| 1. |
- Bohman, Björn
(författare)
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Catches of Euxoa tritici in pheromone traps for Anarsia lineatella are due to the presence of (Z)-5-decenyl acetate as an impurity
- 2023
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Ingår i: Entomologia Experimentalis et Applicata. - 0013-8703 .- 1570-7458. ; 171, s. 821-827
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Tidskriftsartikel (refereegranskat)abstract
- Traps baited with the synthetic pheromone of Anarsia lineatella Zeller (Lepidoptera: Gelechiidae) frequently captured also Euxoa tritici L. males (Lepidoptera: Noctuidae) in field tests in Hungary. As (E)-monounsaturated compounds are uncommon among sex attractants or pheromone components of Noctuidae, it was hypothesized that the Euxoa catches may have been due to impurities of the (Z) isomer in synthetic (E)-5-decenyl acetate, which is the major component in the pheromone lure of A. lineatella. Traps baited with synthetic (Z)-5-decenyl acetate captured large numbers of E. tritici, and the compound showed a clear dose-response effect. Reanalysis of the synthetic batch of (E)-5-decenyl acetate used in preparation of the A. lineatella lure showed the presence of 10% of the (Z) isomer. Traps baited with synthetic (Z)-5-decenyl acetate can be used in the future for detection and monitoring purposes of E. tritici, a widely distributed pest of cereals and other field crops. The compound also showed attraction of Euxoa seliginis Duponchel.
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| 2. |
- Jordan, Anna, et al.
(författare)
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The potential of the solitary parasitoid Microctonus brassicae for the biological control of the adult cabbage stem flea beetle, Psylliodes chrysocephala
- 2020
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Ingår i: Entomologia Experimentalis et Applicata. - : John Wiley & Sons. - 0013-8703 .- 1570-7458. ; , s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- The cabbage stem flea beetle (CSFB), Psylliodes chrysocephala L. (Coleoptera: Chrysomelidae), is a major pest of oilseed rape, Brassica napus L. (Brassicaceae), within the UK and continental Europe. Following the withdrawal of many broad-spectrum pesticides, most importantly neonicotinoids, and with increased incidence of pyrethroid resistance, few chemical control options remain, resulting in the need for alternative pest management strategies. We identified the parasitoid wasp Microctonus brassicae (Haeselbarth) (Hymenoptera: Braconidae) within CSFB collected from three independent sites in Norfolk, UK. Parasitism of adult CSFB was confirmed, and wasp oviposition behaviour was described. Moreover, we show that within captive colonies parasitism rates are sufficient to generate significant biological control of CSFB populations. A sequence of the M. brassicae mitochondrial cytochrome oxidase 1 (MT-CO1) gene was generated for rapid future identification. Moroccan specimens of Microctonus aethiopoides (Loan), possessing 90% sequence similarity, were the closest identified sequenced species. This study represents the first description published in English of this parasitoid of the adult cabbage stem flea beetle.
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| 3. |
- Karlsson, Miriam Frida
(författare)
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Habitat factors associated with Fopius caudatus parasitism and population level of its host, Ceratitis cosyra
- 2020
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Ingår i: Entomologia Experimentalis et Applicata. - : Wiley. - 0013-8703 .- 1570-7458. ; 168, s. 28-40
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Tidskriftsartikel (refereegranskat)abstract
- Biotic and abiotic factors affect herbivores and their natural enemies and understanding of their requirements may permit habitat modification enabling conservation biological control. Ceratitis cosyra Walker (Diptera: Tephritidae), an African-native fruit fly pest is mostly parasitized by the parasitoid wasp Fopius caudatus Szepligeti (Hymenoptera: Braconidae). To assess F. caudatus habitat, the wasp parasitism levels and infestation of its fruit fly host were examined in Sarcocephalus latifolius (Smith) Bruce (Rubiaceae), a shrub of which the fruits are among the preferred hosts of C. cosyra and F. caudatus. Fruit-collection site descriptions, including plant species presence, were analysed in relation to the target insect abundances (emergence from target fruit). Ceratitis cosyra and F. caudatus emerged from all sites; nonetheless, their population levels were associated with both abiotic and biotic factors, of which some can be manipulated. Several factors, such as cultivation level, topography, and vegetation coverage, were correlated with F. caudatus parasitism. Ceratitis cosyra infestation level was correlated with factors such as density of S. latifolius, vegetation cover, cultivation practices, temperature, altitude, rainfall pattern, and stoniness. Proximity to other fruit fly host plants correlated with both pest abundance and F. caudatus parasitism level of the fruit fly. The findings that insects' interactions and abundance are influenced by habitat structure and that parasitism is positively related to natural habitat indicates the importance of maintaining natural habitats in closeness to cultivated areas with the aim of enhancing pest suppression by parasitoids. Further studies should attempt to identify how plant species composition in and around orchards could affect the management of tephritid fruit fly pests.
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| 4. |
- Martel, Véronique, et al.
(författare)
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Host-dependent larval migration and parasitism risk in a polyphagous moth
- 2024
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Ingår i: Entomologia Experimentalis et Applicata. - 0013-8703 .- 1570-7458. ; 172, s. 523-532
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Tidskriftsartikel (refereegranskat)abstract
- Female herbivorous insects are expected to oviposit on the host plant providing the best performance of the offspring. However, in some insects the larvae are mobile and are not totally dependent on the mother's choice. They can change host plant when conditions for development or exposure to natural enemies vary between individual plants within a patch. Here we study larval migration and preference between two host plants, cotton and alfalfa, in the Egyptian leafworm, Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae). Previous studies have shown that although larval performance is better on cotton, females prefer to oviposit on alfalfa, and this preference corresponds to a higher survival of the eggs. In this study, S. littoralis larvae showed directed movement between host plants and were found to prefer alfalfa over cotton in field test in Egypt, as well as in laboratory selection of feeding site assays. To determine effects by natural enemies, the parasitism rates and various life-history traits were measured for one larval parasitoid, Microplitis rufiventris Kokujev (Hymenoptera: Braconidae), on several host plants including cotton and clover (equivalent host plant to alfalfa). Overall, parasitism was higher on cotton and parasitoid performance (cocoon mass, adult longevity, and female egg load) was better on cotton compared to clover. This fact suggests an enemy-free space on clover and alfalfa, as parasitism rate is higher on cotton, and the parasitoid performance is also better on cotton-fed larvae.Larval migration was investigated in the Egyptian leafworm, Spodoptera littoralis (Lepidoptera: Noctuidae). Larvae showed directed movement between host plants and were found to prefer alfalfa over cotton in field and laboratory tests, even though larval performance is better on cotton. However, parasitism rates were higher and parasitoid performance (cocoon mass, adult longevity, and female egg load) was better for the larval parasitoid Microplitis rufiventris (Hymenoptera: Braconidae) on cotton, suggesting enemy-free space on alfalfa.image
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