REPORT OF THE STATE ENTOMOLOGIST I918 39 



was dealing with was identical with Cecidomyia tritici 

 of Europe, a species regarded as being more abundant than C. 

 mosellana. Later this Moselle midge was described by Wagner 

 as Diplosis aurantiaca and was briefly noticed by 

 Kaltenbach as Cecidomyia aurantiaca. It has been 

 referred by Kieffer and Kertesz to the genus Clinodiplosis and was 

 briefly noticed by Noble as Itonida tritici, this last in the 

 belief that he was discussing the European Contarinia tri- 

 tici Kirby. Kieffer in 19 13, designated the Moselle midge as the 

 type of a new genus, Sitodiplosis, separating it from Thecodiplosis 

 on characters which in our estimation hardly justify the erection of 

 a new genus and for the present at least we prefer to leave this wheat 

 midge in the genus Thecodiplosis. 



Life history and habits. The yellowish maggots of the wheat midge 

 pass the winter in the soil or in the chaff, transforming to pupae in the 

 spring, the delicate yellowish flies appearing early in June, particularly 

 during a hot, sultry period. Doctor Fitch states that the appearance 

 of the flies coincides with the first hoeing of Indian corn and the fading 

 of the white flowers of honey locust. He estimates the duration of 

 adult existence at about 3 weeks and states that they usually dis- 

 appear toward the middle or last of July. This protracted flight 

 explains in part the very uniform infestation of large fields. The 

 presence of the maggot in almost equal abundance in early and late 

 sown wheat is also made clear by this extended period of adult 

 life. 



The eggs, according to observations by Doctor Fitch, are deposited 

 in winter wheat when it is a little more than knee high and as the 

 heads are just protruding from their sheaths. Two to four or more 

 maggots may be found around each developing grain. We obtained 

 73 from one head. This latter is exceptional under present condi- 

 tions though nearly a handful was the record for earlier days. Doctor 

 Fitch states that the fly is active and perfectly at home in a himiid 

 atmosphere and that as a consequence the midge is unable to remain 

 about wheat heads during the day time in ordinary weather. Fur- 

 thermore, wheat upon lowlands and along river flats is always more 

 injured than that upon dry uplands. In addition the delicate mag- 

 gots, like the flies themselves, must have a certain amount of moisture 

 or they will not thrive; consequently a severe infestation, even if 

 there be an abundance of midges, is impossible if the weather is dry 

 at the time the heads begin to appear and if a change from a period 

 of considerable moisture to one of relatively low himiidity occurs 

 shortly after the eggs are laid, the chances are decidedly against 



