Investigations of the host feeding preferences of Sitona weevils found commonly on white clover (Trifolium repens) in the UK

Abstract

A series of laboratory and field studies were done to evaluate a range of leguminous plant species for their feeding potential by adult weevils of the genus Sitona Germar. (Coleoptera: Curculionidae). Three species of Sitona, S. lineatus L., S. flavescens Marsh. and S. hispidulus E all of which are found commonly on white clover (Trifolium repens L.) in the UK were offered a range of 11 legume species, Z repens (white clover, cv. Olwen), T. pratense L. (red clover, cv. Marcom), T. fragiferum L. (strawberry clover, cv. Palestine), T. hybridum L. (hybrid clover, cv. Tetra), T. incarnatum L (crimson clover), T. dubium Sibth. (lesser yellow trefoil), Lotus corniculatus L. (birdsfoot-trefoil, cv. Leo), L. uliginosus Schkuhr. (large birdsfoot-trefoil), Melilotus alba Desr. (white melilot), Medicago sativa L. (lucerne, cv. Europe) and M. lupulina L. (black medick) in two laboratory experiments. The weevils were offered a choice of these legumes in one experiment whilst in the other they did not have a choice of food material.These legumes were also sown in the field and a number of measurements of damage, together with counts of Sitona spp., were made. In the laboratory S. lineatus and S. hispidulus favoured some of the legumes to a greater or lesser extent than white clover. S. flavescens was more restricted in its feeding than the other two weevil species. In the field study S. lineatus invaded the experimental area quickly and tended to favour Medicago spp. and Melilotus spp. Later in the year S. flavescens dominated the sitona fauna on the experiment, with the exception of aggregations of S. lineatus on M. sativa and M. alba. In a separate screen of 5 varieties of white clover (cvs Donna, Menna, Kersey, Olwen and Grasslands Huia), cv. Olwen appeared to be the most susceptible to sitona attack.

Field release, establishment and initial dispersal of Irish Microctonus aethiopoides in Sitona lepidus populations in northern New Zealand pastures

“…Also, in contrast to Europe, there is little competition from other weevil species for resources and niches (Gerard et al 2009) and two generations a year. In the northern hemisphere, several species of Sitona attack white clover (Murray and Clements 1994;Goldson et al 2004) and S. lepidus is univoltine in its habitat, with adults emerging in spring (Levesque and Levesque 1994) or late summer (Culik and Weaver 1994;Mowat and Clawson 1996). However, in northern New Zealand there is a large adult emergence in late spring that overlaps a smaller autumnal one.…”

“…It prefers white clover (Trifolium repens L.) (Murray and Clements 1994) and has become an economically important pest in New Zealand where the pastoral industries are dependent on ryegrass (Lolium perenne L.)/white clover pastures for year-round quality forage. This new pest not only damages roots and seedlings, but also the first instar larvae feed specifically on the nitrogen-fixing root nodules, which were not targeted previously by any of the resident pest species in New Zealand.…”

Host specificity testing and suitability of a European biotype of the braconid parasitoidMicroctonus aethiopoidesas a biological control agent againstSitona lepidus(Coleoptera: Curculionidae) in New Zealand

“…A pest of white clover (Trifolium repens L.), this species was first recognised in New Zealand in March 1996 by Barratt et al (1996a). The clear preference of S. lepidus for T. repens (Murray & Clements 1994;Hardwick 1998) results in nitrogen stress with ensuing loss of pasture vigour and forage quality (e.g., Eerens et al 1998;Gerard 2002). Trifolium repens is estimated to be present in over 13.5 million ha of grassland and therefore has an important role in New Zealand's pastoral agriculture (Caradus et al 1995).…”

Intraspecific variation in Trifolium pratense: impact on feeding and host location by Sitona lepidus (Coleoptera, Curculionidae)

“…While adult feeding by S. lepidus is known to be highly Trifolium speciWc (Murray and Clements 1994), Hackell and Gerard (2004) found no diVerence in nodule preference by Wrst instar S. lepidus larvae between a variety of red clover and white clover. This implies that it is likely that the stimuli that enables the Wrst instar larvae to locate nodules in red and white clover are the same and that larval populations observed in the Weld are likely to be the outcome of adult distribution, rather than larval behaviour (Hackell and Gerard 2004).…”