On the assumption that the pulsation of the dorsal vessel was a movement of elastic body, the cardiograms were recorded by means of FRANK'S method. The transmission velocity of pulsation along the dorsal vessel was measured. The contracting and expanding movement of vessel did not occur irregularly at various parts in the dorsal vessel. During the duration of the normal pulsation, the contracting movement began at the posterior segment and moved successively toward the anterior segments of the dorsal vessel. Following the contracting movement, the expanding one occurred in the same order. The duration of the expanding movement was longer than that of the contracting one in the heart, and vice versa in the aorta. The transmission velocity of pulsation along the dorsal vessel was 1.2-7.6cm per sec in average, and higher in larvae as compared with in pupae and adults. The velocity during the duration of the normal pulsation was higher than that during the reverse one. The pulse-frequency was correlated with the duration of a pause of expanding movement. The rest phase was obscured with the rapid pulse-frequency.

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The synthetic sex pheromone of the almond moth, C. cautella, cis-9, trans-12-teradecadien-1-ol acetate (c-9, t-12-TDDA), was permeated from 20 pheromone holders into a clear plastic box (36×36×36cm). The mating behaviors of 2 female and 2 male moths confined in the box were observed for 84hrs immediately after their emergence. When a sufficient quantity of c-9, t-12-TDDA (350μg each of 20 holders) was released the males could not orient toward the females which were, neverthless, in calling pose during each dark period. On the contrary, all females mated in the untreated boxes within the first 2 nights. When the dose of the pheromone in a holder was decreased to 35, 3.5, 3.5×10^-2 and 3.5×10^-4μg, the mating frequency and the number of eggs laid were increased to the numbers almost comparable to that of the untreated box. Therefore, it was concluded that c-9, t-12-TDDA can disrupt the sex pheromone communication in C. cautella. cis-9-Tetradecen-1-ol acetate (c-9-TDA), an analogue of the sex pheromone, was also permeated into the plastic box and the mating behaviors of 2 pairs of C. cautella were observed similarly as in the case of c-9, t-12-TDDA. The disruption of communication between both sexes was obtained, when the same amount of c-9-TDA (350μg each of 20 holders) was applied. The sex pheromone showed its sex stimulatory activity at the amount of 10^-2μg, whereas the c-9-TDA required 10⁴ times as much as this dosage. It is very interesting that c-9-TDA disrupts the sex pheromone communication with the same dosage as c-9, t-12-TDDA, although the former elicits their excitation with much larger dosage than the latter does.

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Suppression of the melon fly, Dacus cucurbitae, was conducted in Kume Is., ca. 6000 ha in area, as a part of the eradication programme. Before the suppression the maximum density was approximately 1000 males per 1000-trap-days in November 1972. The aerial distribution of cane fiber board squares, 60×60×9mm, containing 24g of cue-lure (97%) and naled (3%) solution was made in the island from December 1972 to June 1973 and from January to March 1974. The squares were dropped at the rate of about two or three per 100m² per month, but no remarkable decline of the density was observed. After June 1974, the following methods were used: 1. From June 1974 to January 1975 protein-hydrolysate solution mixed with malathion was applied from the ground in a bush area of ca. 440 sa where the feral host plants were abundant. A total of 16 applications were made at approximately two-week intervals. 2. From October to December 1974 cotton strings, 5mm in diameter and 50-mm long, containing 2g of cue-lure (97%) and naled (3%) solution were dropped throughout the island at a rate of 40 per 100m² per month. Then, the number of flies caught in the monitor traps became less than 20 per 1000-trap-days during the application.

