Effect of temperature and host plants on fitness traits and demographic parameters of Thrips parvispinus (Karny) (Thripidae: Thysanoptera)

Abstract

Defining and forecasting the life cycle and population dynamics of thrips depend on understanding their developmental and reproductive responses to varying temperatures. The goal of this investigation was to gather precise data on biological fitness and demographic parameters of Thrips parvispinus on two selected hosts (Chilli, Capsicum annuum; Solanaceae and Beans, Phaseolus vulgaris; Leguminosae) at four constant temperatures (15, 20, 28 and 30 °C). The total pre-adult duration found longest at 15 °C and shortest at 30 °C on beans, while longest at 20 °C and shortest at 30 °C on chilli. Adult longevity was recorded longest at 15 °C and the shortest at 30 °C on both beans and chilli depicting that 30 °C shortened the adult lifespan of T. parvispinus. Fecundity was documented to be highest on beans and chilli at 30 °C, and lowest at 20 °C on beans and on chilli at 15 °C. The total pre-oviposition period was found to be shortest at 30 °C both on beans and chilli. Significant differences in the population parameters revealed net-reproductive rate and finite rate of increase to be highest at 30 °C on both chilli and beans. The shortest mean generation time was recorded at 30 °C on both chilli and beans. This study is first of its kind in investigating the comparative biology of T. parvispinus on chilli and beans under different temperatures. Since, there exists a lack of knowledge on the fitness traits and demography of T. parvispinus, these findings would prove significant for predicting population responses to climate change and tailoring integrated pest management strategies.