New Zealand Entornolopst, 1996, Vol. 19 Sitona lepidus Gyllenhal (Coleoptera: Curculionidae) , a potential clover pest new to New Zealand B.I.P. B ~ T T AgResearch, Invermay Agricultural Centre, Private Bag 50034, Mosgiel, New Zealand G.M. BARKER & P.J. ADDISON AgResearch, Ruakura Agricultural Research Centre, Private Bag 3123, Hamilton, New Zealand ABSTRACT Silonu lepidus Gyllenhal (syn. S. Javescens (Marsham) ) (Coleoptera: Curculionidae) , a potential legume pest species new to Ncw Zealand, is reported from near Hamilton. A key is provided to distinguish S. lepidus from S. discoideus Gyllenhal, a lucerne pest already established in New Zealand. Information is given on the distribution of S. lepidus in New Zealand and overseas, the biology and life cycle, mostly derived from the literature, and potential pest status and control. Keywords: Sitona lepidus; New Zealand; new record INTRODUCTION The genus SitonaGermar (Curculionidae: Brachycerinae: Entimini) comprises a large number of species, many of which are pests of legumes (Bright 1994). Silonn discoideus Gyllenhal was first reported in New Zealand in 1974 (Esson 1975) from Napier. It rapidly became established in lucerne (Medicago sativa L.) crops throughout New Zealand, causing considerable crop losses (Kain & Trought 1982;Goldson &French 1983). Adult weevils feed on lucerne foliage causing distinct notches on the leaf margins, and the larvae feed on the root systems. Newly emerged larvae feed inside the root nodules, but later stages feed externally on root nodules and roots (Goldson & French 1983). In 1982 a parasitoid, Microclonus aelhiopoidesLoan (Hymenoptera: Braconidae: Euphorinae) was introduced as a biological control agent for S. discoidezls (Goldson & Profitt 1986). This parasitoid was released at sites throughout the South Island and has now established in S. discoideus populations throughout New Zealand (Stufkens et al. 1987; Ferguson et al. 1994; Barker & Addison, unpubl.), providing good control in South Island lucerne crops (Goldson et al. 1994). This paper reports the arrival in New Zealand of Sitona l~pidus Gyllenhal , the second species of Sitona to become established in this country. A key to distinguish between S. lepidus and S. discoideus is presented, and available information is about the distribution, biology, phenology, pest status and control of S. lepidus is summarised. TAXONOMY Weevils in the genus Sitona Germar are characterised by a short, broad rostrum, with a narrow, median, longitudinal groove on the frons and extending on to the rostrum. The mandibles lack a mandibular scar, but bear scales. The surface of the pronotum is often densely punctured. An impressed transverse groove is present on the prosternum, anterior to the coxal cavities. The elytra bear 10 striae marked by longitudinal rows of impressed punctures, clothed with scales, and usually with erect setae (after Bright 1994). Silonaspp. can be distinpised from other broad nosed weevils (Brachycerinae: Entimini) in New Zealand by the presence of scales as well as setae on the epistome and mandibles (Barratt & Kuschel in press).