THE DENIZENS OF AN OLD CHERRY TREE. 5 



elapse ere the rich, deep, normal shade of blue-black finally 

 appears. Its first appearance forms such a strange contrast to 

 that of the more matured insect, that we killed and set a newly- 

 emerged specimen for our collection. The perfect insects made 

 their appearance in our boxes at various intervals from April 27th 

 to May 8th, on which latter date we found several half-grown 

 larvae in the borings. We frequently observed the imago with its 

 head projecting from the mouth of the burrow made by the larvae, 

 into which it rapidly backed on our attempting to capture it. 

 These beetles are quick runners, and appear to emerge from the 

 burrows only after dark. The general hue of the larva is cream 

 colour, with pale-brown head. The jaws are darker and of a 

 horny nature, admirably adapted for eating its way into the wood, 

 and at the same time forming the burrows needed for its protec- 

 tion then and also in its future stages. Fig. i, PI. II. ^ shows 

 magnified dorsal view of the jaws of the larva. 



The three pairs of legs, which are situated on the three seg- 

 ments next the head of the larva, enable it to move along its 

 burrow, and, combined with the sudden contraction of the seg- 

 ments, to perform the curious feat of repeatedly turning quite over 

 sideways, which feat we witnessed by placing several larvae on a 

 level surface. When put into a glass tube, they could in this 

 manner move along it, from which we infer that the larva not only 

 propels itself corkscrew fashion, but removes by the same means 

 the accumulating wood refuse of its labours. The larval stage 

 appears to continue for some considerable time, probably for more 

 than a year, but the pupal form seems to end in a few weeks. In 

 this stage it can move along the burrow by means of its angular 

 spine-studded segments and the two spine-tipped processes on the 

 lower side of the last segment. These burrows were more or less 

 filled with the wood particles evacuated by the larvae, whose sole 

 pabulum appears to be the rotten wood. From this strange food 

 Nature provides nutriment and builds up the insect through its 

 wonderful transformations. 



We observed no insect parasites in the burrows of this beetle, 

 but on May 31st, on raising a block of the cherry wood containing 

 borings occupied by the young larvae of this beetle, we found a 

 female specimen of Pompilus spissus at rest on the wood, as if only 



