Pristiphora ezomatsuvora n. sp. feeding on the needles of Picea glehnii MASTERS, is described and compared with P. saxesenii (HARTIG).

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Adults of the rice gall midge collected at Prae Rice Experiment Station in Thailand were distinctly larger in body size such as fore wings, halters, femora and tibiae than those of the Central Rice Research Institute at Cuttack and the Chakli farm at Sambalpur in India. Number of ovarian eggs per female was more abundant in Thailand than in India. Abdomen of the insect collected in Thailand was covered with long and soft hairs in contrast to minute and smaller hairs in India. A peak of insect occurrence in paddy fields was seen earlier 30 days, the middle of September, in Thailand than in India where the peak was in the middle of October. It is indicated that geographical differentiation of the rice gall midge has occurred between Thailand and India.

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The population densities of three species of pine bark weevils, Shirahoshizo spp. (including S. rufescens ROELOFS, S. insidiosus ROELOFS and S. pini MORIMOTO), Pissodes nitidus ROELOFS and P. obscurus ROELOFS, living within bait logs (70-80-cm long, 15-20 cm in diameter) of Pinus densiflora SIEB. et ZUCC., were estimated in a pine forset. In all species, the larval density reached maximum at about forty days after the beginning of the attack by adults, thereafter the densities decreased throughout the larval stage. The initial larval density of Shirahoshizo spp. was the highest of all but it decreased rapidly after the peak. While the changes in larval density of P. nitidus and P. obscurus did not show such a great decrease and the pupal density of these species was higher than that of Shirahoshizo spp. A large number of larvae disappeared during their growth period, which accounted for 93.69, 80.75 and 52.00 percent of the total mortality of Shirahoshizo spp., P. nitidus and P. obscurus respectively. Parasitism was a severe factor operating on the old larval stage of Shirahoshizo spp. and P. nitidus, while larvae of P. obscurus seldom suffered parasitism.

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A graphic method for quickly estimating an animal population density and the precision of the estimate in field survey is proposed in this paper. The properties of this method are as follows : (1) The density estimation is made only from the frequency of sampling usits having zero individuals and one individual assuming a negative binomial or Poisson distribution as the spatial pattern of the animal; (2) No preliminary survey before the main survey is required; (3) Estimates of the population density and the precision of these estimates are obtained in the field; (4) If required, one can improve the precision by taking more additioanl sampling units immediately in the field; (5) Much time and effort in counting individuals and estimating their density may be saved by using this method.

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The model ecosystem devised by METCALF et al. (1971) was modified slightly by changing organisms associated with the food chains to fit the local conditions, and the fate of metabolic constituents of organisms in the modified model ecosystem was examined. Sweet-potato leaves labeled with ¹⁴C and ¹⁵N were fed to tobacco cutworm larvae, and the distribution of ¹⁴C and ¹⁵N in the organisms was examined. At the end of the experiment, ¹⁴C concentration per mg fresh weight in the organisms was lower than that in the aquarium water. In spite of the short exposure time to the aquarium water, ¹⁴C concentration of water-soluble and ether-soluble fractions in fish was higher than that in the other organisms. Concentration of ¹⁴C in the ether-soluble fraction of the fish and snail was much higher than that in algae, suggesting that there is an intrinsic difference between animals and plants in the metabolism of lipid and related materials as a reservior of persistent and lipid-soluble chemicals. Incorporation of ¹⁵N into the 80% aqueous alcohol-insoluble fraction of the organisms was low, in descending order of snail, algae and fish. When insect larvar were fed with ³²P-labeled sweet-potato leaves, the distribution of ³²P was highest in the algae, followed by the snail and fish. The results of fractionation of ³²P-labeled metabolites in the organisms showed that the incorporation rate of ³²P into trichloroacetic acid-soluble, lipid, nucleic acid and protein fractions was different among the organisms, and that ³²P concentration per mg phosphours in the snail was high as compared with that in the other organisms. It was suggested that there is large variety in the magnitude of metabolic pool of the three elements among the organisms. It was probable that the three elements show different behaviours in the model ecosystem.

