1. Microclimatic temperatures of environments such as those of store-, green- or vinylhouses as well as of underground during the winter all of which may serve as a hibernation shelter of either maggots, pupae or flies will alter the judgement a little on the possibility of establishment in the oriental countries hitherto described basing upon the macroclimatic grounds.
2. Outdoors almost no host plants of melon fly are found during the winter of the oriental countries. On the other hand for the oriental fruit fly various kinds of citrus fruits are on the trees. They are however green and hard. Unless they are readily available, the survival is sure to be highly difficult, because the life of the both pests is never longer than 10 days during the midwinter of Japan.
3. The number of individuals actually introduced into northern countries in the past had to be negligibly small. This will hold true also in future. The percentage of mortality sustained by the insects during exposures to the experimental low temperatures as well as during starvation for only a short period is always exceedingly high.
4. The general conclusions we arrived at finally are as follows:
Eggs, maggots and pupae each may be able to live and develop to the adult stage and the flies may reach maturity and oviposit with success during the warm seasons extending from spring to autumn in the temperate countries. But they will be unable to survive the winter cold in their preimaginal periods in these areas excluding Ryukyu Arch., Ogasawara Is. and Izu Is. If food is unavailable, the same may hold equally good in the case of adults. If there is a sequence of favorite hosts, the overwintering of the adult flies may not be always impossible in the west-southern half of Japan. The facts that the insects exposed experimentally to the winter low temperatures of the temperate climate always suffer a significantly high mortality and that the chances of spread and the individuals that could reach successfully, have been neither frequent nor large in numbers will tell why they have never become established in those countries. We suppose that this may be true also in future.

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An improved method for eliminating the effect of variance in body weight on the result of the bioassay experiment of PCP for the ‘Dojo’ fish was presented in this paper.
1) A linear relation was obtained between the log body weight of ‘Dojo’ fish and the log lethal time in various concentrations of PCP.
2) The time at the average body weight of all fishes tested in the regression line mentioned above was considered as the median lethal time. The median lethal concentration derived from the relation between the median lethal time and log concentration coincided well with the result obtained by the usual median lethal concentration is evaluated at 24 hours after dipping.
3) The median lethal concentration determined from large numbers mentioned above also coincided completely with that determined from small numbers.

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Resistance problems of the injurious insect pests of fruits are becoming more serious in recent years because of the mass-application of insecticides and acaricides. This paper reported, in relation to development of acaricide resistance, the results of acaricide application on apple orchards for controling the European red mite, Panonychus ulmi (KOCH), during four seasons from 1959 to 1962.
1. Tedion (2, 4, 4', 5-tetrachlorodiphenyl sulfone), first used in 1959, was highly effective against the mite, on these test field. Two seasons after, however, the tedion resistance in the mite developed as high as 61 times in LC-50 as compared with a non-resistant population.
2. Slight resistance against Miteran (Sappiran 25 per cent and DMC 25 per cent) and Sappiran (p-chlorophenyl-p-chlorobenzene sulfonate) developed as a result of application in the field. Also a lot of the San Jóse scale and the mulberry scale, Pseudaulacaspis pentagona TARGIONI occurred in the test field.
3. Resistance to Phenkapton (o, o-diethyl-s-(2, 5-dichlorophyenyl mercapt methyl) dithiophosphate) was found from the first season in the test, but it seemed to be cross-resistance to Parathion which had been sprayed several times before the test as initiated.
4. Kelthane (1, 1-bis (p-chlorophenyl) 2, 2, 2-trichloroethanol) and Akar (ethyl 4, 4-dichloroben-zilate) were both effective against the mites which selected with either Tedion, Miteran, Sappiran or Phenkapton.
5. Phenkapton-resistant mites were most effectively controlled with Pestan (ethyl-n-(diethyl-dithiophosphoryl acethyl)-n-methyl carbamate) and Metasystox (o, o-dimethyl o-2-ethylmercapto-ethylthionophosphate).

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A 2³ factorial experiment on alternative storage conditions for insects before and after treatment and the adjuvant effect of soy bean oil to solvent in topical application was designed to test toxicity of p, p'-DDT against the common house fly, Musca domestica vicina MACQUARDT. The house flies were stored in either at 30°C or 20°C for 24 hours before treatment, and also in either 30°C or 20°C for 24 hours after treatment. Soy bean oil was used as a 2 per cent (v/v) solution in acetone. As is seen in the estimated relative dosage values or relative potencies shown in Table 6 or 7, among the three factors concerning the toxicity of p, p'-DDT against the common house fly, the effect of storage temperature after treatment was much bigger than that of storage temperature before treatment, and the adjuvant effect of soy bean oil was the smallest. The toxicity of DDT in lower temperature was bigger than that in higher temperature, and it was verified from this experiment that the temperature coefficient of the lethal action of DDT to insect is negative for some range of temperature. The adjuvant effect of soy bean oil added to acetone was also recognized to some extent.

