Gardener's Larva Guide

This guide is aimed at gardeners in the United Kingdom, and it doesn't cover weevil larvae which have no legs.

Larvae photos are on millimetric paper, 1 mm smallest division. With some browsers when you move your cursor over the photos, you will be able to get more information about the pictures. In particular the larval head capsule width (HCW).

	Stag beetle *Lucanus cervus*	Lesser stag beetle *Dorcus parallelipipedus*	Rose chafer *Cetonia aurata*	“Cockchafer” or Summer chafer *Amphimallon solstitialis* [1]
Larva
Description	C-shaped. Very pale cream coloured soft transparent body, very plump almost cylindrical with segments not raised in three folds, nice to the touch. It has six stout orange legs, and an orange coloured head with very sharp brown slightly curved pincers. Anal opening longitudinal, surrounded by 2 characteristic lobes. For more click here.	C-shaped. Almost identical to the stag beetle larva, its head is somewhat paler and the pincers are straighter, also it doesn't reach the same size as the stag beetles. Generally, the gut contents are pale; they spend their time feeding only in the wood, and unlike stag beetles have little contact with the soil. Anal opening longitudinal, surrounded by subtly different lobes. For more click here.	C-shaped, very tightly curved sometimes, a bit like a concertina. It has a very small head and a very large bum, very short legs too; its body is very wrinkly and very firm to the touch, covered with very fine pink hair. Anal opening transverse. It is the easiest larva to identify correctly. Click on the picture for a better view of the larva.	C-shaped. Creamy coloured hairy body darker and thinner than the stag beetle, with folded segments, longer legs and not such a distinct chestnut coloured head, with curved pincers. Anal opening transverse.
Zooming in on the Spiracles All the larvae are on their backs with their heads to the right.	C shaped, all facing the same way.	C shaped, all facing the same way.	Kidney shaped, practically circular, rather dark.	Kidney shaped; the spiracles nearer the head face the other way.
Size	When fully grown, up to 8 cm long and nearly 2 cm thick. See here for larvae at different stages of development. When mature it is the biggest larva to be found in a garden in the U.K.	Doesn't reach the same size as the stag beetle larva. Around 6.5 cm. For instance, the larva shown is fully grown, compare its size with the one on the left, also in the last instar.	Around 3.5 cm when fully grown.	Around 3.5 cm when fully grown, but other root-chafer species can be much bigger.
Habitat	Tree stumps, old trees and shrubs, rotting fence posts, decorative logs, compost heaps and leaf-mould piles. Mostly under the ground in natural situations. However it can be found feeding above the ground in log piles, etc. Note the galleries that the larvae have made. Scale is in 1 cm divisions.	Shares the habitat with the stag beetle but it prefers to feed above the ground. It is a kind of upstairs-downstairs arrangement. Above is a picture of its larval galleries in a fence post which they shared with the stag beetles. The rule at the top is 15 cm long.	It may share the habitat with the stag beetle, but it is very frequently found in compost, leaf-mould and manure heaps in great numbers. They are the equivalent of earth worms and help break things down so they are very beneficial. Gardeners quite often believe that they are stag beetle's larvae, which is no problem as both are very beneficial decomposers. Click on the picture for another clutch.	Feeds on fresh roots, does great damage; usually associated with lawns. They are not to be found in decaying wood or the compost heap.
Behaviour	Curls up in a C or rolls up on its back as if being tickled. Also it often defecates as a reaction to being handled. Video	The same as for the stag beetle. It also defecates often, like it does in this video; lighter coloured frass because it does not feed in the soil-wood interface.	If placed on a flat surface will crawl on its back! Video In the U.S.A. larvae with similar behaviour are called “crawly-backs”.	If placed on a flat surface it will 'run' dragging its tail end behind. Video
Pupa	Below the surface in a soil compacted cocoon, the size of an orange.	Above the ground in the wood where it has been feeding.	In the soil/compost in a soil compacted cocoon, the size of a blackbird's egg.	In the soil, near where it has been feeding. This is the pupa from the larva shown at the top. Notice its exuvia, top right corner.
Imago	Click on the picture to view more photos.	Click on the picture to view more photos.	Click on the picture to view more photos.	Click on the picture to view another likely culprit, the true cockchafer. [1]
Action	Stag beetle larvae will not damage your trees, crops or flowers. Just leave them where they are as they don't seem to respond well to being moved.	The same as for the stag beetle larvae.	Just leave them. First, they work on your compost; then, the adullts look absolutely delightful on your flowers, which they will not damage.	Pest. However if you aren't absolutely sure of their identification, take them to your nearest wild life centre/ natural history museum.

LINKS:
Rose Chafer Survey - Please enter your records even if they are null, as it would be very interesting to get an update view on the distribution of this beetle.

[1] - The larva shown at the top right was picked up in my allotment where summer chafers, or June bugs, Amphimallon solstitialis, are often seen flying during summer evenings from late June; they emerge around the summer solstice, hence their common and scientific name. Among the allotmenteers they are known as “cockchafer”; elsewhere they can also be called chafer grubs or rook worms. However there is some confusion here as regards these common names, the true cockchafer, or May bug, is supposed to be Melolontha melolontha, which it is very rare in this area. It really doesn't matter as either of these chafer grubs feed on fresh roots. But it does show how misleading common names can be. For instance, billywitch is another popular name attributed to at least three beetles.

The results of the National Stag Beetle Survey 2002 [PDF] showed that 70% of the stag beetle sightings come from gardens, let's make them a safe haven for stag beetles.

Acknowledgements

Last modified: Sat April 28 2018