Location: Southeast Watershed Research
2019 Annual Report
Objectives
1. Determine biological, ecological, and structural mechanisms driving stink bug population dynamics in landscapes composed of agricultural (e.g., corn, peanut, cotton, and soybean) and non-agricultural habitats to design management strategies for stink bugs in the Southeastern Region of the United States.
1.A. Determine the seasonal occurrence and biology of stink bugs in non-crop habitats in agricultural landscapes.
1.B. Determine stink bug dispersal from non-crop hosts into cotton and the impact on cotton in terms of boll injury.
1.C. Investigate the potential for host-associated differentiation (HAD) in parasitoids of stink bug adult, nymph and egg stages.
1.D. Deploy use of Long-term Agricultural Research (LTAR) sites and eco-informatics to establish causal relationships between environmental and geospatial data, management strategies, and pest control success in vegetable crops such as cucurbits, fruiting vegetables, onions, cabbage, leafy greens and sweet corn.
2. Develop and test biologically-based management strategies, including augmentative releases of parasitoids, trapping insect pests with pheromone traps, elimination of non-crop sources of stink bugs, biopesticides, and multifunctional trap cropping systems, to monitor and/or control native and naturalized stink bugs and the invasive kudzu bug and the brown marmorated stink bug in the Southeastern Region of the United States.
2.A. Determine the efficacy of augmentative releases of kudzu bug parasitoids in reducing kudzu bug populations.
2.B. Monitor populations of the newly invasive brown marmorated stink bug using pheromone-baited stink bug traps.
2.C. Determine the effect of selected biopesticides on the kudzu bug in soybean.
2.D. Examine the utility of eliminating non-crop host plants of stink bugs along field edges for reduction of stink bug dispersal into cotton.
2.E. Evaluate the effectiveness of using a soybean trap cropping system to manage stink bugs attacking cotton.
Approach
Collect data on the seasonal occurrence, development and feeding and mating behavior of stink bugs in known and potential non-crop habitats surrounding row crops in 10-12 agricultural landscapes. Conduct a study of stink bug dispersal from known non-crop hosts into cotton and their impact on cotton boll injury in 6-8 agricultural landscapes. Conduct a study on the presence of host-associated differentiation in parasitoids of stink bug adults, nymphs and eggs collected in cotton and soybean fields and from nearby known non-crop host plants. Conduct a study on the effects of augmentative releases of an exotic kudzu bug egg parasitoid on kudzu bug density in 10 kudzu patches in North and South Georgia and nearby soybean fields. Monitor populations of the newly invasive brown marmorated stink bug north of the Coastal Plain in Georgia using pyramid stink bug traps baited with lures and map its distribution and spread in Georgia. Conduct studies in experimental plots on selected biopesticide effects on kudzu bug populations in soybean. Conduct a study on the elimination of known non-crop host plants of stink bugs along 6 cotton field edges on stink bug dispersal into the cotton field. Conduct a study in a grower’s peanut-cotton farmscape on the effect of a soybean trap cropping system on the density of stink bugs attacking cotton.
Progress Report
The fourth year of a study determining the genetic structure and parasitism rates of stink bug parasitoids on crop and non-crop host plants is underway and all specimens have been collected with molecular analyses to begin this year. The third year of a study to assess seasonal occurrence and biology of stink bugs in non-crop hosts has been completed. Data on number of brown marmorated stink bug (BMSB) in pheromone-baited traps continues to be collected throughout Georgia and Alabama. Data has been collected on dispersal of stink bugs from non-crop hosts into cotton.
Accomplishments
1. Tracking populations and parasitism rates of the newly invasive brown marmorated stink bug. Reproductive populations of the invasive brown marmorated stink bug (BMSB) are rapidly building in the Piedmont and expanding into Coastal Plains Regions of Georgia and Alabama. Consequently, ARS researchers in Tifton, Georgia, conducted a study to evaluate parasitism of BMSB sentinel egg masses by native parasitoids in woodland habitats and orchard, vineyard, row, and vegetable crops alongside these habitats in the southeastern U.S. Laboratory-reared BMSB egg masses were hung as sentinels on plants for 48-72 h. In the laboratory, retrieved egg masses were held for emergence of adult parasitoids. Of the ten parasitoid species, three species were the most prevalent ones in woodland and orchard habitats, one species occurred primarily in orchards, two species were the predominant species in row crops, and two species were mainly present in vegetables. Thus, the prevalence of parasitoid species emerging from BMSB eggs was mainly habitat specific. Two of the species recovered from BMSB egg masses were new records for this invasive stink bug. Percent parasitism ranged from 0.4-72.3%. In conclusion, native stink bug parasitoids are serving as biological control agents of BMSB in the southeastern U.S. and thus providing nectar-producing flowers in agroecosystems could enhance parasitism of BMSB by these parasitoids.
