Sap beetle

Abstract: A novel trap designed to catch sap beetles and many other insects is de­ scribed. This trap is durable, being manufactured from PVC pipe and brass screen. The modular trap orients in the wind such that air flows over screened-off bait compartments and through a screen funnel entrance. Insects approach and enter from down-wind and become trapped after passing through a wire mesh funnel. They subsequently move through a connecting tube, through an additional funnel, and into a removable collector. Catches of sap beetles were superior to a commercially available Japanese beetle trap. Several thousand sap beetles (primarily Carpophilus lugubris ~vlurray) could be captured with appropriate baits over a 1-wk period. Fungi from the trapped sap beetles included Aspergillus jlavus Link:Fr. and numerous common genera with species recognized as plant pathogens, entomopathogens, saprophytes, or biocontrol agents. Other families of insects that contain pests and were captured include Cantharidae, Chrysomelidae, Elateridae, Culicidae, Drosophilidae, Muscidae, Vespidae, and Noctuidae.

Abstract: The relative toxicity of proenzyme and protease-activated forms of maize seed ribosome-inactivating protein (b-32) to several insect species was determined. Only the protease-activated form had significant toxicity to any caterpillars when fed in diets at 1 mg/g of diet. Activity ranged from 70% mortality to cabbage looper (Trichoplusia ni) to no effect to Indian meal moth (Plodia interpunctella). Neither form of the protein showed activity against larvae of the Freeman sap beetle, (Carpophilus freemani). However, the proenzyme and protease-activated forms were approximately equally deterrent in choice assays to other sap beetles and maize weevils (Sitophilus zeamais), with relative feeding rates reduced by up to 6-fold. Because this protein can naturally occur at the 1 mg/g endosperm range in the endosperm of Opaque-2 (normal) plants versus 2 orders of magnitude lower in opaque-2 mutants, it is likely that this RIP plays a natural defensive role against insects. However, some insects appear to have adapted to this protein.

Abstract: Community assembly is an integral process in all ecosystems, producing patterns of species distributions, biodiversity, and ecosystem functioning. Environmental filters and colonization history govern the assembly process, but their relative importance varies depending on the study system. Dead wood decomposition is a slow process, allowing decomposer communities to develop within a slowly changing substrate for decades. Despite this, there are few long-term studies of priority effects from colonization history in this ecosystem. In this study, we investigate the importance of insects in early succession of dead wood on the fungal community present one decade later. Sixty aspen trees were killed in two study landscapes, each tree producing one aspen high stump and log. Insects were sampled with flight interception traps during the first 4 years after tree death, and fungal fruiting bodies were registered in year twelve. We found positive priority effects of two fungivorous beetles, the sap beetle Glischrochilus quadripunctatus and the round fungus beetle Agathidium nigripenne, on the Artist's bracket (Ganoderma applanatum) and a positive priority effect of wood-boring beetles on the ascomycete Yellow fairy cup (Bisporella citrina). The Aspen bracket (Phellinus tremulae) did not respond to insects in early succession of the dead wood. Our results suggest that early successional insects can have significant, long-lasting effects on the late successional fungal community in dead wood. Also, the effect can be specific, with one fungus species depending on one or a few fungivorous beetle species. This has implications for decomposition and biodiversity in dead wood, as loss of early colonizing beetles may also affect the successional pathways they seem to initiate.

Abstract: A male-produced aggregation pheromone was identified for the Australian sap beetle,Carpophilus davidsoni Dobson (Coleoptera: Nitidulidae), by bioassay-guided fractionation of volatiles collected from feeding beetles. The most abundant components were: (2E,4E,6E)-5-ethyl-3-methyl-2,4,6-nonatriene, (3E,5E,7E)-6-ethyl-4-methyl-3,5,7-decatriene, (2E,4E,6E,8E)-3,5,7-trimethyl-2,4,6,8-undecatetraene, and (2E,4E,6E,8E)-7-ethyl-3,5-dimethyl-2,4,6,8-undecatetraene. The relative abundance of these components in collections from individual males feeding on artificial diet was 100:7:9:31, respectively. Pheromone production began within several days after males were placed onto diet medium and continued for at least 20 weeks. Peak production was >3 µg total pheromone per male per day. Males in groups of 50–60 emitted less pheromone (the peak level was 0.09 µg per beetle per day), and the emissions from groups contained relatively little tetraene (proportions of the components listed above were 100:7:2:7, respectively). Three additional trienes and one additional tetraene were identified in minor amounts; the entire eight-component male-specific blend is qualitatively identical and quantitatively similar to that of the North American sibling species,C. freemani Dobson. A synthetic blend of the four major components on rubber septa, prepared to emit in the same proportions as from individual males, was highly attractive in the field when synergized with fermenting whole-wheat bread dough. Cross-attraction was observed in the field involving the pheromones ofC. davidsoni, C. hemipterus (L.), andC. mutilatus Erichson. Potential uses of the pheromones in pest management are discussed.