REPORT OF THE STATE ENTOMOLOGIST I915 II3 



Schizomyia petiolicola Felt 



1908 Felt, E. P. N. Y. State Mus. Bui. 124:379 



1909 Ent. Soc. Ont., 39th,Rep't, p. 45 



This species was reared April 24, 1908 from oval or fusiform 

 petiole or tendril galls occurring on the summer grape ( V i t i s 

 b i c o 1 o r). The galls were taken at Westfield, N. Y., in October 

 1907 and were locally rather abundant. Polygnotus sp. was reared 

 from this gall. 



Gall. The gall produced by this species has a length of about 

 2.5 cm and a diameter of .7 cm. The color is usually a light brown, 

 and in the case of those occurring on the petioles at least, there is 

 frequently a rather characteristic striation, due to the rupturing of 

 the outer bark and the light brown color of the recently exposed 

 tissues. Occasionally two galls may occur on the same petiole. 

 The walls are rather thin, hard, and the oval cavity is occupied 

 by brown or black honeycombed, spongy tissue. Four to five 

 larvae may occur in a gall. This gall presents a close resemblance 

 to a smaller, very similar oval or fusiform petiole or tendril gall 

 taken at Hamburg on the northern fox grape (Vitis labrusca). 

 Possibly the two are made by the same insect and the difference in 

 appearance is due to a variation in the habit of growth of the two 

 plants. 



Larva. Length 4 mm, rather long, slender, yellowish white, 

 the segmentation not very apparent, the skin finely shagreened. 

 Head small, with a width less than one-fourth that of the body 

 and tapering to a narrowly rounded apex. Antennae rather large, 

 the single segment being stout, with a leng 

 about three times its diameter. Breastbone 

 long, slender, distinct, tridentate, the median 

 tooth about one-half the length of the lateral 

 triangtilar teeth. Posterior extremity broadly 

 rounded, with a few rather short, stout setae; 

 anus slitlike. 



The association of this larva with the above- 

 named adult is provisional. 



Male. Length 1.5 mm. Antennae a little 

 longer than the body, thickly haired, dark -^zrvi^ j-j. 



brown, the basal segments yellowish, 14 seg- 

 ments ; the fifth with a length about five times Fig. 9 S c h i z o - 

 its diameter. Palpi; the first segment short, myia petio- 

 stout, somewhat expanded distally; the second licola. Termi- 

 rather long, broad, narrowly oval; third one-half nal antennal seg- 

 longer and more slender than the second ; fourth ment of male, en- 

 one-half longer and much more slender than the larged (original) 



