Using four marker genotypes of F₂ hybrids derived from crosses between aphid resistant and susceptible barley lines, the effects of leaf color, epicuticular wax and gramine indole alkaloid on aphid infestation were studied in natural populations of cereal aphids, mainly the corn leaf aphid (Rhopalosiphum maidis) during 1994-1995. Resistant lines, OUH603 and OUH689 (Hordeum vulgare subsp. spontaneum), were the normal type (green waxy) with a higher amount of gramine. However, susceptible line, OUL117 (Hordeum vulgare subsp. vulgare), was the yellow waxless type with a lower content of gramine. In the F₂ populations of OUL117×OUH689, OUH603×OUL117 and OUL117×OUH603, the aphid densities on the marker genotypes were low in the normal type, intermediate in the green waxless and yellow waxy types, and high in the yellow waxless type. Gramine content was low and did not differ significantly among the genotypes measured in 158 F₂ plants of OUL117×OUH689 in 1994. Additionally, there was no significant correlation between aphid density and gramine content within each genotype in the F₂ populations. These results showed that the genes controlling color and wax types had additive effects on normal plant genotype resistance to aphids, but did not affect gramine content.

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The rice water weevil (RWW), Lissorhoptrus oryzophilus KUSCHEL, has widely infested paddy fields which are located at altitudes of 270 to 1, 200 m in Nagano Prefecture. The appearance and development of the RWW in the higher elevation area (alt. 1, 150 m) were observed ca. 10-20 days later than in the lower area (alt. 400 m). Population density was higher in the higher elevation area than in the lower one. Immigrant adults that were collected immediately after transplanting laid eggs at temperatures of higher than 20°C in the laboratory. Almost all eggs were laid in the first 2 weeks after the start of rearing at 20-30°C. It is considered that the temperature of a flooded paddy field is favourable for oviposition by immigrant adults, and that intensive oviposition by adults prevented a delay in the subsequent larval occurrence. There was no remarkable difference in survival rate from egg to adult emergence between the higher and lower elevation areas and mortality during the winter is not particularly high. It is, therefore, considered that the periods before entering hibernation in autumn and before immigration into the paddy field in spring are crucial for survival in the next generation.

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The time of sperm movement was examined in pupae of Polygonia c-aureum in relation to seasonal form and imaginal diapause. Although the duration of the pupal stage was one day shorter under long day-length than under short day-length, the initiation of sperm movement and the progression of adult development of summer-form pupae also occurred one day earlier than autumn-form pupae. Apyrene sperm movement started two days before adult eclosion and eupyrene sperm movement started the day before eclosion. No significant difference was observed in the pattern of sperm movement between the two types of pupae. It is concluded that the initiation of sperm movement is not influenced by the seasonal form and the presence or absence of imaginal diapause.

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We investigated the species composition of Orius spp., predacious natural enemies of Thrips palmi KARNY in eggplant fields and surrounding vegetation. At Chikushino, O. sauteri (POPPIUS) was dominant on eggplant, followed by 0. minutus (LINNAEUS) and 0. nagaii YASUNAGA. 0. sauteri also dominated the sample on white clover, while the other two species occurred with an extremely low frequency. In contrast, on Gramineae plants such as rice, forage crops and weeds, 0. nagaii was exclusively dominant, while the other two species were rarely found. These results suggest that the habitats surrounding an agro-ecosystem serve as reservoirs for Orius spp. occurring in eggplant fields. The species composition on eggplant varied with sampling date and locality. In the three IPM fields where selective chemicals were applied, the first peak of abundance on leaves was found in early and mid-July, indicating that Orius spp. adults begin to immigrate into eggplant fields from early June. From results of direct count on leaves and sticky trap data, Orius spp. colonization and subsequent reproduction appeared to be influenced greatly by prey population size.

