Original description:
Cryptocercus relictus
Bey-Bienko 1935
♂. Very
similar in general appearance and principal morphological features
to the single known representative of the genus, viz. C.
punctulatus Scudd. from N. America but
much smaller and heavier. Body smooth, shining with
scattered puncturation. Head flattened, scarcely visible from above,
face smooth, puncturation denser and more delicate than on the upper
surface of the body; eyes not projecting, ocelli completely absent;
maxillary palpi very short, apical (fifth) joint a little longer
than forth, third joint subequal in length to apical, distal truncation
of the apical joint practically euqal to half the length of that
joint. Puncturation of pronotum denser and deeper
than on the other tergites; anterior transverse concave area between
elevated anterior margin and the begining of the deep median longitudinal
depression with small but very distinct granules, longitudinal depression
near its posterior end touching with a very distinct and short transverse
linear depression, T-shaped. Meso- and metanotum, as well as all
abdominal tergites including the sixth (apical) tergite only delicately
punctured, without minute rounded projections. Sixth tergite triangularly
produced, apex rounded; sixth sternite similar in the shape to the
six tergite but somewhat larger. Supraanal plate, cerci and subgenital
plate concealed, completely enveloped by the sixth tergite and sternite;
supraanal plate of the same type as in
C. punctulatus Scudd. but lateral margins
not sinuated, straight in their apical tow thirds, more convergent
apically, the apex narrowly rounded; cerci as in C.
punctulatus; subgenital plate as broad
as the supraanal plate, hind margin with two distinct lateral emarginations
from which relatively small cylindro-conical and quite similar styli
arise, the hind margin between these styli distinctly undulate,
with not strong, rounded, obtuse median emargination; the distance
between the styli distinctly greater than width of the produced
triangular part of the supraanal plate. Legs as in
C. punctulatus,
but heavier and differ in the number of spines; anterior femora
with 2-5 subapical spines on anterior lower margin and with 2-3
spines on posterior lower margin, dorsal genicular spines absent;
all other femora without subapical spines or the middle femora,
with only one spine on anterior lower margin; dorsal genicular spines
on median and posterior femora developed but very small. ♀.
Resembling the male sex in all external features excepting the shape
of the sixth ventral segment, which is characterized by presence
of two feeble but distinct rounded excisions on lateral margins
before the apex, hind margin between these excisions truncate or
with very feeble rounded excision of the same type as two subapical
excisions; this feature permits to determine the sex without removing
the six ventral abdominal segment. Supraanal plate concealed as
in the male sex, and quite similar in form and structure; subgenital
plate absent. General coloration uniformly shining
brownish-black or almost black but specimens which probably have
recently moulted, as well as the larvae are dark reddish-brown;
lower surface slightly lighter, with a distinct dark-reddish-brown
shade. Length of body ♂ 17-21, ♀ 18.3-23.5, pronotum
♂ 5-5.6, ♀ 5.5-6.2, maximum width of pronotum ♂ 7.2-7.5, ♀ 7.5-9.2,
length of hind femora ♂ 3.7-4, ♀ 3.8-4.2 ㎜. This
extremely interesting insect differs strongly from C.
punctulatus in its smaller and heavier
body, structure of maxillary palpi and pronotum, in quite distinct
type of puncturation, in a presence of small but distinct genicular
spines on the middle and hind femora; this last mentioned feature
usually has in Blattodea a generic importance but all other structural
features and the general appearance of both species are so similar
that I hesitate at present to separate C.
relictus into an independent genus. The
discovery of an Asiatic representative of the genus Cryptocercus
has a very great zoogeographical importance and shows a very remarkable
distribution of the genus. I do not want at present to speculate
on the reasons of such distribution but it shows that the genus
Cryptocercus
belongs to a very ancient group of animals and its present disjointed
area is a relic of former wide distribution. Two
female specimens from the Szechuan prov., China, differ from the
Ussurian and Manchurian specimens in larger size and in more coarsely
punctured lateral parts of abdominal tergites and of the whole surface
of the sixth tergite; it is very probable that they belong to an
independent species but I hesitate to describe a new species on
the female sex alone.
|