GREYBACK CANE BEETLE, LEPIDODERMA ALBOHIRTUM. 23 



v.e can only judge by tlie time that the main body of the beetles are in 

 evidenee, for, as stated above, there is no question that the eggs 

 continue to develop as long a,s the adults live. Moreover, on this ])oint 

 it is interesting to note that the last beetles captured on the feeding-trees, 

 8th February, 1921 — almost three months after the first emergence — 

 still had eggs in all stages of development ; in two the ovaries were 

 empty, showing that they had just laid, probably their third or fourth 

 set, and were back on the trees to try it over again, even at this late 

 date ; eight had new .sets of eggs well under way, more than half-formed : 

 the remaining six had fullv developed eggs, readv to lav again, as 

 follows:— 21, 24, 24, 24, 25," 24, hence an average of 23-66.' From this 

 we see that the number of eggs in these late sets do.es not fall much 

 below those for the earlier ones, which averaged about 26 to 28. 



To show the continued reproductive ability of these aged beetles, 

 1 have sketched egg-tubes from specimeus collected on 8th Fe])ruary. 

 Plate 6, fig. 3, is from a beetle taken on the feeding-tree, and fig. 4 

 of this same plate, from one taken on a cane-leaf where she was resting 

 after depositing her eggs preparatory to taking flight back to the 

 feeding-trees. In each case it Avill be seen that there were sufficient 

 ova alreadv in the tubes to form new sets. 



Duration of Aerial Life. 



As ha.s been suggested above, it is a difficult matter to know how 

 long the beetles live under natural conditions, since they do not take 

 kindly to confinement. Mr. Dodd (91) found that the greatest length 

 of life of adults taken from the forest, when supplied with food in 

 cages, was thirty days, and that the females lived longer than the males. 

 Furthermore, these results have been borne out by our subsequent 

 observations. Nevertheless, we know that the beetles live much longer 

 under natural conditions — probably two months or more, as indicated 

 above. Early in the season the two sexes are almost equal in numbers 

 on the feeding-trees, but later, during brief periods while many of the 

 females are away ovipositing, the males may be found greatly in excess. 

 For example, on 4th January, 1921, in a lot of beetles from the feeding- 

 trees I found that 85 per cent, were males, and most of the remainder 

 (females) had empty egg-tubes, showing that they had just laid. These 

 conditions suggested that most of the females were away ovipositing 

 at the time, which supposition wa,s apparently correct, for a few days 

 later the numbers of the two sexes were approximately ecjual again. 

 Toward the end of the season, however, the males evidently begin to die 

 off first, as is indicated by their lessening numbers in the feeding-trees — 

 in fact, the last lot that we collected, on 2iid February, had only 15 per 

 cent, males. As to the habits of this sex. it appears that they spend 

 their whole aerial life among the feeding-trees, never returning, as do 

 the females, to the soil. 



Stages ix Development. 



The Egg. — Considerable has already been said in regard to the egg 

 istage above, but I have hardly more than suggested the remarkable 

 increase in size which takes place as the incubation period advances. To 

 illustrate this feature I have sketched the eggs at various stages of their 

 development, using the camera lucida to get the comparative sizes exact 

 (Plate 5). As indicated, they are all magnified five diameters. Fig. 4 



