Development, Survival, and Reproduction of Megacopta cribraria (Heteroptera: Plataspidae) at Different Constant Temperatures.

Abstract

The plataspid Megacopta cribraria (F.), an economic pest of soybeans, Glycine max (L.) Merrill, in Asia recently invaded North America and has become not only an important pest of soybean but also a nuisance pest. Although much is reported about M. cribraria in its native and invasive range, little information has been documented on the effect of temperatures on its development, longevity, and reproduction. We evaluated the influence of five constant temperatures (17-33°C) on the development, survival, fecundity, and population growth of M. cribraria in the laboratory. The developmental time for egg and nymph stages was shortened significantly with increasing temperature. The developmental time from egg to adult emergence was 114.81, 76.26, 44.54, and 38.54 d at 17, 21, 25, and 29°C, respectively. The nymphs of M. cribraria could not complete full development at a constant 33°C. The developmental threshold temperature estimated for egg to adult was 14.25°C, with a thermal constant of 849.56 degree-days. Females had the longest preoviposition period at 21°C (54.33 d), and the preoviposition period was shortened significantly as the temperature increased. Females had the longest oviposition period (35.33 d) and the highest fecundity (159.67 eggs per female) at 25°C and did not lay any eggs at 17°C. Female longevity was found to be shortest (44.0 d) at 29°C, and similar (75.67-81.50 d) at 17-25°C. The population trend index of M. cribraria was the highest (46.47) at 25°C, followed by 29°C (10.84) and 21°C (6.70). The results will be useful for predicting the phenology and population dynamics of M. cribraria and will provide some biological information on the invasive species in its nonnative range.