Worcestershire Record No. 17 November 2004 pp. 26-27

THE LILY BEETLE LILIOCERIS LILII AND THE HARLEQUIN LADYBIRD HARMONIA AXYRIDIS: TWO SPECIES WORTH LOOKING OUT FOR

Harry Green

The lily beetle Lilioceris lilii

This species has been spreading throughout Britain and is a serious garden pest in parts of southern England, attacking various garden lilies and fritillaries. There are quite a few records from Worcestershire (VC37) but it is probably under-reported to WBRC. Please look out for the beetle and send in records. They appear in spring and early summer, eating holes in the leaves and weakening the plants.

The beetles are 6-8 mm long, bright red with a black head, legs and underparts. Both they and the reddish grubs attack the plants. The beetles lay clusters of red eggs. Be sure you can distinguish them from other species, such as cardinal beetles, though the latter occur in quite different habitats. If in doubt send specimens to the WBRC office.

A web search will provide readers with plenty of interesting material! A useful start is the Royal Horticultural Society web site www.rhs.org.uk

The Harlequin ladybird Harmonia axyridis

This is an Asian species. It was introduced in to SE United States about 25 years ago and has now spread throughout North America. It is a voracious eater of aphids but unfortunately if these run out it will eat a wide range of other insects, both adults and larvae of, for example, other ladybirds, hoverflies and lacewings. When it runs out of food is soon flies to pastures new! Once common North American ladybird species have declined following its arrival. Despite this there have various European introductions (for pest control) and it appears to be spreading rapidly in Europe. It was first reported in Britain 19th September 2004 in north Essex. Since then further records have followed in SE England, with some large clusters of beetles. In October it had reached Derby.

It is highly likely that this ladybird will soon be everywhere and it will be interesting to record its progress into Worcestershire so please keep a lookout and let us know if you find any.

Identification. This is a large lady bird 6-8 mms long, the same as the familiar 7-spot ladybird or larger. The Harlequin is very variable in colour through red, orange and yellow, and also in melanic forms (which are very rare in 7-spot ladybird). The elytra have zero to 19 black spots, which vary in size, or it may be black with four red patches. There is a single triangular white mark on the head which seems to missing from some melanic forms according to pictures I have seen. The pronotum is usually straw-yellow with up to five black spots or with lateral spots usually joined to form two curved lines, an M-shaped mark, or a solid trapezoid.

There is much more information with pictures on www.ladybird-survey.pwp.blueyonder.co.uk , a site well worth visiting and pictures are in BBC Wildlife December 2004 and gardening magazines. Web searches will provide plenty of information

Harmonia axtridis, the Harlequin ladybird.

 This diagram gives some idea of the range of varieties in this species.

 

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