FAMILY PLATYPODIDAE 629 



Beetle. Elongate, narrow, shining. Head dark chestnut-brown or black ; thorax 

 chestnut-brown ; elytra pale yellow, slightly tinged with chestnut on basal margin and merging 



into pale chestnut-brown in upper third, becoming chestnut-brown in 



Description. apical fourth. Antennae yellow, legs chestnut-brown. Head vertical, 



not broader than thorax, rugose, with scattered spiny yellow hairs on 



front. Thorax about a quarter as long again as wide, only slightly emarginate at sides 

 below middle, anterior margin straight ; glabrous, and finely punctate. Elytra striate-punctate ; 

 four striae prominent at base, the outer marginal one most prominent, the second from suture 

 becoming less marked soon after leaving base, the first interstice from suture raised, the fourth 

 strongly raised and convex, with scattered large punctures ; a depression between second and 

 third striae depressed at base ; apex truncate, showing eight well-defined ridges, the depressed 

 portion in $ set with five teeth on side and four apical ones, of which the outermost is prolonged 

 and turned outwards ; $ unarmed ; the truncate portion and marginal edges of elytra set with 

 yellow spiny hairs, denser apically. Under-surface brown, abdominal segments dark-brown to 

 black, and very short; concave and rugulose in $. Anterior tibiae toothed on outer edge. 

 Length. $ 4.7 mm., $ 3.9 mm. 



This insect was first found by Ranger B. C. Sen Gupta tunnelling into 

 sundri (Heritiera littoralis) wood in June 1902. An examination of some 



pieces of attacked timber showed that the insect bored 

 Life History. right down into the heart-wood, the gallery made by 



the beetle being quite straight. The following year 



the Ranger was able to make some further observations on its habits in the 

 beginning of April. The following is a summary of his valuable investiga- 

 tions. He found two beetles of different sizes in the pieces of wood 

 (probably $ and $). His study of the habits led him to conclude that the 

 adults bore through the wood into the sapwood and lay their eggs. They 

 probably do not go into the heart-wood at this stage, as he found that in 

 all the newly attacked wood the heart-wood was left untouched ; it was 

 only after some period that the galleries were found in the heart-wood. 

 Only a few eggs are laid in each tunnel ; the number, however, has 

 not been observed. The larvae did not appear to bore galleries in the 

 wood, but were to be found at the bottom of the parent's tunnel. This 

 latter may branch (or curve?) when it has been carried right down into the 

 wood. The larvae pupate at the ends of the galleries, and the adults on 

 maturing make fresh borings into the timber as long as it is sufficiently 

 fresh for their purpose. The galleries are very small (about one-thirteenth 

 of an inch in diameter), and the adult beetles continually move- up and down 

 the tunnels. This insect is another of the so-called "ambrosia" beetles, and 

 the reason for the non-discovery of larval tunnels is due to the fact that the 

 larvae probably live upon a fungous growth which develops on the \\.ills of 

 the tunnel of the parent beetle. Since the mature insect is found in April 

 and again in June there are evidently two generations in the year, and 

 probably several. These beetles attack sundri wood as soon as it has been 

 felled, and as long as it is fresh. They will not touch dry wood. Their old 

 galleries can be seen in this latter, but no living beetles are ever found in 

 them. The}' only attack the sundri in this locality. Other kinds of wood, 

 green and half dry, are left untouched. 



