Ascogaster reticulatus WATANABE is an egg-larval parasitoid of the smaller tea tortrix moth, Adoxophyes sp. Diel patterns of adult emergence and mating in this parasitoid were observed in the laboratory, and the effect of adult age on the mating was also analyzed. Most of the adult parasitoids emerged within a few hours after light-on, and the emergence peak of the male was earlier than that of the female by one day. High mating activity of these parasitoids was observed in the latter half of a light period when the walking activity of both sexes was also high. Premating period of males was longer than females. The combination of 3-day-old males and 1- to 2-day-old females was most appropriate for mating. High mating rate was obtained from the density of up to 5 pairs in a container (ca. 2 l). In addition to the conditions for mating, mating behavior is briefly described.

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Ascogaster reticulatus WATANABE (Braconidae) is an egg-larval parasitoid of certain tortricids, e.g., Adoxophyes sp. (Ad) and Adoxophyes orana fasciata WALSINGHAM (Ao). In this study, the host preference by A. reticulatus was tested among two habitual hosts, Ad and Ao, and three unusual host species, Pandemis heparana DENIS et SCHIFFERMULLER (Ph), Homonamagnanima DIAKONOFF (Hm), and Hoshinoa longicellana WALSINGHAM (Hl). The tow-choice tests showed that the order of oviposition preference among the five tortricids was Ad=Ao>Hm>Hl>Ph. Female parasitoids deposited eggs in all of the tortricid egg masses. Among parasitized egg masses of the unusual host species (Ph, Hm and Hl) artificially reared, parasitoid larvae egressed only from Ph larvae, made cocoons and then emerged. Parasitoid eggs hatched in Hm and Hl eggs and became 1st-instar larvae, then grew after the host eggs hatched. However, the parasitoid 1st-instar larvae were encapsulated by the hemocytes of these host larvae of later instars. The Hm egg mass coated with the Ad egg mass extract containing the kairomone increased oviposition time and percent parasitism by A. reticulatus. To the noctuid moth, Leucania separata (WALKER) (Ls), the parasitoid showed no response to the egg mass, but coating of the kairomone on the egg mass stimulated oviposition. The parasitoid eggs hatched in Ls eggs, but the 1st-instar larvae were soon encapsulated with melanin on their surface.

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The presence of a pheromone-like substance regulating the ovipositional behavior in the cigarette beetle, Lasioderma serricorne (F.) was shown. When small tobacco-disc-composites were arranged at 36 sites in a petri dish (12 cm diam), a gravid female laid her eggs one by one on each disc-composite uniformly. In the two-choice test using a previously female-conditioned disc and an unconditioned fresh disc, the number of eggs on the conditioned disc was significantly small, whereas the number on a male-conditioned disc or an unconditioned disc was relatively large. Some of the fractions chromatographically obtained from the body extract of cigarette beetles were shown to have a strongly inhibiting activity for ovipositional response. It was confirmed that beetles recognize certain-oviposition inhibiting chemicals with their antennae.

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The relationship between the responses of female grape borer Xylotrechus pyrrhoderus and the blend ratios of two synthetic male sex pheromone components, (2S, 3S)-octanediol (S, S-diol) and (2S)-hydroxy-3-octanone (S-ketol), and their synthetic stereoisomers was examined in a wing tunnel. Females were much more attracted by certain mixtures of S, S-diol and S-ketol than by the individual components alone, and sometimes exhibited a hovering style of flying typical of the female to the pheromone-releasing male. The optimum blend ratio of the two components was approximately 80 : 20 of S, S-diol and S-ketol. Females responded similarly to mixtures of R, R-diol or S, R-diol and S-ketol (80 : 20 ratio), but weakly to the mixture of R, S-diol and S-ketol. Furthermore, the mixture of S, S-diol and R-ketol did not elicit notable behavioral response in females; instead, R-ketol acted as an inhibitor.

