The yellow secretion of idolothripine thrips, Bactrothips brevitubus (Thysanoptera : Phlaeothripidae) was analyzed by GLC, GC-MS and TLC. Decanoic, trans-4-decenoic, dodecanoic, cis-5- and trans-3-dodecenoic acids were identified, in which trans-4-decenoic acid was a major component (48.5%). Juglone (5-hydroxy-1, 4-naphthoquinone) was also identified in the yellow substance.

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Chemotaxis and anemotaxis of nymphs of the German cockroach, Blattella germanica (L.)to their aggregation pheromone were investigated in the linear track olfactometer at different doses. The chemotaxis response consistently increased in accordance with dose. Odour-modulated anemotaxis response was initiated simultaneously with chemotaxis, but had an optimum dose level and decreased at higher doses. This decrease may be the result of the transition to the pin-point local search using solely chemotaxis. In addition to absolute odour presentation of the standard chemotaxis experiment using clean control air, odorous air was also provided to the control, and nymphs were exposed to varying concecntrations. Comparison of results revealed that the nymphs sensed not only the presence or absence of the odour but variance within the odour concentration itself. They discriminated concentration ratios of at least 1 : 1.6.

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Ascogaster reticulatus WATANABE (Hymenoptera : Braconidae) is an egg-larval parasitoid of the smaller tea tortrix Adoxophyes sp. (Lepidoptera : Tortricidae). Host finding behavior of A. reticulatus was observed and the role of host wing scales analyzed. Female parasitoids released on tea twigs in a container tended to search more actively on the leaves on which host moths had stayed overnight than on control leaves. A. reticulatus females responded with antennal searching to the leaves which were closer to the oviposition site of the host. Higher searching activity was found on leaves with moth scales. Female parasitoids released in an arena (20 cm dia., 5 cm ht.) changed their behavior from straight to meandering walk after contact with an area treated with female wing scales, wing extract, or egg-mass extract, Parasitoids could locate a host egg mass placed in the center of the treated areas more efficiently than one in an area without treatment, although more time was required. Female parasitoids may use kairomones from host moth scales scattered around the oviposition site as a cue to find host egg masses.

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Egg hatching time was observed for the populations of the spirea aphid, Aphis spiraecola, collected from different host plants and localities in Japan. Eggs from 6 populations on citrus hatched almost a month later than those from populations on spirea Spiraea thunbergii SIEB.The form on citrus is hence classfied into the citrus overwintering group. The citrus group is distributed over citrus growing area in Japan. Its populations in Okinawa do not produce any eggs. Eggs from populations on spirea hatched mainly in February. The form on spirea is hence classified into the spirea overwintering group. Eggs from populations on apple and pear hatched slightly later than those of the spirea group, and it is not clear to which group these populations belong. The timing of egg hatching in a loquat-inhabiting population was the same as that in the citrus group.

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Development and mortality of eggs of a stored-grain pest in Canada, the rusty grain beetle, Cryptolestes ferrugineus (STEPHENS) (Coleoptera : Cucujidae), were observed at 15 to 35°C and 50 to 90% relative humidity (RH). At 15°C no eggs hatched. Mortality was higher at 15 and 19°C than at 25, 30 and 32°C. The developmental rate (1/day), D, was expressed by a linear regression function of temperature, T; D=0.0169T-0.258. Mortality and developmental rate was unaffeted by the relative humidity. Eggs of C.ferrugineus were more tolerant to high temperatures and low relative humidities than eggs of the flat grain beetle, Crytolestes pusillus (SCHONHERR), a closely related pest.

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Factor analysis was performed on the parthenogenesis of silkworm ovarian eggs. The method of ASTAUROV (1967) was used for the induction of parthenogenesis and experiments designed for factor analysis were performed according to the formulae of MATHER. The percentage of parthenogenesis of eggs varied widely among tested strains and was generally higher in hybrid strains than in their original races. Heterosis was found in these hybrid strains. When the percentage of parthenogenetic eggs was compared in terms of cross and reciprocal cross F₁ generations which had the same genetic structure, a higher percentage of parthenogenesis of eggs was found in hybrid strains with highly parthenogenetic original races. This result indicated that some maternal factors might influence the occurrence of parthenogenesis. Results of the factor analysis revealed that unfixable genetic factor had the highest genetic influence followed by fixable genetic factor and environmental factor.

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To evaluate host plant suitability, five parameters-survival rate (S), growth index (I), phloem ingesting time (I_p), net reproductive rate (R₀) and intrinsic rate of increase (r)-of three species of green leafhopper (Nephotettix cincticeps UHLER, N. virescens (DISTANT) and N. nigropictus (STÅL)), on two species of weeds (Zizania latifolia TURCZ and Leersia hexandra SWARTZ) and six cultivars of Orysa sativa L. rice (Nihonbare, Reiho, IR42, IR36, Taducan and Te-tep) were compared. R₀ can be used as an evaluating criterion without consideration of generation time. The evaluation results for S and I were almost the same as that for r.There was a linear relationship between I_p and S in N. cincticeps and N. nigropictus.

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Synthetic pyrethroid esfenvalerate, reduced the incidence of the rice stripe virus disease transmitted by smaller brown planthoppers, Laodelphax striatellus, in the greenhouse. To make clear the mechanisms preventing virus infection, the effects of esfenvalerate on vectors were investigated. This compound showed a high repellent activity against smaller brown planthopper which is a stripe disease vector, and green rice leafhopper, Nephotettix virescence, which is a tungro vector. Electronic measurement of insect feeding behaviour revealed that 1 ppm of esfenvalerate inhibited the ingestion and salivation of both species. These results suggested that insecticide lethality, repellency and/or activity inhibiting ingestion and salivation behaviour contributes to prevention of virus infection by planthoppers and leafhoppers.

