24 INSECTS INJURIOUS TO SUBTROPICAL FRUITS. 
was never observed, but Urich 2i observed it in flight in the cool 
of the evening. The writer has never observed the male and it seems 
to be quite rare, as Urich observed it on only a few occasions. Repro- 
duction for portions of the year is parthenogenetic, but at other 
times bisexual. The adults seem to be very sensitive to lack of 
moisture and die rapidly in breeding vials. On mango trees in the 
greenhouse individuals have been observed to live as adults for from 
14 to 17 days, when, although still very active, they were lost. Prob- 
ably this adult has a more extended period of life as the author has 
kept specimens of a related species, Heliothrips fasciatus, alive for 
three months. 
HATCHING OF THE EGG. 
The eggs, as they near the end of the period of incubation, become 
considerably swollen, so that if the scale covering each egg is removed 
there is a slight elevation of the leaf noted. The larva hatches by 
the same process as that used by Heliothrips hsemoy^rhoidalis, but 
emerges from under the dried scale at one side, and in many cases, as it 
moves away, carries this scale on its back. 
HABITS OF THE LARVA. 
The larvae feed on the leaves in company with the adults and 
generally prefer the underside, but the writer has frequently observed 
them in large numbers on both sides of the leaf. They feed clustered 
together in colonies, in folds of the leaf, or along the main vein, or 
even under red-spider webs. As they feed, the leaf becomes full of 
minute brown spots where the chlorophyll has been extracted, and in 
severe cases these run together and the entire leaf becomes brown and 
dried up. At all times the larva holds the tip of the abdomen in the 
air and bears a drop of reddish liquid, which is held more or less in 
place by the stout anal hairs. As this increases in size it falls to the 
leaf and the surface becomes covered with drops of excrement, as 
occurs with plants affected by Heliothrips hsemorrhoidalis. The 
larvae when disturbed crawl rapidly away, or, if exposed to the light, 
endeavor to reach the shade again. In some cases the molted skin 
was observed being carried on the tip of the abdomen, but this may 
have been accidental. 
The larvae when full grown cluster in a fold of the leaf, near the 
midrib or under the web of a red spider, to change to prepupae. The 
skin at the head then splits and gradually, by contractions of the 
body, the prepupae work their way out. When they have emerged 
they leave the empty skins on the leaf, or in some cases carry them 
around on the end of the abdomen. 