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Longevity, daily oviposition and lifetime fecundity of adult females of Pieris melete were measured in the laboratory under a temperature condition of 25°C and a photoperiodic condition of 16L-8D. Variations in longevity, lifetime fecundity, age of first oviposition and age of maximum oviposition were considerably high among females, however, the female size did not explain the variation of these reproductive parameters. The mean longevity was 13 days and the mean lifetime fecundity was 199 eggs. Most of the females (64%) began to lay eggs at the age of 2-days but others began at earlier or later ages. The number of eggs laid was usually largest at the age of 3-days (59% of females), and then decreased with age.

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Ovipostion behavior of E. zinckenella on a soybean plant was observed in both field and laboratory cages. Gravid females tended to oviposit several separate eggs on a plant at each arrival. They exhibited behavioral sequences composed of several kinds of events after alighting on the host plant. The most common sequence was as follows : A female that alighted on a host plant bent her abdomen downward immediately after touching its surface with her antennae, and began to walk foward while dragging her ovipositor tip and tapping the surface alternately with her antennae. Detecting the oviposition site, she stopped walking, raised the anterior portion of her body, and deposited an egg. After raising her body, however, the occasionally searched the surface intensively with the ovipositor tip alone. The insect often repeated this sequence several times, laying an egg each time. Additionally, ordinary walking and pausing were sometimes included in the sequence. She stayed on the host ovipositing in this way for about 4 min on an average and then flew away. In general, such an oviposition bout was repeated in the early part of the dark period accompanied by flying and resting respectively, before and after it. Most females remained quiescent in the middle or latter part of the dark period.

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Total mortality during the nymphal stage of Palomena augulosa MOTSCHULSKY was 54% in both the group fed alfalfa till the 7th day of 2nd instar and thereafter fruits of kidney bean (AB-7) and the group fed sucrose till the 7th day of 2nd instar and thereattar fruits of kidney bean (SB-7), not significantly different from that in the group fed fruits of kidney bean throughout the nymphal stage (B-control) (46%). However, mortality was 80% in both the group fed alfalfa till the 14th day and then fruits of kidney bean (AB-14) and the group fed sucrose till the 14th day and then fruits of kidney bean (SB-14). The total mortality of Eurydema rugosum MOTSCHULSKY was 0% in the group fed fruits of rape through-out the nymphal stage (C-control), 10% in the group fed sucrose till the 6th day and thereafter fruits of rape (SC-6), 80% in the group fed sucrose till the 10th day and then fruits of rape (SC-10), 40% in the group fed alfalfa till the 3rd day and then fruits of rape (AC-3) and 100% in the group fed alfalfa till the 6th day and thereafter fruits of rape (AC-6). In P. angulosa, the growth of the nymphs fed alfalfa (AB-7 and AB-14) or sucrose (SB-7 and SB-14) in the 2nd instar was retarded in the early nymphal stage (2nd and 3rd) but recovered in the later nymphal stage (4th and 5th). In E. rugosum, the growth of the nymphs fed alfalfa or sucrose (AC-3, SC-6 and SC-10) in the 2nd instar was also retarded and the retardation was never recovered till adult stage. Weight gain per day of P. angulosa in the 2nd and 3rd instars was smaller in temporal food fed-groups than in B-control, whereas the weight gain in the 4th and 5th instars was larger in the former than in the latter. Adult weight of P. angulosa and E. rugosum was not significantly different among different food groups.

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Changes in polyamines and DNA concentrations in the midgut epithelium of the silkworm infected with a densonucleosis virus (Bombyx DNV) were investigated. Three kinds of polyamines, spermidine, putrescine and spermine, were detected in the midgut epithelia of both infected and healthy silkworms. However, the ratio of these polyamines was somewhat different from that of Bombyx DNV. In the DNV-infected midgut, lower accumulation of spermidine and putrescine, and lower spermidine/spermine ratio were observed as early as 24 hr after DNV inoculation as compared to healthy midgut. DNA concentrations in DNV-infected midguts fluctuated considerably during the course of DNV infection, but the pattern was rather constant as compared to those of healthy ones. These results suggest that infection with Bombyx DNV rapidly affects the physiological condition of host cells, and interferes with normal growth and/or the proliferation of cells.

