June, 'OS] JOURNAL OF ECONOMIC ENTOMOLOGY 225 



OBSERVATIONS ON THE GENUS CONTARINIA 

 By E. P. Fext, Albany, X. Y. 



This genus is of economic importance, despite the fact that the 

 insect Americans have hitherto known as Diplosis or Gontarinia tritici 

 Kirby can not be referred thereto. In passing, we wish to state that 

 there is some question as to the identity of Diplosis tritici, and the 

 writer would appreciate most thoroughly any assistance other ento- 

 mologists could give in the way of securing additional material this 

 season. Similarly, Diplosis violicola Coq., though a species of much 

 importance to violet growers, can not be retained in this genus. 



One of the best known members of the genus is C. pyrivora Riley, 

 an insect which was brought into this country about 1877 and which 

 has caused a large amount of injury to pear growers, particularly in 

 Connecticut, Ncav York and New Jersey. This importation is a very 

 well marked form, differing so widely from American species that one 

 antennal segment of the male is sufficient for its recognition. Careful 

 comparisons between American-bred insects and others received from 

 Europe have established the identity of the two beyond question. 

 There is but one generation annually > the larvee wintering in the 

 ground in oval, silken cocoons, the adults appearing about the time 

 pears are in bloom. According to Schmidberger, the eggs are depos- 

 ited on the anthers of the closed blossom to the number of 10 or 12, 

 and in warm weather hatch in about four days. The young larvse 

 develop rapidly, penetrating to the core and feeding upon the interior. 

 The affected fruit becomes characteristically deformed. June rains 

 cause it to crack and decay rapidly, thus allowing the larva? to escape 

 and enter the soil, imagoes developing the following spring. 



The recent studies of Mr. C. R. Ball have shown that Contarinia 

 (Diplosis) sorghicola Coq. may be responsible for the failure of sor- 

 ghum to produce a full crop of seed in our southern states. This 

 trouble, ]Mr. Ball states, has been variously attributed to fungi, insects 

 and unfavorable meteorlogical conditions, such as excessive precipi- 

 tation, high humidity, severe drought and hot winds. Mr. Ball's 

 experiments showed that heads protected from the midge were uni- 

 formly fertile where the growth was normal, while those exposed dur- 

 ing the first half of anthesis and then protected were sterile in the up- 

 per portion and well seeded below. Mr. Ball succeeded in rearing 

 from 500 to 1,160 midges from each of several infested heads. He 

 also reared a parasite from this insect referable to the genus Apros- 

 tocetus. 



