Reproductive Readiness and Niche Differences Affect Responses of Conifer Root Weevils (Coleoptera: Curculionidae) to Simulated Host Odors
| Autor: | George D. Hoffman, D. W. A. Hunt, S. M. Salom, Kenneth F. Raffa |
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| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | Environmental Entomology. 26:91-100 |
| ISSN: | 1938-2936 0046-225X |
| Popis: | Four species of pine-root feeding weevils, Hylobius radicis Buchanan, H. assimilis Boheman, H. pales (Herbst), and Pachylobius picivorus (Germar), comprise a major pest guild on plantation pines in the Great Lakes region. The former 2 species breed in living trees, whereas the latter 2 species breed in dead or dying trees or stumps. This study develops an ecological and physiological context for the diversity of responses to a common chemical signal among closely related species exploiting common hosts. All 4 species respond to a mixture of terpenes and ethanol but show different temporal and behavioral patterns. H. radicis and H. assimilis have a spring peak and midsummer decline in attraction to turpentine-and ethanol-baited pitfall traps, and females are the predominant gender captured. The period of attraction of H. pales and P. picivorus to baited traps extends somewhat later into the summer, and males and females are captured in equal numbers. For all species, capture rates in passive screen traps decline later than those in pitfall traps. Dissections of captured female weevils show that volatile-emitting pitfall traps are selective for reproductively mature individuals of all species, whereas the passive screen traps catch nonreproductive and reproductive females in equal numbers. Ninety-seven percent of the males captured were reproductively mature, so their decline in attraction to pitfall traps is not directly related to reproductive status. Niche differences among the 4 species can explain some of the differences in the attraction of the weevils to baited pitfall traps. |
| Databáze: | OpenAIRE |
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