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The susceptibilities to insecticides of the green rice leafhopper (Nephotettix cincticeps UHLER) and the smaller brown planthopper (Delphacodes striatella FALLEN) were determined by the microtopical application method. The method used here was modified from that of KERR described on the microdevice for application of toxicants by microburett. The main modifications were as follows. a) The solution of toxicants was driven out by means of low pressure of air supplied from a pulsating type pump connected with the microburett, b) ethyl alcohol was used as the solvent, and c) the volume of toxicants applied to each insect was measured by the scale engraved on the microburett, therefore all operations were carried out without using the darkroom.
Though there are some problems to be improved such as the measurement of variation in the volume of toxicants applied to each insect and the manipulation of test insects especially of the male of the smaller brown planthopper, this method was useful for the authors' purpose.
The seasonal fluctuations of susceptibility of the green rice leafhopper to malathion, DDT and carbaryl were determined and it seemed that any difference was not recognized in the susceptibilities among the hibernated, first and fourth generations.
Distinct differences were recognized between the green rice leafhopper and the smaller brown planthopper, in both the order of eight insecticides tested and their lethal doses.
With both species, the susceptibility of female adult was lower than that of male adult even in lethal dose of toxicant per body weight.
In comparison with the data reported by KOJIMA et al., it was considered that the green rice leafhopper collected in Chikugo city might be different in the susceptibilities to some of the tested insecticides from that of collected in Odawara city.

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In an effort to develop the suitable synthetic food medium for rearing the rice stem borer for successive generations, it was found that female insects of the borer require ascorbic acid in their larval food.
In this paper, the relation between the electrophoretic pattern of haemolymph protein of female larvae and their fecundity is examined, in connection with nutritional role of ascorbic acid in their food.
The results obtained were summarised as follows:
1. If the larvae were fed to the diets lacking in ascorbic acid, the concentration of all the fractions of the haemolymph protein reduced remarkably as compared with that of normal larvae.
2. The concentration of a globulin fraction moving to anode side, increased with increase of ascorbic acid level in the diets up until 100mg per 100g of diet.
3. It is supposed that the inspection of protein fractions in haemolymph by means of an electrophoresis is a useful method for estimating physiological weakness of insects.

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Thin sections of epidermal cells of the larvae of Antheraea pernyi GUÉR.-MEN. and Samia cynthia pryeri BUTLER infected with the nuclear-polyhedrosis viruses revealed some of their developmental stages. In the early stage of infection, a chromatin mass appeared in the center of the nuclei to which many virus rods attached. These rods were released into the surrounding nucleoplasm, where the rods acquired developmental membranes singly or in groups of up to 14. The membrane-covered rods became enclosed within polyhedra. In the late stage of infection the central chromatin mass dissappeared and the nuclei were filled with many polyhedra. The nuclear-polyhedrosis viruses of A. pernyi and Bombyx mori were experimentally transmitted to S. cynthia pryeri. These viruses retained their morphological characteristics even if they multiplied in the new host.
The nuclear-polyhedrosis virus of Hyphantria cunea DRURY was larger in size than the viruses of A. pernyi and S. cynthia pryeri. There were from 2 to 14 rods within one developmental membrane.

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Carbohydrate composition of the honeydew excreted by Ceroplastes pseudoceriferus (GREEN) and of tea twigs on which the the scale insects live, were analyzed by paper chromatography.
In the honeydew, glucose, maltose, raffinose, stachyose, ribitol, and D-mannitol were detected. Ribitol and D-mannitol were isolated as crystals from the honeydew. Carbohydrate composition of the honeydew varies with clones of tea plant on which the insects live.
In the tea bark, fructose, glucose, sucrose, maltose, raffinose, stachyose, and ribitol were detected. The relative amount of these carbohydrates was assumed to be in the following order: sucrose>glucose>fructose=raffinose>maltose=stachyose>ribitol. The presence of D-mannitol could not be confirmed in the tea bark.
From these results obtained it was suggested that Ceroplastes pseudoceriferus (GREEN) living on tea twigs mainly utilizes fructose and sucrose contained in their food. It is possible to assume that ribitol ingested by the scale insect was excreted without any change.
The fact that the reducing sugars content of the honeydew of the scale insect is remarkably smaller than that of aphids, seems to indicate that waxy substances of the scale insect would mainly be originated from the reducing sugars in the tea plant.

