| 1. |
- Da Silva, Maycon R., et al.
(author)
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Identification of two additional behaviorally active gland constituents of female Diatraea saccharalis (Fabricius) (Lepidoptera Crambidae)
- 2021
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In: Journal of the Brazilian Chemical Society. - : Sociedade Brasileira de Quimica (SBQ). - 0103-5053. ; 32:1, s. 225-230
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Journal article (peer-reviewed)abstract
- The sugarcane borer, Diatraea saccharalis (Fabricius), is the major pest insect attacking sugarcane crops in Brazil. Population control by insecticide treatment is not efficient due to simultaneous presence of all developmental stages of the insect throughout the year, and alternative control methods are needed. Two female-produced sex pheromone components, (Z,E)-hexadeca-9,11-dienal and (Z)- hexadec-11-enal, have previously been reported to elicit antennal activity and behavioral response of males in flight tunnel experiments. However, the attractiveness of these compounds in field tests has been very low. In this study, two additional female-produced compounds in D. saccharalis eliciting consistent antennal response in males were identified as (Z)-hexadec-9-enal and hexadecanal. In flight tunnel assays, the behavioral response to a quaternary blend was significantly higher when compared with the previously identified binary blend. Subtracting (Z)-hexadec-9-enal or hexadecanal from the full blend did not reduce attraction, indicating redundancy in the communication channel. We conclude that additional compounds are part of the sex pheromone of D. saccharalis, which may improve the efficiency of trap lures for monitoring of this pest.
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| 2. |
- Anderbrant, Olle, et al.
(author)
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Occurrence of Z- and E-strain Ostrinia nubilalis in Sweden shortly after first detection of the Z-strain
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In: Journal of Applied Entomology. - 0931-2048.
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Journal article (peer-reviewed)abstract
- Introduction: The European corn borer (ECB), Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), is a major pest insect in maize. New cultivars and climate change have allowed range expansion of the crop northwards in Europe, and a similar range expansion of associated pests has been predicted. ECB exists as two distinct pheromone strains using different blends of (E)-11-tetradecenyl acetate and (Z)-11-tetradecenyl acetate for sexual communication; in addition, the Z-strain feeds almost exclusively on maize. In Sweden, the maize cropping area has increased tenfold during the last two decades, increasing the potential for spread of the Z-strain, which was recorded for the first time in the country in 2010. Aim of the study/methods: In this study, we performed trapping experiments with strain-specific lures in maize fields in southern Sweden during 2013–2022 to monitor the presence and relative abundance of the two ECB strains and evaluate the potential increase of the Z-strain. Trapping was also performed at least 5 km away from maize fields. Molecular markers were used to verify the strain identity of trapped males and larvae that fed on maize. Results: Catch data revealed that both pheromone strains were present in the major maize cultivation areas of Sweden, as predicted by recent modelling studies. Our data indicate that the flight period of ECB in southern Sweden lasts from the middle of June to late August, with peak flight in July. Catches of both strains were low at all trapping sites and throughout the study period and decreased further during the years following the dry summer of 2018. No Z-strain males were trapped far away from maize fields. Conclusion: Based on our results, and the low levels of ECB-related damage observed in local maize fields, the Z-strain is currently not imposing a threat to Swedish maize growers.
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| 3. |
- Anderbrant, Olle, et al.
(author)
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Odour signals for detection and control of indoor pyralid moths
- 2009
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In: IOBC/WPRS Bulletin. - 1027-3115. ; 41, s. 69-74
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Journal article (peer-reviewed)abstract
- Three pyralid moths, the Mediterranean flour moth (Ephestia kuehniella), the almond moth (Ephestia cautella) and the Indian meal moth (Plodia interpunctella), infest food products all over the world and cause severe problems in factories, shops and households. For health and environmentalreasons chemical control becomes more and more restricted. We here present some promising results offering efficient detection and control of these species based on semiochemicals, and line up a number of remaining questions to be answered in order to improve the reliability and competitiveness of the methods used. For P. interpunctella and E. cautella we found that more complex pheromone blends were superior to the commercially available one-component blend in attracting males, andshould be used if increased sensitivity is desired. The almond moth, males as well as females, can be trapped in buckets with tap water, which will give an estimate of the population level without use of pheromone traps. All three species show positive response to odours identified from chocolate, and this could possibly be developed further and used to determine relative population densities. For population suppression the pheromone-mediated mating disruption technique was employed inlocalities with infestations of all three species. Based on several indirect methods to estimate the population densities we conclude that this technique has a large potential for controlling all three mothspecies.
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| 4. |
- Askri, Dalel, et al.
