The ultraviolet light perception in insect vision may serve as a target physiological process for the action of soft and selective pesticides, since it is essential for the survival of insects while it is missing in mammals. In order to develop an assay method for evaluation of the effect of potential visual inhibitors on the ultraviolet light receptor complex, the extraction methods of the complex which is sensitive to the chemical additives should be established first.As such a preparation, an aqueous dispersion of the complex was obtained with a phosphate buffer solution. Illumination of this dispersion with UV lamp (the maximum at 360 nm)gave, in a difference absorption spectrum, the minimum at 340 nm and the maxima at 333 nm and 353 nm. From the regeneration effect observed after the dark reaction immediately following the UV illumination, the 340 nm band was attributed to bleaching of the complex.The maximum at 333 mn was attributed to formation of thiazolidine-like linkage by the retinal molecules released in the photochemical bleaching of the complex while that at 353 nm was attributed to Schiff base linkage by the released retinal. Lack of the dark interaction of hydroxylamine indicated the absence of free retinal in unilluminated samples. Hydoroxtylamine under UV illumination showed Schiff base formation with retinal by an enhancement in absorbance at 350-360 nm together with the absence of the dark regeneration effect.

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A simple artificial diet for the mass rearing of Leucania separata has been devised. The diet, composed of wheat bran, corn powder, driet yeast, ascorbic acid, linseed oil, agar, water and three mould inhibitors, satisfactorily supports the development of L. separata and L. loreyi.The larval development of L. separata on the artificial diet did not differ from that reared on some graminaceous food plants. The weight of pupae reared on the artificial diet was heavier than that reared on the food plants. The ensuing adults laid as many eggs as did those emerged from larvae reared on the food plants.Sorbic acid added to the artificial diet as a mould inhibitor caused pupal deformity.The rate of emergence from larvae reared on the diet containing sorbic acid fell remarkably in L. separata, but none of the adverse effects of sorbic acid on pupation and emergence were observed in L. loreyi.

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Populations of S. furcifera and N. lugens were studied for 3 seasons of rice cultivation at Kalugomuwa, Kandy District, Sri Lanka. In 2 of the 3 seasons, S. furcifera was superior in abundance to N. lugens. Both species were similar in seasonal trend of adult population to each other, but the proportions of brachypterous forms to the whole adults fluctuated in different ways between the 2 species. N. lugens was less aggregative in spatial distribution than S. furcifera. Parasitic activities of Elenchidae, Dryinidae, Pipunculidae and Nematoda were sometimes considerably high, but they were neither persistent nor regulative against the host population.

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Inhibition of duetonymph molting of Parasitus gregarius, a manure-inhabiting predacious mite, was observed by prohibiting contact with other individuals. The highest rate of adult emergence was obtained when two duetonymphs of different sex were reared together in the same container. Intense crowding of individuals of the same sex had less effect on the molting than the pairing of deutonymphs of different sex. The molting rate increased as the time of maintaining mites in crowds was prolonged. Contact with protonymphs or with dead mites induced molting in some deutonymphs, though at a lower rate than in the case of the live inter-deutonymphal combination. Other gamasine species or manure components has no effect on molting. It seemed probable that molting of the deutonymphs was induced most effectively by direct contact with other mature individuals of apposite sex of the same species.

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Preliminary observations and experimental analyses were made on the mating behavior of the pale grass blue, Zizeeria maha argia. Adult emergence took place from about 18 : 00 to 11 : 00 and flight behavi8or of adult buterflies could be seen from 8 : 00 to 18 : 00. Males flying in search of females approached any male or female resting with wings closed. Field experiments with a variety of models revealed that males were generally attracted not only by wing-closed females but also by wing-closed males. Furthermore, males were also attracted by an undersurface model of the same size as the pale grass blue. In this experiment attraction of the male to the wing undersurface was observed regardless of the model shape, although the model size was of primary importance. Spectroscopic examination showed that the reflectivity pattern of the wing undresuface in both sexes was approximately similar. It therefore seemed that the sexual behavior of the flying males was first of all released by the color of the wing undersurface, and not of the uppersurface. Thus, male adults discover conspecifric individuals by means of recognizing the color of the wing undersurface.

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From laboratory and field experiments the male behavioural response to the female Spodoptera litura sex pheromone was obtained over a range of wind velocities. The male response of interest here is the maximum distance at which incipient movement toward the source occurs. In the windless laboratory, males responded to the pheromone only within a short distance of the source. In the firld, the maximum distance for incipient male movement increased with an increase in wind velocity until a maximum was reached at a wind velocity of 1.0 m/sec. Males displayed a different behaviour to each component of the sex phermone. Cis-9, trans-11-tetradecadienyl acetate emitted by virgin females, resulted in incipient movement at greater distances than did cis-9, trans-12-tetradecadienyl acetate.

