FAMILY CERAMBYCIDAE 297 



deep, winding galleries, which remove all the bast below the outer bark and 

 groove deeply into the sapwood. When nearly full-grown, they tunnel down 

 into the heart-wood and eat out a pupal chamber in this, which is more 

 or less at right angles to the long axis of the tree. About August- 

 September the larva is full-fed, and changes into the pupal state within the 

 curious calcareous cocoon peculiar to this insect. Fig. 206, from a photo- 

 graph taken by M. E. Stebbing, shows these cocoons in situ in the tree. 

 Pupation takes place at various depths in the tree. If some of the cocoons are 

 broken open at the end of November the fully developed beetles will be found 

 inside them, mature, but not ready for flight, as their outer covering is still 

 soft. The pupal state is evidently a short one, but the beetle on maturing 

 rests within the cocoon between December and March, whilst its outer 

 parts are slowly hardening. If the insect is examined in December, it will 

 be seen that the elytra are still quite soft, and that the legs and antennae are 

 by no means ready to perform their respective functions properly. The 

 beetle can walk about only in a weak, halting manner. It is probable that 

 this habit of the beetle of maturing and resting for some months is the 

 cause of the statement so often made that the insect appears on the wing in 

 November and March in the Siwaliks. It is improbable that the insect 

 would appear when the sharp winter of the North-West has set in, 

 although it can be easily obtained at this season. The writer has had 

 numbers brought to him during the winter months. Fuel-choppers con- 

 tinually come across them, and it is probable that the beetles obtained 

 by them have given rise to the statement. From the above it will be 

 evident that this insect takes a year to pass through all the various stages 

 of its life history from egg to mature beetle. 



The late Mr. R, Thompson, Conservator of Forests, was probably 

 the first to draw attention to the damage committed in the forest by this 

 pest in his Report on Insects injurious to Woods and Forests, published by the 

 North- West Province and Oudh Government in 1878. 



On p. ^y Mr. Thompson wrote: "They" (the cocoons) "were 

 discovered beneath the bark, embedded between it and the wood, in a felled 

 tree of the Butea frondosa, or dhak. The larvae had apparently only lived 

 on the sapwood, and underwent the second metamorphosis on the site of 

 their original operations. Another remarkable fact was that these beetles 

 are in the perfect state as early as March. . . . 



" I have since obtained numerous specimens of these beetles and their 

 cocoons embedded to a depth of eight inches in logs of Odina ivodier and 

 Bouibax lieptaphylluni. They are the commonest and earliest variety of 

 Monochami out, the perfect insects having been obtained as early in the 

 season as November." 



We also bred out this beetle at Dehra Dun from the mango logs sent 

 from Chicacole, Ganjam, in December igoS, as seriously infested by the 

 Batocera titana borer (see p. 367). The Plocwderus beetles issued in the 

 breeding-cage at Dehra on 17 March and 7 April 1909. 



