Description of a New Species of Elytrurus and a Catalogue of the Known Species (Coleoptera: Curculionidae: Otiorhynchinae) ELWOOD C. ZIMMERMAN1 SIR GUY MARSHALL has asked me to describe to those of Elytrurus (see Fig. 1). In no island, a new species of Elytrurus which was col­ however, do both genera occur together, and lected on Niue Island by A. C. Gerlach and the reason for the unusual distributions of the sent to the Commonwealth Institute of En­ two groups has not yet been discovered. The tomology for identification by W. Cottier, eastern-most species of Elytrurus occur in Department of Scientific and Industrial Re­ Samoa, and the Samoan forms are the most search, New Zealand. I am pleased to de­ divergent of the genus. I have collected sev­ scribe the new species, because it is the first eral thousand specimens of the two genera, to be found on the island of Niue,and it and they appear to be counterparts. The eggs thus fills another gap in the knowledge of of Rhyncogonus are deposited on leaves, and the distribution of this interesting genus of the young larvae drop to the ground to make broad-nosed weevils. Niue (lat. 19 0 02' S, their way to the roots of plants where they long. 1690 55' W) lies south of Samoa, and feed. I presume that Elytrurus has similar Vavau, Tonga, which is about 240 miles to habits, but I did not search for their early the west, is the nearest island. Niue is an stages during my expeditions to Samoa and emerged coral island which rises somewhat Fiji. more than 200 feet above sea level. The flora The new species and Elytrurus cinctus Bois­ is quite varied for a small coral island, and duval, to which it is most closely allied, share considerable areas of forest remain. It is un­ the character of reduction in the development fortunate that so little is known about the of the bevel of the corbel of the hind tibia, insect fauna of the island. a tendency toward the formation found in With this new species it is appropriate to Rhyncogonus. In Rhyncogonus the bevel is ob­ present a catalogue of Elytrurus and append solete, and this character has been found some notes on the geographical distribution useful in separating the two genera. However, of the genus and its relationship to Rhyn­ it has not been pointed out that there is much cogonus. In the Pacific east of Samoa, Elytrurus variation in the development of the corbel in is replaced by the genus Rhyncogonus the ap­ Elytrurus, and without an expert knowledge pearance and habits of whiGh are very similar of the formation of the bevel in these genera, one might easily be led astray. In its most 1 This research was completed at the British Museum highly developed form the bevel is a prom­ (Natural History) during the tenure of a United States inently differentiated, shiny area set off ob­ National Science Foundation grant, and this paper is a tangent contribution to the project "Insects of Hawaii." liquely or angulately from the outer face of Manuscript received August 23, 1955. the tibia, and entirely surrounded on the inner 286 j~, •• , ".' Elytrurus - ZIMMERMAN 287 A 5 I A •.I'!idway ' i M"ARIANA5 ~WAII ake , . "i . ~.'"<> . 0 ' 20 ~ PHILIPPINE. luam /~R5HALL . i ~~ .' ... CA.. ROLINE. (/.t:!~. '0' .' BORNE.O q) .. .' .;. .;--o." • :.: ... ,;:':: . • . ""(};fj{-Cf.LE:~~1 :' .palau ..• • . ';' GILBf.RT .••F~nnin9 o "~ . , . ..'. ..~t~" ..... '''BI5MARCK' -'". PHOE.NIX . ~ 0 o~ NE. ,. :' 1\): , . '- .' . :', . ~"'1' -.=::: ~"., ~, UINE.A .~ 'i> .~OLOMON ·':E.LLICl· • • M .~RQUE5A5 "1 JAVA "" c7 .: ".: '.' .;" 5~~.1E.:rY ' ·::-:r. UAMOS . ~OOK ·Tahit;·::.. .;" . ',: • Mang rev a AUSTRALIA AUSTRAL' • '. " '1 ' · E.A5Tf..R Rap!" r:.!1c irn Q . :Lord Howe .:kermadec R NEW~ZEALAND TA5MANIAt! tl ~Chatham FIG. 1. Map showing the distribution of the genera ElytruruJ ("E") and RhyncogonuJ ("R"). (tarsal) and outer (ectal face) sides by a dense The adult weevils feed upon the leaves of palisade of stiff spines. In many species of plants, and many species are abundant and ElytrufUs, including the new ~pecies and voracious feeders. Plants such as Piper are cinetus, the outer row of bristles has been frequently heavily attacked. It is possible that almost entirely lost. In Rhyneogonus there is some species may become pests in areas where no trace of the outer palisade of bristles, and cultivated crops are grown adjacent to native at most only the faintest indication of an forests or in clearings in the forest. One spe­ area which might be interpreted as an indica­ cies, griseus, has become very widespread in tion of the remnant of a bevel can be dis­ the Fijian islands, evidently through the aid tinguished in some species. The eyes of of man. Should certain of the species be ElytrufUs are larger and Batter than those of carried to other regions and become estab­ Rhyneogonus. Many species of Rhyneogonus have lished some damage to economic crops might strongly protuberant eyes. occur. The larvae are, as noted above, pre­ Marshall (1938: 71 ) noted of