FAMILY CERAMBYCIDAE 323 



Instinct of Beetle. — The beetles are gifted with an instinct which enables 

 them to seek out unerringly newly felled or standing trees in the forest in 

 the condition they require for oviposition. This can easily be proved by 

 felling a green tree in the forest. One such felled on 13 May was inspected 

 next morning, and a large number of both male and female beetles were 

 found on the lower side of the bark between the trunk and the ground. 



Pairiuf:; and Egg-laying. — The male seeks the female in such places 

 and pairs with her on the bark of the tree. It has been noted that the 

 insects vary greatly in size, but this fact appears to be immaterial in the 

 pairing of individuals, a small male pairing with a large female or vice versa. 

 Opportunities occurred of watching the insects in coitu, and the procedure 

 is rather curious. The male insect mounts on to the back of the female, 

 and oviposition alternates with the act of fertilization. The penis of the 

 male is hard and horny, very long, and curved scimitar-shape backwards and 

 downwards. The actual act of pairing appears short. The female possesses 

 a long, flat, bluntly-pointed, tapering, telescopic ovipositor about half an inch 

 in length and brown in colour. With this she deposits her eggs here and 

 there in crevices in the bark or on the flakes of bark. The ovipositor is very 

 flexible, and is used for groping and searching out suitable places for 

 oviposition. 



Position ivhere Eggs are Laid. — The eggs, which evidently develop very 

 rapidly in the ovisac, are laid singly, and are scattered about in a most 

 erratic manner. The female appears to choose preferably moist sappy areas 

 of bark on the lower sides and under-side of the fallen trees, or on the shady 

 side of standing ones ; but eggs are also to be found in dry crevices and on 

 the outer surface of dry bark, or amongst short wet moss on the bark. They 

 are found most numerously, however, in the moist bark areas. She will also 

 deposit them on the upper surface of the bark of felled stems and on the 

 sunny side of standing trees in dull weather, and very little attention appears 

 to be paid to the actual site chosen for deposition. I have even found them 

 forced down the entrance-holes of the Sphaerotrypes bark-boring beetle in the 

 bark. Pairs tn coitu were watched. The female walked slowly over the bark, 

 laying an egg here and there at intervals, and in the intervals the insects 

 paired. It was thought that the beetles commonly laid eggs in the sleepers 

 or on barked logs, but although young larvae have been found in both I do 

 not think it has been yet proved that, as a general rule, the eggs from which 

 they hatched had not been previously laid in bark which was subsequently 

 removed. Mr. Rama Nath Mukerjee took in June some eggs on newly 

 converted green sleepers, and I myself found some small larvae two weeks 

 or so old in logs brought out shortly before to the forest tramway. 



Number of Eggs Laid. — I have not yet been able to ascertain the number 

 of eggs laid by a female. Some countings were, however, made to ascertain 

 the number of eggs laid on a tree. On a 15-ft. strip of bark taken round 

 the whole circumference of a newly felled tree 150 eggs were laid between 



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