100 NEW YORK STATE MUSEUM 



arc especially well developed on the thoracic and first abdom- 

 inal segments, on which latter they form conspicuous conical 

 processes on the top of the swollen red portion. This stage is so 

 peculiar that it is easily recognized. The young caterpillar 

 presents an approach to these conditions, as will be seen from 

 the following description: 



Length 6 mm. Head shining jet black, bilobed, with a pair of 

 submedian setose tubercles. Body mostly yellowish orange, 

 mottled obscurely with reddish and with narrow sublateral and 

 lateral yellowish' lines. Dorsally there are submedian rows of 

 rather large, black, setose tubercles, those on the thoracic seg- 

 ments and on the 1st, 8th, 9th and 10th abdom'inal segment, 

 especially the latter, being markedly larger. These abdominal 

 segments show a slight enlargement. There are also sublateral, 

 lateral and suprastigmatal lines of smaller, black, setose tuber- 

 cles. The true legs are black, while the prolegs are yellowish, 

 the apexes laterally being dark brown or black. 



The parent moth is rather inconspicuous with dark brown 

 fore wings, grayish on the outer margin, a dot near the middle, 

 a spot near each angle and several longitudinal streaks along the 

 hind margin, all dark brown. The female deposits her eggs in 

 clusters on the under side of the leaves during the month of 

 July. They hatch soon and the young caterpillars at first con- 

 sume only the under surface of the leaf, leaving the upper un- 

 broken, though as they increase in size the entire leaf is 

 devoured. The caterpillars are social in habit, remaining in 

 rather compact groups when not feeding and attain maturity 

 in this latitude during August or early September. This gre- 

 garious habit frequently results in one or more branches being 

 entirely stripped. There is but one brood in the North though 

 in the South there are said to be two generations. This pest 

 is seldom abundant, and while displaying a marked preference 

 for apple, also occurs on plum, cherry, rose, thorn and pear. 

 It is easily controlled by thoroughly spraying with an arsenical 

 poison, preferably arsenate of lead (15 per cent arsenic oxid) 

 used at the rate of about two pounds to fifty gallons of water. 

 Numerous specimens of the small, grayish Tachinid, A c 1 1 a 

 p i 1 i p e n n i s Fallen, were reared in early August from the red- 

 hum] icd larvae of this common pest received from Amcnia, N. Y. 

 Nothing seems to have been published earlier respecting the food 

 habits of this parasite in America, though it has been recorded 

 from the White Mountains, N. II., New Jersey, District of Colum- 

 bia and southern Illinois. It was first studied in America by 