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The acctylcholinesterase (AChE) of the Toyama strain (Toyama) of Culex tritaeniorhynchus showed extremely low sensitivity to various kinds of organophosphorus insecticides (OPs) and carbamates. Several characteristics of the AChE of Toyama have been tested and compared with those of the OP susceptible strain (Taiwan). The AChE of Toyama is different from that of Taiwan in many respects. It showed no clear optimum pH and substrate concentration (AChE of Taiwan had both the optimum pH and substrate concentration). Affinity for ACh was high (K_m value for ACh is 0.65 times the value of Taiwan), but affinity for the substrate declined significantly for acetylthiocholine and propionylthiocholine. I₅₀ values for OPs were extremely high (66.1-7, 079 times the value for Taiwan), and those for carbamates were also higher than those for Taiwan (20.4-112 times). These results suggest that the structure of the AChE of Toyama has changed to an ACh specific form which has a remarkably lower affinity to the OP compounds.

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The attractiveness of methyl anthranilate for both sexes of the adult soybean beetle, Anomala rufocuprea was evaluated by trapping at a tobacco field. The total catch by traps baited with methyl anthranilate was approximately 15 and 5 times as large as those baited with eugenol and the female sex pheromone, respectively; the female ratio in the overall catch was 57.5%, whereas that with the sex pheromone was 4.7%. combined use with the sex pheromone exhibited a higher performance even for females: The catch by the combined attractant was much larger than the simple sum of the catches by each single attractant. These results suggest the potential use of methyl anthranilate as a lure for mass trapping, as well as for monitoring.

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Adults of Thrips nigropilosus living on Artemisia princeps were sampled from April 1990 to March 1992 and the female adults and their offspring were reared outdoors from September 1990 to May 1991, in Kyoto, to clarify the reproductive periods and overwintering stages of this thrips and the seasonal changes in wing form composition of the females. On A. princeps, adult thrips were found almost throughout the year, and in females, the proportion of the brachypterous form was higher in cooler seasons and that of the macropterous form was higher in warmer seasons. Female adults did not oviposit from early December to late February and thrips from eggs laid in mid-November developed uninterruptedly even in the coldest season. Most females moulting into adults from late October to March were brachypterous, whereas those moulting into adults in the other periods were usually macropterous. These results suggested that this thrips usually overwinters in the adult stage, and that most of the overwintering females are the brachypterous form.

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The yellow hexane extract from Uroactinia hirschmanni HIRAMATSU (Acari: Mesostigmata) consisted of 2 compounds by GLC analysis, which gave the same molecular ion at m/z 188 with similar sets of fragment ions, and each of which was isolated by a preparative TLC. One was identified as plumbagin (5-hydroxy-2-methyl-1, 4-naphthoquinone) by GLC, GC/MS and NMR analyses using authentic compounds. The other was suggested to be its isomer from mass spectrum and was identified as 7-methyljuglone (5-hydroxy-7-methyl-1.4-naphthoquinone) by NMR spectrum. Glandular pores, responsible for emitting these naphthoquinones, were detected as black spots on the body surface, by dipping mites bodies in a Tollen's reagent (aqueous AgNO₃-NH₄OH). This study represents the first time these naphthoquinones have been demonstrated in such a time.

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Summer diapause in mature third-stadium larvae of Chlorops oryzae MATSUMURA was controlled by a quantitative photoperiodic response. When eggs were kept under LD15:9. pupation in the Akita strain (bivoltine, 39°N) was synchronized under both short and intermediate days with a larval stage of about 14 days. Under LD15:9 at 23°C, the complete larval stage was 68 days because the mature larval stage lasted 40 days. In contrast, the larval stage in the Aichi strain (trivoltine, 35°N) was 14 and 16 days under LD12:12 and 15:9, respectively. Under LD 14.5:9.5 at 23°C, the larval stage was 60 days including the mature larval stage of 40 days. The critical photoperiod for the induction of summer diapause in both strains was shortened with increasing temperature. Photoperiod from LD14:10 to 15.5:8.5 in the egg stage did not influence the quantitative photoperiodic responses of either strain. C. oryzae entered a winter diapause in the first stadium when the egg stage was exposed to LD12:12 but the diapause was terminated by intermediate and long days in the larval stage. There was no clear influence of photoperiod on larval development in either strain after the termination of winter diapause.

