Effects of temperature, photoperiod and humidity on the life history of Gargaphia decoris

Abstract

The sap-sucking lace bug Gargaphia decoris Drake (Hemiptera: Tingidae) is a biological control agent released in New Zealand to control the invasive small tree or shrub Solanum mauritianum Scopoli (Solanaceae). The aim of this study was to investigate the effect of temperature, photoperiod and humidity on selected G. decoris life history traits. The selected traits were measured at six different temperatures (10, 15, 20, 25, 27.5 and 30 °C), three photoperiods (L:D 6:16, 14:10 and 16:8) and two relative humidity (RH) levels (50 and 70 ± 10%). Eggs and nymphs did not survive in the 10 °C and 30 °C treatments. The net reproductive rate (R0) resulted in population growth at all temperatures, but was highest at 25 °C. Egg hatch rate was highest at L:D 8:16, and nymphal and adult survival was better at L:D 16:8. Egg hatch was higher at 50 ± 10% RH and adult survival and population growth were higher at 70 ± 10% RH. These results will help to predict the persistence of established G. decoris populations and the potential for establishment at new release sites.