COLEOPTERA > CHRYSOMELOIDEA > Chrysomelidae > Galerucinae > Galerucini

Galerucinae is a large subfamily, split into two well-defined tribes; the Galerucini, as described here, consisting 20 species of skeletonising leaf beetles, and Alticini, which is sometimes treated as a separate subfamily, including 127 closely related species commonly known as flea beetles, as described on the following page.

The primary distinguishing character between these two groups is the form of the hind femora and whether it is modified and enlarged for jumping, in which case it is most likely, although there are always odd exceptions, a flea beetle.

Members of the Galerucini are known as skeletonising leaf beetles as the larvae of many species, and indeed some of the adults, primarily feed on leaf membranes leaving the stalk, veins and edges intact. They can cause a lot of damage as can be seen in one of the photos below where new generation adults of the Alder Leaf Beetle have stripped leaves bare. The British representatives of this subfamily vary somewhat in terms of size and form, but most are in the region of 4-8mm long with a generally elongate shape with the base of the pronotum being narrower than width of the elytra across the shoulders.

I'm not sure exactly how many of these beetles are likely to be encountered locally, but from a quick bit of research I think that there are probably eight that are regarded as reasonably common and a further three, possibly four, that could be found. To date I've seen seven, including one of the rarely recorded 'nationally scarce' species.   

Agelastica alni (Alder Leaf Beetle)

This deep metallic blue species was thought to be extinct until a few years ago when it was effectively rediscovered and, although still regarded as rare, has since been recorded across a number of central and southern counties. Adults are active from early spring until June and July and are most likely to be found in open wetland habits or alongside streams and rivers where Alder is growing. They feed on the buds as well as the leaves and although Alder is the favoured host plant, the larvae can develop on other shrubs such as Hazel, Goat Willow and Downy Birch.

Calomicrus circumfusus

This distinctive little beetle has widespread, but very local distribution with few reported sightings. Although there are some coastal locations around the West Country where it is regularly encountered, elsewhere it is very scarce. Most of the sightings in Dorset have been on heathland where it may be found on Gorse or Broom. Adults are active from April until September or early October.

Galerucella calmariensis (Black-margined Loosestrife Beetle)

Typical habitats for this locally common skeletonising beetle are wetland margins, marshes and coastal grasslands where Purple Loosestrife is growing. The species is typically pale brown with a black head and scutulum; and with variable darkened areas, usually consisting of a black mark on the centre of the pronotum, and broad longitudinal bands along either side of the elytra, which are best seen when viewed from above. Similarly, with the elytral explanate margin that, in this species, is normally nicely defined and reasonably consistent throughout. Overwintering adults become active from April with the females laying up to 400 eggs over the next couple of months. The eggs are are white and spherical, neatly deposited in small groups and usually topped with frass, as can be seen in the photo. Once hatched, the yellow, black speckled larvae feed on the leaves and, as they develop, will start causing extensive defoliation.

Galerucella lineola (Brown Willow Beetle)

A reasonably widespread species that is very similar to Galerucella calmariensis, but with a more uniform plain yellowish-brown appearance. In comparison, the head has a large dark mark on top rather than being entirely black, and the explanate elytral margin is narrower tapering off towards the base. The pronotum has a slightly different, broadest about the middle and strongly narrowing to both the anterior and posterior angles. It is perhaps more likely to be confused with Galerucella tenella. The main food plants of that species are meadowsweet and strawberries, and that alone is a good indicator regarding identification as Galerucella lineola is the only member of the genus associated with trees, notably willows, occurring mostly in wetland habitats, such as marshes or around lake margins.

Lochmaea crataegi (Hawthorn Leaf Beetle)

The distinctive dull reddish-brown colouration, coupled with a pair of longitudinal dark markings of varying length and intensity on each side of the elytra, makes this species very easy to separate from the other two members of the genus. Adults are mostly associated with hawthorn, usually emerging in early spring a week or two before the blossom starts to appear. At this time, they may be found on other shrubs and trees such as blackthorn. They are most likely to be seen from mid-April to around mid-June; widespread across southern and central areas, becoming more local further north.     

Lochmaea caprea (Willow Leaf Beetle)

A widespread and relatively common species that may be found in various habitats, especially wetlands, where Willow (Sallow) or Birch are growing. The head is completely black, with the body varying in colour from yellowish- brown to dark brown.  

Lochmaea suturalis (Heather Beetle)

Widespread and common, and very similar to Lochmaea caprea, but occurring primarily on heathland where Heather (Calluna vulgaris and/or Erica spp.) are present. The habitat is normally a sufficient indicator, but in areas where both species may be present, Lochmaea suturalis can be identified by having a shinier pronotum than Lochmaea caprea and elytra where the suture is usually narrowly darkened. They also have a yellowish to brownish spot in front of the eyes, although difficult to see. Colour varies as in the previous species, with some individuals being very dark. Although the adults cause some damage, it's the larvae that strip the heather bare and, in some seasons and areas, particularly on upland moors, this can be devastating if grasses start taking over.