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Neryl formate, (Z)-3, 7-dimethyl-2, 6-octadienylformate, was identified as the alarm pheromone of Rhizoglyphus setosus and Rhizoglyphus sp. 1. The compound was also confirmed as a major pheromone component of Rhizoglyphus sp. 2, in addition to neral [(Z)-3, 7-dimethyl-2, 6-octadienal], geranial [(E)-3, 7-dimethyl-2, 6-octadienal] and α-acaridial [2(E)-(4-methyl-3-pentenyl)-butanedial]. Although citral (a mixture of neral and geranial) was not always detectable in the 4 species including R. robini, all four Rhizoglyphus mites exhibited weak activity. On the other hand, α-acaridial only indicated the activity against Rhizoglyphus sp. 2. Neryl formate was found to be commonly distributed as the major alarm pheromone component in the four Rhizoglyphus mites, and therefore, it is concluded that the alarm pheromone was non-species-specific among these species.

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The distribution pattern of leaf galls induced by Dinipponaphis autumna on its host plant, Distylium racenosum, was studied to clarify whether this aphid can select better galling sites in order to achieve its maximum fitness. The results demonstrated that this species cannot select an optimal site for galling at the leaf position level, due to the short life-span of stem mothers under starved conditions and the relatively short period of time at which a leaf is suitable for galling. Thus, the galling position among leaves was determined by the synchronization between the appearance of stem mothers and the leaf-opening phenology. However, at leaf part level, the present study supported the preference-performance hypothesis, since stem mothers preferred the basal intermediate part (B-part) of a leaf blade for galling. On this leaf part, aphids produced larger galls containing more alates.

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Pre-germband stage eggs of the larval endoparasitoid, Venturia canescens, developed up to the pupal stage in an insect cell culture medium, MGM-450, mixed with an equal amount of pupal extract of the host, Galleria mellonella. Among the pupal extracts of various stages tested, that from 1 day old pupae was most effective, and supported development of approximately 95% of the eggs to the last stadium. The matured larvae successfully pupated if rearing wells were plugged with cotton. One of the pupae obtained reached the pharate adult stage, but failed to ecdyse to an adult. Larval development was retarded when the concentration of pupal extract was reduced, and no larvae on a 3.1% pupal extract larvae ecdysed to the 2nd stadium. However, larvae which showed arrested growth in such medium developed to the last stadium after the medium was changed to the one containing 50% pupal extract. The growth-promoting ability of the pupal extract was lost by heat-treatment at 80°C for 10 min or by passage through a molecular sieve of 100, 000 M.W., suggesting that the growth-promoting factor(s) in the host pupal extract was protein.

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The optimum conditions for attachment to second-stage juveniles (J2s) of the root-knot nematode by Pasteuria penetrans sonicated spores, and their host-attachment range were studied. P. penetrans isolates MIP, MAP and MHP from Meloidogyne incognita, M. arenaria and M. hapla, respectively, were used. Spore attachment increased with increasing spore sonication time. Spores sonicated for 30 min had maximum attachment to J2, and attachment tended to decrease when spores were sonicated for 50 min. the increase in attachment with sonication was much higher in MIP than in MAP or MHP. When McIlvaine buffer of pH 4.0, 6.0 and 8.0 was used, the optimum pH for spore attachment shifted to a higher pH after spore sonication. The number of spores attached to J2 increased markedly with increases in temperature from 15 to 30°C. Each isolate of P. penetrans retained its host-attachment range after spore sonication. further, the sonicated spores of MAP, MIP MHP were examined for their host-attachment range among 10 Japanese Meloidogyne species. MAP attached in large numbers to only M. arenaria of both esterase types A-1 and A-2, and MIP to M. incognita, M, javanica and M. camelliae. However, MHP attached to a rather wide range of species, M. camelliae, M. hapla, M. mali, M. suginamiensis and a species close to M. mali.

