クロハナムグリの生活史を屋外飼育実験により推定した。その結果,本種は年1化性であり,成虫の活動期間は4月下旬から8月下旬であった。幼虫は3齢が終齢であった。産卵は初夏に行われ,8月中旬には新成虫となり地上に出現した。しかしながら,野外において晩夏から秋季にかけて成虫を発見できないことから,自然状態では新成虫は羽化後も朽木内に留まり,そのまま越冬すると考えられる。初年度の越冬態は成虫であり,翌春に休眠から覚めた成虫は地上に出現し,摂食活動と生殖活動を行った。なお,成虫の一部は2年間生存し,2回の繁殖期があった。野外においても体表が磨耗し2年間生存していると推測される個体が時折確認されることから,一部の個体は自然条件下においても多回繁殖を行っていると考えられる。成虫の寿命は1年から2年であった。これらの結果から本種の生活史型は,年1化・成虫越冬・多回繁殖型と言える。このように,クロハナムグリは一部の成虫による多回繁殖という戦略を持つことによって,朽木という数少ない餌資源を長期に探索し,次世代を残すことが可能な能力を備えていた。なお,成虫の訪花植物について調査した結果,1綱7目8科23種が確認された。

The life history of Glycyphana fulvistemma (Coleoptera : Scarabaeidae) was studied by an outdoor breeding experiment. The chafer was found to be univoltine, and the adult active period was from the last 10 days in April to the last 10 days in August. The larvae pass through a total of three instars. Oviposition was observed in early summer, and the hatched larva grew until it became adult and emerged in mid-August. However, because the adult was not discovered outdoors from late summer to the fall, it was thought to inhabit rotten wood after adult eclosion and hibernate over winter. Hibernation form in the first year was adult, the adult that awoke from dormancy the next spring appeared on the ground, and feeding and reproductive activity took place. Some of the adults in the breeding experiment lived for 2 years and had two breeding periods. In the field, adults were occasionally discovered with rubbing surfaces on their bodies. Such adults were thought to continue to live for 2 years. The possibility of having breeding periods at numerous times was thought to be high for these adults under natural conditions. The adult lifetime was 1 year or 2 years. Therefore, the chafer has [one-year life history]-[adult hibernation]-[numerous time breeding period]-life history type. In this way, the adult of the part of this chafer lived for two years and had two breeding period. Such reproduction strategy was supposed to be a result of being adaptable to limited food resources, e.g., rotten wood. After investigating the flowers that adult chafers visited for feeding, 23 species in 8 families of 7 orders of 1 class were confirmed.

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