356 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4TH Ser. 
Family ApPIpz 
10. Xylocopa colona Lepeletier. — 
This large carpenter-bee has been taken on many of the 
Galapagos Expeditions and is to be found on probably all the 
larger and on some of the smaller islands of the group. The 
female is blackish and the male tawny brown; this sexual 
dimorphism being common in the genus. The males are faster 
fliers and have a more highly pitched buzz than the females. 
There are numerous examples in the collection of the Cali- 
fornia Academy of Sciences, taken in 1905 and 1906, from 
Chatham, Charles, James, Indefatigable, South Seymour and 
Albemarle Islands. 
The species in the Galapagos has gone under several names, 
viz., X. mordax Smith, X. brazilianorum, and X. colona Lep., 
but I have followed Rohwer who had Galapagos specimens 
compared with X. colona from the Galapagos, in the British 
Museum. The genital armature of specimens from several 
of the islands of the Archipelago were dissected out and com- 
pared by me and proved to vary to a small extent. There is, 
however, a tendency for insular variation in this insect notice- 
able in the tint of the wings in the females, those in the col- 
lection of the California Academy of Sciences show a greenish 
blue iridescence from Charles, Chatham and James Islands, 
with those taken on Albemarle, Indefatigable and its small 
neighbor, South Seymour Island, exhibiting a distinctly bluish 
purple tint. 
This bee is rather a common insect and occurs chiefly at 
low levels and even along the sea beaches. It nests in wood, 
the several-celled borings having been found in the branches 
of Hibiscus tiliaceous, Croton sp., Bursera, and particularly in 
the very soft wood of Erythrina. Its larva is parasitized by 
the grub of a cantharid beetle which has a hypermetamor- 
phosis, the young active larve and the quiescent arcuate larve 
being several times found in the bees’ burrow at James Bay, 
James Island. More recently Beebe (Galapagos, World’s 
End) found the triungulin stage of what was probably this 
