Influence of Temperature and Humidity Regimes on the Developmental Stages of Green Vegetable Bug, 'Nezara viridula' (L.) (Hemiptera: Pentatomidae) From Inland and Coastal Populations in Australia

Abstract

Laboratory studies were conducted to assess impacts of temperature and humidity regimes on the development of Nezara viridula (L.) (Hemiptera: Pentatomidae) from inland and coastal populations in NSW, Australia. Four temperature regimes, 25±2ºC, 30±2ºC, 33±2ºC, and 36±2ºC and two humidity regimes, 40±10% and 80±10% RH were applied in the experiment with a constant photoperiod of 14:10 h (L:D). The developmental time of the nymphal stage of N. viridula significantly decreased with increasing temperature. Percentage nymphal survival significantly decreased with increasing temperature or high humidity (80% RH) regimes. Longevity of N. viridula adults declined with increasing temperature or high humidity regimes and female longevity was longer than males. High temperatures (30, 33 and 36ºC) or high humidity significantly reduced reproductive performance and capacity of N. viridula compared to low temperature (25ºC) or low humidity (40% RH). However, high humidity significantly increased egg hatchability of N. viridula compared with a low humidity regime. Interactions of temperature and humidity regimes significantly changed incubation period, adult longevity, mating frequency, pre-mating period, egg-mass size and egg hatchability of N. viridula. Interactions of population location (coastal or inland), temperature and humidity regimes significantly changed incubation period and pre-oviposition period of N. viridula. Temperature and humidity are important environmental factors for the development and reproduction of N. viridula. Higher temperatures shorten the length of nymphal duration, but reduce nymphal survival. The optimum temperature for the development and reproduction of N. viridula was 25ºC with 40 ± 10% RH. No differences in nymphal duration, nymphal survival, adult longevity or reproduction performance between inland and coastal N. viridula populations were found under different climate conditions. We show the importance of assessing all life-stages in the response to varying temperature and humidity regimes, especially in terms of assessing responses to climate change.