(author)
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A blood test to monitor bee health across a European network of agricultural sites of different land-use by MALDI BeeTyping mass spectrometry
- 2024
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In: Science of the Total Environment. - 0048-9697. ; 929
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Journal article (peer-reviewed)abstract
- There are substantial concerns about impaired honey bee health and colony losses due to several poorly understood factors. We used MALDI profiling (MALDI BeeTyping®) analysis to investigate how some environmental and management factors under field conditions across Europe affected the honey bee haemolymph peptidome (all peptides in the circulatory fluid), as a profile of molecular markers representing the immune status of Apis mellifera. Honey bees were exposed to a range of environmental stressors in 128 agricultural sites across eight European countries in four biogeographic zones, with each country contributing eight sites each for two different cropping systems: oilseed rape (OSR) and apple (APP). The full haemolymph peptide profiles, including the presence and levels of three key immunity markers, namely the antimicrobial peptides (AMPs) Apidaecin, Abaecin and Defensin-1, allowed the honey bee responses to environmental variables to be discriminated by country, crop type and site. When considering just the AMPs, it was not possible to distinguish between countries by the prevalence of each AMP in the samples. However, it was possible to discriminate between countries on the amounts of the AMPs, with the Swedish samples in particular expressing high amounts of all AMPs. A machine learning model was developed to discriminate the haemolymphs of bees from APP and OSR sites. The model was 90.6 % accurate in identifying the crop type from the samples used to build the model. Overall, MALDI BeeTyping® of bee haemolymph represents a promising and cost-effective “blood test” for simultaneously monitoring dozens of peptide markers affected by environmental stressors at the landscape scale, thus providing policymakers with new diagnostic and regulatory tools for monitoring bee health.
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| 5. |
- Carrasco, David, et al.
(author)
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Characterization of olfactory sensory neurons in the red clover seed weevil, Protapion trifolii (Coleoptera : Brentidae) and comparison to the closely related species P. fulvipes
- 2019
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In: Journal of Insect Physiology. - : Elsevier BV. - 0022-1910 .- 1879-1611. ; 119
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Journal article (peer-reviewed)abstract
- Protapion trifolii and P. fulvipes (Coleoptera: Brentidae) are major pests in European clover seed production. Previous studies have reported a high host plant fidelity of these weevils for red and white clover species, respectively, driven by host plant olfactory cues. Given the specific host preferences observed in these weevils, we aimed to elucidate to which extent such selectivity is reflected in their peripheral olfactory systems. Using an electrophysiological approach, we performed the first functional characterisation of olfactory sensory neurons (OSNs) in P. trifolii to a panel of volatile compounds emitted by red clover plants, and compared the results with the reported OSN types of P. fulvipes. Nineteen OSN classes were characterized in P. trifolii, with the majority of these neurons responding strongly to common volatiles released by the host plant. Based on response profiles, eight of these OSN classes have clear matches to OSN classes in P. fulvipes. The OSN colocalisation patterns and antennal frequency of these classes are similar in the two species. Additionally, the responses of these OSNs are generally highly conserved in the two species, with clear response shifts only revealed for two of the OSN classes. These response shifts in combination with additional response dissimilarities for compounds that vary in abundance between red and white clover plants may underlie the species-specific host preferences. Further behavioural and field experiments should focus on these differentially detected compounds to elucidate their potential role in host selection and use in semiochemical-based control of these pests.
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| 6. |
- Dam, Marie Inger, et al.
(author)
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Sex pheromone biosynthesis in the sugarcane borer Diatraea saccharalis : paving the way for biotechnological production
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In: Pest Management Science. - 1526-498X.
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Journal article (peer-reviewed)abstract
- BACKGROUND: The sugarcane borer Diatraea saccharalis (Lepidoptera) is a key pest on sugarcane and other grasses in the Americas. Biological control as well as insecticide treatments are used for pest management, but economic losses are still significant. The use of female sex pheromones for mating disruption or mass trapping in pest management could be established for this species, provided that economical production of pheromone is available. RESULTS: Combining in vivo labelling studies, differential expression analysis of transcriptome data and functional characterisation of insect genes in a yeast expression system, we reveal the biosynthetic pathway and identify the desaturase and reductase enzymes involved in the biosynthesis of the main pheromone component (9Z,11E)-hexadecadienal, and minor components hexadecanal, (9Z)-hexadecenal and (11Z)-hexadecenal. We next demonstrate heterologous production of the corresponding alcohols of the pheromone components, by expressing multiple steps of the biosynthetic pathway in yeast. CONCLUSION: Elucidation of the genetic basis of sex pheromone biosynthesis in D. saccharalis, and heterologous expression in yeast, paves the way for biotechnological production of the pheromone compounds needed for pheromone-based pest management of this species.
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| 7. |
- Harvey, Deborah J., et al.
(author)
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Making the invisible visible : Determining an accurate national distribution of Elater ferrugineus in the United Kingdom using pheromones
- 2017
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In: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 10:4, s. 1-11
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Journal article (peer-reviewed)abstract
- To date, conservation-status saproxylic beetle species in the UK have been monitored by chance findings or by monitor-based observational studies. Here, using Elater ferrugineus as our target species, we present the first national distribution survey carried out in the UK or across mainland Europe on such a species using chemicals produced by the insect. Over 3 years, mark-release-recapture studies were performed across the UK, using 416 lured (pheromone) traps monitored by volunteer recorders; the first survey in Europe to do so. Traps were baited with 7-methyloctyl- (Z)-4-decenoate, a compound previously identified as a female sex pheromone. The results were used to plot a distribution map and investigate factors that may influence the distribution, including summer temperatures, possible habitat availability and larval food source. The survey revealed a south-eastern distribution of E. ferrugineus in the UK, which was suggested by previous casual studies. A correlative model was fitted to the data, indicating that 55% of the variation in the distribution of E. ferrugineus was explained by climatic variables (temperature and wind speed).
