Horizontal niche differentiation of ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) within the standing trunk of Quercus serrata

Abstract

Niche differentiation, in terms of time and space, has been reported within a community of ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) in a tree trunk. Two platypodid ambrosia beetles, Platypus quercivorus (Murray) and Platypus calamus Blandford, utilize a similar height range with respect to the Quercus serrata Murray (Fagaceae) trunk. The sapwood and heartwood (i.e., wood types) are known to differ in their physical and chemical characteristics. The objective of this study was to determine the differences among ambrosia beetles, in terms of wood type preferences, in a Q. serrata tree trunk. We analyzed the horizontal distribution patterns of ambrosia beetles within two mature Q. serrata tree trunks. Platypus calamus and the other ambrosia beetles [P. quercivorus, Ambrosiodmus lewisi (Blandford), Ambrosiophilus atratus Eichhoff, and Xyleborus sp.] showed different horizontal distribution patterns within the wood. The former tended to utilize the heartwood, whereas the latter utilized the sapwood. These results suggest that the wood type can be regarded as one of the niche dimensions of ambrosia beetles in a Q. serrata trunk.

Keywords:

• Ambrosia beetles
• Horizontal niche differentiation
• Japanese oak wilt
• Platypus calamus
• Quercus serrata

Acknowledgments

The authors are much obliged to Hideaki Goto, a research fellow of the Kyushu Research Center, Forestry and Forest Products Research Institute, Incorporated Administrative Agency, for species identification of all the dried specimens of ambrosia beetles captured in the related study (Iidzuka et al. 2016). We are deeply grateful to Naoki Okada, Makoto Ando, Takahito Yoshioka, Hiroaki Fujii, Masatoshi Ito, Masafumi Todoriki, Jun Nagaoka, and all members of Kamigamo Experimental Station and Laboratory of Forest Ecology at Kyoto University, for their considerable support in our study. This study was supported by Grant-in-Aid for JSPS Fellows (No. 26·1228) to Hiroaki Iidzuka and Grant-in-Aid for Scientific Research (No. 26292084) to Naoya Osawa.