Aphid Parasitoids: Aphidiinae (Hym., Braconidae)

Abstract

Various aspects of the knowledge on the aphid parasitoids (Hymenoptera, Aphidiinae) with regards to the biological control of pest aphids are presented. The aphidiines are exclusively associated with aphids and can be found in various natural and agro-ecosystems. There are both specific and generalist aphid parasitoids, which can be used in various biological control programs. In taxonomic point of view, a good knowledge of Iranian Aphidiinae is now compiled together with their host associations, which provide a background data for many subsequent research. Many studies have been done on various aspects of their biology including, life history and demography, functional response, foraging behavior and host preference. These surveys are generally focused on the economically important aphids and their parasitoids under laboratory conditions and in the field to a lesser extent. Occurrence of the aphid parasitoids in various ecosystems including arable lands, fruit orchards, urban areas and their impacts on the population of the host aphids are discussed. Efficiency of the aphid parasitoids can be impaired by different factors i.e. hyperparasitism, intra-guild predation and agricultural activities. So, a conservation program is necessary in most cases to be done. A simple, but important definition as refugium should be receive further priority in all conservation programs, which include some parts of natural or obligatory migration of the aphid parasitoids inside their ecological niches. Many researches have been centered to search and find potentially useful parasitoids in Iran to be introduced into new area for the biocontrol of some invasive pest aphids. On the other hand, there are some invasive aphids in Iran, free of parasitoids and in pest status. Among several potentially effective aphid parasitoids, few species can be commercially produced. Successful mass rearing of the aphid parasitoids is a crucial aspect of the aphid biological control especially in glasshouses. A brief review of the potential species, as well as the significance of factors affecting the cost-effective mass production is discussed.