322 FAMILY CERAMBYCIDAE 



Larva. Elongate, tubercular, with a squarish section, consisting of the head and twelve seg- 

 ments. Head black, transverse, with powerful mandibles. The segment following the head 

 (the prothorax) is greatly enlarged, dark yellow in colour, with a dorsal shining plate of thicker 

 consistency than the rest of the body ; the following two prothoracic segments are narrow. They 

 and the other nine segments of which the body is composed are yellow in colour. There are 

 two prominent elevations or tubercles placed transversely on the dorsal surface of segments 4 

 to 10 inclusive. The twelfth segment tapers to a blunt point behind. There are a pair of minute 

 legs on each of the thoracic segments, and a pair of short sucker-feet on each of the segments 

 4 to 10, being most prominent on segments 7 to 10. Length of full-grown larva, 3^ in. ; size 

 variable. In pi. xxii. fig. I, 2 show a two-thirds grown and fully grown larva. 



Pupa. -Whitish yellow in colour. Exhibits the form of the perfect insect in part. The 

 head is, however, pressed down upon the upper part of the chest, upon which, below 

 it, are folded the legs and the rudimentary wings, the latter being curved round so as to 

 lie in this position. Seven abdominal segments are visible on the dorsal surface of the nymph. 

 The antennae are curved backwards, and lie pressed against the sides of the insect. Length, 

 2 in. ; variable in size. In pi. xxii, fig. 3, 4, 5 show side and ventral views of female pupae. 



Of such importance is this beetle in the sal forests of the country that I 

 have deemed it expedient to give here in full the life 



Life History. history of this insect as it has been ascertained, with the 

 valuable and untiring help of Mr. W. F. Perree, I.F.S., 

 and one of his Range Officers, Mr. Rama Nath Mukerjee, for Assam; and 

 with the assistance and observations of Mr. C. P. Percival, I.F.S., in the 

 Central Provinces. The careful and systematic investigations carried out by 

 these officers in the course of their ordinary divisional duties have proved, 

 if indeed such proof were necessary, how greatly executive officers can 

 assist in the study of the forest insect pests of the country. The work 

 done also shows how essential it is that the Provincial and Ranger classes 

 should have a thoroughly sound knowledge of economic forest zoology. 



The life history of this insect in Assam, as detailed in my monograph 



Life History on ^ ome Assam Sal Insect Pests, will be first considered. 



in Assam. The Assam area may be taken to include Assam, the 



Bengal Duars and Terai sal areas, and adjacent sal 



tracts in Nepal. 



Appearance of Beetle on the Wing. This beetle was exceedingly plentiful 

 in the Kachugaon forests of the Goalpara Division in the latter half of 

 May 1906. Mr. Perree is of opinion that it first begins to appear towards 

 the end of March or beginning of April. It is present in the forests all 

 through June, but begins to get scarce in July, as proved by the observations 

 made by Rama Nath Mukerjee after my departure from Goalpara at the end 

 of May. He kept some careful enumerations by felling trees to attract the 

 beetles. I shall allude to these later on. 



I cannot at present say whether this insect is again found on the wing in 

 Assam later on in the year, but I think it is just possible that it may appear 

 again in September-October. Immature specimens of the beetle were taken 

 from the pupal chambers in green standing trees in the Apalchand Range, 

 Jalpaiguri Division, in November. 



