Halys Fabricius

NDSU image

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 4^th 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 4^th 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

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