ゴキブリの卵鞘形成に対する紫外線の阻害効果 (I)

抄録

The effects of ultraviolet rays on the oothecal formation were studied on the two species, Peri-planeta americana and P. australasiae. The females at different stages of the oothecal formation were exposed under UV rays mostly composed of 253.7nm in W.L., using a germicidal lamp (100μW・(cm)^<-2>・(sec)^<-1>) for 10min. Irradiation was performed on the whole body or head or thoracoabdominal segments. The resorbation of the genital pouches or deposition of abnormal oothecae of various types were observed frequently by the UV irradiation as shown in Fig. 2. In the first group of females irradiated on the whole body, those that received the irradiation at the early stage in the oothecal formation (the 1st stage as shown in Fig. 1) deposited abnormal oothecae at the high rate as shown in Table 1,suggesting that the most sensitive stage to UV rays was the Ist stage in the oothecal formation. In the second group of females irradiated on the head, abnormal oothecae were also formed at the high rate. However, the third group irradiated on the thoracoabdominal segments proved to deposit normal oothecae as shown in Table 2. These results demonstrate that the receptive site for UV ray stimuli is on the head. This inhibitory effect of UV rays was also observed in four other domestic species, P. fuliginosa, P. japonica, P. brunnea and Blatella germanica. However, in two semi-domestic species, Parcoblatta kyotensis and Nauphoeta cinerea, the inhibitory effect was not observed when irradiated with the same dose of UV rays as shown in Table 3. A possible mechanism of the inhibitory effect of UV rays on the oothecal formation was discussed, including dysfunction of the neuroendocrine systems.