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A technique was developed for rearing and continuously observing the adults and immature stages of the minute pine bark beetle. A sheet of bark of the Japanese red pine, Pinus densiflora SIEB. et ZUCC., was placed between two transparent plastic plates which were then sealed with glue around the edges. A pair of parental beetles was introduced through a small entrance hole in the upper plate. Several sets of plates were wrapped in a black vinyl sack when not under observation. The method proved to be very suitable fbr observing various activities of the adults and their developing broods through the lower plate under a binocular microscope. Female beetles could not usually construct normal egg galleries without feeding during their callow adult stages in the pupal chambers. They laid about twenty eggs cyclically at intervals of several days and the number of eggs dcposited correlated significantly with the length of egg galleries and longevity. Hatched larvae began mostly to mine from the ends of the egg gallery. Larvae pass through two instars.
When the density excceded the optimum level in the initial attack, some of the parental beetles escaped from the host. Female beetles could re-attack and establish a second brood when the fresh logs were supplied at low density of entrance holes. They constructed longer egg galleries and on average laid more eggs than in the first attack. These observations provide further infbrmation on the mcchanisms of both increase and regulation of population size.

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A prevalent disease was observed among the larval populations of the cupreous chafer at Shizuoka and Nara Prefs. and an entomopoxvirus (EPV) was found as the causative agent. The EPV multiplies in the fatbody and hemocyte, and two types of inclusions, spheroid and spindle-like inclusions, were formed in the cytoplasm. The spheroid inclusions, 5×8μ in size, contains numerous virions and have a crystalline lattice structure of 116Å in distance. The spindle-like inclusion, mostly octahedral with obtuse edges, has also a crystalline structure of 50∼57Å in distance, but devoid of virus particles. The spherical immature virus particles gradually differentiated and occluded within paracrystalline inclusions, which develop to spheroids. The virus particles are 4400Å in length and 2500Å in width with mulberry surface. The core is bound by a core shell which is about 200Å thick consisting of electronlucent outer and inner layers, and is concave on one side and convex on the other. It contains a rope-like structure about 350Å in diameter.

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Diel activity rhythms of the oriental fruit fly, Dacus dorsalis HENDEL, were studied by exposing insects to various conditions of light and temperature. The peak of ovipositing activity occurred between 12:00 and 14:00 (Japanese standard time) under the natural conditions, but any diel rhythmicity of hatching was not observed under either the natural conditions or in darkness at 25°C. The larval jumping behavior and the adult emergence showed no diel rhythmicity in constant light or darkness at 25°C. When exposed to naturally fluctuating temperatures either in the natural light conditions or in darkness, the greatest number of larvae jumped out from the culture at around sunrise, although the peak appeared a little later in the latter conditions. Under the same conditions of temperature in continuous light, many larvae jumped out in the night but the diel rhythm was not conspicuous. Adults emerged at about 10:00 when the insects had been subjected to the natural environment in November. The timing of the adult emergence seemed to be determined by the diel rhythm of environmental conditions during the larval stage, but it might be modified during the pupal stage. There was no fixed phase relationship between the jumping activity of larvae and the emergence of adult.

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The preference of two aphidiid parasites, Diaeretiella rapae (=Dr) and Aphidius gifuensis (=Ag), for Myzus persicae, a common host on cruciferous plants, was comparatively studied in the laboratory. One female parasite was released in a cage with a radish leaf on which ten 1st- or 2nd-instar (=S), ten 3rd-instar (=M) and ten 4th-instar nymphs (=L) of the aphid were placed simultaneously, and their behavior was observed for 30 minutes. The results obtained with 5 females for either parasite were as follows: (1) Ag was superior to Dr in the relative frequencies of host-findings, oviposition attempts, and actual oviposition (=number of eggs deposited). Ag oviposited 5 times more than Dr did in total. (2) Dr showed higher efficiency of oviposition on S and M hosts than on L, whereas Ag was more efficient on M than on S and L. (3) The aphid responded to the paratite attacks by kicking, walking-out, or secreting honeydew; the frequency of host response was higher to Dr than to Ag and increased in proportion to the body sizes of the aphids, S, M and L. In comparison with Dr, Ag was apparently active and extensive in searching for the host. Differences between these parasites were also noticed in body size and antennal characters. The differential ovipositional efficiencies can be explained from their behavior and morphology.

