2009 年 44 巻 3 号 p. 363-370
To develop a better system for rearing ambrosia beetles, we tested semi-artificial diets with different ingredients and structures. For the rearing of Xyleborus pfeili (Ratzeburg), we prepared diets composed of Douglas-fir sawdust, potato starch, dried yeast, sugar, and distilled water. The addition of antibiotics (streptomycin and penicillin) to a diet with a single-layer structure did not inhibit fungal contamination, and resulted in fewer X. pfeili offspring. Diets containing neither the starch nor the yeast effectively prevented fungal contamination, but did not produce offspring. A diet with a two-layer structure, in which different diets were placed in the lower layer (all ingredients) and the upper layer (sawdust, sugar, and water) in a glass tube, greatly increased the reproductive success of X. pfeili. The length of the gallery system, the number of offspring, their sex ratio, and the timing of gallery boring and oviposition by mother beetles on the two-layer structure were not significantly different from those on a three-layer structure used in previous research that also contained a thin layer of Douglas-fir resin. Thus, the diet with a two-layer structure appears to be a useful and simpler method for rearing ambrosia beetles.
