LIBRARY

TRICHOPTERA
EXTERNAL ANATOMY-Continued
Larvre Adults
Mandibles strong and with one or two cut, Mandibles well formed or rudimentary, or
ting ridges and more or less dentate. almost absent.
Maxillary palpi are four- to five-segmented. Maxillary palpi four- or five-segmented.
Labial palpi rudimentary, two-segmented. Galea small or wanting.
Lacinia absent.
Hypopharynx well developed.
Labial palpi three-segmented.
Wings-two pairs normally present.
Females of some species almost apterous.
Hind wings aborted in both sexes of some
species.
Fore pair usually narrow.
Venation primitive-many longitudinal
and few cross veins.
Macrotrichia or hairs abundant on membrane
and veins of most species. almost
absent on others.
Prosternal horn present in certain families Scales may also be present. coupled by
of eruciform larvre only. iugallobe. anal fold, or hooks.
Legs short and stout for clinging. crawling, Legs long and slender for running.
and swimming; and armed with hairs CoXal much elongated.
and spines. Coxre large and strong. Tibire with median and apical movable
Tarsi one-segmented. Claws single, long. spurs.
stout, simple or with a tooth or basal Tarsi five-segmented.
spines. Claws-one pair with empodiwn or a
pair of pulvilli.
Abdomen naked or slightly hairy, with soft Abdomen lO-segmented.
integument and often with chitinized Fifth segment may be specialized to
dorsal plates. form lateral pockets or into a slender
Mid-dorsal and lateral processes may be process.
present on the first segment. Eighth segment of !jl may carry a sub-
A pair of caudal hooks or pro!egs on the genital plate.
last segment serve to anchor the larva in Ninth segment of (/' with one- or twoits
case or to a support. segmented cerci or claspers and a pair
of lateral processes.
10th segment greatly reduced and may
have a dorsal process and a pair of
preanal appendages.
Gills absent in first-hatched larvre and Spiracles-two thoracic and eight abdQmthroughout
life in certain species. inal.
Filamentous tracheal gills. variously arranged,
are present in most cases; anal
blood gills present in some.