Int. J. Insect Morphol. & Embo'oL, Vol.9, pp. 321 to 368. 0020 7322"80/1201-0321502.00/0
© Pergamon Press lad. 1980. Printed in Great Britain.
COMPARATIVE ANATOMY OF THE DEFENSIVE GLANDS,
OVIPOSITORS AND FEMALE GENITAL TUBES OF
TENEBRIONID BEETLES (COLEOPTERA)
WALTER R. TSCHINKEL
De ~artment of Biological Science, Florida State University, Tallahassee, FL 32306, U.S.A.
and
JOHN T. DOYEN
Department of Entomological Sciences, University of California, Berkeley, CA 94720, U.S.A.
(Accepted 7 May 1980)
Abslract With the ultimate objective of determining higher phylogenetic relationships, the
cuticular portions of the defensive glands, ovipositors and female genital tubes of 247 species
from 178 genera were studied after clearing in sodium hydroxide. On the basis of these studies,
the following evolutionary hypotheses are put forward. The most primitive tenebrionids are
the lagriine groups and their allies. Ancestral tenebrionids were without defensive glands and
som,~ modern groups still are. Defensive glands evolved 4 times independently, once between
sterna 8 and 9, and 3 times between sterna 7 and .8. Only one of the 7/8 glands shows much
diversification beyond the primitive state. Primitively, these glands are simple, eversible,
conical pouches with the gland tissue scattered on the reservoir dorsum. Advanced glands
show increased reservoir size, localization of gland tissue, contriction of exit ducts, and
spec ializations of reservoir walls.
A:acestral tenebrionids have a female tube consisting of a blind, primary bursa copulatrix
with ventral entry of the common oviduct and dorsal entry of the single, slender spermathecal
gland tube. This condition persists in the lagriines and their allies. A strong tendency to evolve
a separate, non-glandular spermatheca has led to its evolution at least 4 times independently.
These are (1)a multiple, short-tubular spermatheca derived from the bursa copulatrix; (2)a
single, short- to long-tubular spermatheca from the same source; (3)a cannister-shaped
spermatheca derived from the basal portion of the spermathecal gland: and (4) a saccate
spermatheca derived from the apical portion of the spermathecal gland. These 4 con-
figurations are strong characters defining major lines of tenebrionid evolution.
The ancestral ovipositor was probably elongate and appendage-like, and this condition is
still present in some lagriines and their allies. The primitive ovipositor contains 2sets of
scler tes. The proximal paraprocts are rather simple and cyclindrical. The distal coxites are
divided ventrally into 4lobes with the fourth lobe bearing the gonostyles terminally. The
paraprocts are stiffened ventrally by a pair of longitudinal baculi, while the first lobe of the
coxites (the valvifer) are stiffened by a pair of transverse baculi. Much of the evolutionary
change has involved reductions of various structures, but reorientation of the baculi and
elongation and shortening of paraprocts and coxites have been important in certain groups.
There is a strong tendency for the gonostyles to move to a lateral or dorsolateral position, and
this i~; often accompanied by a reduction of the fourth lobe of the coxites.
OrL the basis of these and other characters, several major lines of tenebrionid evolution
become apparent: (1)the lagriines and their allies, probably including the adeliines,
pycn,~cerines and goniaderines; (2)the diaperines and their allies; (3)the coelometopines,
cnodalonines, strongyliines, talanines and their allies; (4)the tenebrionines, opatrines.
helopines, toxicines, amarygmines and their allies. Some groups, such as the bolitophagines,
share features with more than a single lineage and are difficult to place. Phylogeny within the
major lines is discussed in general terms, as is the importance of internal characters for higher
classification of Tenebrionidae.
Index descriptors (in addition to those in title): Ovipositor, female genital anatomy,
Tenebrionidae, phylogeny, spermatheca, vagina, bursa copulatrix, coxites, paraprocts,
spermathecal accessory glands.
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