Antibiosis in soybean breeding lines to the invasive kudzu bug, Megacopta cribraria (Hemiptera: Plataspidae)

The exotic invasive kudzu bug, Megacopta cribraria Fabricius, was initially discovered in

Georgia in 2009, and has since spread quickly throughout the southeastern U.S.  While M.

cribraria primarily feeds on kudzu (Pueraria spp.), it has also become a serious pest of

soybeans, Glycine max Merrill, reducing yield by 19% on average. Soybean hectares infested

with kudzu bug increased from 148,000 to 233,600 from 2012 to 2013, while hectares treated

for kudzu bug increased 6 fold during this time. Host-plant resistance to insect attack presents

an alternative to broad-spectrum insecticide use to manage this economically damaging pest.

However, there are no commercially available soybean cultivars with known resistance to M.

cribraria. Eleven soybean breeding lines with resistance to soybean aphid, Aphis glycines

Matsumura, were evaluated for cross resistance to kudzu bug in a no-choice greenhouse assay.

Of these eleven, two promising soybean plant introductions (PI’s) were selected for further

screening. Additionally, two soybean breeding lines (N7103 and Vance) with antixenotic

resistance to kudzu bug were evaluated for possible antibiosis. Our results suggest that M.

cribraria reared on aphid resistant soybean genotypes PI 567336A and PI 567352B suffer

significantly greater mortality (70-80%) when compared to susceptible soybean genotypes (10-

20% mortality). While M. cribraria reared on N7103 and Vance experienced low mortality,

males and females reared on these genotypes weighed significantly less than their counterparts

reared on susceptible control cultivars. Lower body weight has been linked to decreased

fecundity and overwintering success in other insects, and may explain the non-preference of

N7103 and Vance observed in previous field studies. Our results providing new insight for

soybean breeding programs wishing to develop pest resistant cultivars.