Topic
Hypera postica
About: Hypera postica is a research topic. Over the lifetime, 548 publications have been published within this topic receiving 4894 citations. The topic is also known as: Phytonomus variabilis.
Papers published on a yearly basis
1 / 2
Papers
TL;DR: Benefits achieved, especially from reduced need for insecticides in alfalfa production, mark this as one of the great success stories of classical biological control in North America.
Abstract: Alfalfa weevil, Hypera postica (Gyllenhall) (Coleoptera: Curculionidae), is of Eurasian origin. This destructive pest of alfalfa (lucerne) was accidentally established in North America on three separate occasions. These introductions are commonly identified in the literature as biological strains: western alfalfa weevil, Egyptian alfalfa weevil (=Hypera brunneipennis Boheman), and eastern alfalfa weevil. Alfalfa weevil has been the target of classical biological control almost since its discovery in North America more than 90 years ago. These efforts have resulted in establishment of at least nine exotic parasitoids and egg predators: Bathyplectes curculionis (Thomson), B. anurus (Thomson) and B. stenostigma (Thomson) (Hymenoptera: Ichneumonidae); Microctonus aethiopoides Loan and M. colesi Drea (Hymenoptera: Braconidae), the latter of undetermined origin; Oomyzus incertus (Ratzenberg) (Hymenoptera: Eulophidae); Dibrachoides dynastes (Forester) and Peridesmia discus (Walker) (Hymenoptera: Pteromalidae); and Anaphes luna (Girault) (Hymenoptera: Mymaridae). A fungal pathogen, Zoophthora phytonomi Arthur (Phycomycetes: Entomophthoraceae), of undetermined origin, is becoming an increasingly important alfalfa weevil mortality factor. Most major USA alfalfa production areas now benefit from a complex of alfalfa weevil biological control agents. Collectively, these agents have effected substantial reduction in the economic importance of alfalfa weevil across the northern USA However, biological agents provide only partial control of alfalfa weevil, and importance of their contribution differs considerably with production area. Still, the benefits achieved, especially from reduced need for insecticides in alfalfa production, mark this as one of the great success stories of classical biological control in North America.
96 citations
TL;DR: Positive responses of B. curculionis to sugar sprays recorded in this study suggest application of this material may be beneficial to the wasp throughout the 1st crop of alfalfa if aphid densities and associated availability of natural honeydew remain low.
Abstract: Sugar spray applied to crop foliage may serve as a surrogate for homopteran honeydew in meeting the nutritional needs for self-maintenance in adult parasitoids of crop pests. We tested the importance of timing of application of sugar spray and the interaction between sugar spray and naturally occurring aphid honeydew in influencing the local abundance of the alfalfa weevil parasitoid Bathyplectes curculionis (Thomson). Plots of hay alfalfa in northern Utah were sprayed with sucrose dissolved in water (sugar plots) or with water only (control plots) early, midway, or late during the preflowering period in the 5th yr of production. When sampled 2 d later, numbers of adult parasitoids were consistently higher in sugar plots than in control plots. Increased wasp density in response to local pea aphid density also occurred, but only in plots that did not receive sugar spray. Weevil parasitism was elevated in sugar plots compared with control plots only when sprays were applied late in the 1st crop. Lack of enhanced rates of wasp oviposition in sugar plots early and midway during the 1st crop may have resulted from poor weather, mutual interference among the wasps, or wasp feeding. Our study was conducted in a field harboring relatively low numbers of aphids. In general, sugar sprays may be redundant for adult parasitoids in a crop when naturally occurring homopteran honeydew is abundant. But the positive responses of B. curculionis to sugar sprays recorded in this study suggest application of this material may be beneficial to the wasp throughout the 1st crop of alfalfa if aphid densities (and associated availability of natural honeydew) remain low.
70 citations
TL;DR: Three transgenic lines, including TL6, TL8 and TL11 showed significantly higher levels of insect resistance against H. postica larvae (mortality rate of 73–90 % after infestation), in comparison with the control plants during the two-year bioassays.
Abstract: To introduce genetic resistance against alfalfa weevil (Hypera postica), leaves and petiole explants of three commercial alfalfa genotypes, including Km-27, Kk-14 and Syn-18 were transformed with Agrobacterium tumefaciens strains GV101, LBA4404 and AGL01. All the Agrobacterium strains used harbored the recombinant binary vector pBI121 containing a synthetic cry3a gene under the control of CaMV35S promoter as well as the nptII gene as selectable marker. Transformed explants were cultured on callus-induction medium, and the germinated somatic embryos were then transferred to the regeneration medium. The primary transformants were evaluated by PCR and Southern blot analysis. The results indicated successful integration of the target gene into the genomes of primary transgenic lines. Moreover, the expression of Cry3a protein in the transgenic plants was confirmed by ELISA method. Three transgenic lines, including TL6, TL8 and TL11 showed significantly higher levels of insect resistance against H. postica larvae (mortality rate of 73–90 % after infestation), in comparison with the control plants during the two-year bioassays. All transgenic plants were fertile and no irregular behavior in terms of growth and the morphological traits were observed. Transgenic plants developed during the course of this study are currently being grown in greenhouse and will be crossed with each other for seed production.
68 citations
TL;DR: It is suggested that availability of pea aphid honeydew in alfalfa fields may enhance the realized fecundity of B. curculionis and the presence of peA aphids in moderate numbers may be beneficial for biological control of the alFalfa weevil.
Abstract: The ability of parasitoids to attack their hosts may be influenced by the availability of adult food sources such as homopteran honeydew. To test this hypothesis for the wasp Bathyplectes curculionis (Thomson), a parasitoid of the alfalfa weevil, Hypera postica (Gyllenhal), we performed laboratory experiments to determine whether availability of pea aphid, Acyrthosiphon pisum (Harris), honeydew influenced adult longevity and fecundity of the wasp. Adult wasps caged with alfalfa, Medicago sativa L., and pea aphids fed on the aphid honeydew and lived a50% longer than wasps caged with alfalfa alone. In a related experiment, newly emerged, unmated B. curculionis females were allowed to feed for 2 d on pea aphid honeydew, sucrose dissolved in water, or water alone, and were then dissected to determine the number of eggs in a lateral oviduct. Egg production was slightly (11–15%) but significantly greater in females with access to pea aphid honeydew or sugar water than in females with access to water only. These results suggest that availability of pea aphid honeydew in alfalfa fields may enhance the realized fecundity of B. curculionis . Hence, the presence of pea aphids in moderate numbers may be beneficial for biological control of the alfalfa weevil.
65 citations
TL;DR: Topical treatment of the alfalfa weevil, Hypera postica (Gyllenhal), with the synthetic juvenile gonadotropic hormone 10,11-epoxyfarnesenic acid methyl ester effectively terminated summer diapause.
Abstract: Topical treatment of the alfalfa weevil, Hypera postica (Gyllenhal), with the synthetic juvenile gonadotropic hormone 10,11-epoxyfarnesenic acid methyl ester effectively terminated summer diapause.
61 citations
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Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 2 |
| 2024 | 4 |
| 2023 | 6 |
| 2022 | 17 |
| 2021 | 9 |
| 2020 | 5 |