46 



MIS(.^ELLANE0US RESULTS OF WORK OP BUREAU IX. 



California. It has been collected in Iowa and Pennsylvania and 

 recently in the Barbados and the island of St. Vincent. 



Because of the fact that it has been collected in such widely dis- 

 tant places in all sections of the country, we can safely say that Tlcli- 

 othrips Jisemorrhoidalis is generally distributed in greenhouses through- 

 out the United States. 



DESCRIPTION. 



Ileliothrips hxmorrlioidalis belongs to the family Thripid?e, the 

 genus being characterized by having antennae . with 8 segments and 

 the body with a markedly reticulated surface. This is especially 



Fig. 15.— Greenhouse thrips {Heliothrips hxmorrhoidalis): Adult female, enlarged about 50 diameters, 

 and greatly enlarged drawing of antenna underneath. (Original.) 



pronounced on the head and thorax. The legs are unarmed and 

 the wings are characterized by having the fore-wings broad at the 

 base, with 2 longitudinal veins. 



The adult (fig. 15). — When the adult first emerges the abdomen is 

 pale yellow, with the head and thorax darker, and the antennse, legs, 

 and wings appearing white. In the course of several hours, however, 

 the insect becomes fully colored. The head and thorax are then 

 dark brown, the abdomen yellowish brown, fading at the apex to 

 brownish-yellow. In the female the antennae are twice as long as 