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The compound eye of a nocturnal dung beetle, Bolbocerosoma nigroplagiatum, was observed by light and electron microscopy and compared with that of other scarabaeid beetles. The eye is completely divided into two parts by a well developed canthus into relatively narrow dorsal and comparatively wide ventral eyes. The inner surface of the cornea protrudes inwards and forms an exocone, while at the same time the crystalline cone is much reduced. Such a condition of a "duocone" dioptric apparatus seems to have been found so far only in Omorgus of the Trogidae. The retina is of the scotopic type, and the configuration of the rhabdom is different in dorsal and ventral eyes. The rhabdoms of several rows of the dorsalmost region in the dorsal eye are composed of three rhabdomeres in which parallel and long microvilli are orientated in three directions, and four V-shaped rhabdomeres in transverse section. In the remaining part of the dorsal eye as well as in the entire ventral eye, the rhabdoms exhibit a seven-lobed pattern. One of the rhabdomeres is formed by parallel and linear microvilli which are less electron-dense. a microvillar arrangement such as this suggests a special function e.g. polarization vision.

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Rhizome of a tropical yam, Dioscorea hispida SCHLUSSEL, which has been used as a traditional pest control agent in the Philippines, was extracted with methanol and the extract was further separated into alkaloid and non-alkaloid fractions by thin layer chromatography. Each fraction was examined to evaluate feeding deterrent activity, developmental effects and toxicity of the fractions against larvae of the diamondback moth (DBM), Plutella xylostella. The methanol extract showed strong feeding deterrent activity to DBM larvae. Two alkaloids, A and B, were isolated as active components from alkaloid fraction. Alkaloid A was more active than alkaloid B at 100 to 250 μg/ml, and a binary mixture (1:1) of these two alkaloids inhibited larval feeding at lower concentrations (50 to 100 μg/ml) than either alkaloid separately. Both alkaloids significantly retarded larval molting and reduced larval weight gain, and high mortality at the larval stage (70 to 86%) and during emergence (98 to 100%) resulted when DBM larvae were reared on treated radish seedlings. No conspicuous effect was observed against DBM larvae when the alkaloids were incorporated in water medium taken by the seedlings or when applied topically on larvae and pupae.

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Phosphoglucoisomerase (PGI) and malate dehydrogenase (MDH) enzyme differentiations were compared among seven species of spider mites of the genus Tetranychus by poly-acrylamide gel electrophoresis. PGI and MDH were considered to be coded on a single locus in all of the species studied. PGI and MDH were considered to be coded on a single locus in all of the species studied. PGI was a polymorphic and dimeric enzyme in T.piercei, T. urticae and T. kanzawai, and so was MDH in T. urticae and T. kanzawai. T. viennensis, T. ludeni, T. phaselus and T. okinawanus, however, showed fixed single bands for both enzyme loci. the elctrophoretic mobilities of the bands of the two enzymes were different amongst the seven species, indicating that the alleles for the two enzyme loci differed among them. We propose that these enzymes, if combined, can be useful markers for the classification of Tetranychus species.

