Searching behavior and prey preference by the predatory mirid bug Tupiocoris cucurbitaceus, a potential biocontrol agent of tomato crops in Argentina

Abstract Generalist arthropod predators usually exhibit a degree for prey acceptance and this behavior can ultimately determine their potential as biocontrol agents. The South American tomato leafminer Tuta absoluta is a key pest of tomato crops worldwide. Biological control has gained interest as a reliable and environmentally safe pest management technique, and particularly the use of predatory mirid bugs has shown positive results to control T. absoluta and other horticultural pests in several countries. In a laboratory study we assessed: 1) prey searching behavior and 2) feeding preference of late nymphs and adults of both sexes of Tupiocoris cucurbitaceus, a mirid bug present in Argentinian tomato crops with the aim of deepen its status as a biocontrol candidate of T. absoluta. Predatory individuals were offered simultaneously three patches of prey: the target patch (TP) with T. absoluta eggs and two non-target patches (NTP) with Ephestia kuehniella eggs and Trialeurodes vaporariorum late-instar nymphs. First, a 30-min trial was analyzed using EthoVision® software in which we found that mirids equally accepted TP and NTP, and only nymphs preferred to feed on T. absoluta eggs. After 24 h, predatory nymphs consumed proportionally more of the three prey offered, but mainly lepidopteran eggs. These results prove that T. absoluta eggs can be part of the prey diet of T. cucurbitaceous especially for the nymphal stage. Further studies on prey availability in field conditions are needed to use T. cucurbitaceus as a biocontrol agent of T. absoluta in Argentina.