The experiments were done to clarify the modes of action of some nematocides to American cockroach, Periplaneta americana. The LD-50 values of the nematocides for the adult male of the roach, 72 hours after injection, were as follows: ethylene dibromide (EDB) 0.398μg; 1, 2-dibromo-3-chloropropane (DBCP) 0.955μg; cis-1, 3-dichloropropene (cis-D) 0.059μg.
EDB poisoned insects paralyzed slowly anddied, while insects poisoned with cis-D or DBCP showed hyperactivity and paralysis, and then died. From the entomographic study of nematocide poisoning of the insect, it was found that the insect treated with DBCP or cis-D showed hyperactivity and tremor simultaneously, being similar to the case of DFP poisoning. On the other hand, the insect treated with EDB showed a response of tremor alone.

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This paper describes a technique for mass rearing of rice stem borer, Chilo suppressalis for successive generations on rice seedlings in glass bottles (diameter 10cm, depth 10cm). The rice seedlings were germinated from 50g of rice seeds in the glass bottle, and fifty hatchlings were placed in a bottle and allowed to feed. The larvae were transferred to a new glass bottle with the seedlings after 15 days from the hatch. The pupae were transferred into a plastic box from the glass bottle, and adults emerged were removed to an oviposition net cage, in which the potted rice plant was provided as oviposition site. This experiment was carried out at 25°C with a day length of 15 hours. The results of rearing are summarized in the table.
Chemical constitutions of the mature larvae reared are as follows: water content, 67.6 per cent in live material ; crude fat content, 41.4 per cent and total nitrogen content, 4.77 per cent in dry material. Median lethal dosage of parathion applied topically on mature larvae is 3.30μg per gram of the body weight. These physiological properties were consistent with those obtained from the larvae in the field, indicating that this rearing method is well suited for the practical purpose.

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A word “possible” is used in the title, as QUAYLE (1931) did in the relation of Mediterranean fruit fly to the United States, because the distribution of both flies in Japan, etc. will be possible only in so far as the temperature and host conditions are favorable. Even if there were chances of being introduced from Formosa, Okinawa and other tropical countries, the melon fly (Dacus cucurbitae COQUILLETT) and the Oriental fruit fly (Dacus dorsalis HENDEL) have never been found in Japan, Korea and other adjacent northeastern countries. In order not only to search for the reason why they have not survived in the temperate countries but also to find out whether they can establish there in future, experimental researches were undertaken on the followingitems:
a. Ranges of effective and favorable temperatures for the development and the reproduction,
b. Developmental and reproductive zeros,
c. Total sums of effective temperatures for the development and the reproduction,
d. Least exposures to cold lethal for 100 per cent of the insects in all stages,
e. Longevities of larvae and adults deprived of food in low temperatures,
f. Discussions of the obtained data in comparison with the actual distribution and abundance of the flies in the world.
All the temperatures treated were constant, varying and gradually falling ones actually found in the cold seasons of the temperate climates.
Abbreviations: A: adult flies, E: eggs, G: gradually falling temperatures, K: constant temperatures, M: maggots, P: pupae, V: varying temperatures.
The present report includes the results of items a, b and a part of f.
1. Temperatures concerning development and reproduction determined experimentally are shown in the accompanying table.
2. The favorable temperatures for the development and the reproduction shown above tell very well the actual status of the distribution and abundance of both flies as well as the natural infestations of fruits and vegetables in the world.
3. It was suggested from the experiments of favorable temperatures that, because the mean temperatures of the coldest month are lower than 8°C and those of the warmest one are higher than 16° in Japan and in the neighbouring countries, the insects in all the stages will either become inactive or fall into cold death in winter of these countries, though in warm seasons the development and the reproduction may take a place.
4. Agreement was found in regard to the relation between the developmantal and the reproductive zeros and the actual distribution of both species in the globe.
5. The development and the reproduction of both flies will cease in winter in the areas north of the line connecting Hachijo Is. to Tokara Is., though in the southern islands such as Hachijo, Ogasawara, Okinawa and Formosa they can no doubt live throughout a year, for the isothermal line of January temperatures of 10°C runs completley coinciding with the line above mentioned.

