ABSTRACT
The term ‘beneficial insect’ may be applied to any insect from which humans derive direct or indirect benefit. Commensalism is common in insect/vertebrate associations. Many scavenger insects, for example, feed and breed as inquilines in birds’ nests and in the dens or ‘homes’ of other vertebrates, including humans. Mutualistic or symbiotic partnerships are well-established within the insect world; the close relationships between ants and honeydew-excreting aphids. Relationships between insects and other invertebrates have arisen in which the latter are parasitic upon the former. The microscopic nematode Sphaerularia bombi is an obligate endoparasite of adult bumblebees. The lifecycle of Dicrocoelium dendriticum, a trematode parasite of grazing mammals, is a wonder of evolution. Honey bees are greatly prized as producers of honey. They are also of importance as pollinators of crops and other plants. Honeydew is a sugary solution excreted by aphids, psyllids, scale insects, whiteflies and other phytophagous, phloem-feeding bugs.