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| 8. |
- Hederström, Veronica, et al.
(author)
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Dispersal and spatiotemporal distribution of Protapion fulvipes in white clover fields : implications for pest management
- 2022
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In: Journal of Pest Science. - : Springer Science and Business Media LLC. - 1612-4758 .- 1612-4766. ; 95:2, s. 917-930
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Journal article (peer-reviewed)abstract
- Yield loss caused by insect pests remains a substantial problem in agriculture. Chemical control, with potential negative effects on non-target organisms, is still the main tool for pest management. For pest species with limited dispersal capacity, rotation of the crop in time and space has potential as an alternative management measure. This is particularly important in organic farming, where most agrochemicals are prohibited, but also relevant as a complementary pest management strategy in conventional agriculture. Clover is an important crop used for animal feed and as green manure; however, seed-eating weevils can severely limit the seed yield. We hypothesized that the previous year’s clover seed fields constitute the major sources of weevil pests. Consequently, a greater distance to, and a smaller pest load from, this source should reduce the number of weevils colonizing the new seed fields. To map population dynamics and dispersal range of Protapion fulvipes, an economically important seed weevil specialized on white clover, we conducted field studies over four years in 45 white clover seed fields. We found that P. fulvipes overwinters close to its source field and disperses to new fields in early spring the following year. Pest abundance increased with pest load in the previous year’s seed field, but decreased by 68% per km distance to the previous year’s field. Thus, separation of seed production fields between years by 2–3 km would create a spatiotemporal pest management tool to reduce the pest infestation below the estimated economic injury level.
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| 9. |
- Hederström, Veronica, et al.
(author)
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White clover pollinators and seed set in relation to local management and landscape context
- 2024
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In: Agriculture, Ecosystems and Environment. - 0167-8809. ; 365
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Journal article (peer-reviewed)abstract
- Bees are declining, which is worrisome since they both have intrinsic conservation value and play a major role as pollinators in both natural and managed ecosystems. Land use change and lack of suitable habitats are often suggested as driving forces of bee decline. To propose mitigation measures to halt bee decline, it is important to understand how land use relates to bee abundance and diversity, and to explore consequences for their provision of pollination services. White clover, Trifolium repens, is an outcrossing mass-flowering crop, which could serve as an abundant, although ephemeral, food resource for bees. We investigated how the bee community in 39 fields of white clover grown for seed, related to local field management (organic, conventional without insecticides and conventional with insecticides) and landscape context (proportion semi-natural land), and how this pollinator community related to white clover seed set. The honey bee, Apis mellifera, was the most commonly observed bee species, and two generalist bumble bee species, Bombus terrestris and B. lapidarius, were the subsequently most common. We observed fewer non-Apis bees, and a lower bee species richness in organic white clover seed fields compared to conventional fields independent of insecticide treatment. Bee species richness in both conventional and organic fields were positively related to the proportion of semi-natural land in the landscape, likely because of a larger species pool in such landscapes. Initial seed set in immature inflorescences was positively related to bee abundance, whereas final seed set in mature inflorescences was unrelated to bee abundance, possibly as a consequence of seed-eating weevils consuming a large proportion of the seeds. We conclude that both bee visitation and seed set in white clover benefit from conventional management and that landscapes rich in semi-natural habitats will make future crop production more resilient. The observed positive relationship between bee abundance and initial seed set suggests that if we can mitigate pest impacts and increase bee abundance in clover seed fields, the final seed yield can be increased. Thus, bee decline should be considered and mitigated both to maintain biodiversity in general and for crop seed production specifically.
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| 10. |
- Heydorn, Per, et al.
(author)
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Long-term rearing affects pheromone-mediated flight behaviour of the Indian meal moth, Plodia interpunctella
- 2019
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In: Journal of Applied Entomology. - : Wiley. - 0931-2048 .- 1439-0418. ; 143:10, s. 1193-1195
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Journal article (peer-reviewed)abstract
- The pest Plodia interpunctella (Hübner) is reared in many research laboratories. In a culture established in 1996, attraction of males to the female-produced sex pheromone in flight tunnel assays gradually decreased after ≈15 years of rearing. A new culture was established to enable comparison with the old culture regarding traits associated with mate finding. Female calling activity, pheromone titre and male antennal response to pheromone components did not differ between cultures. In contrast, very few males from the old culture reached the pheromone source in flight tunnel assays compared with 61%–81% of males from the other culture. Our results highlight the importance of maintaining viable insect cultures for research purposes and suggest frequent evaluation of traits involved in chemical communication in such cultures to ensure reliable results in experiments.
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