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The pupa of the Asiatic common looper, Autographa nigrisigna WALKER, shows colour diversity dependent on temperature; it becomes deep black in colour when reared at 20°C or lower, yellowish brown when reared at 30°C, and intermediate coloured when reared at 25°C.
1) As a result of experiments in which temperature was reversed at various stages of development, it is found that the pupal colour is determined by the environmental temperature received during the period ranging from the middle stage of the larval period to hardening of the pupal cuticle after pupation. The temperature received before this period has no influence upon the pupal colour.
2) When the temperature conditions change at the beginning of the last (5th) instar period or prior to it, the pupal colour was largely affected by the temperature after the changing, regardless of the temperature sequence; low (18°C) to high (30°C) or high to low.
3) In cases of changing the temperatures at various age of the last instar period, the effect of the second temperature was far more remarkable when the change is made from low to high. In general, this high temperature after the low strongly eliminated the effects of the preceding low temperature. The low temperature after high was less effective for producing high percentage of intermediate-type pupae due to the incomplete eliminating effect of the preceding high temperature. The colour grade of intermediate-type pupae obtained by this experiment varied with the mode of temperature changing.
4) Wing pattern, wing shape or other characters of the adults of Autographa nigrisigna showed no appreciable difference between those emerged from black-type and yellowish brown-type pupae.
5) When the insects were ligated between the 2nd and the 3rd abdominal segments at early prepupal period at which the temperature was changed from high (30°C) to low (18°C), the pupal cuticles were melanized only in the part anterior to the ligature. In the same series of experiment where the temperature reversal was made from low to high, however, the pupal cuticles were yellowish brown without black spots in both anterior and posterior parts. It is considered that the centre of response to low temperature may exist in some part anterior to the 2nd abdominal segment of the larval body, and that the transmission of some factor towards the posterior part may be prevented by ligation. It seems that this factor is of endocrine nature. When the temperature changed from low to high, the reaction of melanization is supposed to be suppressed in every part of the body directly by high temperature following ligation, since it was possible that the darkening reaction was already progressing in both parts prior to the time of temperature reversal.
6) Although there were some differences in the actual range of colour grade among species, the fourteen species of Plusiinae so far examined showed the similar tendency of the pupal colour response to temperature as Autographa nigrisigna, that is, the melanization of the cuticle increased under low temperature and reduced under high temperature.

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[in Japanese]

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Biology of Bledius salsus MIYATAKE, the most injurious species of insect in the clay-bed of the sloping salt-fields of Japan, was investigated.
1. This species of Staphylinid beetle usually has three generations a year, whereas a small number of individuals appears to have four generations. Overwintering is done in the adult stage with exceptional individuals hibernating in the pupal stage.
2. There are three egg laying periods as follow: the first period lasts from midApril to the end of May or the beginning of June, the second period from the latter part of June to the middle or end of July, and the third period from the latter part of August to the latter part of September.
3. The developmental stages are: egg 14∼20 days, larva 40∼50 days, prepupa 2∼4 days and pupa 6∼8 days under natural conditions.
4. Five instars are observed in the larval stage.
5. Length of the life for the adults of both sexes is 20∼40 days during the warm season and 2∼4 months or more in winter.
6. Egg laying seems to take place two to three times during the life of the female, only 5∼10 eggs each.
7. Most of the activities of the adult, such as flying, creeping, burrowing galleries in the clay-bed etc. take place at night. The beetles show a marked positive phototaxis, especially to a fluorescent lamp.
8. The copulation probably takes place in a characteristic breeding room of the gallery which is relatively larger than other chambers. Egg laying might also take place in these rooms.
9. The feeding habits of the adult and larvae have not been clearly determined, but abundant organic matter in the clay particles of the bed may be utilized as food.
10. All the developmental stages inhabited in the salt-fields particularly in the clay-bed near the sea-water supply.
11. Distribution of Bledius salsus is wide and cover all the existing salt-fields in Japan.
12. Damage of the clay-bed is due to the destruction of the surface conditions, and the clay-bed proper. This results in reduction of the salt-water concentrating efficiency, and leakage of the salt-water through the clay-bed.

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