The vertical distribution of freshwater planarians in the Shiretoko National Park district in Northeast Hokkaido (Lat.43°40′N. to 44°20′N. and Long. 144°30′E. to 145°30′E.) is reported. The Park consists of two topographic units, one is the narrow part of the Shiretoko Peninsula and the other is the basal part of the peninsula (including the northern part of the Konsen Waste Land). The park is characterized by the volcanoes of the Chishima Volcanic Zone (Mt. Shari, Mt. Unabetsu, Mt. On'nebetsu, Mt. Rausu, Mt. Yuo in activity, Mt. Shiretoko, etc.). The highest peak, Mt. Rausu (1661 m above sea level), is at the central corner of the mountain chain. The main river systems of the area surveyed are the Shari, the Churui and the Shibetsu ; there are many short rivers in the Shiretoko Peninsula draining into the Okhotsk Sea (Fig. 1). The average air temperature of the year is about 5 to 6℃ and the rainfall amounts to about 1000 mm at the seashore district. The surveys of most stations were made in July 26〜29,1965. In the area surveyed, six species of freshwater planarians, Dugesia japonica ICHIKAWA et KAWAKATSU, Phagocata vivida (IJIMA et KABURAKI), Polycelis sapporo (IJIMA et KABURAKI), Polycelis akkeshi ICHIKAWA et KAWAKATSU, Polycelis schmidti (ZABUSOV) and Dendrocoelopsis ezensis ICHIKAWA et OKUGAWA, were found. D. japonica was found only in the biotopes of warm water near the Rausu Hot Spring along the Nemuro Strait. Ph. vivida, one of the common planarian species in South, Central and East Hokkaido, was found in the biotopes below the altitude of about 500 metres. This species was, however, rather rare in the district along the Okhotsk Sea. Two white Polycelis species, Pol. sapporo and Pol. akkeshi, were found in the stations below the altitude of about 380 metres. Pol. akkeshi is the dominant species in the Shiretoko National Park district Pol. schmidti was common in the stations both near the seashore and in the mountainous districts. This species was, however, found only in the cold-water springs in the district along the Nemuro Strait. Den. ezensis was found only in the station along the Okhotsk Sea. The inhabitable water temperature ranges of the above-mentioned species of freshwater planarians which were found in the Shiretoko National Park district are as follows : D. japonica (16.0〜21.1℃) ; Ph. vivida (5.6〜14.0℃), Pol. sapporo and Pol. akkeshi (7.8〜15.6℃) ; Pol. schmidti (6.6〜12.3℃) ; Den. ezensis (8.6℃). The type of the vertical distribution in the area surveyed is shown as JSVC-SVC-VC-C (J : D. japonica, V : Ph. vivida, S : Pol. sapporo and Pol. akkeshi, C : Pol. schmidti). The biotopes are described in detail. No planarian was found in the stations which were polluted with toxic water of the Chiesaku'etonbi River (a tributary of the Shari River) and in many stations of the Konsen Waste Land, a vast peat bog of East Hokkaiko (Nemuro and Kushiro). The distribution of planarian species in the adjacent districts of the Shiretoko National Park is also described. Ph. vivida, Pol. sapporo, Pol. akkeshi and Dendrocoelopsis lacteus ICHIKAWA et OKUGAWA were collected from Akkeshi-cho, Kushiro (cf. ICHIKAWA & KAWAKATSU 1963). Ph. vivida was collected from some springs of the southern part of the Konsen Waste Land.
The effect of day-length on the occurrence of the macropterous form in a cricket, Scapsipedus aspersus WALKER was investigated. For the photoperiodic study three light conditions were prepared, i.e. 8,12 and 16 hours in day-length. For the test of the density effect two densities were set, i.e. one and two nymphs per Petri dish (12cm in diameter, 7cm high). The results show that when only one nymph is reared in a Petri dish the occurrence percentage of the macropterous form is not affected by the change of the day-length keeping a very low value, but when two nymphs are reared in a Petri dish it becomes higher at 16 hours day-length than at 8 hours or 12 hours day-length. Moreover, in the case of the long-day (16 hours day-length) the number of the moults increases being irrespective of the population density, and the larval period becomes longer and the head width of the adult larger. There is no relation between the wing form and the number of moults, the head width or the larval period. It seems from the above that the day-length affects the occurrence of the macropterous form of the present cricket in relation to the rearing density and also affects the number of the moults irrespective of the density.
