NOTULAE ENTOMOLOGICAE - Helda

ROBERT B. BENSON, WEAR AND DAMAGE OF SAWFI^Y SAWS 137
Wear and Damage of Sawfly Saws
(Hymenoptera, Tenthredinidae)
Robert B.Benson
British Museum (Natural History), London.
Normal saws in sawflies have the marginal teeth progressing in a regular
sequence from apex to base. If the middle teeth therefore are less prominent
than those at the base or the apex, this, on a microscope slide, may be due to
the toothed margin of the saw being recurved. This often happens in the
delicate saws of Nematinae and is a common cause of error.
In such genera as Tenthredo and Rhogogaster of the Tenthredininae adults,
especially females, may survive long enough for the wings to develop infuscate
patches and frayed tips and the saws to have their middle marginal teeth
eroded. That these teeth are eroded can usually be seen by their thin and
jagged edges and by comparing them with the better preserved teeth at the
base and apex of the saws (see figures).
I have sometimes had old worn specimens of the Tenthredo arcuata and
the Rhogogaster viridis complexes etc. submitted to me as possible undescribed
species, simply because the middle marginal teeth of the saws had been worn
down. Such examples can be found in any series of old worn females.
I am indebted to Mr. E. IVINDQVIST (Helsingfors) for lending me the holotype
of Rhogogaster similis Lindqvist 1958 = R. viridis (L.), syn.n., and for
sending me the specimens from which the saws shown in figs. 2 and 4 were
extracted. He also lent me the male which he associated with these females
(LINDQVIST 1963) and I wish to confirm that in my opinion it is R. chlorosoma
(BENSON).
References.
LINDQVIST, E. 1958. Neue Blattwespen aus Fennoskandien (Hym., Tenthr.).
Notul. Ent. Helsingf., 38; 68—72 (68). — LINDQVIST, E. 1963. Bemerkungen
iiber palärarktische Blattwespen (Hym., Symph.). Notul. Ent. Helsingf., 42
(1962): 105—127 (122).
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