THE CANADIAN ENTOMOLOGIST. 



53 



SEXUAL FORMS OF TOXOPTERA GRAMINUM, ROND. 



IJV Y. L. WASHBURN, SI'. AMIIONV PARK, MINN. 



We have not found sexual forms of the so-called "green bug" in the 

 field in Minnesota, nor have we been able to rear them outside in cages, 

 but have had no trouble in getting this form in the insectary. Mr. R. A. 

 Vickery, who has charge of our insectary work, reports them as appearing 

 indoors on Oct. 15, shortly beginning egg-laying. 



The winged males are smaller than the viviparous females, and have 

 a larger number of sensoria on their antennae. The oviparous females can 

 readily be distinguished from the apterous viviparous females by their 

 swollen hind tibiae, by the eggs, which can be seen through the walls of 

 the abdomen, and by the presence of circular sensoria on the antennae. 



In ovipositing, most of the eggs were placed on the upper side of 

 dead leaves of grain. Apparently one female lays quite a number of eggs. 

 Mr. Vickery reports finding ten nearly mature eggs in one female. The 

 viviparous females continue producing yoting during and after the 

 appearance of the sexual forms, and young were freely produced in the 

 cold room of the insectary, although the temperature has been down to 

 ten degrees above zero. The following is a brief description of the sexual 

 forms of this species : 



Oviparous Female. — (Fig. 5.) Length, 2-2.25 nim.; colour, yellowish- 

 green, median line of abdomen darker green ; head and prothorax some- 



v.'hat paler than the rest of the body. Eyes 

 black ; antennae black, except the two basal 

 joints, and the basal half of the third, which 

 are of the same colour as the head. Legs 

 yellowish, tibiie brownish toward the apex, 

 tarsi black \ cornicles greenish, their apex 

 black ; cauda greenish. Antennre slender, 

 hardly one-half the length of the body, no 

 circular sensoria. Cornicles slightly taj^ering, 

 not reachinLT to the end of the both-. Cauda 

 slender, somewhat constricted above the 

 middle, about two thirds the length of the 

 cornicles. Tibia of hind leg swollen and 

 thickly covered with sensoria-like swellings. Lateral tubercles small and 

 single. 



Fcliruary, 1908 



F'k:. 5. - 0\ ip.Trou^ fcin.-ilc. (Origiii.-il.) 



