The species composition and abundance of the chironomid midges were investigated by using a board trap during the period from March to May 1994 at three different stations along the shoreline in the eastern part of Lake Kawaguchi. A total of 38,498 adult midges were collected, the great majority (98.4%) of which were Biwatendipes tsukubaensis Sasa et Ueno. This was followed by Glyptotendipes tokunagai Sasa, (1.1%) and then a very low representation of Chironomus yoshimatsui Martin et Sublette and C. plumosus Linnaeus (0.5%). The dominant species of chironomids which emerged from the littoral region of the lake, however, changed with the month. First, massive emergence of B. tsukubaensis began from mid-March to late April, and then G. tokunagai from late March to early May. From mid-April, C. yoshimatsui emerged and was followed by C. plumosus. Thus, the period in which the four main chironomid species continuously emerged was from mid-March to early May. Therefore, throughout the spring season people living around the lake have the strong impression that the nuisance of chironomid midges has continuously increased and that these are attracted to the light of hotels, houses and some buildings during the breeding season.

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Determination of the chemical properties of the venom of Chiracanthium japonicum, which is well known as the most medically important spider in Japan, was studied. The venom was prepared by dissecting out the venom glands from mature female spiders. Then the glands were homogenized in phosphate buffer solution (PBS) with a glass homogenizer. The clear, viscous surpernatant obtained by centrifugation was stored in a small vial and regarded as the crude venom. This venom was fractionated on a Sephadex G-200 column. The white mice (JCL) were injected intraperitoneally with 0.2ml of different concentrations of the fractionated venom. The lethal activity was noted. Lethal activity was fractionated on a CM Sephadex C-50 column. The fractions were regarded as the purified venom. The toxic responses to mice were dyspnea, prostration, flaccid paralysis and death. The lethal activity was determined to be neurotoxic in action. The minimal lethal dose (MLD) of the purified venom for mice was 10μg. The house-fly was used for the toxicity test. The LD_<50> was 0.069μg/honsefly. The erythematic activity on rabbit hide was examined by injecting the venom intradermally. The minimal redness dose (MRD) to evoke 10×10mm size of redness in the rabbit was 0.7μg. The molecular weight of purified protein was 63,000±2,000. The toxicity to mice was completely destroyed by heating at 60℃ in 10 minutes and lost at 0℃ in five to seven days.

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Efficacy of several insecticides against a main vector of Chagas disease in Guatemala, Triatoma dimidiata (Hemiptera; Reduviidae) was evaluated in the laboratory. Diazinon, fenitrothion, permethrin and propoxur were found to be effective showing high mortality of more than 90% at a dose of 250mg/m^2 within 24 hours. The knockdown effect of these chemicals to the 3-5 instar nymph and the adult was lower than that to the 1st instar nymph. Although 100% mortality was obtained with 240- and 60-minute-contact to almost all the insecticides, the mortality with 15-minute-contact varied between 46.7% and 96.7%. The high knockdown effect of permethrin lasted for 57 days, while the residual effect of the other 3 compounds was reduced steeply. When the nymphs were arbitrarily exposed to the insecticide in their hiding place, the mortality after 24 hours increased in a dose-dependent manner (from 2.5mg/m^2 to 250mg/m^2 of the active ingredient). The mud wall (bajareque) decreased the knockdown effect of 7 formulations. Emulsifiable concentrations of permethrin and etofenprox showed quick action with filter paper while they were affected by the absorption property of the wall. These results suggested that the selection of formulation was important for field application as well as the selection of insecticides.

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An investigation of the life history of Boettcherisca septentrionalis Rohdendorf was made in Nagasaki Prefecture, Western Japan from January 1990 to December 1994. A trap baited with horse meat was maintained at each of 3 altitudes, 5m, 500m and 1,000m, on Mt. Gokahara-dake. The number of flies captured was recorded once a month. The larvae and pupae which had bred from meat in the trap were also counted and transferred into a separate trap for emergence. The middle region of the mountain was considered as a primary habitat of this flesh fly. At altitude 5m, all pupae were observed to enter diapause in fall. At altitudes 500m and 1,000m, most pupae entered diapause, but some adults emerged in fall and might be overwintered at the middle of mountain. Adults emerged at altitude 1,000m probably migrated to the middle of mountain for hibernation before winter. After hibernation, males and females copulate in April, and females migrate again to higher altitudes for larviposition in early summer. From diapause pupae, adults emerged in May (alt. 5m), May to June (alt. 500m) and May to July (alt. 1,000m). All life stages were observed during summer when it seems to be the best season for breeding at all altitudes (51,000m). Boettcherisca septentrionalis is a long day insect and have 1-2 generations during summer in Western Japan.

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The mature larvae of the flesh fly, Boettcherisca peregrina, normally required 12 days to develop to adults at 25℃ in dry condition. When the mature larvae were immersed in water, their development was arrested. However, their further development was resumed when they were transferred to dry condition. The rates of survival and adult emergence in the mature larvae did not change during 10 days of immersion but these rates decresed to zero by the additional immersion for another 5 days. During immersion for 14 days, the total lipid content of the immersed larvae decreased drastically from 6% to 1% of body weight, although that of the normal developing larvae placed in dry condition did not decrease markedly. One of main fatty acids in the lipid of B. peregrina was arachidonic acid and this fatty acid comprised of 10.5% in the total fatty acids extracted from the mature larvae. During normal adult development, absolute amount of arachidonic acid decreased to 43% of that in the normal mature larvae. This decrease was more conspicuous in larvae immersed in water. The amount decreased to 22% after 10 days and 9% after 14 days immersion, respectively. Whereas other fatty acids did not decrease so marked as arachidonic acid. These results suggest that there may be a threshold content of arachidonic acid to complete successful larval-pupal and pupal-adult development in B. peregrina.

