FAMILY CERAMBYCIDAE 



337 



Fig. 225. 

 Young and ma- 

 ture larvae of 



Di a leges 

 pauper^ Pascoe. 



the elytra somewhat denser and arranged so as to give short, ill-defined longitudinal bands 

 or patches of lighter or darker shades (the latter often looking black), according to the 

 play of light upon them, the reflexions in certain lights being silvery; two bands, darker 

 in colour than the rest, are situated near together a little behind the middle of each 

 elytron. Head elongated posteriorly, the eyes being completely divided. 

 .Antenna one-third or more longer than the body in (J, about one-sixth 

 longer than the body in $ ; second joint as broad as long ; third nearly 

 or quite as long as fourth and fifth together ; fourth to eighth and apex 

 of third fringed beneath with hairs in $. Prothorax constricted before 

 and behind, longer than its width across middle in $, shorter in 5 ; 

 transversely but irregularly wrinkled above, and marked with some longi- 

 tudinal or oblique depressions. Elytra truncate at the apex, each armed 

 with a short spine at the suture and tooth at the outer angle. Femora 

 stout in the $, hind tarsus narrow, first joint much longer than the next 

 two united. {Descr. after Gahan.) Length, 16 mm. to 31 mm.; breadth, 

 3^ mm. to 8 mm. 



Larva.— The grubs are of the ordinary longicorn type and are shown 

 in tig. 225. White with blackish-brown heads and mandibles, and 

 orange streaks on the thoracic segments The youngest found was \ in. 

 Fully mature grub i in. to 2 in. in length. 



A generation of the beetles appears on the wing about 

 the middle of April. The eggs are evi- 



Life History. dently laid in the interstices of the bark of the tree. Thev 



probably soon hatch out, and the young grubs feed at 

 first in the bast. As they grow in size they feed in the bast and sapwood, 

 mining out irregular galleries which are shallow and packed closely with woody 

 excrementitious particles. The larval galleries are rotighly eight to twelve 

 inches in length or at times longer. When the larva is full-grown it bores into 

 the sapwood at an angle to its previous direction, going in three to four inches, 

 and then gnaws out a pupal chamber in the longitudinal axis of the tree! 

 This pupal chamber is always made in the sapwood. Near the upper end it 

 is covered over with a cap of some calcareous material white in colour and 

 similar to that made by Hoplocerambyx spinicornis, but much smaller and 

 without the keel-shaped edge. The gallery in the sapwood is square in 

 section and a quarter of an inch across. The pupal chamber is ih in. long. 



The insect was found in both larval and beetle form on 29 April. 

 The larvae were either quite young or mature. I do not know the length of 

 time spent in the larval and pupal stages, but it is probable that the mature 

 larvae and the beetles found were those of the first generation of the year, 

 and that the young larvae were those of a second gen'eration. As only a few 

 beetles were found active it appeared probable that the majority 'of the 

 insects had already left the tree and laid their eggs. The insect may pass 

 through two life-cycles in the year. 



This insect was evidently plentiful in the Anguri Block of the Hultugaon 

 Damage Committed ^""'f (Goalpara) in iQob. Dead trees showed the^sap- 



in the Forest. °°^ °^^^" tunnelled out from top to bottom with the 



larval galleries, and dead beetles were cut out from the 



pupal chambers in such trees. Stag-headed or dead tops of living trees also 



9003 ^ 



