286 COLEOPTERA 



The modes of life of Cerambycid larvae exhibit considerable 

 variety, and much perfection of instinct is displayed by the larvae, 

 as well as by the mother beetles. The larvae of Saperda populnea 

 are common in certain woods in the South of England in the 

 stems of aspen ; they consume only a small quantity of the 

 interior of the stem, and are probably nourished by an afflux of 

 sap to the spot where they are situated. Elapliidion villosum is 

 called the oak-pruner in North America. The parent beetle lays 

 an egg near the axilla of a leaf-stalk or small stem, and the 

 young larva enters this and feeds on the tender material ; as it 

 grows it enters a larger limb, and makes an incision within this 

 in such a manner that the wood falls to the ground with the 

 larva within it, the dead wood serving subsequently as pabulum 

 and as a shelter, within which the metamorphosis is completed. 

 The species of the American genus Oncideres are called girdle rs, 

 because the parent beetle, after laying an egg in a small branch, 

 girdles this round with a deep incision, so that the portion 

 containing the larva sooner or later falls to the ground. The 

 growth of a Longicorn larva frequently takes more than a year, 

 and under certain circumstances it may be enormously prolonged. 

 Monohammus confusus has been known to issue from wooden 

 furniture in a dwelling-house when the furniture was fifteen 

 years old. Individuals of another Longicorn have issued from 

 the wood of a table, twenty and even twenty-eight years after the 

 felling of the tree from which the furniture was made. Sereno 

 Watson has related a case from which it appears probable that 

 the life of a Longicorn beetle extended over at least forty-five 

 years. 1 It is generally assumed that the prolongation of life in 

 these cases is due to the beetle resting quiescent for long after it 

 has completed the metamorphosis. Kecent knowledge, however, 

 renders it more probable that it is the larval life that is pro- 

 longed; the larva continuing to feed, but gaining little or no 

 nutriment from the dry wood in these unnatural conditions. Mr. 

 C. 0. Waterhouse had for some years a Longicorn larva under 

 observation, feeding in this way in the wood of a boot-tree ; 2 the 

 burrows in the wood contained a great deal of minute dust 

 indicating that the larva passed much matter through the ali- 

 mentary canal, probably with little result in the way of nutriment. 



1 Packard, 5th Rep. U.S. Ent. Comm. 1890, p. 689. 

 2 Not a growing tree, but the instrument used for stretching boots. 