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Anticoagulant activities of the salivary glands (SG) of the blood sucking kissing bug, Rhodnius prolixus, were analyzed. The crude SG extract showed strong activity to prolong activated partial thromboplastin time (APTT) and also weak activity in elongation of prothrombin time (PT). Inhibition activities of SG extract to the factors in the intrinsic and common coagulation pathways were analyzed. SG extract showed high inhibition activity to the IXa/VIIIa/phospholipid (PL) complex (Xase complex) and low to serine protease, kallikrein, factor XIIa, and factor IIa. However SG extract did not show inhibition activity to factors XIa and Xa. These results indicate that SG contains a strong inhibitor of Xase complex in the intrinsic coagulation pathway and an inhibitor of factor IIa in the common pathway. Both anticoagulant factors were separated into two fractions by gel filtration (GF).

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Proteins in venom glands of Latrodectus hasseltii collected in Osaka area were analyzed by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Several main bands with molecular weight of 110-120kD were clearly recognized after protein staining. Around 45kD area several distinct bands were also presented and another many bands were presented from smaller than 20kD to greater than 200kD. Monoclonal antibodies against α-latrotoxin of L. tredecimguttatus bound to 110-120kD bands and also 45kD bands. Lyophilized venom gland-extract imported from Australia showed a different pattern of protein bands on SDS-PAGE gel, i. e. 110-120kD bands were not clearly recognized as major bands and new band appeared around 77kD area. From the result of binding of monoclonal antibodies to 77kD bands it was suggested that these bands are degraded product of α-latrotoxin. All mice injected with venom gland-extract of one female spider died within 2 days after injection. Lyophilized venom gland-extract showed less toxicity than our preparation of venom glands of the red back spider collected in Osaka-City. Clear decrease of body weight of mice injected with the venom was observed during 2 days after injection. Present results clearly showed that red back spiders collected in Osaka had an α-latrotoxin in their venom glands and the toxicity was not weak referring to previous data of toxicity of widow spiders.

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The normal and insecticide-stimulated antennal and leg grooming activity of Blattella germanica from a laboratory, VPI, and field, RHA strain was investigated. The grooming/min by adult males following exposure to glass plates without insecticide, and with residues of 0.025 and 0.049μg cypermethrin/(cm)^2 (VPI), and 0.049 and 0.392μg cypermethrin/(cm)^2 (RHA) was recorded during 20 min exposure periods. Exposure to insecticide residue caused the antennal grooming/min of VPI strain to increase by more than 3-fold and the leg grooming/min to decrease by more than 3-fold. Exposure to insecticide residue caused the leg grooming of RHA strain to increase by more than 2-fold and the antennal grooming to increase slightly. The differences in the antennal and leg grooming activity between these two strains may be attributed to adaptions to the mass rearing conditions characteristic of laboratory colonies (VPI), and the organic and inorganic debris that may contaminate household substrates of a field strain (RHA).

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[in Japanese]

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Five species of natural enemies are reported for the first time from blackfly larvae in mainland China. The chytrid fungus Coelomycidium simulii infected less than 15% of two species. The microsporidian protozoa Amblyospora bracteata, Janacekia debaisieuxi, and Polydispyrenia simulii infected 2.4% of S. equinum, 8.3% of S. nikkoense, and 3.8% of S. taiwanicum, respectively. The trichomycete Harpella melusinae was attached to the peritrophic membrane of Simulium taiwanicum.

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The fauna and distribution of the blackflies in Hiroshima Prefecture were studied based on the collections of larvae and pupae from streams and of adults flying around the collectors at 84 sites in spring of 1993. A total of 8,892 blackflies, 7,313 larvae (82.2% in total number), 1,574 pupae (17.7%) and 5 adults (0.1%), were collected at 83 sites. All these blackflies were classified into twenty species of the two genera Prosimulium and Simulium. Twelve species, Prosimulium (Prosimulium) kanii, P. (P.) kiotoense, P. (P.) yezoense, Simulium (Nevermannia) konoi, S. (N.) mie, S. (N.) subcostatum, S. (Gomphostilbia) ogatai, S. (Gom.) shogakii, S. (Gnus) daisense, S. (Gn.) nacojapi, S. (Simulium) quinquestriatum and S. (S.) rufibasis were newly recorded from Hiroshima Prefecture. The most abundant species was S. (N.) uchidai (40.2% in total number), followed by S. (N.) konoi (13.5%), S. (Gn.) bidentatum (11.9%), S. (S.) japonicum (10.2%) and S. (S.) arakawae (9.9%). The most widely distributed species was S. (N.) uchidai (70 sites), followed by S. (Gn.) bidentatum (33 sites), S. (S.) arakawae (32 sites), S. (S.) japonicum (29 sites), S. (N.) subcostatum (28 sites) and S. (O.) aokii (26 sites).

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