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The author indicated in previous reports (KATO, 1973, 1975) that in Bombyx mori pieces of larval integument, if transplanted to a pupa, produced two different layers of cuticle in the process of pupal-adult transformation. In the present experiments, attempts were made to examine the occurrence of the extranumerary cuticle deposition in transplants by preparing the larval donor from different stages of development and by using hosts possessing different hormonal conditions. Pieces of integument taken from larvae of an earlie instar (1st, 2nd or 3rd) and transplanted to a pupa deposited two different layers of cuticle at a higher rate than those from larvae of later instars (4th or 5th) before the host pupa ecdysed to na adult. When placed in a penultimate or last-instar larva, integument pieces from earlier instars always deposited only a single layer of cuticle at the time when the host moulted to the next stage. The extranumerary cuticle deposition in transplants took place even when allatectomized or decapitated pupae were employed as the host. Furthermore, this evidence was obseved in both male and female pupae as the host.

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The neurosecretory cells (NSC) in the brains of larvae destined for pupal diapause and of diapausing pupae of Mamestra brassicae were compared with those of larvae destined for pupal non-dispause and of non-diapausing pupae histologically and functionally. In the larval stage, the group I-NSC in the medial part of brain showed no differences in stainability with paraldehyde-fuchsin (AF) between the larvae destined for diapause and those for non-diapause. These NSC were stained well in early instars or at the end of the last instar but stained only slightly from the second to the fifth day of the last instar. In the pupal stage, the stainable neurosecretory material of the type II-NSC in medial part was apparent in the brain of diapausing pupae, but was much reduced in the brain of non-diapausing pupae. When NSC-ablated brains or NSC-clusters were implanted into dauer pupae or neck-ligated larvae to ascertain the role of NSC on adult development or pupation, both the medial NSC (MNC) and the lateral NSC (LNC) showed the activity secreting prothoracotropic hormone (PTTH), however, the activity of the MNC being higher than that of the LNC. These histological studies and implantation experiments indicate that the type II-NSC in the MNC of M. brassicae pupal brain may be able to secrete PTTH.

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The role of the sex pheromonal components (Z)-9-tetradecen-1-ol acetate ((Z)-9-TDA) and (Z)-11-tetradecen-1-ol acetate ((Z)-11-TDA) in sexual isolation between the smaller tea tortrix (STT) and the summer-fruit tortrix (SFT) was evaluated. Release rates of the pheromonal components from virgin females were almost equal (1×10^-2 μg/female/night) between the two species. The ratio of the two components, (Z)-9- and (Z)-11-TDAs, was 63 : 37 in STT and 82 : 18 in SFT. Under laboratory conditions, male moths of each species were sexually stimulated more strongly by teh synthetic mixture of conspecific ratio. The difference in the male responses of each species to the two synthetic mixtures was amplified by the difference in the mating times between the two species. Species-specific attraction by virgin females in a field cage, however, was explained by neither the difference in the ratio of the two pheromonal components nor the difference in the time of mating. Intensity and species-specificity of attractiveness of virgin females in comparison with the synthetic mixtures suggested the presence of at least one additional pheromonal component in each species.

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Two compounds were isolated as active components of the female sex pheromone of the peach fruit moth, Carposina niponensis WALSHINGHAM. The major components was identified as (Z)-7-eicosen-11-one, and the minor one was suggested to be (Z)- or (E)-7-nonadecen-11-one. (Z)-7-Tricosen-11-one was also isolated but this compound was not biologically active. (Z)- and (E)-isomers of 7-alken-11-ones of carbon numbers ranging from 17 to 23 were synthesized. Biological activity of synthetic (Z)-7-eicosen-11-one (compound A) and (Z)-7-nonadecen-11-one (compound B) as attractants for male moths was verified in the field. The activity was synergistically enhanced by mixing the two compounds in the ratio of 20 to 1 for compound A to compound B.

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From abdominal tips of virgin females of the Asiatic leafroller moth, Archippus breviplicanus WALSINGHAM, (E)-11-tetradecenyl acetate (compound A) and (Z)-11-tetradencenyl acetate (compound B) were isolated and identified as sex pheromone components. These two compounds were individually inactive, but a potent biological activity was revealed by mixing them. The ratio of compound A to compound B was 70 to 30 in virgin females. Tetradecyl acetate was also detected in virgin females. Mixtures of synthetic (E)-11-tetra-decenyl acetate and (Z)-11-tetradecenyl acetate in the ratio of 75 : 25 to 65 : 35 strongly attracted the male Asiatic leafroller moths in the field. The attractiveness of the mixture of the two compounds (total 1 mg, in the ratio of 70 : 30) was as strong as that of ten virgin females. Tetradecyl acetate showed a weak synergistic effect but dodecyl acetate did not.

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