The ambrosia beetles are interesting not only from the biological and ecological viewpoints, but have also been of great concern to agronomists, foresters and plant protection officers because of the serious economic damages.
Resulting from numerous publications containing many systematical aspects, extreme limitation were forced upon this review.
The certain concepts and assumptions that were developed or clarified in the recent year with regard to the ecological, systematical, physiological aspects, artificial rearing, symbiotic relationships and control of ambrosia beetles were discussed in point of Xyleborus germanus, Xyleborus compactus attacking tea plant.
From the literatures in this review, the author claimed that the establishment of rearing methods and the exact determination of specific ambrosia fungus to each beetle, are the most urgent problems. To identify a fungus is a specific ambrosia of a certain beetle exactly, it must be decided the following procedures, i. e. isolation from beetle, culture on plate, artificial transmission in mycangia, normal reproduction of beetle and re-isolation of the fungus from the beetle.

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The qualities of the first crop were tested in the various F₁ progenies which were bred in the combination with the Assam varieties.
High correlations were observed between the qualities (aroma, liquor, taste, colour of infused tea) of parent plants and those of F1 progenies.
The qualities of F₁ progenies combined with the Assam varieties were influenced by the qualities of the other parent, and it is not easy to get any good individual even though good varieties were crossed with each other, so it is necessary to get a wide variation in a large scale crossing combination.
A close correlation was not found between the quality of tea and the vigor of plant or the yield of leaves.
The quality had scarcely any significant correlation between the cold resistance, so it will be able to get various grade of the cold. resistant individuals having a good quality of the Assam varieties by cross breeding with the Assam varieties.

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By using the breeding materials with or without wind guard, the influence of wind in winter o n the cold resistance of tea plant was investigated.
In the case of the individual group with wind guard, the winter injury was not so large as that of the group without wind guard.
Annual correlation coefficient of cold resistance was higher in the group with wind quard.
In the group with wind guard, it was observed that cold hardiness was corresponded to cold resistance in many materials, so it was easy to presume the cold hardiness of plant from its cold resistance.
No significant correlations were not found between cold resistance and vigor of plant or yield, but it was found that vigor of plant became to influence on cold resistance in the poor cold resistant F₁ progenies utilizing the Assam varieties for crossing.
The heritability value of cold hardiness in the group without wind guard was 0.755, and this value was as nearly same as that of the group with wind guard.
Comparing cold resistance on the combination with the same grade of cold hardiness, the group without wind guard suffered from more severe winter injury. It may be said from the above results that the. cold damage is promoted by exposure to the wind.
Distinct differences in the winter injury were observed in different localities, so it is necessary to establish a good test method for cold resistance which will be available in any where

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The promoting effects of rooting and growth in tea cutting which was treated by the etiolation method (pretreatment of cutting by shading mother bush), were investigated. The results obtained may be summarized as follows.
By the etiolation treatment, the growth of treated shoot was retarded remarkably. In addition, it was observed that the assimilation rate and chlorophyll content were decreased, and the percentage of leaf water was maintained highly.
When the treated shoots were exposed to the sun light, the growth and the assimilation rate were promoted, but at the optimum stage for cutting the characters of treated shoots were not superior to those of the control.
After the cuttings were set in nursery bed, it was observed that the treated cuttings had the highest rate of dry matter production. This tendency was based on the high net assimilation rate (NAR) and leaf area ratio (LAR) in treated cuttings.
It was observed that the high NAR in treated cuttings was based on the quick recovery of the assimilative power which was caused by promoted rooting effect.
Summing up these results, it can be concluded that the promoting effect of growth caused by etiolation method was mainly due to the superiority of dry matter production.

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1. The tea red spider mite, Tetranychus kanzawai KISHIDA, is one of the serious pests of tea plant in Japan. Phencapton and Estox had been used since 1957 and 1964 respectively for the control of mites and showed very effective as acaricides in the tea fields. However, the controlling effect of Phencapton and Estox seemed to be decreased remarkably since 1961 and the late autumn in 1964 respectively in some tea fields.
2. The author investigated the resistance responses of mite to Phencapton and Estox by the laboratory and field tests.
3. The mite caught in the tea field in which Phencapton and Estox showed less effective, showed clear resistances to these chemicals. From the above results, it was considered that these resistances probably occurred between 1961 and 1962 on Phencapton and between. the spring and the autumn in 1964 on Estox in the tea field of Tea Research Station at Kanaya, Shizuoka prefecture.