2. Use of pheromone traps to assess populations of stink bugs in cotton. Stink bugs are economic pests in most fruit, vegetable, grain, and row crops. Stink bug traps baited with lures with compounds attractive to stink bugs capture these pests in the field. ARS researchers in Tifton, Georgia, examined the impact of traps baited with brown and green stink bug lures on stink bugs in cotton. The brown and dusky stink bug were the most prevalent stink bug species in cotton. In 2015 and 2017, the number of stink bugs was higher on the row of cotton immediately adjacent to a pheromone-baited trap than on the second row from the trap. Stink bug number was lower on the seventh row of cotton beyond the trap in 2015 and on the fourth, eighth and sixteenth rows of cotton in 2017 compared to the two rows nearest the trap. These results indicate that adult stink bugs aggregate mainly on the two rows of cotton near a trap. Cotton boll injury, though, was similar for each cotton row indicating that the presence of stink bugs on cotton near a baited pheromone trap did not negatively impact boll damage. Therefore, pyramid traps baited with the stink bug lures can be used to assess the relative abundance and distribution of these pests in cotton and not affect boll injury near the traps.
3. Assessing brown marmorated feeding and reproduction in chinaberry host trees. The invasive brown marmorated stink bug (BMSB) is an agricultural and nuisance pest in Georgia. Chinaberry trees are a major BMSB host plant and commonly grow in dense thickets along roadsides and in woodlands adjacent to agricultural crops in the state. Thus, we conducted this study to determine if the BMSB that feed and grow on chinaberry perhaps serve as a potential source of this pest into crops. Specifically, we examined mortality and feeding of young BMSB nymphs on chinaberry leaves versus carrot and searched for BMSB on chinaberry in woodlands at two locations where this stink bug has become established. Overall of the sampling dates and locations, the number of BMSB in chinaberry was very low, and only six individuals were observed feeding on chinaberry. Percentage feeding by BMSB early nymphs was lower for individuals given chinaberry leaves versus those provided with carrot indicating antifeedant activity of compounds in chinaberry against these nymphs. Mortality of nymphs on chinaberry was very high. We conclude that chinaberry is an unlikely host plant for BMSB.
Review Publications
Balusu, R., Cottrell, T.E., Talamas, E., Toews, M., Blaauw, B., Sial, A., Buntin, D., Vinson, E.L., Fadamiro, H., Tillman, P.G. 2019. New record of Trissolcus solocis (Hymenoptera: Scelionidae) parasitizing Halyomorpha halys (Hemiptera: Pentatomidae) in the United States of America. Biodiversity Data Journal. 7:e30124. https://doi.org/10.3897/BDJ.7.e30124.
Athey, K., Ruberson, J., Olson, D.M., Harwood, J. 2019. Predation on stink bugs (Hemiptera: Pentatomidae) in cotton and soybean agroecosystems. PLoS One. 14(3):e0214325. https://doi.org/10.1371/journal.pone.0214325.
Xavier, S., Coffin, A.W., Olson, D.M., Schmit, J. 2018. Remotely estimating beneficial arthropod populations: Implications of a low-cost small unmanned aerial system. Remote Sensing. 10:1485-1498. https://doi.org/10.3390/rs10091485.
Tillman, P.G., Cottrell, T.E. 2019. Influence of pheromone-baited traps on stink bugs (Hemiptera: Pentatomidae) in cotton. Journal of Insect Science. 19(1):1-7. https://doi.org/10.1093/jisesa/iey140.
Tillman, P.G., Cottrell, T.E., Buntin, D. 2019. Potential of Melia azedarach L. as a host plant for Halyomorpha halys (Stal) (Hempitera: Pentatomidae). Florida Entomologist. 102(1):222-226. https://doi.org/10.1653/024.102.0136.
Tillman, P.G. 2019. Density and egg parasitism of stink bugs (Hemiptera: Pentatomidae) in mimosa. Florida Entomologist. 102(1):227-230. https://doi.org/10.1653/024.102.0137.
Cottrell, T.E., Tillman, P.G. 2019. A physical barrier reduces capture of Euschistus servus (Hemiptera: Pentatomidae) in pheromone-baited traps near peach trees. Florida Entomologist. 102(1):281-283. https://doi.org/10.1653/024.102.0155.