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The role of certain environmental factors in influencing the substrate-borne acoustic communication associated with the sexual behaviour of the leafhopper, Amrasca devastans (DISTANT) was studied under the laboratory conditions. The sound emission as well as the sexual behaviour was high at 28±1°C and was inhibited by a low (18±1°C) or a high temperature (38±1°C). A high humidity (⪀80% r.h.) was found to inhibit the sexual communication and behaviour of this leafhopper whereas a low humidity (30-40% r.h.) had no effect on these responses. Singing by the sexes in complete darkness was as high as in the presence of light. However, the copulatory responses were reduced in the dark. The leafhoppers kept under a short day-length (8L-16D) for 5 days after emergence sang and copulated as high percentages as those kept under a long day-length (13L-11D) for 5 days after emergence. The sexual communication leading to mating was not done by the two sexes being present on different leaves which had been in out of contact with each other; but was done by those being present on the same leaf. This fact imposes a severe limitation in the reproduction of these insects since no air-borne distance stimulus is involved in their communication.

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1-Citronellyl-5-phenylimidazole (KK-22) was applied topically and orally to and mixed in the diets of 4th instar silkworm larvae, and its anti-juvenile hormone (JH) activity was determined by the induction rates of precocious metamorphosis. Larvae were more sensitive at the earlier stages of 4th instar to KK-22 and there were no significant differences in induction of precocious pupation among the administration methods, topical application, oral ingestion and feedng on diet. Anti-JH activity of KK-22 vanished when methoprene, a JH analogue, was applied immediately after KK-22 treatment.

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The mating behavior of wild melon flies, Dacus cucurbitae, was observed under field conditions. Males congregated and engaged in wing vibration in the late afternoon on non-host plants such as Bidens pilosa, Amaranthus lividus and Crassocephalum crepidioides, which populated over bordering cucurbit fields. Males defended their calling sites from other males through wing vibration, fighting or mounting. The rate of mating success per male in relation to female encounters was extremely low (1 : 61), suggesting that each female exerted "female choice." Judging from these results we conclude that males of the melon fly form leks.

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To elucidate whether Bacillus thuringiensis spores germinate in natural soils, the population dynamics of vegetative cells and spores of B. thuringiensis in soils were studied using peptone-polymyxin medium and BTV medium, a selective medium for vegetative cells. B. thuringiensis spores were capable of germinating in sterilized soils but not in natural nonsterilized soils. B. thuringiensis vegetative cells inoculated into natural soils disappeared rapidly in 1-2 days. B. thuringiensis vegetative cells were able to form spores in antural soils, depending on the soil type. It is suggested that the spore is the only state in which B. thuringiensis persists in natural soils.

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Etiella hobsoni (BUTLER), a new podborer of soybean was found in Indonesia. General appearance of the insect and larval-caused damage to pods are quite similar to those of E. zinckenella (TREITSHKE). Diagnostic characters in morphology of E. hobsoni and E. zinckenella are given for each developmental stage. Both species are widely distributed throughout Indonesia. E. zinckenella is common everywhere, while E. hobsoni is abundant in West and Central Java but rather rare in other districts (East Java, Sumatra and Sulawesi).

