JOINTWORM FLIES. 



it kills the entire plant. The larva de\'e]ops within and right at 

 the base of the plant, usually making the plant somewhat bulblike 

 at this point (fig. 5). This generation emerges during March and 

 April in the Eastern and Central States, while in Washington and 

 probably in other Pacific States it emerges in 

 April. This spring generation usually is wingless, 

 though occasionally specimens may have wings. 

 These winged individuals usually are imperfect 

 in that they often have only two or three wings. 

 Sometimes only the front pair are present, and 



Fig. 4. — Wheat straw-worm : Stage of de- 

 velopment of wheat plant at time of 

 oviposition of spring form (Harmolita 

 grandis, form minuta). Enlarged illus- 

 tration at right shows the point where 

 egg is deposited. (Webster and Reeves.) 



Fig. 5. — Wheat straw-worm : Pupa of sum- 

 mer form {Harmolita. grandis, form 

 grandis) as it normally occurs in- the field. 

 The tiller thus attacked is always kiUed. 

 (Webster and Reeves.) 



again only the hind wings. Males occasionally occur in this genera- 

 tion, though rarely. 



The summer form (fig. 6) {H. grandis, form grandis) emerges in 

 May and deposits eggs (fig. 7, d, e) in the growing wheat plants 

 slightly above the joints, often placing the eggs directly in the 

 cavity of the stem, where they hatch in about 5 days. Sometimes 



