Rapid Tactical Response to Threat by Invasive Kudzu Bugs to Soybean in Georgia

Summary

Research on pest management strategies for invasive kudzu bugs has identified an array of chemical, biological and cultural control tactics that can be used individually and collectively to manage this serious new pest of soybean in Georgia.

Situation

Invasive kudzu bugs were first detected in Georgia in 2009 and severe infestations in soybean occurred in central Georgia by 2010 and have spread throughout most of the state during 2011. There was little information available from Asia, the origin of kudzu bugs, on control methods, so we basically had to start from scratch in 2010 conducting research of biology and control methods. Kudzu bugs have spread rapidly in Georgia and surrounding areas and of the various hosts besides kudzu, they are particularly adapted to soybean. Large infestations of up to 100 adults per plant (soybeans are planted with 6-8 plants/foot of row with about 15,000 linear feet of plants/ acre = 12 million bugs/acre) have occurred in many parts of Georgia. Yield loss of over 50% has occurred in research plots with losses of 15-30% common. Obviously these type impacts cannot be sustained by soybean growers and information on managing kudzu bugs is needed as rapidly as possible to offset the threat.

Response

Our research in 2011 included greenhouse testing and 16 field experiments at the UGA Plant Sciences Farm (PSF), Southeastern Branch Research and Education Center (SEBREC) and Mountain Branch Research and Education Center (MBREC) in soybean involving: Cultural controls: a. Influence of tillage practice (one test at PSF (no-tillage vs plow tillage, etc.). b. Influence of planting date one test each at PSF and SEBREC. c. Influence of soybean maturity group (one test at each PSF and SEBREC. d. Cage test with infested and noninfested plots to do yield component analysis. e. Host preference, observations of kudzu bug infestations on snap beans and peanuts. Host Plant Resistance: a. Influence of native insect resistance genes identified via marker assisted selection and introgressed into an elite cultivar 'Benning' used in six field tests at three locations at different planting dates. Chemical control: a. Insecticide seed treatments: 4 tests at the three locations above. b. Sprayable insecticides: 5 tests at PSF and SEBRC.

Impact

Results from research demonstrate that invasive kudzu bugs can be managed effectively so that growers can continue to grow soybean profitably in Georgia. Manipulation of planting date, soybean maturity group and use of herbicide + insecticide mixtures are cultural control tactics that show promise. Soybean breeding efforts have resulted in the identification of resistance to kudzu bugs. We have research information that will lead to establishing economic thresholds of kudzu bug populations for triggering insecticide sprays. Extensive insecticide testing efforts have resulted in identifying effective, cost efficient chemical controls which can be recommended to soybean growers for managing kudzu bug infestations.

State Issue

Agricultural Profitability and Sustainability

Details

• Year: 2011
• Geographic Scope: International
• County: Clarke
• Program Areas:
  • Agriculture & Natural Resources