To investigate the biosynthesis of the red fluorescent protein which is considered to possibly play some protective role against polyhedroses, comparative experiments with the larvae, reared on mulberry leaves and artificial diets, were conducted by four methods:
a) column-chromatography, b) DISC-electrophoresis, c) incorporation of the C¹⁴-Leucine, d) immunological method. In larvae fed on mulberry leaves the red fluorescent protein was formed in the anterior part of the mid-gut and secreted from there into the digestive juice. In larvae fed on artificial diet this protein was found too, but the red fluorescence of this protein was not observed as expected. The red fluorescence strength of the protein from the latter, estimated at 625mμ by a fluorometer, appeared with the addition of fresh chloroplast fraction of spinach to the diet. This protein seemed to be a conjugated protein bearing certain bile pigments similar to the non-proteinous part attributed to mulberry leaves in the diet. From these results, it is highly probable that this protein is biosynthesized de novo in the mid-gut tissue of the silkworm and not from certain precursors contained in the mulberry leaves of the diet.

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Mulberry sucker, Anomoneura mori SCHWARZ (Hemiptera-Homoptera: Psyllidae), is one of the serious pests of the mulberry tree, distributed throughout Japan. This insect has only one generation per year, and overwintering takes place in the adult-stage. The resurgent adults assemble on the young tender shoots of the mulberry tree as early as the latter part of May in Hokkaido, and the female deposits its eggs on the under surface of young leaf blades. The incubation-period is about 18 days. The nymph takes about 22 days for its growth. During its growth the nymph has invariably four moults making five instars. By advancing instars antennal segments increase their numbers, viz. I: 3, II: 3, III: 4, IV: 8, and V: 10. One of the remarkable habits of this nymph is the secretion of a white thread-like waxy substance. When the eggs and the young nymph suckers are supplied with mulberry leaves by an oversight, the silkworms do not dislike to eat them. In such cases, however, delay of pupation and decreases of weight and size of the cocoon as well as the reduction of resistance against diseases are recognizable. The moths from such silkworms have a tendency to show shortened longevity. These phenomena may not be due to harmful food disagreement by feeding on eggs or nymphs of sucker, but may be attributed to the indirect influence of the disability of alimentation as a result of eating the wrong food.

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From 1954 to 1957 at five localities in Tokushima prefecture, Shikoku, ethyl-parathion emulsion, as a 0.02% solution, was sprayed once for the first generation larvae and as 0.04% solution once or twice for the second generation larvae of the rice stem borer, Chilo supressalis WALKER, and yields and the percentage of injured stem of the rice plant were recorded. When comparisons were made between sprayed and unsprayed plots at each locality, in 8 test examples the yield was apparently higher in the sprayed plot than in the unsprayed plot, and in 5 other examples there were no substantial differences in the yield between sprayed and unsprayed plots. From the results obtained, it was estimated that the insecticidal application brings on an economic effect when the percentage of injured stem in unsprayed plot is above 2% at the end of the period of injury of the first generation, and above 3% at the same period of the second generation. Also, the percentage of injured stem at above or below 2% at the end of the first generation might be expected when it is above or below 6.0±3.2% (2 Sx) at just before the application time for the first generation. In the same way, that at above or below 3% at the end of the second generation might be able to presume when it is adove or below 2.3±1.3 (2 Sx) at the end of the first generation.

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The structural precursor of the stylet sheath is a proteinaceous substance secreted from the A-follicle of the principal salivary gland of Nilaparvata lugens STÅL and Laodelphax striatellus FALLÉN, and from the IV-cells of the principal salivary gland of Nephotettix cincticeps UHLER and Inazuma dorsalis MOTSCHULSKY. This substance was also found to be impregnated with a lipoid substance, which is secreted from the G- and H-follicles and the V-cells to prevent the proteinaceous substance adhering onto the stylets during coagulation. It is considered that a quinone-tanning reaction is involved in the stylet sheath formation: In N. lugens and L. striatellus, the proteinaceous substance from the A-follicle is solidified by quinones elaborated in the E-follicle where a polyphenol oxidase occurres; while in N. cincticeps and I. dorsalis, the polyphenol compounds secreted with the proteinaceous substance from the IV-cells become oxidized to quinones by the action of polyphenol oxidase discharged from the V-cells, and the resultant quinones react with the proteinaceous substance. These structural precursor and quinone-tanning reagents are thought to be secreted separately so as to avoid the gelling of the proteinaceous substance within the ducts and the salivary cannal. It is doubtful that disulphide bonds are concerned in the coagulation of the sheath material, because no histochemical evidence indicated the occurrence of SH-rich proteins in the salivary glands of the rice plant leafhoppers. It is likely that the stylet sheath serves to bundle the stylets protruded beyond the rostrum, and anchors the mandibular stylets to facilitate the penetration of the maxillary stylets into the plant tissues.

