The relation between the seasonal and daily abundance of flies (such as horse fly, stable fly and so on) attacking the grazing cattle and the number of times for swishing the flies with the tail, the number of times for sweeping the flies by the legs was investigated. The number of attacking flies was the most abundant at day-light in the summer, no flies at night and winter. There was a positive correlation between fly abundance and frequency of swishing flies with the tail, that of driving away flies with legs.

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Many techniques of numerical classification, as a method of multivariate analysis, have recently been developed. If different techniques are used for analysis, different classifications will be obtained; if different variates or different samples are used for classification, different results will be obtained. These results are also different from the classification by systematics. Hence a similarity measure for comparing classifications is required. A measure using BRILLOUIN'S (1962) information theory is proposed in this report for this purpose. This measure is modified slightly from a diversity measure which has been used by community ecologists such as MARGALEF (1958) and PIELOU (1974). The properties of this method are shown by numerical illustrations, and are compared with other methods such as those developed by RAND (1971) and BORKO et al. (1968).

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The relation between oviposition by a syrphid, Episyrphus balteatus, and the density of the green peach aphid, Myzus persicae, on cabbage plants was studied in a field cage. The number of eggs laid by Episyrphus was significantly larger on the plant infested with a large number of aphids. Further, the female flies laid more eggs on leaves infested with a high density of aphids within the plant. The degree of overlapping between aphids and syrphid eggs, however, was by no means complete and the mean number of syrphid eggs per aphid tended to decrease with increasing aphid density.

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The male pupae at the various stages were treated for 24, 48 and 72 hours with high temperature (38°C). The marked effects were observed in the apyrene spermatozoa, while the eupyrene spermatozoa were slightly affected. In the groups treated for 48 hours within 48 hours and for 72 hours within 120 hours after pupation, a large number of apyrene sperm bundles of abnormal shape appeared in the testicular follicle. Markedly shrunken apyrene spermatozoa appeared in the seminal vesicle of the males by the treatment for 24 hours at 144 hours after pupation and for 48 hours at 48 hours and at 144 hours. The treatment for 72 hours caused the same abnormal apyrene spermatozoa in all the groups. When such abnormal males, in which the markedly shrunken spermatozoa were observed, mated with normal females, the females of which a part of eupyrene sperm bundles were not separated in the copulatory pouch and no spermatozoa were found in the seminal receptacle were often obtained. When the observation mentioned above and the percentage of unfertilized eggs studied in the previous paper were considered together, it was suggested that abnormality of apyrene spermatozoa in the seminal vesicle was closely related to male sterility.

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A sugarcane borer, Tetramorea schistaceana SNELLEN, was reared aseptically on artificial diets containing powder of dried sugarcane leaves and stalks as a leaf factor. Successive rearing could be done for at least three generations on a diet consisting of 1g agar, 0.7g glucose, 0.5g sucrose, 1g casein, 1g dried yeast, 0.2g choline chloride, 0.2g WESSON'S salts mixture, 0.02g cholesterol, 5g ‘leaf-factor’ and 30ml distilled water. Addition of L-ascorbic acid did not result in any significant change in rates of adult eclosion.

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Agrotis fucosa larvae were placed on sawdust of the Japanese cedar spread in plastic boxes, and were fed on an artificial diet consisting mainly of the diet for the pregnant rabbit, kidney beans and water. The population density of the larvae at the sixth instar had to be limited because interferences among individuals reduced the rate of emergence. The laboratory culture was maintained continuously for more than 10 generations.

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The process of silk secretion by T. urticae was observed under one or two hundredfold magnification. The webbing of each active stage (except quiescent stages) and adult of T. urticae was examined under constant temperature with three different relative humidity conditions. The webbing produced by the ovipositing female was also examined at 2 day intervals for 16 days under constant temperature and humidity conditions. Furthermore, the webbing of the newly emerged female was investigated under six different temperatures and five different humidities. These experiments were conducted on red clover leaves by use of the methods mentioned in a previous paper (SAITÔ, 1977). The observations showed that the mite secretes threads through the palpus in the process of walking. It was indicated that all stages of the mite were producing silk and the amount of webbing increased from stage to stage. The distribution of the silk threads per square suggested the adult male had a characteristic pattern of webbing. The number of eggs deposited by the female, the amount of webbing and the number of fecal pellets in 16 days showed parallel relationships. The results under various physical conditions demonstrated that the amount of webbing increased with temperature rise, but the pattern of increase did not appear to have a linear trend. The webbing was affected by changes of relative humidity. The amount of webbing showed a peak at 33% RH, and decreased gradually at lower or higher humidities.

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The feeding activity of the silkworm was seriously inhibited when mulberry leaves dipped in 10ppm chlordimeform hydrochloride solution were offered, and when the larvae were topically applied or injected with 100ppm chlordimeform hydrochloride solution. Regarding the feeding behavior, the larvae kept away from mulberry leaves and walked toward the margin of the Petri dish moving their mouthparts in all treatments, and they ceased to eat mulberry leaves. The silkworm larvae were fumigated with 10, 000ppm chlordimeform hydrochloride solution in a plastic cup for 2hr at 25°C, and thereafter the amount of fresh mulberry leaves consumed was measured. Inhibition of feeding was also observed. These results suggest that the antifeeding effects of chlordimeform on the silkworm larvae may not be caused by gustatory and olfactory sensation. The feeding behavior or food selection may be considered as the factors involved in this inhibitory mechanism.

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Selection pressure designed to produce 50% mortality was applied to alternate generations of T. kanzawai, using dicofol and phenthoate on adults and chlordimeform on eggs. The development of resistance was relatively slow in the initial period in chlordimeform-selected and phenthoate-selected strains, and very rapidly intensified resistance and increasing slope were clearly observed with each succeeding generation. On the other hand, the development of resistance in the dicofol-selected strain was almost unchanged through ten generations, and the resistance developed slowly with succeeding generations. Therefore, the number of treatments required to develop resistance in these strains varied with the acaricides used. Adults of resistant strains were crossed with susceptible reference strains, and the F₁ and backcross were tested for resistance. There was little difference between the composition of the F₁ reciprocal crosses or between the backcrosses derived from them, and they partitioned into a 1:1 ratio of resistant and susceptible phenotypes in the backcross. The resistances of these acaricides were considered to be due to a single, incompletely dominant autosomal gene in the case of chlordimeform and phenthoate, and to an incompletely recessive autosomal gene in the case of dicofol.

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