著者

田中,和夫

出版者

東京昆蟲學會

雑誌

昆蟲

巻号頁・発行日

vol.24, no.2, 1956-05-05

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Habits and life histories of 5 Japanese species (see p. 1) of Chlaenius observed in confinement are summarized as follows : (1) Adult beetles feed on various kinds of living small insects or fresh meat, and under full supply of such food reject vegetable substance. (2) The female beetle deposits its eggs in mud cells, which are generally oblong, rounded and rough in surface, and occur on pebbles, grass leaves (Pl. 1, f. 3) or stems (Pl. 1, f. 1), dead grass stems (Pl. 1, f. 6), slim pieces of wood or bamboo (Pl. 1, f. 2, 7&8), or on the wall of a china pot in which the beetles are confined. Each cell contains one egg and is placed singly, but in a limited place it happens that many are crowded in a cluster (Pl. 1, f. 1). (3) The mud cell of C. pallipes is most dexterously constructed ; it is somewhat quadrate and has a side opening which is closed with a thin lid in a complete cell. The lid is represented, before the deposition of the egg, by a flap projecting from the upper edge of the opening (Pl. 1, f. 4). The hatching larva makes its emergence by breaking open the lid. The inner form of the cell is ellipsoidal and smoothfaced ; the 8th and 9th abdominal segments of the female seem to take part in its construction. The female does not oviposit within the year of its emergence, but does, after hibernation, from May to July. (4) Mud cells of C. circumdatus xanthopleurus and C. pericallus are similar to those of C. pallipes, but inferior to in elaborateness. Cells of C. inops and C. sericimicans are very roughly made. (5) Eggs are generally white, oblong and smooth. They are characterized in their striking softness, so that it could be thought that the protection of the mud cell had vital importance for them. Egg periods are shown in table 1. (6) The larvae of all the 5 species moult thrice and, with the exception of the case of C. circumdatus xanthopleurus, more or less change their coloration with stages. (7) Food of larvae is restricted to small living insects or fresh meat. (8) The full-grown 3rd stage larvae enter the soil, making a round cell for pupation. Duration of larval and prepupal stages is given in table 2. (9) Pupa is generally white and smooth, emits a bad smell. Duration of pupal stage is given in table 3. (10) C. pallipes takes about a month from oviposition to emergence of adult. (Tab. 4).