Seasonal Population Dynamics of Megacopta cribraria (Hemiptera: Plataspidae) in Kudzu and Soybean, and Implication for Insecticidal Management in Soybean

Abstract

Megacopta cribraria (F.), an invasive species introduced from Asia in 2009, is now prolific in the southeastern United States. Megacopta cribraria develops primarily on kudzu and soybean completing two generations. It is not well understood how this economic pest is affected by changes in geographic distribution in the United States or how population levels have changed since its establishment. The effect of insecticide application timing on field populations of M. cribraria is not well documented. These studies seek to understand how population dynamics of M. cribraria vary with geographic regions in Georgia. Effect of application timing on populations throughout the growing season was also examined. Weekly from 2012 to 2013, all life stages were enumerated from kudzu and soybean environments at several locations throughout Georgia from sweeps samples and flight intercept captures. Coordinates were recorded for locations, and classified as belonging to the Piedmont or Coastal Plain region of the state. Single spray trials were conducted from 2011-2014, and applications were made to soybean at intervals throughout the season. From 2012 to 2015, two kudzu patches near Griffin, GA, were monitored to detect population changes. Differences in population dynamics from locations around the state were found, but no clear effect of latitude, longitude, or region was observed. Insecticide applications applied in July suppressed nymph populations significantly better than treatments made earlier or later. Megacopta cribraria populations declined in 2014 and 2015 compared with 2012 and 2013. These studies provide the critical information for M. cribraria management in soybean in the southeastern United States.

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“…In the current invasive range, overwintering M. cribraria adults generally necessarily oviposit on kudzu, which emerges earlier in the spring than soybean, which is typically planted later in the summer. Evidence suggests, however, that, when available, early‐planted soybean (i.e., planted from April to June) is at greater risk for yield loss due to M. cribraria than later‐planted soybean (Blount, Buntin, et al, ; Blount, Roberts, et al, ). Findings of increased juvenile survival and more rapid development on soybean than on kudzu indicate that early‐planted soybean could fuel rapid population growth of M. cribraria that could then carry over for the rest of the season.…”

“…In its expanded North American range, M. cribraria is widely reported on soybean (Gardner et al, ), suggesting that soybean is a suitable host plant for invasive M. cribraria (Blount, Buntin, & Roberts, ; Blount, Roberts, et al, ; Del Pozo‐Valdivia & Reisig, ; Seiter, Greene, & Reay‐Jones, ). Adults consume other legumes and some additional angiosperms and conifers as well (Blount, Buntin, & Sparks, ; Lovejoy & Johnson, ; Medal, Halbert, Cruz, Smith, & Davis, ; Medal, Halbert, Smith, & Cruz, ).…”

Diel flight pattern and size‐dependent flight speed of kudzu bug, Megacopta cribraria (Fabricius)

“…They are pests of severe economic concern throughout much of Asia (Wang, Wang, Chen, Zhuge, & Tong, ) and have proven destructive in North America (Blount, Buntin, & Sparks, ), where they have been shown to reduce the yield of soya bean in caged plots by nearly 60% (Seiter & Greene, ). Despite their rapid expansion, their numbers may be declining due to an unintentionally introduced wasp, Paratelenomus saccharalis Dodd (Hymenoptera: Platygastridae) (Gardner et al., ) and the spread of an entomopathogenic fungus, Beauveria bassiana (Blount et al., ). Observation of their range through time (Lahiri & Reisig, ) suggests that they may be reaching the limit of their potential range in North America.…”