21 research outputs found
Isolation and identification of a male-produced aggregation-sex pheromone for the velvet longhorned beetle, Trichoferus campestris.
The velvet longhorned beetle, Trichoferus campestris (Faldermann) ("VLB"; Coleoptera: Cerambycidae), is native to eastern Asia where it infests and damages a wide range of deciduous and coniferous tree species, including orchard and timber species. Immature stages of VLB are transported to new countries via international commerce, and populations have established outside the native range of the species. Here, we show that identification of pheromones of invasive pest species can be expedited by knowledge of the semiochemistry of related taxa. Histological sectioning revealed subcuticular, male-specific prothoracic glands connected to pits in the cuticle, which, in related species, are diagnostic for production of male-produced aggregation-sex pheromones, usually characterized by 2,3-alkanediol/hydroxyketone structural motifs. However, in preliminary field bioassays, beetles were not attracted by any known cerambycid pheromones. Subsequently, we identified a novel variant of the hydroxyketone motif ("trichoferone") from headspace volatiles of males. In field bioassays, synthetic trichoferone was more attractive to both sexes of VLB than previously developed high-release-rate ethanol lures, and attraction was strongly female biased. This study demonstrated the utility of the prothoracic gland trait for predicting pheromone use in cerambycid species in the subfamily Cerambycinae, and that identification of pheromones of novel species can be expedited by knowledge of pheromones of related species. Trichoferone should prove to be a valuable tool for detection of VLB in regions where the beetle is or may become established
Electrophysiologically determined spectral responses in Lobesia botrana (Lepidoptera: Tortricidae)
Electrophysiological methods were used to test the visual sensitivity of European grapevine moth, Lobesia botrana (Lepidoptera: Tortricidae) to wavelengths ranging from 300 to 700 nm. For male and females tested, a main, peak response occurred in the 460-540 nm range (blue-green wavelengths) with females having a generally lower response to wavelengths in that range. A second smaller peak was observed for both sexes at the 340-420 nm range. A general linear model indicated that males, virgin females, and mated females did not react differently to changes in wavelength. No moths showed any obvious sensitivity to wavelengths between 580 and 700 nm. Based on our retinal recording data we suggest that UV light traps (≤480 nm) could be utilized alongside pheromone traps when monitoring L. botrana in high risk areas
Technology and the dis-placing of learning in educational futures
Common visions of online education entail radically re-configuring the experience of learning: a technological displacement from the spatial order of classrooms into the more diffuse arena of digital networks. One assumption seems to be that the very spatial order of classrooms creates an undesirably rigid sense of place for schooling, one that is depressingly impervious to change; and that the attendant solution is to escape the realm of the ‘physical’ altogether – into an online realm more supportive of collaboration and free of face-the-front conventions. In the present paper we seek to challenge this oppositional view. We consider several ways in which digital technology can restructure the traditional spaces of educational practice, and identify design dynamics that may be neglected in the wake of ‘virtualisation’. Discussion first highlights two theoretical perspectives that will inform many such designs: namely, situativity and sociality in learning. Three examples are then provided of how digital technology can intersect with learning space design to create novel interpersonal frameworks for learning and to destabilise conventional senses of ‘place’ in those settings. The examples concern, respectively, the organisation of collaborative, expository, and community-based social structures for learning. Those examples represent an illustrative counterpoint to models of online schooling and illustrate a potentially productive synergy between the opportunities afforded by digital technologies, the desires of those who wish to dis-place learning online, and a well-established interest in learning space design
Observation of gravitational waves from the coalescence of a 2.5−4.5 M⊙ compact object and a neutron star
Protein digestion in larvae of the red oak borer \u3ci\u3eEnaphalodes rufulus\u3c/i\u3e
In the Ozark Mountains of the U.S.A., the red oak borer Enaphalodes rufulus contributes to the destruction of red oaks. To understand nutrient digestion in E. rufulus larvae, digestive proteinases are compared in both larvae fed heartwood phloem and those transferred to artificial diet. The pH of gut extracts is approximately 6.3 in the midgut and foregut and decreases to 5.5 in the hindgut region. The hydrolysis of casein by midgut extracts from E. rufulus larvae fed either artificial diet or phloem from tree sections increases in buffers greater than pH 6.19, with maximum hydrolysis being observed at pH 10.1. Casein zymogram analysis reveals two major proteinase activities in larval midgut extracts of diet-fed larvae, with molecular masses of approximately 25 and 40 – 60 kDa, whereas phloem-fed larvae have proteinase activities corresponding to 40, 45, 60, 80 and \u3e100 kDa. Substrate analysis indicates at least one major trypsin-like activity in both gut extracts with a molecular mass of \u3e100 kDa, but two chymotrypsin-like activities of approximately 25 and \u3e200 kDa are found only in diet-fed larvae. Inhibitors of serine proteinases are most effective in reducing the general proteolytic activity of midgut extracts from larvae fed either food source. The data indicate that serine proteinase inhibitors have the potential to reduce E. rufulus larval damage to oaks. In particular, transgenic technologies incoporating trypsin inhibitors may be effective in reducing protein digestion in phloem-feeding larvae
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Isolation and identification of a male-produced aggregation-sex pheromone for the velvet longhorned beetle, Trichoferus campestris.
The velvet longhorned beetle, Trichoferus campestris (Faldermann) ("VLB"; Coleoptera: Cerambycidae), is native to eastern Asia where it infests and damages a wide range of deciduous and coniferous tree species, including orchard and timber species. Immature stages of VLB are transported to new countries via international commerce, and populations have established outside the native range of the species. Here, we show that identification of pheromones of invasive pest species can be expedited by knowledge of the semiochemistry of related taxa. Histological sectioning revealed subcuticular, male-specific prothoracic glands connected to pits in the cuticle, which, in related species, are diagnostic for production of male-produced aggregation-sex pheromones, usually characterized by 2,3-alkanediol/hydroxyketone structural motifs. However, in preliminary field bioassays, beetles were not attracted by any known cerambycid pheromones. Subsequently, we identified a novel variant of the hydroxyketone motif ("trichoferone") from headspace volatiles of males. In field bioassays, synthetic trichoferone was more attractive to both sexes of VLB than previously developed high-release-rate ethanol lures, and attraction was strongly female biased. This study demonstrated the utility of the prothoracic gland trait for predicting pheromone use in cerambycid species in the subfamily Cerambycinae, and that identification of pheromones of novel species can be expedited by knowledge of pheromones of related species. Trichoferone should prove to be a valuable tool for detection of VLB in regions where the beetle is or may become established