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Gall parasitism by moth larvae in the unisexual galls produced by Andricus mukaigawae (MUKAIGAWA) on Quercus serrata THUNB. in Nose, Osaka, Japan, was surveyed by dissection of the galls. Almost all moth larvae found in the galls were Oedematopoda sp. This is the first record of this genus from insect galls. Overall, 53.4% of A. mukaigawae galls examined were attacked by the moths, but A. mukaigawae larvae were fed on by moth larvae in 12.7% or less of the galls examined. Larval feeding habits of Oedematopoda sp. were examined under laboratory conditions. the moth larvae were able to feed on Q serrata leaves, but preferred unisexual galls of A. mukaigawae. Furthermore, almost all larvae tested fed on artificially exposed larvae or pupae of A. mukaigawae or larvae of Synergus japonicus WALKER, although the results of gall dissection indicate that the moth larvae were usually cecidophages and seldom became predators of gall-formers or inquiline gall wasps under natural conditions. Thus, the well-developed parenchymatous tissues surrounding the sclerenchymas protect the gall-formers or inquiline gall wasps in A. mukaigawae galls from attack by moths.

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The aggregation attractant pheromone of the German cockroach comprises high volatile 1-dimethylamino-2-methyl-2-propanol and alkylamines, and their release from the substrate was controlled by acidic components. Ion chromatographic analysis showed that hydrochloric acid was the major constituent, accounting for 81% of the total equivalent of anions. Methylated organic acids analysed by GC-MS comprised 4-(methylsulfinyl)-butanoic, oxalic and lactic acids and other dibasic and hydroxyl acids. The attractiveness of each amine mixed individually with hydrochloric, nitric, sulfuric and the three major organic acids was evaluated by olfactometer assay. the mixtures with hydrochloric acid showed almost the same attractiveness as those with the natural acidic fraction. The most active mixtures were those with 4-(methylsulfinyl)-butanoic acid, and the activity was retained irrespective of the increase in the amount of acid. The attractiveness of trimethylamine hydrochloride assayed at various humidities indicated that the release of an amine from salt is modulated by humidity and reduced in moist conditions.

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The stink bug, Pyrrhocoris sibiricus, is a ground-dwelling seedfeeder. The effects of temperature and photoperiod on nymphal development and adult body size were investigated under six rearing conditions with different temperature (20, 25 and 30°C) and photoperiod (12L-12D and 16L-8D) regimes. The survival rate in the nymphal stage was higher and the nymphal developmental period was shorter at higher temperatures. Adult body size in terms of body length became larger with increases in temperatures. Adult body size in terms of body length became larger with increases in temperature, and was largest at 30°C under 12L-12D. These results showed that this species is adaptive to high temperatures. In the field, the body size of adults that emerged from mid-August to late September was largest (SAKASHITA, unpublished data). This coincided with the fact that adult body sized was larger at high temperatures under short day length. The nymphal developmental period of this species was shorter under 12L-12D than under 16L-8D at 20°C. It is considered that this leads to completion of nymphal development before the onset of the winter season.

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Methanol extracts from 84 samples of 49 Indian plant species in 30 families were tested for insecticidal activities against the brown planthopper (Nilaparvata lugens STA^^°L), using a topical application method. The activity varied with both plant species and tissue sampled. At a dose of 0.5μg/female, the following 11 extracts indicated significant insecticidal activity: Adhatoda vasica leaves (100% mortality), Annona squamosa seeds (100%), Nerium indicum stems (100%), Clerodendrum inerme whole plants (90%), Pongamia pinnata seeds (95%), Prosopis chinensis stems (90%), Vitex negundo leaves (90%), Azadirachta indica seeds (89%) and stems (85%), Aegle marmelos leaves (88%), and Madhuca indica seed oil (88%). However, the extract of A. squamosa seeds alone exhibited significant activity (100% mortality) even at 0.25μg/female. As naturally occurring insecticides, these tropical plant-derived materials could be useful as an alternative for synthetic insecticides in management of field populations of N. lugens.

