INSECTS. Q] 
since the discovery. The butterflies are not especially striking to the 
casual observer. Among them is the widely spread tawny-colored 
milkweed butterfly, Avos/a plordppus Fabr., which has found its way to 
Guam, together with the introduced clsclepius curassavica, on which 
its larva feeds. Both the plant and the insect, although of American 
origin, now occur on many islands of the Pacific Ocean. Among the 
night-flying lepidoptera there is a large sphinx moth (/roteparce ecleus 
Hbrt.), the larva of which feeds on the tobacco plant and resembles 
very closely the tobacco worms of America. It is possible that this 
insect may haye lived on the island before the introduction of tobacco, 
feeding upon some solanaceous plant, but it is probable that it came to 
Guam with the tobacco. Possibly its eggs were brought on dried 
leaves of the plant. Among the other pests introduced by the 
foreigner are clothes moths (Zine pell/onela L.). In the zoology of 
the Freycinet expedition several butterflies collected in Guam, includ- 
ing an Argynnis and two species of Danais, were described as new. 
Among the hymenoptera there are several interesting species of 
wasps and ants. One wasp, probably a species of Polistes (2. hehracus 
Fabr. 4), is social in its habits. During the greater part of the year 
it frequents open fields, building its nests in bushes a foot or two 
from the ground, attaching them toa limb by a peduncle with the 
mouth of the cells pointed downward, and not covered by a papery 
wall, as in our hornets’ nests. In these cells the eggs are laid and 
the larve are fed. When about to undergo transformation the 
larvee spin a covering which seals up the cell. The males differ 
from the female in appearance and are stingless. Besides the males 
and perfect females there are workers. Both the females and the 
workers sting, but their sting is not very severe. These insects 
are very abundant all over the island, especially in abandoned clear- 
ings grown up to guayas and other low bushes. It is almost impos- 
sible to cross such a field without stirring up a nest or two, and 
one of the commonest occurrences on an excursion is to hear a loud 
outery on the part of your guide, whose naked legs are covered 
with the stings of the ‘‘sasata,” as they are called. In revenge he 
usually finds a dry leaf of a coconut, which he converts into a torch 
and burns the nest. These wasps are not very pugnacious, and will 
only sting when they think their nest is attacked. After it has been 
burned they fly round and round the place without attemptiug to take 
vengeance. In the winter time (the month of December) they flock 
into houses in great numbers and settle upon some prominent point 
on the ceiling or on a chandelier, clinging together in masses like 
swarming bees. There they remain for a month or two in a state of 
torpidity. They are disagreeable guests, as they have a habit of drop- 
ping to the floor from time to time, and it is not unusual on getting out 
of bed in the morning to step on one of them, too stupid to fly but 
