Biological control by natural enemies debach paul 9780521098359 books amazonca skip to main contentca hello select your address books hello sign in account lists account returns orders cart all gift cards best sellers prime gift ideas new . Natural enemies an introduction to biological control hajek ann e eilenberg jorgen 0001107668247 books amazonca. Natural enemies and biological control 3 flower flies flower flies figure 3 are black and yellow insects which resemble honey bees as the name suggests they often are found hovering about or feeding on flowers the larvae however are voracious predators and especially fond of aphids figure 4 the larvae are maggot like in appearance