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Three criteria necessary for larval overwintering of Spodoptera litura were determined from the results of laboratory and field experiments in order to predict the overwintering areas of this insect in Japan. the first criterion is for the daily minimum temperature in winter to be higher than -5°C, which is the lethal low temperature of the larvae. On the other hand, larvae are known to require a daily effective temperature for development (DET) of more than 0.9 degree-days (DD). this necessary DET is decided in accordance with cold intensity and duration of sub-zero temperatures per day. Surplus or deficient DET for long term survival of larvae per day was calculated by subtracting the necessary DET from the actual DET. Consequently, the second criterion is summarized as follows: cumulative surplus DETs≧cumulative deficient DETs in winter (Dec. 15th to Mar. 15th). The third criterion is for the number of consecutive days with deficient DET to be 30 or less. these three criteria must be met in order for overwintering of S. litura larvae to occur. the likely overwintering areas of S. litura in Japan were predicted by analyzing temperature data of the Automated Meteorological Data Acquisition System (AMcDAS) on the basis of the three criteria mentioned above.

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Cell lines were established from pupal ovaries of the common cutworm, Spodoptera litura, SL7B cells, one of the cell lines established had a doubling time of about 20.8 h at 28°C in TNM-FH medium. Results of isozyme analysis showed that this cell line differed from five other lepidopeteran cell lines. The karyotype was typical of lepidopteran cells, containing numerous microchromosomes, with an average of about 147±60. Wild type Autographa californica NPV and recombinant viruses containing chloramphenical acetyl transferase (CAT) and hepatitis B surface antigen (HBsAg) gene were used to evaluate the expression of enzyme and virus occlusion body formation in SL7B, SF21AE, and SF9 cells. The SL7B cell produced 2-3 fold more CAT protein than did SF21AE and SF9 cell lines, and produced 1.5-2 fold more occlusion bodies than the other two cell lines.

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Ovipositional behaviour, diel periodicity of oviposition and egg distribution on the host of the parasitoid fly, Exorista japonica were studied in the laboratory. The hosts provided were larvae of Mythimna separata. The rate of adult fly emergence, and the number of eggs destroyed by hosts were also examined when one egg per host was laid on different body segments of a host. When provided with two hosts every 4 h from 22:00 on day 4 for 4 consecutive days, females laid more eggs in the morning and the rate of oviposition reduced with the passage of time towards evening; no eggs were laid during the period of darkness. The mean number of mature eggs, determined by dissection, showed a similar tendency to oviposition with a peak just after the end of the dark period and a subsequent decrease, although the decline was not statistically significant. When hosts were provided for the flies at 08:00 and 20:00 for 60 min each, no significant difference was found between the number of ovipositions at each time. Therefore, there is the possibility that the diel periodicity of oviposition of E. japonica was influenced by the number of mature eggs, which accumulated mainly during the night. The eggs laid on a host were concentrated on the head and thoracic segments when 1, 2 or 3 eggs were laid per host. When one egg per host was laid on different body segments, the rate of adult emergence followed a U-shaped curve, being lower on the 6th and 7th abdominal segments, which may have been mainly due to the host's ability to remove or destroy eggs laid on its body. These results suggested that E. japonica females selectively oviposit on certain parts of the host's body, an adaptation to the defence behaviour of the host.

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Alkylamines, aminoalcohols, and alcohols related to the aggregation attractant pheromone of the German cockroach were examined for their attractiveness to nymphs by using a linear track olfactometer. Free amines and aminoalcohols, which were too volatile to be retained on a dispenser, were continuously applied as aqueous solution onto the air-intake of the olfactometer, and amine hydrochlorides were dispensed on metal disks as dry material to simulate the natural condition where the attractant amines occur as salt. All the examined C1-C6 alkylamines including primary, secondary and tertiary amines represented both chemotaxis and anemotaxis, potencies of which were evaluated as ED₅₀ by probit analysis. the potencies of free amines were almost the same: chemotaxis ranged from 0.56 nmol/min of trimethylamine to 4.1 nmol/min of pyrrolidine, whereas those of hydrochlorides were separated into moderately active primary and more active secondary and tertiary amine hydrochlorides. In the aminoalcohols structurally related to the principal pheromonal component 1-dimethylamino-2-methyl-2-propanol, 1-dimethylamino-2-propanol was the most potent at 0.0098 nmol/min.