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Field studies on the seasonal prevalence and changes in the number and size of the egg masses laid by Prodenia litura FABRICIUS were conducted in Kanoya, Kagoshima Prefecture in 1968. The egg mass number laid on three field crops such as taro, sweet potato and peanut was recorded at weekly intervals from June to October. All egg masses found during the studies were collected and kept singly in glass vials in order to count the number of hatched larvae instead of the number of eggs. Judging from the fluctuation of the egg mass number laid on taro, a total of four generations was distinguished from July to October, during which the highest number of egg masses was found in September. Among these crops, the number of egg masses laid on taro was more abundant than those on sweet potato or peanut. The size and the variation of egg masses laid on taro in July were apparently smaller than those of later months and the mean egg mass size of each month were 269, 520, 653 and 453 for July, August, September and October, respectively. No significant differences were found in the mean egg mass size laid on the different crops studied. The frequency distribution of the size of egg mass fitted well with the log-normal distribution. No egg parasite emerged from the collected egg masses.

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Accumulation and distribution of uric acid in the silkworm, Bombyx mori, were studied in relation to histolysis and histogenesis during the pupal period. Injected 2-¹⁴C-uric acid was not metabolized any further, from which it is concluded that uric acid is really the end-product of nitrogen metabolism in silkworm pupae. Uric acid is distributed mainly in the fat body during the early half of the pupal period, but in the mid-pupal stage it is largely transferred to the rectal sac. After eclosion it is excreted with the meconium. In the male, uric acid increases rapidly in the mid-pupal stage and again shortly before emergence, whereas in the female it is maintained at a constant level until the late pupal stage, when a rapid increase occurs. The two sexes also differ in the changes of total protein content: in the male protein begins to decrease from the mid-pupal stage, while in the female it changes only a little until shortly before emergence and then decreases rapidly. The sum of the nitrogen lost from protein and free amino acids during the pupal period accounts for the nitrogen gained in uric acid. These results indicate that the lost protein is catabolized to uric acid via the amino acid pool.

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The present report deals with the effects of certain base analogues on larval growth, viability and induction of somatic mutations in the silkworm. The effects of 5-bromodeoxyuridine (BUdR) were tested in addition to those of 5-bromouracil (BU) and 2-aminopurine (AP). A series of experiments were carried out with strains of heterozygous for either genes +^od and od or genes p^s and p by feeding the larvae on BUdR (0.028-0.161μM/individual), BU (0.27-2.21μM/individual) or AP (0.31-2.73μM/individual) during the first instar. In order to examine mutation frequencies, the number of white spots (phenotypically p) induced in certain of the integuments of the fifth instar larvae was counted.
The treatment with BUdR was followed by severe inhibition of growth and finally death, while AP had little effect on growth and survival. BU was not so toxic as BUdR. The number of aberrant spots per integument was larger in the larvae treated with BUdR than those treated with BU. The aberrant spots occurred very rarely in both AP treated and control animals.
The mean size of the spots induced by the base analogues was about half or a quarter as large as those induced by γ-irradiation. But there was no morphologically appreciable difference between the aberrant spots induced by base analogues and those induced by γ-ray.
The enhancement effect of aminopterine on aberrant spot production was observed in the treatment with BU, whereas no such effects were observed in the case of BUdR. There was a sex difference in the frequencies of induction of aberrant spots when the characters of such spots were sex-linked ones. Although the mechanism of such spots is not clear, mutation must have occurred in some of the epidermal cells during their development as a result of the replacement of the normal base in DNA with BU or BUdR.

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Comparative investigations were carried out on the chloride content in the hemolymph, saliva, and whole bodies of Haemaphysalis longicornis and Boophilus microplus of Ixodidae and the whole hemolymph, saliva, coxal fluid, urine, and whole bodies of Argas japonicus and Ornithodoros moubata of Argasidae.
The chloride concentrations in the hemolymph of these four ticks were at relatively constant levels, which were about 1.5 times as high as that of the host blood during the feeding process in ixodids and also argasids in spite of different conditions of stage, sex, and feeding state. The chloride concentrations in the saliva of the ticks were nearly equal to, or higher than, those of the hemolymph and the values of the coxal fluid were in a range similar to those of the hemolymph.
In the chloride balance of ticks, the Malpighian tubules play a secondary role, as compared with insects. Elimination of surplus chloride from the body for osmo-regulation of the hemolymph during the process of condensation of blood components was attributable to the salivary secretion in ixodids and the coxal fluid secretion in argasids. It was presumed that the difference between both families in the manner of chloride balance in the feeding process might be connected to the great difference in their feeding habits; that is, generally ixodid ticks are slow feeders and argasid ticks quick feeders.

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