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The effect of individual components of sex pheromone (cis-9, trans-11-tetradecadienyl acetate (compound A) and cis-9, trans-12-tetradecadienyl acetate (compound B) upon the mating of Spodoptera litura were examined by means of arrangement of tethered females in an experimental field and liberation of marked males in defferent sex ratios. The application of a large amount of compound A and B (7.2 mg/are) in a field had an effect to suppress matings : that is, the mating rate decreased below the level of 50 percent as compared with that of 75-95 percent in blank trials. cis-9-Tetradecenyl acetate (compound C), a related substance of the sex pheromone, was also examined, but the mating was not clearly suppressed. The mating suppression was most strongly appeared when the males were liberated around the field treated by compound B.

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Cytochrome components of mitochrondria in the maize weevil, Sitophilus zeamais(MOTSCH), were determined by the method of the reduced minus-oxidized difference spectra. The α-bands of the cytochrome components were observed mostly in the usual positions : Cyt. a, 603 nm; Cyt. b, 564 nm; Cyt. c, 551 nm, and the γ-peak of Cyt. a was also identified at 443 nm. Contents of these cytochromes were strongly similar to those in thoractic muscle mitochondria of the colorado porato beetle. The order of enzyme arrangement of the electron transport chain in the maize weevil mitochondria will most likely be similar to those of commonly observed mitochondria such as those of rat liver, beef heart, etc.The effect of phosphine (PH₃) on the difference spectrum of the maize weevil mitochondria was essentially similar to that observed with HCN treatment, and PH₃ strongly inhibited the respiration of the maize weevil mitochondria using substrates of pyruvate+malate, succinate, and ascorbate+TMPD.The obervations of the spectral change and the respiratory inhibition of maize weevil mitochondria by PH₃ suggest that PH₃ inhibits cytochrome oxidase.

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Types of surrounding vegetation were evaluated for their influence on numbers of male Spodoptera litura, captured in traps baited with synthetic sex pheromone, a mixture of (Z, E)-9, 11- and (Z, E)-9, 12-tetradecadien-1-ol acetates. A large number of males were captured in traps placed in open vegetable fields, grasslands, and paddy fields. Reduced numbers of males were caught in traps in home gardens. Traps placed in small vegetable gardens surrounded by shrubs and under leafy shade trees caught only occasional males, probably because of the restricted or disturbed air/pheromone movement. In both mass and monitory trapping operations placement of pheromone trap should be made at open areas with short vegetations, the most favorable site to give maximum trap efficiency.

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In order to obtain stable and simple structural aphid alarm pheromone mimics, (E)-2, 6, 10-trimethylundeca-1, 5, 9-triene and several related analogs, so-called nor-farnesenes, were synthesized and tested for alarm pheromone activity against the aphids Schizaphis graminum(RONDANI) and Acyrthosiphon pisum(HARRIS)(Homoptera : Aphididae). Three compounds showed significant alarm pheromone activity and may have potential in aphid pest management.

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In Bombyx mori spermatogenesis promotes with the formation of primary spermatocytes in the 4th instar, but spermiogenesis does not begin until about 24 hours after ecdysis to the 5th instar. C<18>-juvenile hormone (JH) application (100 μg/larvae) delays the onset of spermiogenesis by 4 days. Conversely, allatectomy in the 3rd instar causes the onset of spermiogenesis 4 days later in preparation for precocious pupation.Spermiogenesis occurred normally in 4th-instar abdomens ligated 72 hours after ecdysis, but oinly partially in abdomens isolated before that time. Ten μg ecysterone enhanced the growth of these latter testss (by initiating meiosis), but did not increase the percentage undergoing spermiogenesis. JH prevented spermiogenesis in all cases.Testis from 24 to 48-hour-old 4th instar larvae showed spermiogenesis after in vitro culture in day 4 5th-instar hemolymph or in modified GRACE's medium. Ecdysterone was not required, but JH added to the in vitro medium inhibited spermiogenesis. Thus, ecdysterone is necessary to initiate meiosis in the spermatogonia resulting in the formation of primary spermatocytes. JH inhibits the further differentation of these primary spermatocytes until its level declines in the last larval instar in preparation for metamorphosis.

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Electrosyneresis (ES) method was successfully applied to the detection of the specific antigen on infectious flacherie virus of the silkworm (IFV-specific antigen) with the following results.Precipitated line was formed by ES when the IFV-specific antigen was placed on the cathode side and anti-IFV serum was placed on the anode side. The ES method was far better than the micro-Ouchterlony method in the sensitivity, and the precipitated line was observed at 32-fold dillution of IFV-specific antigen. The IFV-specific antigen was detected from the midgut of silkworms which had been administered with heavy and light inocula of the IFV. This was found 4-5 days earlier than the appearance of the symptom. The ES method is practically applicable to the rapid diagnosis of infectious flacherie of the silkworm.

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