Beetles in the genus Chilocorus (Coleoptera: Coccinellidae) are generalist predators of
armoured scale insects (Homoptera: Diaspididae). Three species of the genus, Chilocorus
bipustulatus Linnaeus, C. cacti Linnaeus and C. infernalis Mulsant were reared in the
laboratory for release as biological control agents against armoured scale insect pests.
The host scale culture, (a mixture of greedy and latania scales, Hemiberlesia rapax
(Comstock) and H. lataniae (Signoret)), normally used to rear the ladybirds was in short
supply, so a supplementary artificial diet was sought. Initially, several agar-based diets
were tested, but without success. Many researchers have used various species of pulverized
insects for rearing ladybirds; for example, Okada & Nijima (1977) used bee brood (the
larvae or pupae of honeybees Apis mellifera L.), blended, freeze dried and then pulverized
as a diet for 17 species of ladybirds. Bain et al. (1984) used the larvae of potato tuber
worm Phthorimaea operculella (Zeller) and Huhu grubs (larvae of Prionoplus reticularis White)
as the bases for 2 freeze-dried diets, in the laboratory rearing of the predatory coccinellid
Cleobora mellyi Mulsant for a biological control programme. Smirnoff (1958) varied a diet
to suit coccinellid species with different feeding requirements, by including the natural
prey as pulverizeddry insects.
This paper reports investigations comparing 3 artificial diets, based on pupae of light
brown apple moth Epiphyas postvittana Walker, pupae of the wasp Vespula germanica (F),
and the larvae or pupae of honeybees Apis mellifera L. respectively. A regular supply of
these 3 insects was available which was a factor in selecting them for our diet evaluations.