Art. XXI.—Notes on Coleoptera.
[Read before the Wellington Philosophical Society, 5th November, 1901.]
With the exception of moths and butterflies, none of the orders of insects occurring in New Zealand can be considered to be catalogued in even a moderately satisfactory manner. The most extensive order, that of Coleoptera, is in almost as bad a state as any, for although much has been done and a long list of species published, yet the number of coleopterous insects occurring here is so great and the students so few that it will be many generations before all the forms are described. Description, though a dry and tedious process, is a needful preliminary to the elucidation of the problems connected with distribution and variation, which are the most attractive portions of the study of natural history.
As in other orders, so among beetles, the male insect is often different in form from the female. Not sufficient cognisance has been taken of this fact, except where the describer of a species has himself been able to study the insects in their homes, or where he has attached some weight to the observations of the field naturalist who has collected for him. Some results of this are evident in Captain Broun's list, and a few are noted below with other synonyms. The frequent description of identical species in New Zealand and England
will not cause so much trouble, as in most instances the identity is obvious.
It is not for me to attempt to criticize the work of the able naturalist who has for a quarter of a century studied this order, but the reflection suggests itself that the larger genera might very well be tabulated by the only one who is at present in a position to do so. Among the genera most in need of such a tabulation are Bembidium, Cyphon, Acalles, and the Pentarthra. Is it too hazardous to say that when a table cannot be prepared, then the species are not, distinct? I have tabulated some families with much advantage to myself, but I am not anxious to publish my work while Captain Broun is able to do the same thing in a more accurate manner.
Descriptions of three new species are submitted, all from the south.
Mecodema bullatum, n. sp.
Elongate, parallel, coppery-black, shining. Head rugosely sculptured, longitudinally on-clypeus and above eyes, transversely on vertex, which is sometimes almost smooth. Neck closely punctate. Eyes moderately prominent. Thorax quite similar in shape to that of sculpturatum, with strongly crenate margins. The central and basal foveæ are well marked, and the surface has, in addition to moderately distant but conspicuous striæ, a band of punctation along both base and apex. Elytra parallel - sided, rounded behind. Each has eight rows of finely punctured striæ, somewhat obscured by transverse rugosities. The alternate interstices are the widest, and, being interrupted, present each the appearance of being formed of from six to ten oblong flattened tubercles. The lateral sculpture is inconspicuous. The sculpture of the underside is similar to that of sculpturatum, but less pronounced. Length, 25 mm.
Puysegur Point; Mr. F. Sandager.
The species belongs to the sculpturatum group, and is most nearly allied to littoreum, the sculpture of whose wingcases might easily be developed into that of bullatum.
Mecodema infimate, n. sp.
Elongate, parallel, medially narrowed, shining fusconigrous; femora, palpi, and basal joints of the antennæ shining-red. Head with the vertex quite smooth, the occiput punctured, the clypeus and the swollen orbits wrinkled. Thorax elongate, not much narrowed in front but considerably so behind, the situation gentle. Its sculpture consists of the usual basal foveæ and central line. The disc bears wellmarked transverse striæ, and the apical and basal margins
are strongly striated longitudinally. The basal foveæ are punctured. The elytra have each nine striæ almost without punctures. The alternate interstices are twice the width of the intermediate, and, with the exception of some scattered punctures, are without sculpture. The underside of the head (except the gula), the til flaks of the prothorax, and the mesosternum are rugosely sculptured. The abdomen is sparingly punctured. The intermediate tibiæ are strongly punctate, as are the front on the apical half of their inner face. Length, 16 mm.
West Plains, Invercargill; Mr. A. Philpott.
This species may be readily distinguished from the others of small size by the almost simple striæ of the elytra.
Lissotes acmenus, n. sp.
♂ Head and thorax black, shining; abdomen shining-brown Head finely and obscurely punctured, most densely on the vertex; the hind angles prominent. That portion of the side margin that encroaches on the eye is more prominent than in helmsi. Prothorax transverse, wider than the elytra, finely and distantly punctured; not so broad in proportion to its length as in helmsi; with a fine medial line and three punctiform impressions, one in the middle of the medial line, the other two midway between that point and the side margin. Its shape is similar to that of helmsi, but the base is more markedly sinuate. Elytra short and broad, shining, each with four obscure costæ, which are more finely punctate than the intervals between them. The margins of the thorax and elytra and the four hind tibiæ externally are clothed with short golden setæ, indistinct traces of which are sometimes seen on the elytral costæ. The mandibles are exactly similar to those of smaller specimens of helmsi. Length, including mandibles, 20–25 mm.
The female will probably be very similar to the same sex of helmsi.
This fine beetle is very closely allied to both helmsi and œmulus; indeed, Dr. Sharp considers that it is identical with the former species. It is sufficiently easily distinguished by its bright appearance, narrower form, and the smaller size of fully developed individuals. I am indebted to Mr. G. Howes, Invercargill, for a good series of males.
As a first step towards a revision of the catalogue, I would suggest the following synonyms as extremely probable:—
Cicindela dunedinensis, Castelnau = C. wakefieldi, Bates.
Mecodema crenaticolle, Redtenbacher = M. lineatum, Broun.
Dryocora howittii, Pascoli = Adelostella punctatum, Broun.
Parabrontes setiger, Broun = P. picturatus; Sharp.
Dasytes stewarti, Broun = D. nigripes, Broun.
Echinopeplus dilatatus, Broun = Heterodiscus horridus, Sh.
Oreocharis picigularis, Broun, ♂ = O. bicristata, Br., ♀.
Acalles maritimus, Broun, ♂ = A. cryptobius, Br., ♀.