270 The Philippine Journal of Science lais 



metallic luster. Species such as A. ocellatus Roel., A. semperi 

 Pasc, A. septemdecimnotatus Roel., and A. smaragdinuLs Roel. 

 belong to this group. The third group consists of species that 

 are oval in appearance, represented by A. pectoralis and A. 

 waltoni Bohem. 



So far nothing seems to have been published of the biology of 

 the Philippine Alcides species. For that reason the following 

 may be of interest. 



BIOLOGICAL NOTES ON ALCIDES SEMPERI PASCOE 



Alcides semperi Pasc. inhabits the mountainous regions of cen- 

 tral Luzon. It lives on Aralia hypoleuca Presl.,* which is found 

 scattered about in the ravines and valleys in the neighborhood 

 of Baguio. On several occasions my attention was attracted 

 to this plant by the dried-up appearance of the young shoots, 

 usually one or two in number. I also noticed that from near 

 the tip of the shoots a resinous substance was exuding. Upon 

 close examination and by cutting the nearly dried-up tips, which 

 is a rather disagreeable work, since the plant is beset very 

 closely with very acute stiff thorns, I found a larva feeding 

 on the pith, working from the top downward. The stem was 

 hollowed, according to the size of the larva; in the case of a 

 full-grown larva the hollowed-out part measured from 30 to 40 

 centimeters in length. Full-grown larvae pupated readily in 

 captivity. The adults that emerged proved to be A. semperi. 

 The egg is evidently laid in the tip of the young shoot of the 

 plant, the larva proceeding in the above-mentioned manner, 

 feeding on the pith. During March and April I found the larvae 

 to be from half- to full-grown. In two cases I observed that 

 the pupal stage lasted from ten to twelve days. The pupa is 

 rather lively and is able to move freely up and down in the 

 hollowed-out stem. After casting off the pupal skin, the beetle 

 emerges only after three or four days have elapsed. Even then 

 it is soft, and the markings are very faint and develop gradually 

 as the beetle attains its natural hardness. The adults are com- 

 mon around Baguio during May and June, the beginning of the 

 rainy season. 



Two rather striking variations are prevalent, between which 

 intermediate forms are very rare. One form is marked with 

 rings, ^ which are usually well separated from each other ; and 

 the other form is marked with round spots, which are large and 



' Kindly determined by Prof. E. D. Merrill. 



° Bovie, Wytsman's Genera Insectorum (1908), fasc. 71, fig. 3. 



