24 INSECTS INJURIOUS TO SUBTROPICAL FRUITS. 



was never observed, but Urich -^ observed it in flight in the cool 

 of the eveinng. The writer has never observed the niak> 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, Heliothrijjs 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 JiseTnorrhoidalis, 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 Heliothriys Tisemorrlioidalis. 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. Wlien they have emerged 

 they leave the empty skins on the leaf, or in some cases carry them 

 around on the end of the abdomen. 



