A species of tarsonemid mites has been found to be widely breeding in stored food products (dried red pepper, dried fish, mushrooms, etc.) and in various drug samples (lactose, albumini tannas, gentiana pulverata, etc.). Its male and female were described and figured, Taxonomic accounts for the previously described four species of the genus Tarsonemus from Japan were given in detail. The present authors came to the conclusion that because of the incomplete and inadequate descriptions by the original authors, it was difficult to identify the present species to any of the four Japanese ones. By reviewing foreign papers dealing with the group of mites, we attained to a decision that the present species shared many of the important morphological characters in common with Tarsonemus floricolis CANESTRINI et FANZAGO, 1876 as was redescribed by EWING (1939), and should tentatively be identified so.
Though parathion has become widely used in controlling rice stem borer, Chilo suppressalis WALKER, which is one of the most important pests of rice plant, the improvements of the applicator and the method of application still remain to be studied. UEJIMA et al (1954), YAMASHINA (1954) and FUKUDA (1955) have studied on the adhesion, systemic action and residuality of parathion on rice plant and proposed the necessity of the improvement of the applicator and the method of application. The authors have studied the effects of the physical properties and the method of application of parathion to control the rice stem borer. The results are summarized as follows: 1. Insecticides used: a. Parathion 47 percent emulsifiable concentrate diluted to 0.002-0.06 percent. b. Triton X-100 added to above as a wetting agent. c. Diazinon 60 and 20 percent emulsifiable concentrates diluted to the same concentrations as parathion. 2. Quantity of spray liquid applied: 5cc, 10cc, 20cc and 40cc. 3. Methods of aplication. a. Sprayed only on the leaf surfaces of rice plant. b. Sprayed only on the leaf sheaths of the rice plant where larvae are bored in. 4. Results: The effect of controlling the first brood rice stem borer was small in case of spraying a large amount of liquid on the leaf sheaths of the plant when the wetting power of the spray liquid is strengthened because a large part of the spray liquid runs off the plant. The effect of controlling the second brood rice stem borer, however, was greater in case of spraying on leaf surfaces because the spray liquid runs down into the leaf sheaths where larvae are bored in. But the effect of changing the physical properties of the spray liquid was not definite when a small amount of liquid was applied and this means that there was no definite difference of the killing effect observed between parathion and diazinon. In consequence, the effect of controlling rice stem borer differed greatly when the wetting power of the spray liquid of parathion to the rice plant is strengthened by changing its physical properties owing to the changes of adhesion and the running off of the spray liquid. The effect of the control also seems to be affected by the method of application and the growth of the rice plant. Therefore, not only the systemic aetion of parathion but also its running into the leaf sheaths seems to play an important role in the control of the rice stem borer.
Published data are collected here on the developmental zero point of various species of insects, which was obtained from the relation between temperature and the duration of development applying it to the theory of total effective temperature. Many collected values are listed in Table 1, where insects are listed in alphabetical order. Frequency distribution of the developmental zero point is like a normal curve (Fig. 1), the mean of which falls at about 11°C. Maximum temperature obtained was 19.5°C and minimum one was -1.1°C. The zero points in the species of Lepidoptera or Hemiptera are somewhat lower than those of Hymenoptera or Diptera (Fig. 2 and Table 2). Even in the same species, the different value of it is shown by the differences of ecological race, sex, developmental stage and environmental condition. Comparative magnitude of the developmental zero in each successive developmental stage is not constant and takes various combinations as shown in Table 3. This is also true in each instar of the larval stage. Interesting ecological implications are shown in the comparison between the developmental zero points in both species of prey and predator or host and parasite (Table 4) and in the comparison of it among closely allied species.