage caused by the ant (estimated in excess of $2.5 billion annually across the southern U.S.) and the environmental problems associated with excessive pesticide use.
Publications
- Lane, M., R. Weih, and L. Thompson. 2002. Modeling soil temperatures using Landsat 7 satellite images: an important variable for red imported fire ant range expansion models. Pg 114-119. Proceedings, 2002 Imported Fire Ant Conference, Athens, GA. Mar 24-26.
- Stephen, F, V. Salisbury, F. Limp, D. Crook, E. Heitzman and L. Thompson. 2002. Red oak borer, Enaphalodes rufulus (Coleoptera: Cerambycidae), a remarkable epidemic of oak mortality in the Interior Highland forests. Proceedings, Arkansas Forest Resources Symposium, Little Rock, AR. May 23.
- Thompson, L.C., and S. Wiley. 2002. Annual losses caused by red imported fire ants to households in the southern U.S. Pg 109-113. Proceedings, 2002 Imported Fire Ant Conference, Athens, GA. Mar 24-26.
- Thompson, L.C., S. Wiley, M. Korzukhin, and S.D. Porter. 2002. Best timing for one application of Amdro bait for red imported fire ant control in the southern U.S. Pg 120-124. Proceedings, 2002 Imported Fire Ant Conference, Athens, GA. Mar 24-26.
- Thompson, L.C., M. Korzukhin, and S.D. Porter. 2002. Cold winter of 2000-01 drastically reduces red imported fire ant populations in southern Arkansas: Using a model to verify what was perceived. Pg 125-130. Proceedings, 2002 Imported Fire Ant Conference, Athens, GA. Mar 24-26.
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Progress 01/01/01 to 12/31/01
Outputs
We predicted the future range of the red imported fire ant (RIFA), Solenopsis invicta, within the US based on max/min air temperatures and their daily and yearly distributions using a dynamic model of colony growth with two time steps per day that calculated colony territory area and queen production. Temperature records at 4,537 weather stations within 24 states were used to grow colonies and accumulate queen production over 6 to 12 years. Queen production was used to assess potential range expansion. Additionally, an annual precipitation limit (510 mm) was selected to indicate regions where arid conditions might prohibit growth in areas without supplemental water sources. Results of our model runs predicted that RIFA will likely move 80-150 km north in OK and AR. It will also likely continue expanding into portions of VA, MD, and DE in the east, and NM, AZ, CA, OR, NV and maybe even UT in the west. We continued our monitoring for the presence of the RIFA
microsporidian disease Thelohania solenopsae, released into southern Arkansas in 1998 by the USDA/ARS. Unfortunately, a very cold winter destroyed all the RIFA colonies at the release site. It appears that RIFA exotic natural enemies may have problems adjusting to Arkansas conditions. We continued development of a procedure to use Landsat 7 satellite thermal imagery to estimate soil temperatures for RIFA model input, rather than using max/min air temperatures from weather stations. We initiated studies using computer simulations of RIFA population dynamics to determine the frequency and timing of applications of the commonly used hydramethylnon (Amdro) bait for RIFA suppression throughout its range in the southern U.S. Results showed that at the northern limits of its range (Tennessee and North Carolina) usually one bait application is needed, while in the extreme southern limits in Florida and Texas, four applications are needed. Two and three applications are needed in between. When
only one Amdro bait application is used, our simulations showed that September is the best time in the northern areas of RIFA occupation while November is better in the extreme southern limits. We collected Collembola from frequently burned and unburned pine forests to assess their sensitivity to prescribed fire. Although there were some differences in collembolan communities between the treatments, differences among replicates within treatments suggest that collembolans are more sensitive to other environmental variables than to burning. Several new state records for the presence of collembolans in Arkansas were discovered, as well as at least one potential new species within the genus Sminthurus. The ground beetles collected from a bottomland hardwood forest in the Mississippi River floodplain (1994 - 1997) that received three harvesting treatments in 1995 (three replicates each of clearcut, selectioncut, and check) are being analyzed to assess the effects of forest disturbance on
beetle biodiversity over time. Beetles in the genus Brachinus accounted for more than 80% of all specimens collected. This genus is closely tied to wetland forests because its larvae are parasitic on dytiscid water beetles.
Impacts
The range of the red imported fire ant continues to expand, and densities remain high in disturbed areas within its current range. Thus, optimizing the frequency and timing of pesticide applications for its control will minimize both the damage caused by the ant (estimated in excess of 2.5 billion annually across the southern U.S.) and the environmental problems associated with excessive pesticide use.
Publications
- Korzukhin, M.D., S.D. Porter, L.C. Thompson and S. Wiley. 2001. Modeling temperature-dependent range limits for the fire ant Solenopsis invicta (Hymenoptera: Formicidae) in the United States. Environmental Entomology 30(4): 645-655.
