462 ENTOMOLOGICAL NEWS, [DcC, 'll 



plant and bordering on the shores of the lake. Here, after 

 nightfall, their webs were very abundant. An abundance of 

 aquatic dipterous and neuropterous insects in the imaginal 

 stage afforded an ample supply of food. These latter were 

 partly from the sewage and partly from the lake. 



Since a single female of this spider probably deposits sev- 

 eral or more masses of eggs during its life, the average given 

 should not be taken as the average total progeny of a pair but 

 rather as the approximate average number of eggs per mass. 



An Aleyrodes on Euphorbia, and its Parasite 



(Rhynch., Hym.). 



By T. D. A. CocKERELL, University of Colorado. Boulder, 

 Colorado. 



A short time ago Mr. E. Bethel collected at Glenwood 

 Springs, Colorado, some material of Euphorbia robusta badly 

 infested by an Aleyrodes. I was able to breed out the adults 

 of the Aleyrodes, and also large numbers of an undescribed 

 parasite. This appears to be the first record of Aleyrodes on 

 Euphorbia in this country, though A. euphorbiae Loew was 

 found on Euphorbia pepliis in Austria. Euphorbia robusta is 

 also the food plant of the very interesting moth Doa ampla 

 (Grote), which I have bred at Boulder. Dr. Dyar, who kindly 

 determined the moth, will describe the larva. 



Aleyrodes pruinosus euphorbiarum n. subsp. 



Adult 9 . — (measurements in microns). Length of body 1200; 

 head and legs grey, thorax grey with the scutellum h'ght yellowish ; 

 abdomen light clear lemon yellow, with the apex broadly grey, and 

 dorsal markings as in A. pruinosus; eyes completely divided; third 

 antennal joint 160; joints 4 to 7 subequal, all together 224; length of 

 antennae about 432; anterior wing about 1595 long and 640 wide; main 

 vein distinctly angulate beyond middle (about 770 from base), but 

 with no upper branch, though this is represented by a slight fold; 

 anterior wings white with a faint greyish patch in apical field; border 

 of wing as in pruinosus. 



Pupa. — Broad-oval, 1280 microns long, 1040 wide, or sometimes 