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Larval development and gonad maturation of a carabid beetle, Carabus yaconinus BATES were studied at six different temperature and photoperiod conditions, i.e., 25°C, 16L-8D; 20°C, 16L-8D; 20°C, 14L-10D; 20°C, 12L-12D; 15°C, 16L-8D; 15°C, 13L-11D. The length of developmental period in immature stages was influenced by temperature but not by photoperiod. Ovarian maturation took place under 16L-8D but was suppressed by both short-day conditions and high temperatures. Fat bodies developed when ovarian maturation was suppressed. The testes matured under all the experimental conditions but fat bodies developed only under short-day conditions at lower temperatures. The suppression of ovarian maturation and development of fat bodies indicated that the adults were in reproductive diapause. These diapause responses were related to the control of the univoltine life cycle of this species.

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Inoculation experiments were conducted at 25°C under laboratory conditions to investigate the infectivity and propagation of Steinernema feltiae (DD-136), S. bibinois, and S. glaseri on the last instar larvae and male adults of common cutworm, Spodoptera litura. S. feltiae was the most infective on S. litura larvae, followed by S. bibionis and S. glaseri. S. feltiae was positively attracted to the intact and ligated larvae, efficiently invaded, caused acute death of the hosts, and propagated rapidly and abundantly. S. bibionis was weakly attracted to the intact larvae, inefficiently invaded, and slowly developed. These properties led this nematode to low competitive propagation against the other steinernematids which were inoculated at the same time. S. glaseri was slowly but steadily attracted, invaded, quickly developed and estabished a high population in the hosts. The propagation of S. glaseri, however, was suppressed by the mixed inoculation with S. feltiae and to a lesser extent with S. bibionis. All species of steinernematids used propagated more quickly and abundantly in the moths from which the infective juveniles emerged earlier than from the larvae.

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To establish the successive rearing method of the lesser mulberry pyralid, Glyphodes pyloalis WALKER, experiments were made with a commercial silkworm diet.Addition of the juice of frozen mulberry leaves or young mulberry leaf powder into the artificial diet improved the diets, so that the larvae were arrested and reared in an open container. The pupal and adult yields on the improved diets were larger than those on the basic silkworm diet.

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Arrestants which keep A. kariyai in the host habitat were isolated from the exuviae of the host larvae and their structures were elucidated by a combination of MS, PMR and CMR spectra. The chemical structurs of the arrestants were found to be a series of 2, 5-dialkyl-tetrahydrofurans. Impregnation of 0.1μg of each arrestant onto a paper disc elicited 70-90% response from A. kariyai.

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The mating behavior was observed in numated adults of Riptortus clavatus. The courtship behavior was initiated with either freezing of the male or approach of the female to the male. Then the male quivered, mounted the female, and attempted copulation. The female was usually receptive, although she sometimes rejected the mounting male. Copulation began in a position with male above female, both facing the same direction, and ended in a position with the pair facing opposite directions. The role of olfaction in the mating behavior was examined by removing the terminal antennal segment. The olfactory stimuli from either sex played an essential role in releasing the courthip behavior of the opposite sex. The olfactory stimuli from a male suppressed the rejection of females.

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EAG responses to 90 n-alkyl compounds, with different functional groups and some homologues, were compared between the two types of the yellow peach moth, Conogethes punctiferalis (GUENEE), fruit-feeding type (FFT) and Pinaceae-feeding type (PFT). Females of both types responded clearly to C₅ or C₆ compounds in all three series of alkanol, alkanal, and alkanoic acid while both males showed prominent bimodal response with C₅ or C₆ and C₉ compounds in aldehyde. The antennae of both sexes in each type more significantly responded to n-hexanal taan to the corresponding alcohol and acid. The FFT antennae were twice as sensitive to n-hexanol and n-hexanal, and 1.5 times more to n-hexanoic acid than the PFT antennae. Females of both types were more sensitive to n-hexanoic acid than the males, particularly in FFT, but no significant difference was observed with n-hexanol and n-hexanal. The threshold dosages of n-hexanol, n-hexanal and n-hexanoic acid to both types were not significantly different, and were within 5×10^-4μl to 1×10^-3μl. The EAG responses of both types to ester homologues were unimodal and bimodal in female and male, respectively, similar to those to aldehyde homologues. From these differences in EAG response and with reference to the morphological and biological differences reported earlier, we conclude that the two types are separate species.

