BULLETIN OF THE SOUTHERN CALIFORNIA
ACADEMY OF SCIENCES
August 26, 1975
TAXONOMIC CHARACTERS OF THE GENUS OCHODAEUS SERVILLE WITH
DESCRIPTIONS OF TWO NEW SPECIES IN THE O. PECTORALIS LECONTE
SPECIES COMPLEX (COLEOPTERA: SCARABAEIDAE)
David C. Carlson^
Abstract: The mandibles, stridulatory peg. and male genitalia of the adults of eight
species of Ochodaeiis found in the United States have useful characters for the delineation of
species and are described and figured. The most useful taxonomic feature of the male
genitalia is the aedeagal sac. The taxonomic characters of Ochodaeiis are reviewed and a
key to the species of the O. pecloralis species complex is presented.
The Ocliodaeiis pecloralis species complex is erected to contain the nominate species
O. pecloralis LeConte and two new species which are described. The other five species
considered are O. biariuuliis LeConte. O. iiuirmatiis Schaeffer, O. kansaniis Fall. O. praesidii
Bates, and O. simplex LeConte. A lectotype is designated for O. iiuirmatus Schaeffer.
The genus Ochodaeiis Serviile is one of six genera
included in the subfamily Ochodaeinae. Approxi-
mately half of the sixty species of Ochodaeiis
occur in the New World (Arrow, 1912) and of
these, twenty are from the United States, ten from
Mexico and Central America, and five from South
America. Species of Ochodaeiis are distributed
throughout North America with the greatest num-
ber occurring in the arid southwestern United
States and northern portions of Mexico. Only
three species are recorded from Canada (Howden.
1968). Previously, only a few species were
known to be common to the United States and
Mexico. Examination of several thousand speci-
mens from the southwestern United States and
northern Mexico discloses that many species are
common to both areas.
The adults are nocturnal. In most areas where
Ochodaeiis have been collected, more than one
species usually is taken, and it is not uncommon
to take three or four species at the same locality
on the same night. Very little is known about
their biology or immature stages.
The last revisionary work on the United States
species of Ochodaeiis was by Fall (1909) and the
genus is cinrently in need of revision. The
present work is an attempt to discover new taxo-
nomic characters and to evaluate their potential
for use in revising the genus.
Serviile (1828) described Ochodaeiis and West-
wood (1852) published the initial synoptic work.
The New World species have been revised by
LeConte (1868), Horn (1876), Fall (1909), and
Arrow ( 1911).
Arrow ( 1904) described the position and mor-
phology of the stridulatory peg and pectinate
mesotibial spur (Fig. 15). Using characters as-
sociated with these structures he erected the sub-
family Ochodaeinae with Ochodaeiis as its only
included genus. Previously, Ochodaeiis was
placed in the Orphniidae. The relationships of
Ochodaeiis to other Scarabaeidae have been con-
sidered by Ritchcr (196')a. b) and Hollosvay
Prcpanilion of the male genitalia.