A laboratory study of the biology and of chemical control of Phytomyza atricornis Mg.

Leaf miners are a very specialized group of insects due to the specialization, modification and the adaptations of the larvae which live inside leaf tissues. Because of the concealed habit of the larvae they are protected from the direct action of the contact insecticides. Because of the high efficiency of the natural enemies, mainly parasites, leaf miners are normally well controlled and their significance as pests is not great. Recently, following the discovery and wide-spread use of modern, non-selective organic insecticides, many have become important pests. There is evidence indicating that this is due to the indiscriminating applications of insecticides that have actually upset the balance between leaf mining insects and their parasites. This is discussed fully in the review of literature. Because of the urgent need for control of leaf miner pests, most experimental work has been performed in the field. Many insecticides have been shown to give excellent control. Nevertheless, field trials to test insecticides are tedious and time-consuming because comprehensive sampling and dissection of mines is necessary to obtain a reasonable degree of accuracy. Also they do not give any indication of the behaviour of the mining larvae towards the insecticides being applied. The purpose of this thesis is to use and to develop laboratory techniques which would give a high degree of accuracy and precision in results and to assess the relative value of some modern insecticides against the adults and larvae of one species of leaf-miner, i.e. Phytomyza atricornis