Laboratory and Field-Cage Demography Studies of Dia-chasmimorpha longicaudata Mass-Reared on Two Ceratitis capitata Strains

Abstract

The reproductive capacity of parasitoid wasps during their lifetime plays a crucial role in understanding their potential as biocontrol agents and the host-parasitoid dynam-ics. An interesting system to study involves the Southeast Asia-native parasitoid Dia-chasmimorpha longicaudata and its host Ceratitis capitata, commonly known as the Med-iterranean fruit fly or medfly, which is a serious invasive fruit fly pest in Argentina. This study compared reproductive parameters of two parasitoid population lines reared at the biofactory San Juan on different medfly strains. One line was mass-reared on medfly larvae of a genetic sexing strain (=Dl(Cc-tsl)), and the other on larvae of a wild biparental medfly strain (=Dl(Cc-bis)). The goal was to provide information for improving parasitoid mass production and evaluating its performance under natural conditions. For this, laboratory and field-cage trials were done at the San Juan biofactory. Firstly, laboratory trials showed that Dl(Cc-bip) females displayed higher reproductive and pop-ulation rates than those of Dl(Cc-tsl) females. Secondly, field-cage trials revealed that fe-males of both Dl(Cc-bip) and Dl(Cc-tsl) had similar and high reproductive potential in late spring and summer, when environmental conditions are temperate-warm. However, unlike Dl(Cc-tsl) females, Dl(Cc-bip) females were reproductively active in early autumn, al-beit at very low rates due to colder environmental conditions. The current study pro-vides novel data to improve the productivity of D. longicaudata mass rearing and to achieve the most effective medfly control through parasitoid releases in semi-arid fruit-growing areas of Argentina.