268 



CHAPTER XV. 

 PHYTOPHAGA {continued)— Family CERAMBYCIDAE. 



{Lony^icorn or Loii^-lwrncd Beetles.) 



The longicorn or long-horned beetles as they are often termed, owing 

 to the pair of long, prominent, jointed antennae which adorn the head, 

 are probably the members of the Coleoptera best known to the Forest 

 Officer. Not that they are to be found commonly on the wing in the 

 daytime, for this is not usually the case, although, as we shall see, there 

 are some diurnal forest-living species, such as, e.g., Thysia wallichii ; 

 nor because they are brilliantly coloured, for dull browns, greys, and 

 blacks predominate in the family. The insects will be known owing to 

 the fact that they are often found in tunnels inside timber — that, indeed, 

 timber is often ruined or disfigured in the forest by tunnels which, in a 

 general way, the Forest Officer attributes to the operations of these insects ; 

 and he is very often correct in his surmises, although in many instances he 

 may be unacquainted with the pest itself, either in the larval or beetle stage. 

 Another manner in which these insects — many of which are of bulky and 

 massive form and lumbering flight when in the neighbourhood of light- 

 bring themselves into prominence, is by entering the bungalow at night. 

 Information of considerable importance to the forester can be gained by 

 their nocturnal visitations ; for their appearance means that the insect is 

 at that period egg-laying in the forest, and for this purpose is searching 

 for newly felled unbarked trees, or for sickly, perhaps dying, standing ones. 

 We thus, by noting these dates of appearance, secure firstly the date of 

 appearance of the insect on the wing, or one of the dates should the beetle 

 pass through more than one life-cycle in the year; secondly, the date, or 

 approximate date, on which eggs are laid in the trees, since but a short 

 period is usually passed by these insects in the perfect, or imago, state ; 

 thirdly, the date, or approximate date, on which the young grubs or larvae 

 hatch out from the eggs, observation having shown that but a short period 

 is passed in the eg^ stage by many of the forest-living members of the 

 family, often forty-eight to sixty hours only. 



The life histories of many of the forest-living Cerambycidae are of con- 

 siderable interest, and in nothing, perhaps, are the beetles so remarkable 

 as in the possession of an instinct which enables them to seek out newly 

 felled or sickly or dying trees. Nothing is more striking than the undoubted 

 possession of this wonderful power or instinct by the beetle Hoplocerambyx 