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Altitudinal distribution and variation of such biological characters as age distribution, mortality in each stage and the development of ovaries of adult females of overwintering populations of arrowhead scale, Prontaspis yanonensis KUWANA collected from nine stations which were arranged along the western and eastern slopes of Mt. Unzen, Nagasaki Prefecture were studied in March of 1953.
The altitudinal distribution of arrowhead scaleranged from the seashore to 280m above the sea level. On the upper part of this range, it was observed that the population density of arrowhead scale become lower and other scales such as Pinaspis strachani and Lepidosaphes gloverii appeared instead.
The age distribution of arrowhead scale from each stations were compared. Almost of all the living scales were immature or mature adult females. The number of living individuals per one leaf was 10 to 20 at the stations which ranged between 20 and 150m in altitude and less than 10 individuals at the stations between 150 and 280m in altitude. At the high altitude stations, overwintering stage was restricted in adult females only. On the contrary, some of the young larvae of both sexes were overwintered at the low altitude stations. The most survivals of the overwintering populations were consist of females. The percentages of survival of each stages were 5 to 20% among young larvae and 50 to 90% among immature or mature adult females. Any significant differences of the percentage of the survivals among stations were not observed.
The development of ovum was examined by the dissection of ovaries of adult females. More of the developed ovum were found in the samples from the lower stations than that of higher stations. The number of developed ovum per one female was generally proportional to the altitude of collecting stations.

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The embryonic and larval development of the root-lesion nematode, Pratylenchus coffeae was studied.
1. About 40 per cent of newly deposited eggs of the nematode were in two-celled stage, about 30 per cent in one-celled stage, and 30 per cent or so in three-celled stage in summer at 30∼33°C.
2. The following is the time-table of the embryonic development of this nematode:
3. The first molt of the nematode occurs in egg-shell. The time necessary for the embryonic development in water ranged from 6 to 8 days at 28°∼30°C.
4. Three molts occur after hatching, during the larval development in potato tubers.
5. Body length of the molting larvae, the development of gonads, stylet length and position of excretory pore for the larvae of every stage are described in the text. By some of these criteria, the stage of larvae is to be distinguished in ecological investigations.
6. Sex of this nematode is distinguishable in the fourth (pre-adult) stage of larvae by the structure of the gonads, while the external appearance of aged fouth-stage males differs from that of females.
7. In water, superimposed molts were found and tiny adult females which bear two undiscarded cuticles were observed in survival investigations.
8. The life span of the nematode in potato tubers was about 27 days in average, under optimum temperature conditions (at 25°∼30°C). Days required for the larvae to complete every stage were not ascertained because of their individual variability, but adult nematodes began to appear in about two weeks after hatching and gravid females in three weeks.

