ツノロウアカヤドリコバチ

1. In this paper, studies on the oviposition habit and reproductive capacity of Anicetus ceroplastis Ishii in the insectary were reported. The parasite used in the experiments were reared from the scales collected in the field. Host scales, Ceroplastes pseudoceriferus Green, used were reared artificially by mass culture on the food plant, Erigeron canadensis L. 2. The adult parasites were able to start oviposition one or two days after emergence. If there are no hosts to lay eggs for a considerable period, ripened eggs in the ovaries would be absorbed. 3. The following six steps were observed in the oviposition behaviour of the parasites. 1) Primarily attracted by the host. 2) Contacting the host lightly with antennae. 3) Mounting on the host body and tapping the host with antennae. 4) Drilling through the host derm with the ovipositor. 5) Probing the inside of the host body with the tip of the ovipositor. 6) Deposition of eggs. 4. The host larvae are seemed to become attractive to the parasites when they become at least seven days old. Number of eggs laid in one individual of the host varied from 1 to 10, usually being about 1 on the first brood and about 3 in the second brood. Density of the parasites per host, host size and temperature in the insectary have a close connection to the number of eggs deposited. Hyperparasitism occurs commonly and limits the effectiveness of the parasite. 5. The reproductive capacity varied greatly according to the broods. In the first brood, eggs deposited by an unmated female parasite varied from 1 to 14 and of a mated one from 1 to 7. In the second brood, eggs deposited by an unmated one varied from 2 to 25 and of a mated one from 2 to 33. 6. It is interesting to note that the seasonal change of the reproductive capacity of this parasite in the insectary was similar to that of the oviposition activity in the field.