Argentine stem weevil(hyperodes bonariensiskuschel) resistance in perennial and hybrid ryegrasses

Abstract

A high level of host plant resistance to Argentine stem weevil (ASW) (Hyperodes bonariensis Kuschel) has been recorded under field conditions in a line of perennial ryegrass (Lolium perenne L.) collected from the Takapau district in Central Hawkes Bay. When compared with the commonly sown cultivars of perennial ryegrass, 'Grasslands Ruanui' and 'Grasslands Nui', this ryegrass suffered minimal adult ASW damage, harboured low number of eggs and larvae, and hence suffered low levels of larval damage. Another ryegrass cultivar, Ellett, was also found to be more ASW resistant than Nui but its superiority over this cultivar was less marked than that recorded for 'Takapau'. The production and persistence of Ruanui and Nui swards was severely affected by ASW damage and as a result these became white clover (Trifolium repens L.) dominant whereas swards of 'Takapau' ryegrass persisted as well balanced grass-clover mixtures. The production ofNui and Ruanui ryegrass was similar but was approximately 60% and 50% lower than 'Takapau' ryegrass production in summer and autumn respectively.

Unexpected presence of larvae of Argentine stem weevil, Listronotus bonariensis (Kuschel) (Coleoptera: Curculionidae), in New Zealand pasture thatch

“…On many occasions larval populations have been estimated visually from tillers cut at ground level (Pottinger 1961; Kain et al 1982). Goldson (1978) developed a heat extraction technique for larvae, based on the observed movement of L. bonariensis larvae from tiller to tiller; this too was used widely (Goldson & Penman 1979; Barker et al 1989).…”

Endophyte in New Zealand ryegrass pastures, an overview

“…ASW has been shown to be an important factor in pasture failure in Canterbury (Goldson 1982) and much of the North Island (Barker et al 1984a). Yield responses of 50-60% in mixed ryegrass-white clover swards were achieved by protecting from ASW with insecticide (Kane et al 1982). In 1991, pasture damage by ASW was estimated as costing New Zealand $46-$200M annually (Prestidge et al 1991).…”

Argentine stem weevil effects on Nui and Ruanui ryegrasses grown with two levels of nitrogen/water nutrition

“…Differences in susceptibility have also occurred within perennial ryegrasses but results have been conflicting. Kain et al (1977) found that Nui ryegrass suffered greater damage than Ruanui and 'Grasslands Ariki' perennial ryegrass «Lolium perenne x L. multi/-lorum) x L. perenne) under well-fertilised but moisture-stressed conditions, whereas Kain et al (1982) found no difference between Nui and Ruanui in susceptibility to larvae under conditions of low moisture stress. These results suggest that cultivar susceptibility to Argentine stem weevil may be affected by factors such as soil moisture and fertility.…”