The present paper deals with the ecological studies of the dragonflies of Lake Biwa, from 1962 to 1963. As the larvae of many dragonflies emerge in spring and summer, the exuviae were collected in those seasons. In autumn and winter, the dragnet was used for the collection of the larvae. Sampling stations are shown in Figs 1,2. 1. About 16 species of dragonflies were found in this lake, and Gomphus was most abundant. 2. In summer the exuviae of Gomphus oculatus and G. annulatus were most abundant, followed by those of Epophthalmia elegans and Ictinogomphus clavaius in this order. The percentage of the exuviae collected at all the surveyed stations is as follows : G. oculatus 56 per cent, G. annulatus 18 per cent, Ictinogomphus clavatus 14 per cent, Epophthalmia elegans 6 per cent. The distribution of G. oculatus and G. annulatus is shown in Fig. 3. At the shore where the littoral region is large, the number of exuviae is large and where the littoral region is small, the number of exuviae is small. 3. Many of the 12 species of dragonflies found in the south basin of the lake, were mostly lenitic species. The exuviae were few along the Seta River. Sampling stations and distributions of the exuviae are ahown in Fig. 4. 4. In autumn in the case of Ictinogomphus clavatus and Epophthalmia elegans, mostly the larvae of the final stage were found. In the case of G. oculatus, the N-1 stage and N-4 stage were found. (The larvae of far younger stage are supposed to exist, but the mesh of the dragnet was too large to catch them.)
The behavior of the adult winter moths in an oak forest were studied in the winter season, in relation to the variation of the temperature and light. Among the 12 species of winter moths distributed around Tokyo, the results of study on Erannis obliquaria and E. dira are as follows : 1) In a deciduous forest near Tokyo, there are three different temperature zones : that is, the southern, the central and the northern part of the forest. Each part was divided into three layers, that is, the lower, the middle and the upper parts. 2) Adult males tended to concentrate at the southern part of the forest, and their movement in the forest was influenced by the variation of temperature and light. 3) The emergence of the moths was seen at noon when the ground temperature reachedthe maximum. After the emergence the female moth climbed up and down the tree, with relation to the variation of the temperature, and during night they remained at the middle layer where the hight temperature was higher than the other layers. 4) The female moths were more active than the male under the lower experimental temperature. The male moths of which wings were artificially eliminated, could walk more at the layer of lower temperature than the normal males, probably because of the wing area. 5) According to the variation of the light intensity, under the experimental hours, the males begun to walk and fly under the light of 5 Lux, and the females begun to walk under the light of 25〜30 Lux, but below 10 Lux, both stopped.
The effect of intra- and interspecific conditioning of host eggs was examined with regard to the discriminative ability of the two mono-parasitic parasites of Nezara viridula L., viz. Asolcus mitsukurii ASHMBAD and Telenomus nakagawai WATANABE. These two species scrape and mark the egg surface with the tip of their ovipositor after oviposition. A female of either species can distinguish the eggs which have been marked by another female of the same species and she will restrain from oviposition. She can not, however, distinguish the eggs previously marked by the females of another species. This resulted in a multiple parasitism followed by larval competition in the host egg, giving rise to A. mitsukurii as the usual victor. Both physical attack and physiological suppression of T. nakagawai by A. mitsukurii were thought as the possible underlying processes to determine the result of larval competition.
1. From Novemler 1962 to January 1965,the life during the non-breeding season of the Black-eared Kite was observed in the Zenkoji basin in the northern part of Nagano Prefecture. 2. The Black-eared Kites in the Zenkoji basin in, winter became separated into 5 roosting flock areas ; they had definite roosting places in each area. The number of birds in each of the roosting flock areas were in proportion to the population of the main cities in that district (Fig. 1,Tables 1,5). 3. A total of 14 roosting places were observed in the northern part of Nagano Prefecture. The vegetation of the roosting places was, almost entirely of the Japanese red pine except for one place which consisted of the Japanese cypress (Table 2,Fig. 1). 4. River-side, slaughter-house, dust-house and sewer were chosen as the assembly places for food-taking, and one or four such places were found in each flock area. There was a strong tendency to flock together especially in the snow season.