EVALUATION OF MEDITERRANEAN FRUIT-FLY TRAPS FOR USE IN STERILE-INSECT-TECHNIQUE PROGRAMS

This paper contains information on a 5-year experimental programme, co ordinated by the International Atomic Energy Agency (I.A.E.A.), on Med iterranean fruit-fly (medfly); Ceratitis capitata (Diptera, Tephritida e) trapping. The aim of the experiments was to standardize trapping me thods for use in sterile-insect-technique programmes under various cli matic and ecological conditions. The experiments were conducted in Gre ece during the months July-September, 1987-1991, in a citrus orchard o n the island of Chios. Seven different trap types and several trap tre atments consisting of combinations of visual and olfactory (food, sexu al) attractants were tested according to the coordinated protocol. Add itional trap types and treatments were also assessed in additional exp eriments. Among the treat ments rested, 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(R) 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 repellen t effects on non-target insects and in part, on medfly females. The sa me treatment without TML was almost as effective as the above treatmen t, capturing predominantly females but also a large number of non-targ et insects which renders it problematic. The IPMT was as effective as the other McPhail Trap version tested, including the classical glass t rap. 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 st icky surface was too small to capture the corresponding proportions of males. Under high population densities, larger sticky traps or dry tr aps with a much bigger carrying capacity are more suitable. Some of th e Nadel-type traps such as Hawaiian and a Moroccan version (the Maghre bmed trap!, or even a dry IPMT baited with TML and DDVP, were very eff ective and are probably suitable for dry and dusty areas. However, wit h some of the traps, such as the Hawaiian type, most of the captured f lies were frequently removed by yellowjacket wasps (Vespula germanica L.) entering into the trap.