LIBRARY

634
COLLEGE ENTOMOLOGY
Family CEPHIDJE Haliday 1840 (Ceph'i·dre, from the Greek K'fjr!JnV, a drone
bee). German, Helmwespen. Stem Sawflies.
Slender, fragile, wasp·like insects scarcely more than 18 mm. long and fre.
quently black with yellow bands and other markings. Head large with conspicu.
i.
I
FIG. 217. The western horntail, Sirex areoiatus
(Cresson). A, larva; B, male; C, female. (From Insects
of Western North America.)
ous eyes. Antennre filiform
with many segments. Pronotum
long, the posterior
margin straight or nearly so.
Legs long and slender; tibial
spurs well developed. Ab·
domen somewhat compressed
laterally and enlarging api.
cally; ovipositor short and
retractile. Eggs oval or
pointed: inserted into living
plant tissues, chiefly grasses,
but also into shrubs and
trees. Larvre pale, C-shaped,
wrinkled, apodous or with
reduced thoracic legs and
vestigial ocelli; with small
! terminal abdominal append-
age or anal spine. Pupre
free, enclosed in thin trans·
parent cocoons in the burrows
of the larvre.
The members of this rather
small family are widely distributed
throughout the
world and occur in grasslands,
forests, and cultivated
areas. Among the important
genera and their hosts are:
Cephus Latr. on grasses and
cereals. The wheat stem
sawfly, C. pygmceus (Linn.),
is an Old World pest of wheat and rye which was introduced into North
America and has been very destructive in some places. Hartigia SchiOdte on
Rubus and other woody plants in Europe and North America. Janus Stephens
on currants, oaks, poplars, pears in Europe and North America.
Members of the small and related family XIPHYDRIIDJE 1 (Leach 1817,
1819) Stephens 1829 are characterized by having the antennre inserted above
the eyes; prothorax conical and pronoturn reduced to a slender collar forming a
1 From the Greek E"pvlipLOV, diminutive of I;lo$, a sword; referring to the ovipositor.