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Mean supercooling points of the spotted cutworm, Xestia c-nigrum, dropped from -8°C to -17--18°C and mean contents (mg/g) of glycerol and trehalose rised respectively from 6 to 12 and from 17 to 26 by cold hardening, although hardening at -5°C for 10 days and 30 days showed no appreciable difference. Mean supercooling points by ice inoculation was -4.4°C. This species is weakly freezing-tolerant. Post-thawing survival was relatively high (57-70%) by spontaneous freezing after cooling to -12°C or by inoculative freezing after cooling to -20°C, but was virtually 0% by spontaneous freezing after cooling to -20°C. No appreciable difference due to instar was found on above aspects. Survival after spontaneous freezing from -6 to -12°C was confirmed under early winter field conditions. Wild larvae kept under field conditions during winter died less than those laboratory-reared ones and did not moult as latter did.

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Larvae of the spotted cutworm, Xestia c-nigrum, were exposed to 5 or 10°C after rearing under long- (16L-8D, 18.5°C) or short-day (10L-14D, 18.5°C) regimes. At such low temperatures, the larvae were able to develop to the advanced instars with feeding activity. The exposure to low temperatures strongly retarded the larval growth but accelerated both freezing-tolerance and accumulation of trehalose. The delay of growth and the increase in freezing-tolerance were conspicuous in the larvae reared under short days before exposure to 5°C : most 5th instar larvae required over 150 days to develop to the next instar and became tolerant to inoculative freezing at -12°C during the first 20 days' exposure. Exposure to 10°C was also effective to increase in freezing-tolerance of the later instar larvae. Short days and low temperatures seem to be important for winter survival of this species.

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A wind tunnel was used to evaluate controlled-release dispensers containing (Z)-9-tetradecenyl acetate (Z-9-TDA), (Z)-11-tetradecenyl acetate (Z-11-TDA), (E)-11-tetradecenyl acetate (E-11-TDA), 10-methyldodecyl acetate (10-Me-DA), a 4-component mixuture (Z-9-TDA : Z-11-TDA : E-11-TDA : 10-Me-DA=70 : 30 : 5 : 20) and a 3-component mixture [Z-9-TDA : Z-11-TDA : (Z)-9-dodecenyl acetate (Z-9-DDA)=1 : 1 : 1] as disruptants for the smaller tea tortrix moth, Adoxophyes sp. Among the 6 candidate dispensers, Z-11-TDA, the 4-component mixture and the 3-component mixture effectively suppressed the male moth catch in a trap baited with 4-component pheromone dispenser in the wind tunnel. The mechanisms of orientation disruption were discussed based on the behavior of male moths in the tunnel.

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Crossing experiments were conducted among three isolates of Bursaphelenchus xylophilus and eight isolates of B. mucronatus from wide geographical sources in Japan. Crossing between isolates of the same species produced fertile hybrids in every case. In all crossing combinations between B. xylophilus and B. mucronatus, F₁ progenies were produced. However, the number of produced hybrids were limited and some of them were aberrant. These F₁ hybrids failed to produce the F₂ generation. Back crossing of F₁ hybrids to their parent adults also failed to achieve progeny production. These results are indicative of a valid separation of B. mucronatus from B. xylophilus, although they are closely related.

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In the silkworm, Bombyx mori, alanine aminotransferase (AT-ase) was high in the midgut and silkglands, whereas aspartate AT-ase activity was much higher in the midgut and fat body than in the silkglands. Alanine- and aspartate AT-ase activity in the three kinds of tissues were significantly lowered by the deficiency of dietary pyridoxine in the presence or the absence of pyridoxal-P in the incubation medium. The enzyme activities were increased with increasing levels of dietary pyridoxine. However, the increase rates of the activities varied among the three kinds of tissues.

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