412 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



The galls made by this insect have long been kaowu. Osten Sacken, * from a study 

 of the galls and the larvse which he saw in them, proposed the name Cecidomt/ia 

 ocellaiis for the species, believing the insect to be a member of the Cecidomijidm. But 

 the fly which I have bred proves to belong to the genus Sciara of the family Myceto- 

 philidwJ This result is quite interesting, for the species of Sciara are usually found 

 "among decaying leaves, in vegetable mold, in cow-dung, under the bark of dead 

 trees," etc.t One other species {Sciara tilicola) is known to produce a gall. This 

 species infests the leaves of young linden ti-ees in shady, sheltered situations. The 

 lemon-yellow larva, capable of leaping like the cheese-maggot, lives in numbers in 

 the stem, generally near the origin of the last or of the two last leaves. Each of them 

 has a hollowof its own, and produces a swelling of the size of a pea, which it abandons 

 before the transformation. ^ 



Description of adult male. — Plate xxxviii, fig. 2, 2&. Head dark, eyes black, kidney- 

 shaped, and meeting in a point on the dorsal surface of the head. Antennae sixteen- 

 jointed, inserted close together; color dark brown, with the basal segment light yel- 

 lowish brown. Epicranium quite large and convex; dark brown; bearing three 

 ocelli, which are whitish and glistening. Pronotum light yellowish-brown. Meso- 

 scutum arched, yellowish-brown in the center and darker at the edges. Scutellum 

 dusky-brown. Metathorax dark brown, almost black. Abdomen, with caudal por- 

 tions of segments, blackish, the cephalic portions yellowish-brown. The claspers 

 lighter brown. Poisers, with knob, blackish and base light brown. Tibiae and tarsi 

 dusky brown; femora lighter; coxae still lighter. The distal end of each tibia fur- 

 nished with two long brownish hairy brushes. (Plate xxxviii, fig. 2a.) 



53. The cottony maple scale. 



Pulvinaria innumerabilis (Rathvon). 



Order Hemiptera ; family Coccin.E. 



(Plate XXXI ; figs. 1, 2, 3, 4.) 



The following account of this pecit is copied from Riley's report as 

 U. S. Entomologist for 1884: 



This scale-insect stands prominent among the species which have been esjiecially 

 abundant during the past summer. Circumstances appear to have been particularly 

 favorable to its development, and, although it does not spread rapidly, its general 

 appearance this season has caused considerable alarm in many States. It was sent 

 to us during the spring and summer by correspondents in New York, Pennsylvania, 

 Maryland, Virginia, Ohio, Indiana, Michigan, Illinois, and Missouri. For the past 

 thirty years it has attracted considerable attention as damaging shade trees, partic- 

 ularly the maples, in different parts of the country, occurring in extraordinary 

 abundance from time to time, and then almost lost sight of for several years. It is 

 more particularly a northern insect, and although it is often numerous in Virginia 

 and Missouri, we have never received it from, nor heard of its occurrence in the 

 extreme Southern States. 



Life-history.— The round of life of this species is not strikingly different from that 

 of other Coccids, and is briefly as follows: 



The young lice (Fig. 1, c) hatch in spring or early summer, walk about actively as 

 soon as born, and settle along the ribs of the leaves (very rarely on the young twigs). 

 They then insert their beaks and begin to pump up sap and to increase in size, a thin 



• Monograph of the Diptera of North Am., Part I, 199. 



tl am indebted to Baron Osten Sacken for the generic determination of this insects 



; Osten Sacken, Proc. Ent. Soc. Phil., i, 159. 



§ Osten Sacken, Proc. Ent. Soc. Phil., i, 164. 



