Location: Southeast Watershed Research
2018 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 third 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 most specimens have been collected to date with final collections and molecular analyses ongoing this year. The third year of a study to assess seasonal occurrence and biology of stink bugs in non-crop hosts has been completed. The second year of a study on dispersal of stink bugs from black cherry and mimosa has been completed. The 3rd year of a study on brown marmorated stink bugs has been completed. Stink bug numbers in cotton fields with and without elderberry has been determined.
Accomplishments
1. Elucidating landscape and natural enemy effects on reproduction of the brown stink bug. The brown stink bug, Euchistus servus, is a pest of many crops in southeastern U.S. The mobility (1000 m per day for foraging and mating range) and reproductive rate (two generations per year) are key factors influencing the economic impact of this pest (insect management and crop losses at $10-$75 per Acre). ARS researchers at Tifton, Georgia and researchers at the University of Georgia, Tifton, Georgia and the University of Minnesota, St. Paul, Minnesota, evaluated patterns of E. servus reproduction and the densities of two groups of their natural predators in 192 fields of four major crops - maize, peanut, cotton and soybean - in 16 landscapes over three years. Land use was the single most important variable associated with reproduction where the highest rate was in soybean and the lowest rate in cotton (likely due to increased frequency of insecticide application). The two groups of natural predators were also associated with low E. servus reproduction. Additional predation from the other predators (six species) within the stink bug complex and typically found in the area indicates that mortality of this pest can be highly significant in the crops studied.
2. Biocontrol agents of the brown marmorated stink bug (BMSB) in the southeast. The invasive brown marmorated stink bug has expanded into the Piedmont and Coastal Plains Regions of Georgia and Alabama. The impact of native and naturalized natural enemies of this pest is unknown in these states. An ARS researcher at Tifton, Georgia, led a team of ARS researchers, the University of Georgia, Clemson University, and Auburn University, to examine parasitism and predation of BMSB egg masses in orchards, row crops and vegetables. They discovered a total of 12 parasitoid species, two of which are new records for the United States, emerging from eggs of this pest. Parasitism of egg masses was very high (70%) in apples, and moderately high in wine grapes (45%), plus (26%), and peach (25%). Several species of chewing and sucking predators were observed preying on BMSB eggs. Predation on egg masses was very high in soybean and cotton (up to 85%) and moderately high in tomato (35%). The study demonstrates that there is a diverse community of natural enemies that are effective biocontrol agents of the BMSB in Georgia and Alabama. Conservation of these natural enemies has the potential to increase their effectiveness against this invasive pest.
Review Publications
Olson, D.M., Prescott, K.K., Zeilinger, A.R., Hou, S., Coffin, A.W., Smith, C.M., Ruberson, J.R., Andow, D.A. 2018. Landscape effects on reproduction of Euschistus servus (Hemiptera: Pentatomidae), a mobile, polyphagous, multivoltine arthropod herbivore. Environmental Entomology. 47(3):660-668. https://doi.org/10.1093/ee/nvy045.
Xavier, S., Olson, D.M., Coffin, A.W., Strickland, T.C., Schmidt, J. 2017. Perennial grass and native wildflowers: a synergistic approach to habitat management. Insects. 8(4):104-117. https://doi.org/10.3390/insects8040104.
Tillman, P.G. 2017. Ecosystem-based incorporation of nectar-producing plants for stink bug parasitoids. Insects. 8:65. http://doi.org/10.3390/insects8030065.
Cottrell, T.E., Tillman, P.G. 2017. Four species of lady beetles (Coleoptera: Coccinellidae) exhibit limited predation on Nezara viridula (Hemiptera: Pentatomidae) eggs and nymphs. Biological Control. 114:73-78. https://doi.org/10.1016/j.biocontrol.2017.08.005.
Saha, U., Endale, D.M., Tillman, P.G., Johnson, W.C., Gaskin, J., Sonon, L., Schomberg, H.H., Yang, Y. 2017. Analysis of various quality attributes of sunflower and soybean plants by near infra-red reflectance spectroscopy: Development and validation of calibration models. American Journal of Analytical Chemistry. 8:462-492. Https://doi.org/10.4236/ajac.2017.87035.
Tillman, P.G., Buntin, D., Cottrell, T.E. 2017. First report of seasonal trap capture for Halyomorpha halys (Stal) Hemiptera: Pentatomidae) and native stink bugs in central Georgia. Journal of Entomological Science. 52:455-459. https://doi.org/10.18474/JES17-56.1.