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The structural polypeptides of polyhedron-derived virions of Bombyx mori nuclear polyhedrosis virus were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) and two-dimensional (2-D) gel electrophoresis. Analysis by SDS-PAGE identified a total of 33 structural polypeptides ranging in molecular weight from 11, 500 (11.5 K)to 125 K, whereas a total of 84 structural polypeptides were identified by the 2-D gel analysis.Of the 84 polypeptides, 40 were resolved on the 2-D gel consisting of isoelectric focusing(IEF) with the pH range from 4.5 to 6.5 in the first dimension and SDS-PAGE in the second dimension, and the remaining 44 were resolved on the 2-D gel consisting of nonequilibrium pH gradient electrophoresis (NEpHGE) with the pH gradient between 7 and 9 in the first dimension. Polyhedrin prepared from protease-inactivated polyhedra had an approximate molecular weight of 31 K on the SDS-PAGE gel, and resolved into at least 3 species in the IEF or NEpHGE dimension by the 2-D gel analysis. Several attempts to isolate nucleocapsides from the enveloped virions were unsuccessful.

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Effect of wire netting method, which had been previously proved to be effective for preventing A. malasiaca oviposition in a young citrus grove, was examined in a mature citrus grove. The following 3 treatments were tried in a grove of 285 trees; (1) netting the tree trunk and piling up soil around the trunk base, (2) netting the tree trunk but not piling up soil around the base, and (3) untreated (control). The proportion of oviposited trees, the mean number of eggs and larvae, percentage of living eggs, and proportion of trees bored by larvae were compared among these treatments. The wire netting proved effective in preventing injuries by A. malasiaca, and further improved by guarding the trunk base with soil.

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The developing embryos of the saturniid silkmoth, Samia cynthia ricini, contain eclosion hormone, which can elicit precocious adult eclosion in Bombyx mori. In this study its activity first become detectable in embryos at the middle stage of embryogenesis. Thereafter hormonal activity sharply increased with age and reached a maximum level (0.23 units/ embryo)just after hatching. Eclosion hormone activity was detected in both the head and thorax-abdomen of embryos. The proportion of the eclosion hormone increase in the head region of the ligated animal was higher than that of the abdominal segment. Eclosion hormone was partially purified 290-fold from Samia embryos. Molecular weight of the embryonic eclosion hormone was about 8, 500±1, 000 daltons as judged by gel-filtration on a Sephadex G-50 (superfine). Eclosion hormone is considered to be involved in hatching induction in Samia cynthia ricini.

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In 4th instar Papilio xuthus larvae, PTTH was secreted in a rhythmic manner even in continuous darkness (DD) following both 8L-16D and 16L-8D. The PTTH secretion rhythm was phase-shifted by exposing larvae to a light pulse (1 hr) in DD. The phase-shift produced in the rhythm represents a typical phase-response. The onset, acrophase and offset of the PTTH-secretion occurred parallel to the mid-points of light (or dark) periods. The rhythm free-ran in continuous darkness (DD) following various LD cycles in which light periods were changed at 2 hr intervals. Coefficients of regression lines (RC-values) for the onset, acrophase and offset of PTTH-secretion were calculated against the lights-on in free-running rhythms were examined in DD and LL (continuous light), and were far smaller in the latter. The RC-values, however, for the 3 phase reference points (∅r's) of PTTH-secretion rhythm increased from one ∅r to the next in DD following LD cycles. The results suggest that PTTH secretion in P. xuthus is gated by a circadian clock which is set twice a day, at dawn and dusk. At dawn the circadian clock may be reset at CT 0 : 00, and again set at dusk to give the same time (CT 18 : 00) amid the dark period of LD cycles.

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Ethyl 4-hydroxybenzoate was identified as a major aromatic volatile in the rectal glands of Dacus cucurbitae males, together with two minor analogs, methyl and propyl 4-hhydroxy-benzoate. The quantity of ethyl ester was very low at early adult stage but increased with sexual maturation up to a level of 10 μg/male. 1, 3-Nonandiol was identified as one of the aliphatic components. It was also demonstrated that D. cucurbitae males which were artificially fed with cue-lure selectively accumulated its hydrolyzed derivative, 4-(4-hydroxy-phenyl)-2-butanone, in the rectal glands.

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Male abdominal exocrine glands of Dermestes ater were examined under light and scanning electron microscopy, and their extracts were chemically analysed by GC and GC/MS. Light microscopy of serial sections of the abdomen showed a simple alveolus gland comprised of hundreds of secretion cells, which was linked to the pore opening in the anterior part of hair bundle on the sternite. These characteristics were quite similar to those of D. maculatus, whose gland has been reported to emit an aggregation pheromone. The gland contained esters of carboxylic acids with 12 to 16 carbon atoms as the main components, a major part of which(90.1%) were isopropyl esters including 65.9% isopropyl laurate.

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The genetic basis of dipause of Tetranychus urticae KOCH was analyzed by reciprocal and backcrosszing experiments, using one diapausing strain (D), which exhibited nearly 100 percentage of diapause, and 4 non-diapausing strains (ND1, ND2, ND3 and ND4), which completely lacked diapause. The strains used were selected from 5 different field populations. F₁ hybrids between D and ND2 exhibited more than 90% diapause regardless of the direction of the crosses, suggesting "diapause" was fully dominant. On the other hand, significant reciprocal differences were observed in the diapause incidences of the F₁ hybrids between D and each of the other 3 non-diapausing strains, showing that a maternal effect is operating.The results from backcrosses usind D and ND2 suggest that "non-diapause" is not controlled by a single recessive but by multiple recessive genes.

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