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Eight species of mites of family Tarsonemidae, four of which are new species, were described.
1. Tarsonemus fusarii COOREMAN, 1941 (Figs. 1-2)
This is the first record of T. fusarii from Japan (Kyushu). Some females collected from a withered grass were reared individually on decayed pear leaves to produce young. Offsprings were examined morphologically.
2. Tarsonemus pallidus BANKS, 1899 (Figs. 3-4)
This particular species was recorded for the first time in Japan (Honshu), as an injurious pest of cyclamen in greenhouse. Though BEER (1954) placed this species in genus Steneotarsonemus, SCHAARSCHMIDT (1959) returned it to genus Tarsonemus, according with the shape of its gnathosoma. The author agrees to the SCHA-ARSCHMIDT'S opinion.
3. Tarsonemus yoshidai ITO, 1962 (Figs. 5-6)
Characteristics of the females were described for the first time in this paper.
Body length including palpi 208, width at widest level 105. Anterior median apodeme distinct almost for its entire length. Transverse apodeme curved forward at both sides of jucture of anterior median apodeme with transverse apodeme. First ventral propodosomal seta situated just behind apodemes I. Second dorsal propodosomal seta about four times as long as the first. Sixth dorsal hysterosomal seta about four times as long as the fifth.
4. Tarsonemus sasai ITO, 1962 (Figs. 7-8)
The previous description of this species was based only on a male specimen. Recently, we found a number of the mite from Evodia-plants.
The female characteristics are described for the first time in this paper. Body oval, in life dark blue, 150 long, 93 wide. Propodosomal shield covering more than the posterior half of gnathosoma, but so variable the feature individually, may be by the mounting technique. Anterior median apodeme distinct only in its anterior half. Transverse apodeme simple. Second dorsal propodosomal seta about one and a half times as long as the first. Tibiotarsus I with a dorsal clavate, annulated sensal seta, situated at mid-length of the segment, with a group of three sensillae. Tarsus II with a clavate, annulated sensal seta and a spine, both situated dorsal near base of the segment. Each dorsal seta of femur II and genu II stout.
5. Tarsonemus evodiae, n. sp. (Figs. 9-11)
Male: Body oval, length from tip of palpi ot posterior end of genital papilla 150, width at widest level 85. Capitulum chestnut-like. Genital papilla subcoadate. Second dorsal propodosomal seta somewhat shorter than the first. Fourth dorsal propodosomals situated slightly behind and lateral from the third. Tarsus I with a dorsal, clavate, annulated sensal seta, about two thirds as long as the segment. Tarsus II with a dorsal long clavate, annulated sensal seta, and with a small spine, situated at behind midlength of the segment. Femur IV 30 long (measured outer margin), distal two thirds of inner margin somewhat expanded, distal third of inner margim creased; proximal seta 4 long; distal ventral seta 16 long; dorsal seta 6 long, situated apical sixth of the segment. Tibia IV 12 long, 6 wide, inner margin concave; dorsal rod-like seta 4 long, situated at the mid-segment; ventral seta about 33 long Claw IV strong, the distal end rounded.
Female: Body oval, 183 long, 115 wide. Capitulum broad, chestnut-like. Propodosomal shield projected, but so variable the feature individually. Anterior median apodeme ending near posterior extremities of apodemes II, with a small knob at mid-length of apodeme. Apodemes I indistinct. Transverse apodeme forming a smooth, shallow arc. Second dorsal propodosomal seta twice as long as first seta. Ventral caudal setae invisible. Apical segment of leg IV short.
Holotype: Male, on Evodia rutaecarpa, Y. ITO, Hachiohji City, Tokyo (Honshu), 25 Sept., 1962.
Paratypes: 5 males and 12 females, same data as holotype.
Remarks: T. evodiae is closely related to T. sasai

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Experiments were conducted to assess the effect of aggregation of larvae upon the developmental rate and mortality in the southern green stink bug, Nezara viridula. Each experiment was set up with eggs from one batch of eggs within 24hrs. after deposition. One egg mass was divided into the following groups, 1, 2, 5, and 10 eggs with replications of 10, 5, 2, and 1, respectively. Larvae were fed with the potato plant or the pods of the common haricot beans.
A good synchronization was observed in both hatching and moulting among the first and the second instar larvae reared in a group of 10. Difference in the duration of each instar was observed in regard to the group size except the first instar. The duration of the second instar became short as the group increased in size, and the reverse relationship was observed for the fourth and the fifth instars. The daily mortality of the second instar was the highest among the isolated larvae and decreased successively to the lowest with the increase of the group size. On the contrary, the daily mortality became the highest in the fifth instar in the crowded culture being accompanied with a prolongation of the pertinent stage. The total duration of the larval stage, however, differed little due to the inverse relation with the grouping between early and late stages. But the total mortality among isolated larvae was three times as high as that of the group of 2 individuals which had the least mortality. In most cases, the decrease in the body weight of the newly emerged adults was significant at a level of 99 per cent confidence with the increase in size of a group.
Factors involved in the determination of the colouration of the larvae seemed to be multiple, and it was suggested that at least the population density besides temperature was responsible for the variation of the body colour. The survival value of larval aggregation under natural conditions was briefly discussed.

