Evaluation of Mediterranean fruit‐fly traps for use in sterile‐insect‐technique programmes

Abstract

AbstractThis paper contains information on a 5‐year experimental programme, coordinated by the International Atomic Energy Agency (I.A.E.A.), on Mediterranean fruit‐fly (medfly); Ceratitis capitata (Diptera, Tephritidae) trapping. The aim of the experiments was to standardize trapping methods for use in sterile‐insect‐technique programmes under various climatic and ecological conditions. The experiments were conducted in Greece during the months July‐September, 1987–1991, in a citrus orchard on the island of Chios. Seven different trap types and several trap treatments consisting of combinations of visual and olfactory (food, sexual) attractants were tested according to the coordinated protocol. Additional trap types and treatments were also assessed in additional experiments. Among the treatments tested, the most effective in terms of total captures was the International Pheromones' Plastic McPhail Trap (IPMT), baited with a water solution containing the protein Nulure 9%, borax 3 % and having a Trimedlure (TML) plug in a basket hung from the trap ceiling. This treatment captured predominantly males and was relatively selective for medflies since, apparently, TML has repellent effects on non‐target insects and in part, on medfly females. The same treatment without TML was almost as effective as the above treatment, capturing predominantly females but also a large number of non‐target insects which renders it problematic. The IPMT was as effective as the other McPhail Trap version tested, including the classical glass trap. The internationally used Jackson Trap baited with a TML plug was the most convenient in terms of handling and performed well under low to medium population densities. However, with high populations, its sticky surface was too small to capture the corresponding proportions of males. Under high population densities, larger sticky traps or dry traps with a much bigger carrying capacity are more suitable. Some of the Nadel‐type traps such as a Hawaiian and a Moroccan version (the Maghrebmed trap), or even a dry IPMT baited with TML and DDVP, were very effective and are probably suitable for dry and dusty areas. However, with some of the traps, such as the Hawaiian type, most of the captured flies were frequently removed by yellowjacket wasps (Vespula germanica L.) entering into the trap.