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In order to search for biologically active compounds to induce the appearance of three-moulters in the silkworm, Bombyx mori L., each of abietic acid and its 37 derivatives and 16 hydrofluorene compounds was added to artificial diet at a dose of 200ppm and continuously fed to the larvae of F₁-hybrid of four-moulters just after third moulting.
Three abietic acid derivatives and 11 hydrofluorene compounds were found to produce three-moulters in the insects. Further, some structure-activity relationships were recognized in these compounds. Of the 14 compounds, compound A-11 (methyl 6, 7-dioxo-5α, 10α-podocarpa-8, 11, 13-trien-15-oate) was the most active and revealed the biological effect even at a dose of 50ppm.

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The experiments were carried out in order to find the effects of photoperiod on development of the pine caterpillar. The larvae were collected from different places and reared mainly in incubators at 25°C under different artificial photoperiods. The results were as follows: 1) The larvae entered diapause under short-days but not under long-days. 2) The critical day-length was 15.0-15.5 hours for the Muramatsu (Ibaraki Pref. ca. 36°25′N) stocks, and 14.5-15.0 hours for the Yamakawa (Kagoshima Pref. ca. 31°15′N) ones. 3) The larvae of the diapause type needed more than 64 days to grow to the end of the 5th instar, and most of them were still in the 6th-9th instars in about 100-150 days after hatching. On the other hand, the non-diapause larvae generally completed their development at the 6th instar in 49.9-72.5 days. 4) The non-diapause larvae were clearly distinguished from the diapause ones in size and colour at the 5th or 6th instar.

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For analyzing the host specificity of 4 species of Polygonaceae-feeding beetles, the feeding stimulation was investigated of 14 oganic acids including oxalic, malic, tartaric and citric acids, of which the latter four are generally the characteristic taste-substances of the polygonaceous plants. To the strawberry leaf beetle, Gallerucella vittaticollis (BALY) which feeds on strawberry leaves besides polygonaceous plants, only succinic acid was stimulative in the presence of sucrose, but none of other 13 acids tested was stimulative, although, malic and citric acids had been identified in strawberry leaves, and citric acid in Rumex obtusifolius leaves. The feeding of Gastrophysa atrocyana MOTSCHULSKY was stimulated by oxalic, malic, tartaric, and citric acids in combination with sucrose, but not without sucrose. Further, 8 saturated dicarboxylic acids from malonic to sebacic acid, and maleic and fumaric acids were also stimulative in the presence of sucrose. Gallerucida bifasciata MOTSHULSKY was stimulated to feed by oxalic, malic, tartaric, and citric acids with or even without sucrose. Four saturated dicarboxylic acids from malonic to adipic acid, and maleic and fumaric acids were also effective with sucrose. Although the tests were limited to 4 acids; oxalic, malic, tartaric, and citric acids, the feeding of Gallerucida nigromaculata BALY was stimulated by all these acids with or without sucrose. From these results, G. atrocyana, G. bifasciata and G. nigromaculata are presumed to require these organic acids as feeding stimulants in their host selection, but G. vittaticollis does not.

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Apanteles glomeratus and a cabbage butterfly granulosis virus, imported from Japanese mainland, were released aiming at the management of population of Pieris rapae crucivora, an introduced insect pest in Okinawa. Both natural enemies could establish easily and continued to propagate even in winter. The apparent mortality due to each natural enemy often exceeded 50 percent. The effect of Apanteles glomeratus on emergence of the butterfly adults was not so remarkable, but that of the granulosis virus was clear. Since the establishment of the virus, the number of 5th-instar larvae was remarkably small as compared with the number of eggs laid and only a small fraction of larvae could reach the adult stage. As the natural enemies were released in the small area the number of eggs laid did not decrease due to immigration of the adults into the area.

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[in Japanese]

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