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The morphological, physical and chemical characteristics of the tea soils of Shizuhata and Nakawara district in Shizuoka-slii were surveyed.
The results were generally summarized as follows:
1. Shizuhata and Nakawara tea gardens mainly distribute on a bill slope and Shizuhata tea soils were classified into 10 types and Nakawara ones into 11 types by the morphological characteristics of profile. But the morphological characteristics of profile of these soil types were comparatively resemble, namely, in general, Shizuhata tea soils were dark brown or black brown heavy soil having much quantity of humus and rock fragment and Nakawara ones were dark brown medium or heavy soils having much quantity of humus and rock fragment.
2. Among the general physical properties, the composition of three phases of soil, hardness, maximum water holding capacity and moisture equivalent were examined.
From the results, it was recognized that the physical properties of these district tea soils were generally suitable for tea plantation.
3. The results of examination on the general chemical properties of these district tea soils were as follows:
1) Shizuhata tea soils.
The pH (H₂O) value was mostly 4 level and the amount of exchangeable Ca of the first layer ranged from trace to 30 me and the degree of base-saturation was mostly below 20%.
The cation exchange capacity was generally large and that of the humic tea soils was largest, but that of general tea soils was mostly 20-30 me.
The organic matter content of the first layerwas generally high, it showed over 5% as humus, but that of some soils was as high as over 10% and the carbon-nitrogen ratio was mostly 11-17.
The available phosphorus content of first layer was as much as 10-50 mg%, but that of second layer was very little.
The nitrogen absorption coefficient was mostly over 200, but that of the humic tea soils was as high.as 500-700 and the phosphate absorption coefficient was mostly over 1000, but that of the humic tea soils was 2000 or more.
2) Nakawara tea soils.
The pH (H₂O) value was mostly below 4.5 and the amount of exchangeable Ca of the first layer was comparatively low from trace to 5.2 me and the degree of base-saturation was mostly below 30%.
The cation exchange capacity was mostly 20 me.
The organic matter content of the first layer was mostly 5-10% as humus and the carbonnitrogen ratio was 13-19.
The available phosphorus content of the first layer was more than that of Shizuhata tea soils and showed mostly over 20 mg%.
The nitrogen and phosphate absorption coefficients were both comparatively low, that of nitrogen was mostly below 400 and that of phosphate was below 1000.
4. The amounts of water soluble and exchangeable aluminum of Shizuhata tea soils were generally more than those of Nakawara tea soils, namely, in Shizuhata tea soils the amount of water soluble aluminum was 1 mg% and that of exchangeable aluminum was mostly 50-100 mg%, but in Nakawara tea soils, the former was 0.5 mg% and the latter was mostly below 50mg%.
5. The relation between the amount of added calcium and pH value change was examined.
From, the results, it was found that in Shizuhata tea soils having comparatively much quantity of clay and humus, the increasing of pH value with the addition of calcium was generally slow, but in Nakawara tea soils, it was comparatively quick.
6.The absorption of ammonium by these tea soils from amm. sulphate, amm. carbonate and amm. phosphate was examined.
From the results, it was found that the order of absorption of ammonium salt by these tea soils was amm. phosphate>amm. carbonate>amm. sulphate and the absorbed quantity of ammonium from these ammonium salt was higher in. Shizuhata tea soils than in Nakawara tea soils.