Elytrurus that sumed to feed underground at the roots of "An exceptional type of dimorphism is to be plants. found in the first segment of the hind tarsi : The described species of Elytrurus are dis­ in the male this segment is clothed beneath tributed from west to east as follows: with soft hairs; but in the female its inner edge on the basal half is set with stiff spines, SOLOMONS-1 species which are sometimes bare and sometimes hid­ anensts den by hairs. " This statement appears to apply only to certain species, and it is not character­ SANTA CRuz-1 species istic of the genus as a whole. lapeyrousei 288 PACIFIC SCIENCE, Vol. X, July, 1956 NEW HEBRIDES-14 forms Elytrurus lliuei Zimmerman, new species alatus mawlieollis Figs. 2- 4 marginatus ambrymensis COLOR: derm mostly reddish brown, venter risbeci aobae mostly darker to nearly black; vestiture mostly eaudatus rustieus creamy white, but with iridescent scales (evi­ santieolus eaudatus erromangoi dently subject to fading) more abundant on tannae eonvexus lower surface; scaling denser and more con­ tannae erromangoana divarieatus spicuous on dorsum of female than male, in FIJI-23 forms latter sex the scales form a pale vitta on sides matukuanus aeutieauda from anterior margin of pronotum to apex moalensis bryani of elytra. eervinus obtusatus durvillei painei STRUCTURE: Head with sides, as viewed evansi prasinus from above, nearly evenly arcuate from pro­ expansus protensus notum to apices of eyes, eyes not obviously foreipatus simmondsi interrupting this contour; breadth at hind granatus smaragdus margins of eyes distinctly greater than length greenwoodi subangulatus from pronotum to anterior edge of an eye griseus subtritus (1.75:1.2); length, measured from side, from griseus taveuni subvittatus pronotum to anterior edge of eye equal to leveri distance between fore edge of eye and base TONGA-1 species of mandible; distance between pronotum and einetus eye equal to length of eye; narrowest frontal NIUE-1 species interocular distance only a little more than niuei one-half the breadth between hind margins SAMOA-3 forms of eyes (10:18); interocular area with a con­ bieolor samoensis setiventris spicuous median pit which marks the ter­ samoensls mination of the raised median line or median FI::;. 2. Elytrurus nittJi, new species, holorype male. 'I. ' . 1 Elytrurus - ZIMMERMAN 289 FIG. 3. Elytrurus niuei, new species, allotype female. carina from pit to epistome; crown and front setiform scales, which are more squamiform with shallow punctures of medium size inter­ on dorsal edge, and longer, decumbent setae, spersed with some minute punctures, most apex not quite reaching as far back as an­ of the larger punctures bearing conspicuous, terior one-fourth of side of pronotum, sub­ decumbent setae which are directed toward equal in length to the seven funicular seg­ the midpoint of the crown; scales oval, dens­ ments combined; funiculus with vestiture less est along upper margins of eyes, rather densely dense and finer than scape, lengths of seg­ continued ventrad to bare median gular sutural ments as follows: 1- 20, 2-22, 3-12, 4-11, line. 5- 10, 6- 10, 7-10; club as long as preceding Rostrum with greatest preapical breadth sub­ four funicular segments together, lengths of equal to length from fore edge of eye to apex segments: 1- 15, 2-12, 3-15, greatest thick­ of mandible, longitudinal dorsal contour ness of segment two 12 (these measurements flattened from just behind interocular pit; with micrometer reading 40 units to one sides beneath scrobes continuously squamose millimeter) . with sides of head and with numerous, con­ Pronotum obviously transverse (28:20), spicuous, slanting, erect setae; dorsum im­ broadest at or just behind middle, anterior pressed on either side of median line which margin broadly, shallowly emarginate, pos­ is consequently elevated as a median carina terior margin weakly convex; longitudinal whose development is variable and may be median contour only slightly arcuate; disc conspicuous or obscure, punctate, squamose punctate-granulate, the punctures on the pos­ and setose as head; epistome rather densely terior sides of the granules bearing fine, de­ set with mostly small punctures, setose only curved setae mostly directed obliquely back­ at sides and without squamae; mentum not ward toward median line; scales on disc setose, with a peduncle about one-fourth to smaller and sparser than on sides, not.covering one-third as long as median length of mentum. the granules which protrude and are moder­ Antennae with scape comparatively densely ately shiny; squamae larger, denser, imbricated clothed with prostrate, narrow, mostly almost on side margins. ~., .1/4 290 PACIFIC SCIENCE, Vol. X, July, 1956 in length to transverse diameter of a meso­ coxa, disc tending to be transversely strigate, squamae there smaller and much sparser than on sides where they are dense but interrupted by rather large setigerous punctures; mete­ pisternum squamose and setose.