. Bulletin. Natural history; Natural history. 242 Illinois Natural History Survey Bulletin Vol. 23, Art. 1 Larva.—Fig. 811. Length 7 mm. Head brown with spots of a lighter shade scat- tered over the entire surface. Pronotum and legs straw color, the pronotum finely speckled with light brown. Labrum with. Fig. 833.—Oecetis cinerascens, case. hairs forming an irregular band across apical third, first abdominal segment with dorsal holding process large and without setae. Case.—Fig. 833. Length 8-10 mm., con- structed of bits of stems and other debris into a somewhat irregular log-cabin case. Adul
. Bulletin. Natural history; Natural history. 242 Illinois Natural History Survey Bulletin Vol. 23, Art. 1 Larva.—Fig. 811. Length 7 mm. Head brown with spots of a lighter shade scat- tered over the entire surface. Pronotum and legs straw color, the pronotum finely speckled with light brown. Labrum with. Fig. 833.—Oecetis cinerascens, case. hairs forming an irregular band across apical third, first abdominal segment with dorsal holding process large and without setae. Case.—Fig. 833. Length 8-10 mm., con- structed of bits of stems and other debris into a somewhat irregular log-cabin case. Adults.—Length 11-13 mm. Color me- dium shades of brown; in life somewhat hoary due to the pale hair; the wing mem- brane with several dark spots situated at the vein forks. Male genitalia, fig. 822: tenth tergite consisting of a single stylelike projection; cerci fairly long and parallel sided, apex rounded; claspers with a wide basal portion which tapers suddenly to a long apical curved filament; aedeagus fairly long, the apex produced into a projecting beak. Female genitalia, fig. 827, with ninth sternite large and almost circular, deline- ated by very distinct arcuate lines, the apical portion of the sternite composed of a pair of concave sclerites; bursa copulatrix simple. The common log-cabin case of this species is one of the most abundant features of many lakes and streams scattered through- out the state. The species is frequently taken in great numbers and occurs on the wing from May to late September, with a constant cycle of generations. This species is widely distributed through the Northeast, and occurs south to Georgia, southwest through the Ozarks to Texas, and northwest to Saskatchewan. We have records from Arkansas, Georgia, Illinois, Maine, Massachusetts, Michigan, Minne- sota, Missouri, New Brunswick, New York, Nova Scotia, Ohio, Oklahoma, Ontario, Pennsylvania, Quebec, Saskatchewan, South Dakota, Tennessee, Texas, Virginia and Wisconsin. Illinois Record
Size: 1106px × 2261px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
