Crioceris-asparagi - Common Asparagus Beetle

Phylum: Arthropoda - Class: Insecta - Order: Coleoptera - Family: Chrysomelidae

Description

The Common Asparagus Beetle is 6 to 8mm in length. Its elytra are black, as is its head and legs, while the thorax is reddish. There are six white or yellowish spots on the elytra (wing cases), each of which has a reddish marginal band.

Habitat

The only places in Britain where you are likely to see the Cmmon Asparagus Beetle are where wild asparagus or, more often, cultivated asparagus grows. This is the more abundant and widespread of the two kinds of asparagus beetle that occur in the UK; the other is an introduced species, the Spotted Asparagus Beetle Crioceris duodecimpunctata, which is not only less common but also considered by farners and gardeners to be a less serious pest.

Distribution

The Common Asparagus Beetle Crioceris asparagi is widely distributed in Britain and Ireland. This species also occurs throughout mainland Europe, parts of Africa the Middle East and much of temperate Asia. This beetle is an introduced invasive pest in many parts of the USA and Canada; it is also known to occur in Argentina.

Life cycle

Eggs of the Common Asparagus Beetle are laid in springtime; they hang singly from the undersides of asparagus leaves and take about a week to hatch.The six-legged larvae, which grow up to 100mm in length, are dark grey with black heads. They look rather like little slugs fitted with stubby black artificial legs. When they are fully grown, which takes a few weeks, the larvae pupate in soil for about a week, after which the adult beetles emerge and begin feeding on asparagus leaves. Two or sometimes more generations of these beetles occur in a year. The final brood of adults overwinters in leaf litter or other plant debris, emerging in springtime to initiate another summmer cycle of feeding and breeding.

Acknowledgements

This page includes pictures kindly contributed by Betty and Tony Rackham.

References

Hubble, Dave (2017) Leaf Beetles, ISBN 9781784271503. Pelagic Publishing.

Harde K.W. & Severa F. (1984) Field Guide in Colour to Beetles. Littlehampton Book Services.

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