THe Brouoey or THE CHRYSOPIDAE 1347 
Chrysopa mgricorms Burmeister (Plate LX XX) 
1839 Chrysopa nigricornis. Burmeister, Handbuch Ent., vol. 2, p. 979. 
1861 Chrysopa nigricornis. Hagen, Synopsis Neuroptera N. Amer., p. 214. 
1903 Chrysopa nigricornis. Banks, Trans. Amer. Ent. Soc., vol. 29, p. 149. 
Chrysopa nigricornis is one of our largest species. Adults ean be 
taken at lights from June to September. This is a tree and shrub species. 
Larvae have been repeatedly taken on maple trees in late summer, when 
the painted maple aphis is most abundant. The species has also been 
taken repeatedly on oak, elm, tulip tree, spiraea, and red osier (dog- 
wood). Specimens have been collected at Ithaca, Milwaukee, Dayton, 
Charlottesville, and Manhattan (Kansas). 
The life history of some of the specimens observed may be sum- 
marized as follows: 
Number of | Date egg Date of Date of Date of |Datecocoon| Date adult 
specimen was laid hatching | first molt |second molt} was spun emerged 
54.1 Sept. 2 Sept. 7 Sept. 11 | Sept. 16 | Sept. 28 +; Wintered 
54.3 Sept. 2 Sept. 7 Sept. 11 | Sept. 17 | Sept. 28 Wintered 
54.2 May 22 May 27 June 6 June 9 June 12 June 25 
56.4 Dec. 9 Dec. 16 | Dec. 21 Dec. 24 Dec. 29 Jan. 9 
67.5 May 22 May 28] June 6 June 9 June 12 June 28 
Egg.—Hlongate elliptical, light green with yeliowish tinge, becoming more 
yellow as embryo develops. Eggs laid singly or in close groups. Length of 
egg, 1.02 to 1.09 mm.; width at middle, 0.38 to 0.42 mm.; length of stalk, 7.5 to 
8.6 mm. 
First-instar larva.—Head grayish or yellowish, large with three spots above. 
Thorax grayish to dark; whitish area on each side of dorsal blood vessel 
throughout its length. Two setae from prothoracic and all lateral abdominal 
tubercles; three setae each from meso- and metathoracic lateral tubercles. First 
two pairs of thoracic tubercles grayish to yellowish; third pair black or reddish; 
first pairs of lateral abdominal tubercles white, fairly well developed. Medial 
setae prominent. A dark spot at base of each dorsal abdominal tubercle. 
Length of newly hatched larva, 1.5 mm.; width of head, 0.32 mm.; width at 
metathorax, 0.32 mm.; length of lateral setae, 0.29 mm. 
Second-instar larva.—Three separate spots on dorsum of head. First two 
pairs of lateral tubercles grayish; third pair dark brown to blackish brown. 
First abdominal segment bearing a pair of small lateral tubercles beset with 
about five short, white setae. Dorsum of abdomen dark; border of gray on 
each side of vessel; near end of instar, reddish spots appearing in this gray 
border. First two abdominal tubercles white to gray; others dark to brownish 
black; tubercles bearing six to ten setae each, two large, the remainder smaller. 
Early second-instar larvae rather dark; late second-instar larvae reddish brown, 
much like ©. oculata; color pattern tending to break up into irregular reddish 
brown patches. Legs wholly gray; distal ends of tibiae and tarsi black. Width 
of head, 0.57 mm.; length of mandibles, 0.49 mm.; length of antennae, 0.8 mm.; 
total length of larva, 5.95 mm.; length of setae, 0.46 mm. 