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Progress 01/01/00 to 12/31/00
Outputs
We continued to monitor the introduction of red imported fire ant (RIFA) exotic natural enemies that were released into southern Arkansas in 1998. The numbers of colonies infected by the microsporidian disease Thelohania solenopsae dropped from eight in August of 1998 to one in August of 1999 and none in August of 2000. Likewise, although second generation wild adults of the phorid fly Pseudacteon tricuspis were collected in the fall of 1998, no adults were found during checks made in 1999 or 2000. It would appear that the exotic natural enemies have had problems adjusting to Arkansas conditions. Daily air and soil temperatures continue to be taken in northwestern Arkansas in preparation for adjusting our RIFA biophysical model to accommodate use of satellite imagery to better estimate the potential limits of RIFA spread into the U.S. and perhaps foreign countries. A mail survey was conducted to determine the economic effects that RIFA infestation has on primary wood
processors. The ants had little effect on these processors, except that the they occasionally get into electrical devices like air conditioners and motors. The biggest expense was for insecticides to keep the ants under control.
Impacts
Establishment of the exotic natural enemies of imported fire ants should reduce population densities. Fewer fire ants means fewer effects on plants and animals, plus reduced pesticide applications, expenses, and environmental consequences.
Publications
- Izhevsky, S.S., F.N. Semevsky, and L.C. Thompson. 1999. A method for predicting the impact of introduced entomophages, with special reference to imported fire ant (Hymenoptera: Formicidae). Russian Entomological Journal 8(3): 229-232 (in English w/ Russian abstract).
- Jones, D.B., and L.C. Thompson. 2000. Winter temperature observations within red imported fire ant mounds in southern Arkansas. Pp 117-120. In: Croker, J.L., K.M. Vail, and R.M. Pereira (eds). Proceedings, 2000 Imported Fire Ant Conference, Chattanooga, TN.
- Wiley, S., M.D. Korzukhin, S.D. Porter, and L.C. Thompson,. 2000. Modeling Amdro applications scenarios. Pp 146-148. In: Croker, J.L., K.M. Vail, and R.M. Pereira (eds). Proceedings, 2000 Imported Fire Ant Conference, Chattanooga, TN.
- Wiley, S., L.C. Thompson, M.D. Korzukhin and S.D. Porter. 2000. A GIS representation of potential red imported fire ant range expansion across the United States. Pp. 110-114. In: Croker, J.L., K.M. Vail, and R.M. Pereira (eds). Proceedings, 2000 Imported Fire Ant Conference, Chattanooga, TN.
- Wilson, J., L. Thompson, D. Jones, and K. Davis. 2000. Imported fire ant control: how frequently to apply insecticides. Pp 141-145. In: Croker, J.L., K.M. Vail, and R.M. Pereira (eds). Proceedings, 2000 Imported Fire Ant Conference, Chattanooga, TN.
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Progress 01/01/99 to 12/31/99
Outputs
The introduction of red imported fire ant (RIFA) exotic natural enemies released into southern Arkansas in 1998 were monitored. The numbers of infected colonies of the microsporidian disease Thelohania solenopsae dropped from eight in August of 1998 to only one infected colony in August of 1999. Likewise, although second generation wild adults of the phorid fly Pseudacteon tricuspis were collected in the fall of 1998, no adults were found during four checks made over the spring and summer of 1999. Although Arkansas had a mild winter, it would appear that the exotic natural enemies did not "like" our winter. In cooperation with the USDA/ARS, techniques for rearing the RIFA parasite Solenopsis daguerrei are being studied in Argentina. Additionally, we used our RIFA biophysical model and temperature records for 438 weather stations throughout the South to assess the frequency of application of Amdro, a popular fire ant bait insecticide. To maximize suppression the number
of bait applications ranged from two on the northern limits of its current range to four in southern Florida and Texas. Yet to be assessed is the optimum timing for these applications. Daily air and soil temperatures continue to be taken in northwestern Arkansas in preparation for adjusting our biophysical model to accommodate use of AVHRR satellite imagery to better estimate the potential limits of RIFA spread into the U.S. A study was initiated to determine the magnitude of the economic effects that RIFA infestation has on broiler production. Poultry company production and processing records were kept separate for control and treated houses so that production and processing parameters (like, body weight, feed conversion, mortality, and condemnations) can be compared. Data analysis is underway.
Impacts
The establishment of exotic natural enemies of imported fire ants should reduce population densities considerably. Fewer fire ants means fewer effects on plants and animals, plus reduced pesticide applications, expenses and environmental consequences. Assessing the effects fire ants have on poultry production will show the economic consequences of fire ant infestation and thus the benefits of controlling fire ants around production facilities.
Publications
- Thompson, L.C., S.D. Porter, and M.D. Korzukhin. 1999. Model analysis of the potential temperature-dependent range for the red imported fire ant Solenopsis invicta, in the United States. Problems of Ecological Monitoring and Ecosystem Modeling, Vol XVIII. (in press and in Russian)
- Thompson, L., M. Korzukhin and S. Porter. 1999. Modeling potential RIFA range expansion in the United States. Pp 13-20. In: 1999 National Imported Fire Ant Conference, Charleston, SC.
- Wiley, S., L. Thompson, M. Korzukhin and S. Porter. 1999. Potential RIFA range expansion - a GIS view. Pp 21-29. 1999 National Imported Fire Ant Conference, Charleston, SC.
- Porter, S.D., L.A. Nogueira, K. Flanders, and L. Thompson. 1999. Field releases of the decapitating fly, Pseudacteon tricuspis.. Pp 102. In: 1999 National Imported Fire Ant Conference, Charleston, SC.
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