The ladybird parasitoid, Dinocampus coccinellae, inserts an egg into the underside of an adult ladybird’s body. Several ladybird species can be attacked but 7-spot ladybird is the most frequent host. The parasitoid larva develops inside the ladybird’s abdomen. When it is fully fed it paralyses the ladybird by destroying its nervous system. It emerges from the host insect and spins a silk cocoon in which it pupates underneath the ladybird’s body. The red and black markings on a ladybird are warning coloration that tell birds and other predators that ladybirds are not good to eat. By hiding itself under the immobilised ladybird’s body, the parasitoid pupa benefits from this protection.
Role of parasitic wasps in gardens
Parasitic wasps, along with other parasitic and predatory insects, play an important part in helping to limit population numbers of insects and spiders. Some parasitic wasps are reared by companies dealing in biological controls and can be purchased for use in gardens, especially against some glasshouse pests. Encarsia formosa is used against glasshouse whitefly nymphs; Anagrus atomus is used against eggs of glasshouse leafhopper; Aphidius colemani, Aphidius ervi and Praon species against aphid nymphs; Dacnusa sibirica against larvae of the chrysanthemum leaf miner; Leptomastix species against mealybug nymphs; Metaphycus helvolus against soft scale nymphs.
References:
1 Owen, J.,Townes, H. and Towns, M. (1981) Species diversity of Ichneumonidae and Serphidae (Hymenoptera) in an English suburban garden. Biological Journal of the Linnean Society, 16:315–336. https://doi.org/10.1111/j.1095-8312.1981.tb01656.x
2 Owen, J. (1991) The ecology of a garden: the first fifteen years. Cambridge University Press
Other sources of information
Books
Gauld, I. & Bolton, B. (editors) (1988) The Hymenoptera. Oxford University Press
Fergusson, N. D.M. (1986) Handbooks for the Identification of British Insects Vol 8 part 1c. Charipidae, Ibaliidae and
Figitidae Hymenoptera - Cynipoidea. Royal Entomological Society
Askew, R. R. (1968) Handbooks for the Identification of British Insects Vol 8 part 2b. Hymenoptera – Chalcidoidea
section a
Ferriere, Ch. & Kerrich, G. J. (1958) Handbooks for the Identification of British Insects Vol 8 part 2a. Hymenoptera –
Chalcidoidea Section a
Fitton, M. G., Shaw, R. T. & Gauld, I. D. (1998) Handbooks for the Identification of British Insects Vol 7 part 1.
Pimpline ichneumon-flies Hymenoptera – Ichneumonoidea (Pimplinae)
Gauld, I. D. & Mitchell, P. A. (1977) Handbooks for the Identification of British Insects Vol 7 part 2b. Ichneumonidae
– Orthopelmatinae, and Anomaloninae
Helyer, N., Brown, K. & Cattlin, N. D. (2003) A colour handbook of biological control in plant protection. Manson
Publishing
Nixon, G. E. J, (1957) Handbooks for the Identification of British Insects Vol 8 part 3dii. Hymenoptera –
Proctotrupoidea Diapriidae subfamily Belytinae
Nixon, G. E. J, (1980) Handbooks for the Identification of British Insects Vol 8 part 3di. Diapriidae (Diapriinae)
Hymenoptera – Proctotrupoidea
Perkins, J. F. (1959) Handbooks for the Identification of British Insects Vol 7 part 2ai. Hymenoptera –
Ichneumonoidea
Perkins, J. F. (1960) Handbooks for the Identification of British Insects Vol 7 part 2aii. Hymenoptera –
Ichneumonoidea
Quinlan, J. (1978) Handbooks for the Identification of British Insects Vol 8 part 1b. Hymenoptera – Cynipoidea:
Eucoilidae
Shaw, M. R. & Huddleston, T. (1991 Handbooks for the Identification of British Insects Vol 7 part 11. Classification
and biology of braconid wasps (Hymenoptera: Braconidae)
The above handbooks are out of print, but available as free dowloads from here
By Andrew Halstead reviewed by Andrew Salisbury edited by Steve Head