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By means of aseptic and semi-aseptic rearing of Adoxophyes orana larvae on synthetic food medium, some chemical properties of the unidentified dietary factor responsible for the larval growth were investigated. The factor is neutral organic substance and soluble in hot water and 50 to 67% aqueous acetone, but insoluble in benzene, chloroform, acetone, ethanol and water-saturated ethyl acetate. The activity is not absorbed into charcoal from aqueous solution, but precipitated by treatment with neutral lead acetate. It is assumed from solubilities in various concentrations of aqueous ethanol that the factor consist of at least two components.
Other than tea leaf, high growth factor activity was detected in the alfalfa leaf concentrate and the water extract of yeast, and weak activity in dried yeast preparations and rendered extract of meat. The rice plant concentrate, peptone, casein soda, bacto-casitone, egg albumin, crude catechins from tea leaf, dextrin and soluble starch have no activity at all.
Some pure compounds tested, with negative results, are as follows: ascorbic acid, vitamin B₁₂, ribonucleic acid, glycine, cystine, glutamine, asparagine, arabinose, xylose, fructose, galactose, mannose, sorbose, rhamnose, sucrose, lactose, raffinose, trehalose, melibiose, cellulose, adonitol, mannitol, aconitic acid, citric acid, fumaric acid, maleic acid, malic acid, oxalic acid, succinic acid, and tartaric acid.

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An attempt has been made to obtain an insecticide resistant strain of the almond moth, Ephestia cautella, under laboratory conditions. The selection pressures on the last instar larvae at an 80% mortality level by contacting on dry residue of methyl-parathion resulted in apparent development of resistance at the 6th generation and 7 times resistance at the 16th generation. The heterogeneity of the selected strain toward the toxicant became great in the early generations of selection and then small as the resistance developed. Decrease of resistance level by the removal of selection pressure was small after the 14th generation. During the course of selection, the resistant strain showed pinkish body color in larvae and whitish wings in adult. However, those color changes did not correspond directly to resistance, but seemed to be due to genetic make-up by chance. The methyl-parathion resistant strain showed cross resistance only to some of dimethyl-ester type organophosphoric compounds such as sumithion, methyl-paraoxon and malathion, and not to diethyl-ester type insecticides such as ethyl-parathion and EPN. Finally, the sensitivity of cholinesterase to methylparaoxon and the activities of aromatic esterase, aliphatic esterase and cholinesterase were compared between the selected and unselected strains.
Cholinesterase and aromatic esterase are not found being responsible for the resistance, but as to aliphatic esterase, no decisive conclusion could be drawn out.

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In this paper some problems concerning the painting, one of the bark treatments, with P=O Metasystox (25%) on fruit trees are discussed. A special attention is paid to the dosage of the insecticide and the bark injury caused by the treatment. The important content of the paper is summarized as follows.
1. The necessary dosage to be given to a branch must be determined according to the volume of the branch.The dosage is considered as 1cc per 1500∼3000cm³ for aphid control, but is 1cc per 1500∼2000cm³ against red spider mites.
2. A simple, practical measure of painting, in which the available dosage mentioned above is concerned, is suggested in order to facilitate the treatment. It is the light painting on branch bark (ca 0.6 cc/100cm²) in the area of 3∼4 times length of branch diameter.
3. The bark injury may be prevented even on citrus trees by keeping away from the two factors such as high temperature and thick painting (more than 0.6cc per 100cm²). The safe and dangerous ranges of phytotoxicity on citrus trees are given in the Figure 4.

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[in Japanese]

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The incidence of infectious flacherie of the silkworm, Bombyx mori L. in a mixed group of health silkworm larvae and infected larvae was investigated in relation to number of infected larvae mixed and length of mixed rearing period.
The more infected larvae were mixed, the higher the incidence of infectious flacherie became. As the period of mixed rearing became longer, the incidence of infectious flacherie was increased.

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