We first recorded the Lily beetle Liloceris lilii on garden lilies on 3rd June 2001. Although we despatch any adults, eggs or larvae, we have recorded it every year since that date. However, this year we noted the larvae on Snake’s-head fritillary Fritillaria meleagris for the first time.

The beetle’s main host plants are Lilium spp. and Fritillaria spp. including F. meleagris. The larvae were feeding on the unripe seed heads of the fritillaries and the photograph below illustrates the damage they can inflict.

I understand that adult beetles feed on a range of food plants almost all of which are within the Liliaceae but their selection of plants on which to lay eggs is more rigorous and precise. Only on these host plants selected for oviposition will the larvae be able to complete their development.

The larvae have the unsavoury practice of covering their backs with a layer of sticky faecal material from the dorsally situated anal opening. This mucus gets transferred to the plant, ruining its attractiveness for the gardener. We are familiar with this practice helping us to locate the larvae, which are more difficult to spot than the adults which are bright red and contrast well against green foliage. I should add that our fritillaries’ provenance is wild stock, legitimately obtained; they are in the part of our lawn dedicated as a wild flower meadow. From a humble beginning of a few seeds and plants we now have 429 flowering heads as counted this year.

Our concern is that if this alien invader increases in number it could pose a threat to this native flower which only survives in any quantity on nature reserves. Our climate appears to be changing to a milder regime and will therefore probably favour the spread of the species. Has this larval activity on seed heads been witnessed in Suffolk previously?

We wish to record our thanks to David Nash for assistance on this subject.