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The annual life cycles of Tetranychus urticae populations were studied in four different Japanese pear orchards in Ibaraki Prefecture, central Honshu. some mites overwintered on weeds in the orchards without entering diapause, and others entered diapause and passed through winter in bark crevices of pear trunks and within the strands of vinyl binding ropes used to bind the branches to a trellis. The seasonal prevalences of mite populations in the four pear orchards were similar, but their abundances varied greatly. Population peaks appeared in July and/or from September to early October. The population peak in July was formed by mites that migrated from ground cover vegetation onto the pear trees in spring. Thereafter, mite densities remained at low levels throughout the summer, and a second peak occurred in autumn. In years in which there was a single population peak in autumn, few or no mites appeared on pear leaves during the period of the preceding spring to summer, suggesting that the autumn mites were immigrants from other places, such as neighboring pear orchards. At 18°C and 10 h of light, the incidence of diapause varied from 15.6 to 67.7% among the four populations. In the filed, the proportion of diapausing females reached 50% between mid-September and early October. Although diapausing females had overwintered in the pear bark crevices and vinyl binding ropes, the number of females gradually decreased as the season progressed. This decrease may be because some females came out of diapause in response to occasional warm days in winter and migrated onto the ground cover vegetation and/or died from starvation during subsequent cold and dry periods.

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A housefly (Musca domestica L.) strain highly resistant to pyriproxyfen, a juvenile hormone analog, was established by laboratory selection of houseflies collected from the 3rd Yumenoshima dumping-island in Tokyo Bay, Japan. the strain developed 4, 900-fold resistance to pyriproxyfen in the 3rd instar larvae by the 17th generation from a level of only 3.8-fold before selection and thus was named YPPF strain. Genetic analysis of pyriproxyfen resistance in YPPF houseflies revealed that resistance to pyriproxyfen in this strain was incompletely dominant and multifactorial. There were at least 4 dominant factors responsible for the resistance, with the most important factor being located on the 2nd chromosome and other factors on the 1st, 3rd and 5th chromosomes. Furthermore, bioassay of synergism showed that the resistance ratio in white pupae of houseflies was depressed to 29-fold from 400-fold by a cytochrome P450 inhibitor, 2-propynyl 2, 3, 6-trichlorophenyl ether (PTPE). These results indicate that P450 monoxygenase plays an important role in housefly resistance to pyriproxyfen.

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The activity of acetylcholinesterase (AChE) of cultured insect cells was measured. A mosquito cell line, NIAS-AeAl-2, showed the highest activity, and a flesh fly cell line, NIH-SaPe-4, the second highest, whereas two Drosophila cell lines showed no activity. Several lepidopteran cell lines showed low activity, and some cabbage armyworm cell lines and silkworm cell lines did not show the activity. In the culture of the NIH-SaPe-4 cells, activity was low right after the seeding of cells. It increased during the first two days of the culture, and then decreased. AChE activity appeared, and increased in the culture media as the culture progressed. When eserine sulfate, an inhibitor of AChE, was incorporated into the culture medium, the growth of the NIH-SaPe-4 cells was not affected by the AChE activity of the cells decreased. The AChE of the NIH-SaPe-4 cells showed strong affinity to acetylthiocholine compared with s-butylthiocholine.

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By screening Drosophila melanogaster strains harboring single P-element insertions for aberrant mating behavior, we isolated a mutant named spinster (spin^pl), in which the females had subnormal receptivity to copulation. The spin^pl females continuously display rejection behaviors typical of immature virgins such as decamping, kicking, and fending in response to courting males. Excision of P-element inserted at 52E in the spin^pl mutant resulted in phenotypic reversion to wild-type, indicating that the spin locus at 52E is responsible for altered receptivity in the mutant females.

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