An immunomarking method to investigate the flight distance of the Japanese beetle

AbstractWe evaluated the effects of free-range chickens and geese on insect pests and weeds in an experimental, nonchemical agroecosystem consisting of an apple orchard with intercropped potatoes. The objective was to assess the potential of these domestic bird species as biological control agents. Four insect pests were studied: plum curculio, apple maggot, Japanese beetle, and Colorado potato beetle. Chickens fed on several potential crop pests, including Japanese beetle. Although Japanese beetles were less abundant on apple trees when chickens were present, the proportion of damaged fruit was not reduced. Furthermore, chickens did not affect weed abundance or crop productivity. In contrast, geese were effective weeders. Their activities reduced weed abundance and increased potato plant growth and yields compared with a minimally weeded control. In addition, the activities of geese indirectly reduced apple fruit damage by plum curculio and increased the proportion of pest-free fruit, possibly because removal of vegetation by the geese reduced humidity at the soil surface and therefore reduced the activity of plum curculio.

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Mechanics-based analysis of selected features of the exoskeletal microstructure of Popillia japonica

Journal of Materials Research ◽

10.1557/jmr.2009.0409 ◽

2009 ◽

Vol 24 (11) ◽

pp. 3253-3267 ◽

Cited By ~ 24

Author(s):

Liang Cheng ◽

Liyun Wang ◽

Anette M. Karlsson

Keyword(s):

Cross Section ◽

Cross Sections ◽

Fiber Orientation ◽

Fracture Resistance ◽

Interfacial Strength ◽

Maximum Tensile Stress ◽

Popillia Japonica ◽

Japanese Beetle ◽

Mechanical Responses ◽

Helicoidal Structure

We explore key mechanical responses of the layered microstructure found in selected parts of the exoskeletons (pronotum, leg and elytron) of Popillia japonica (Japanese beetle). Image analyses of exoskeleton cross-sections reveal four distinct layered regions. The load-bearing inner three regions (exocuticle, mesocuticle, and endocuticle) consist of multiple chitin-protein layers, in which chitin fibers align in parallel. The exocuticle and mesocuticle have a helicoidal structure, where the stacking sequence is characterized by a gradual rotation of the fiber orientation. The endocuticle has a pseudo-orthogonal structure, where two orthogonal layers are joined by a thin helicoidal region. The mechanics-based analyses suggest that, compared with the conventional cross-ply structure, the pseudo-orthogonal configuration reduces the maximum tensile stress over the exoskeleton cross-section and increases the interfacial fracture resistance. The coexistence of the pseudo-orthogonal and helicoidal structures reveals a competition between the in-plane isotropy and the interfacial strength in nature’s design of the biocomposite.

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