PLANT-HOUSE ALEYRODES. 



Aleyrodes vaporariorum Westw. 

 Lewis R. Gary. 



During the summer this species of Aleyrodes lives chiefly out 

 of doors on garden plants, and in the fall larvae and pupae are 

 brought into the greenhouse with the plants, and some of the 

 adults fly in. Here they begin to breed freely as soon as crops 

 are started, multiplying fast enough to keep pace with the 

 growth of the plants. The eggs are very abundant on the under 

 surface of the leaves of various greenhouse plants, frequently 

 occurring in numbers so great that they give the under side of 

 the leaves a decided brown cast. 



The curious manner in which the eggs are deposited has been 

 already observed. Mr. W. E. Britton describes the process * 

 with reference to Reaumur's observation of the habit in Aley- 

 rodes chelidonii. The female inserts her beak into the leaf and 

 with this point as a center she swings about, describing a circle 

 with her ovipositor. The number of eggs in such circles varied 

 in the different instances noted here from six to ten. Much of 

 the time eggs were deposited promiscuously over the leaf. On 

 rough hairy leaves, like those of the Abutilons, the eggs were 

 found without definite arrangement, which agrees with Mr. 

 Davis's observation that on plants like Ageratum the eggs are 

 deposited singly. 



* Report of tbe Connecticut Agricultural Experiment Station, 1902, p. 153. 



Note. Tnese studies were made by Mr. Gary in 1902-3 in the biological laboratory 

 of the University of Maine, under the direction of Dr. G. A. Drew, professor of 

 biology in the University and at that time zoologist to this station. The station 

 greenhouses have been infested with this species of Aleyrodes for several years 

 and thus afforded ample material for the study. Thej^ were most abundant on 

 the leaves of tomatoes and cucumbers, but other kinds of plants were more or 

 less infested. 



