Halys sp. cluster on Pithocelebium dulce tree
Photos courtesy from
Jyoti
Gangurde & Ashok Desai,
Nashik (MS, India) |
Halys Fabricius,
1803
Halys
Fabricius, 1803: 180.
Type Species:
Halys dentatus
Fabricius, 1803, by subsequent designation (Kirkaldy, 1900).
Included Species:
serricollis Westwood, 1837
serrigera (Westwood, 1837)
shaista Ghauri, 1988
sulcatus (Thunberg, 1783)
Ghauri (1988) revised the
genus Halys, excluding all known Asian species except 3 (serricollis,
serrigera, sulcatus), and he described a 4th species as new (shaista).
I have examined specimens of 4 different species, 3 of which match pretty well
with the 3 previously described species; the 4th is close, if not
the same as shaista. There are still several species
from the Middle East and Africa that are still included in this genus. I
have never seen a specimen of true Halys from those regions.
Halys sp. egg mass with lid
Halys sp. nymph |
|
Revised key to species
1
Juga smooth, no lateral
teeth present; paramere viewed in situ showing tooth as integral part of
its head forming dorsoposterior angle; posteroventral surface of
pygophore lacking median projection; female arcus elongate |
serricollis Westwood |
-
Juga toothed near apex,
may also have tooth just in front of each eye; paramere viewed in situ
showing tooth away from dorsoposterior angle of its head; posteroventral
surface of pygophore with distinct median spine-like or conical
projection |
2 |
|
|
2(1)
Paramere with tooth
rather small (may actually be only angulate), located on middle of
dorsal margin of its head |
shaista Ghauri |
-
Paramere with tooth
large, located on exterior surface of disc of head of paramere |
3 |
|
|
3(2) Paramere with discal
ridge very well developed culminating into a tooth located nearer to
posteroventral margin, viewed dorsally continued as bisinuate ridge;
posterior edge of paramere rather robust; distinct, robust tooth located
on lateral wall of genital cup, opposing tooth on paramere; female arcus
narrow; posterior margins of basal plates only slightly sinuous |
serrigera Westwood |
-
Paramere with discal
ridge reduced; only tooth well developed, located away from posterior
margin (more cephalad than in serrigera), viewed dorsally only
the tooth is clearly visible; posterior edge of paramere relatively
thin; lateral wall of genital cup lacking robust tooth opposing tooth on
paramere, but there may be a black, dentate ridge more anteriorly;
female arcus broad; posterior margins of basal plates distinctly sinuous |
sulcatus (Thunberg) |
* H. serricollis is
easy to Identify - the smooth lateral margins of the head are diagnostic, and
the male pygophore is distinct (lacking the medial projection on the
posteroventral surface). In fact, Ahmad & Perveen (1982) described
the genus Neohalys for this species and 3 others they described
as new from the Pakistan region.
* H. shaista is
also fairly distinct, but there is a slight problem. Ghauri (who only
examined 2 male specimens) described shaista as having a small
tooth on the head of the paramere located on the dorsal edge. I have
examined a number of specimens, and they agree with this, except in a
couple cases the small tooth is reduced to a mere angulation. The
problem is that Ghauri also described this species as having the
paramere lacking any teeth on the external (lateral) surface. All
specimens that I have examined have a fairly distinct tooth on the
lateral surface, but it is located more posteriorly and more ventrally
than in either serrigera or sulcatus; it is also somewhat
more elongate.
* The remaining 2 species,
serrigera and sulcatus are difficult to separate without
looking at a series of specimens. There does seem to be some overall
variability in the shape (outline) of the parameral head, but the
location of the tooth on the external surface, the tooth on the lateral
wall of the genital cup, and the shape of the posterior margins of the
basal plates seem to work fairly well. Ghauri also uses the presence or
absence of a small tooth on each juga just in front of the eyes - this
does not seem to work very well for me.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
David A. Rider
Professor of Entomology
North Dakota State University
E-Mail:
David.Rider@ndsu.edu
Published by the
Department of
Entomology
Prospective students may schedule a visit by calling 1-800-488-NDSU.
|