Alfalfa Weevil (Coleoptera: Curculionidae) Biological Control: Spreading the Benefits

Host Density Drives Spatial Variation in Parasitism of the Alfalfa Weevil,Hypera postica, Across Dryland and Irrigated Alfalfa Cropping Systems

“…Of the two, B. curculionis was by far the dominant, occurring at all sites in both years of the study. This supports previous work categorizing B. curculionis as a key biological control agent of the alfalfa weevil (Radcliffe and Flanders 1998), and is consistent with previous work that also has found that B. curculionis dominates the parasitoid complex associated with alfalfa weevil larvae in Colorado and Wyoming (Pike and Burkhardt 1974, Al Ayedh et al 1996, Brewer et al 1997) and the western United States more generally (Kingsley et al 1993). Average para- sitism levels by B. curculionis in this study, 56.9 and 23.7% in 2009 and 2010, respectively, were comparable to those reported previously from Wyoming, 26 and 34.5% (Pike andBurkhardt 1974, Brewer et al 1997), but higher than those reported from Colorado, 2.7Ð5% (Al Ayedh et al 1996).…”

“…Other studies similarly have suggested that B. curculionis is relatively ineffective at high densities of weevil larvae in the northern Great Plains (Al Ayedh et al 1996). However, earlier work found no strong spatial or temporal relationships between parasitism and host density in a study carried out over nine states spanning the east and west coasts of the United States (Kingsley et al 1993), suggesting that the action of B. curculionis was density independent. In contrast with B. curculionis, percent parasitism by O. incertus increased with increasing host density in 2010 (Fig.…”

Detection of live larvae in cocoons of Bathyplectes curculionis (Hymenoptera: Ichneumonidae) using visible/near‐infrared multispectral imaging

“…The impact of pest weevils, including Apion (Protapion) fulvipes Geoff (Coleoptera: Cucurlionidae), is high in organically grown white clover seed production and seed yield may be reduced from 42–50% compared with conventional white clover fields where insecticides are applied . Several species of larval endoparasitoids within the genus Bathyplectes (Hymenoptera: Ichneumonidae) have been used as classical biological control agents to control Hypera weevil pests . The cocoons of one species in particular, Bathyplectes curculionis (Thomson), have recently been suggested for use as a biological control agent against weevil pests .…”

“…3,4 Several species of larval endoparasitoids within the genus Bathyplectes (Hymenoptera: Ichneumonidae) have been used as classical biological control agents to control Hypera weevil pests. [5][6][7][8][9] The cocoons of one species in particular, Bathyplectes curculionis (Thomson), have recently been suggested for use as a biological control agent against weevil pests. 10 Cocoons of this parasitoid are harvested in large quantities from waste material obtained after processing and cleaning harvested white clover (Trifolium repens L.) seeds.…”

An Immunoassay Method for DetectingMicroctonus aethiopoides(Hymenoptera: Braconidae: Euphorinae) Parasitism in the Alfalfa Weevil,Hypera postica(Coleoptera: Curculionidae)

“…M. aethiopoides larvae feed on the host's hemolymph and fat body which leads to a reduction in egg production and life span (van Driesche & Gyrisco, 1979;Mohamed, unpublished data). M. aethiopoides Loan, is the only major parasitoid that attacks adult alfalfa weevils, and is considered the predominant biological control agent in the areas where it is established (Day et al, 1971;Dysart & Day, 1976;van Driesche & Gyrisco, 1979;Kingsley et al, 1993;Hogg et al, 1990).…”