Life history traits and rearing protocol of <i>Microvelia pulchella</i> (Hemiptera: Veliidae): a potential biological control agent and model for behavioural and ecological studies

Abstract

Microvelia pulchella, a semiaquatic predatory bug widely distributed in the Neotropics, holds great potential as a biocontrol agent against disease-vector mosquitoes and pests in paddy rice fields. Moreover, insects belonging to the genus Microvelia have served as valuable model organisms for ecological and behavioural research. Considering this, our study aimed to establish an enhanced laboratory rearing protocol for M. pulchella based on existing methodologies. The protocol encompasses a decision-making flowchart to optimize the rearing process, a standardized method for accurately determining egg and nymph ages, and photographs illustrating all life stages and sexes of the insect. Additionally, we sought to characterize key life history traits of this species. Our detailed rearing procedure involves utilizing different containers tailored to each insect stage and specific requirements. We observed an average development time of 20.6 days from egg to adult at a temperature of 25°C (room temperature). Interestingly, male adults reared in the laboratory exhibited smaller sizes compared to their field-collected counterparts, while females displayed similar sizes across conditions. Female M. pulchella demonstrated an average egg production of 211.77 eggs, with the highest fecundity occurring within the first five weeks. Fertility followed a similar pattern, peaking during this period. In terms of longevity, females exhibited an average survival time of 74 days, whereas males lived for approximately 91 days. M. pulchella proves to be a convenient model organism for conducting non-invasive experiments, given the multitude of informative traits that can be measured. Additionally, the rearing procedure is cost-effective, straightforward, and requires minimal space.