Life history attributes of Anastatus japonicus (Hymenoptera: Eupelmidae) are regulated by nutrition and temperature

Abstract

Anastatus japonicus Ashmead (Hymenoptera: Eupelmidae) is an effective egg parasitoid of Halyomorpha halys Stål (Hemiptera: Pentatomidae). In nature, parasitoids often depend on biotic and abiotic factors such as supplementary nutritional sources (e.g. sugars) and optimum temperature to maximize their life-expectancy and reproductive potential. Our field release trials of A. japonicus against H. halys showed limited efficacy, potentially due to suboptimal nutritional resources and inappropriate ambient thermal conditions during the release period. Thus, the present study aims to understand the impact of 14 distinct naturally occurring sugars and different temperature treatments with respect to their effects on A. japonicus life attributes. Longevity of A. japonicus males and females fed with 1 M stachyose sugar solution was comparatively longer while numbers of total progeny and females’ proportion were relatively highest with provision of maltose, glucose or fructose, respectively. Anastatus japonicus male and female progeny had significantly lengthier and shorter longevity and development time at low (15 °C) and high temperatures (35 °C), respectively. Female development time were found to be longer when fed maltose and water, while shorter with melibiose. Anastatus japonicus performs better on mono- and di- saccharide sugars compared to tri- and tetra- saccharides. In addition, 20–25 °C is the most suitable temperature range to optimize mass rearing. We are assuming that field release efficacy could be improved by planting buckwheat strips providing adequate amounts of maltose, glucose and fructose alongside shelter for A. japonicus in unfavorable harsh environmental conditions. This study opens up opportunities to select food supplements and optimum rearing temperature for inundative biocontrol by using A. japonicus against H. halys.