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The occurrence of flavonols and their glycosides in tea and tea leaves, has been reported in many papers but there are no previous references to flavone.
Three yellow pigments, however, were isolated and other seventeen ones detected on the paperchromatogram from the green tea infusion, and eighteen of them were identified as flavones.
Ultraviolet absorption spectra of these three pigments, designated pigment I, II, and III as shown in Figure 1, were similar to those of apigenin family, especially to saponarin, saponaretin and vitexin. Moreover, as the results of studies on the spectral characteristics, alkaline degradation products and color reactions, it was concluded that these pigments belonged to flavone and seemed to have the same skeleton as apigenin (5, 7, 4'-trihydroxy flavone). Especially pigment III may be one of the important constituents related to the color of green tea infusion, for its high water solubility and a deep greenish yellow color in aqueous solution.
As the results of spectral studies, fifteen of seventeen spots detected on the two-way paper chromatogram, as shown in Figure 5, were identified as flavones, which had the similar structure to the pigment I, II, and III, but two of them did not.
Because the pigments were proved not to be hydrolyzed under such condition that flavonol glycosides were completely hydrolyzed, removal of them from the fraction which was precipitated with lead acetate and ammonia water from green tea infusion, was carried out by treatment with 3.5% hydrochloric acid on a boiling water bath for an hour. After hydrolysis, only the spots of these pigments remained as before, and those of kaempferol, quercetin and myricetin resulted from their glycosides came out. Gallic acid, probably its parent compound occurred in this fraction, was also detected.
The hydrolyzate was first fractionated by shaking with ethyl ether, ethylacetate and n-buthanol. Then further fractionations were carried out by the column chromatography using silica gel or cellulose powder.
Pigment I and If were obtained in small quantities, and seventeen minor pigments were isolated by the preparative paper chromatography, so that the works on them were only performed by absorption spectral studies and paper chromatography. Pigment III was finally purified as an amorphous yellow powder. Yield : about 420 mg. from 2 kg, of green tea. m. p. more than 300°C (begin to change color at about 258°C). acetate : white opaque granules, m. p. 151°C.
Solubilities : very easily soluble in cold water, soluble in hot methanol and insoluble in ethanol, ethylacetate, acetone and ether. Color reactions of them on the paper chromatograms were as follows ; pale yellow in visible light, reddish brown in ultraviolet light and change to yellow when fumed with ammonia, yellow with alkalis and aluminum chloride, and brown with ferric chloride. Reaction of these pigments with magnesium or zinc and conc. hydrochloric acid in ethanol gave pink color.
Pigment III on the chromatograms developed with 2% acetic acid and n-buthanol-acetic acidwater gave distinctly a single spot, but when developed with 75% phenol a tailing spot. After division by preparative paper chromatography, pigment III proved to be a mixture of IIIa and IIIb, which had quite similar spectra as shown in Figure 2c and 2d. But it will be discussed in the following paper.
These pigments exihibited high intensity absorptions at 333-5mμ region (Band I) and 270-3 mμ region (Band II ). From the absorption spectral studies on the aluminum chloride complex and sodium acetate shifts of these pigments, it came to the conclusion that fourteen of eighteen tea flavones had to belong to apigenin family, and had free hydroxyl groups in 5, 7, and 4' positions, and four had no free hydroxyl group in 7-position (Table 2 and Table 6).

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It has been reported that the shoots of Camellia japonica contain only one catechin identified as (-)-epicatechin from paperchro-matographic studies. However, a predominant presence of a (+)-catechin like substance was noticed in addition to (-)-epicatechin in the shoots of a certain variety i. e. var. Benikarako or var. Soinegawa. The ratios of both substances in the leaf of Camellia japonica are shown in Table 1.
In this paper, the isolation of (-)-epicatechin and (+)-catechin from the leaf of Camellia japonica var. Benikarako and the infra-red spectral comparison of catechin and epicatechin gained from various materials are reported.
The matured leaves of Benikarako were homogenized with ethyl ether. The extracts were filtered and then concentrated under reduced pressure in a current of nitrogen. Then to the residue was added a small volume of water and the precipitated pigments were removed by a super-centrifuger. The aqueous solution was freeze-dried. and the polyphenol mixture containing (-)-epicatechin predominantly was obtained as an orange powder.
The polyphenol mixture in the shoots was obtained by the same procedure as described above. This mixture was consisted mainly of the (+)-catechin like substance and other two polyphenols. Then the (+)-catechin like substance was fractionated in a 50- tube Craig distribution train by the solvent system of ethyl ether and beznene mixture as the upper phase and water as the lower phase.
The crude powder containing (-)-epicatechin or the (+)-catechin like substance was purified by the recrystallization from water, then the final crystals were obtained.
Furthermore both crystals were compared with the authentic catechins from other sources on the infra-red spectral property as shown in Figure 3. The spectrum of the (+)-catechin like substance from Camellia japonica coincided with that of (+)-catechin from Gamnbier. The spectra of (-)-epicatechin from Camellia japonica, Acacia catechu and tea leaf, and (+) epicatechin epimerized from (+)-catechin of Gambier resembled closely one another whether it was (-) or (+) form. Furt her it was supposed that the infra-red spectrum of (-)-epicatechin from Camellia japonica which was reported in the previous paper seemed to be the same as that of (+)-catechin.

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