198 ENTOMOLOGICAL NEWS [Juty' '22 



The above data were obtained during August and September 

 when the weather was warm. Of course, the various stages 

 would be much longer during the cooler weather. During these 

 experiments the temperatures at the laboratory in Orlando, 

 Florida, were as follows : 



For August the daily maximums ranged from 90" F. ID 100" F. 

 with a mean of 94 F. ; the daily minimums 65 F. to 75 J F. with a 

 mean of 71.2 F. ; mean temperature for month 82.6 F. ; greatest 

 daily range 29 F. ; precipitation 4.13 inches. For September the daily 

 maximums ranged from 91 F. to 103 F. with mean of 95.9 F. ; 

 the daily minimums 67 F. to 73" F. with mean of 69.6 F. ; mean tem- 

 perature for month 82.8 F. ; greatest daily range 32* F. ; precipitation 

 1.93 inches. 



Contrary to the sex ratio of many species of thrips, the per- 

 centage of males for this species seems to be relatively high, 

 often as many as 50% of those captured being males. The 

 same phenomenon has been observed among those bred in jars 

 in the laboratory, a large number being males. The adults of 

 both sexes have a habit of congregating together and copulation 

 has frequently been seen to occur in the breeding jars. In 

 fact it is very doubtful if this thrips will breed partheno- 

 genetically. In a large number of experiments the adults reared 

 in jars would die without laying eggs when they were not mated 

 with males. 



All stages of the thrips are found around the terminal bud 

 and on the new shoots. The young larvae on hatching feed on 

 the newly unfolding leaves, causing brown and dead spots to 

 appear. The later stages of the larvae, as well as the pupae 

 and adults, also feed on the new growth. When very numerous 

 on a tree they will sometimes kill the buds, but ordinarily no 

 damage is done. Although small areas are killed on the nc\v 

 leaves, the leaves later outgrow this injury. The thrips do 

 not cause lesions or other injury to the bark, and no instances 

 have been observed where trees, or even limbs on a tree, have 

 been killed. This, of course, would be expected of a native 

 insect on its natural host. 



The adult thrips are always active and usually walk about 

 on the stems and leaves with a rapid motion. They have a 

 characteristic habit of carrying the tip of the abdomen curved 



