Small Yellow Spots Research Articles

Histopathology of Red Stripe of Rice.

A histological study of red stripe of rice was conducted to elucidate the mode of infection of the causal bacterium Microbacterium sp. When pin-point-sized spots first appeared at 3 days after inoculation, the bacterial cells had entered through stomata and multiplied in the intercellular spaces of substomatal parenchymatous tissues. With the early appearance of small yellow spots at 4 to 5 days after inoculation, the bacterium was detected in some xylem vessels as well as in parenchymatous tissues, and it had apparently translocated directly from parenchymatous tissues to transverse vascular systems through spiral vessel walls. With the appearance of typical red stripe symptoms comprised of orange lesions and halos at 8 days after inoculation, bacterial masses were present in transverse and longitudinal vascular bundles in areas with orange lesions. In the areas with orange to light brown spots, granules that stained dark blue using Stoughton's method appeared in the protoplasm of the host parenchymatous cells, which later became necrotic. In halo areas, bacterial masses were observed only in some cases, and chloroplasts were disorganized. Bacterial infection was also confirmed by observing sections of naturally infected samples, and the distribution of bacteria was much more extensive than in artificially inoculated samples.

Botia kubotai, a new species of loach (Teleostei: Cobitidae) from the Ataran River basin (Myanmar), with comments on botiine nomenclature and diagnosis of a new genus

Botia kubotai, new species, is distinguished from all other species of the genus by its unique body colour pattern. In juveniles, three black stripes and five black bars leave four pairs of elongate yellow blotches; with increasing age, the bars and stripes widen, the yellow blotches become more slender and rows of small yellow spots are added in the stripes and in the bars. The nomenclature of Botiinae and the systematics of the South and Southeast Asian taxa are discussed. A new genus is named: Chromobotia (type species: Cobitis macracanthus). Hymenphysa is a synonym of Botia and species usually placed in Hymenphysa should be called Syncrossus.

How drone flies ( Eristalis tenax L., Syrphidae, Diptera) use floral guides to locate food sources

In this study we show how inexperienced syrphid flies, Eristalis tenax, orient on artificial flowers by means of floral guides. To test the effect of floral guides such as line and ring markings on the probability and speed of the location of a potential food source, we exploited the spontaneous proboscis reaction triggered by yellow colour stimuli. We tested whether and how fast the flies, when placed on the edge of a circular dummy flower, found a small central yellow spot and touched it with the proboscis extended. The flies found the central yellow spot more often and faster if guide lines from the margin to the yellow spot were present. The effect of guide lines was dependent on the colour of the dummy flower, and independent of the colour of the guide lines, except for yellow guide lines releasing the proboscis reaction. The effect of guide lines was stronger if the yellow spot was hidden in a 2 mm deep depression and thus not as easily visible to the flies. Ring guides had a significant effect on performance only when the intensity of the central yellow spot was low.

Squash Yellow Leaf Curl Virus: A New Whitefly-Transmitted Poty-Like Virus.

A severe yellow and leaf curl disease affecting field squash was found in the Batinah region of the Sultanate of Oman. The symptoms appear as small yellow spots, diffuse veinal yellowing, and leaf curling of young leaves. The inciting virus was easily transmitted by mechanical inoculation and by the whitefly Bemisia tabaci in a semi-persistent manner. The host range of the virus was restricted to two cucurbit species. Leaf dip preparations contained few flexuous particles about 700 to 750 nm long. Pinwheel-like inclusion bodies were observed in thin sections of diseased squash tissues. Serological tests by enzyme-linked immunosorbent assay showed that the virus is serologically related to watermelon mosaic virus-2, but not to zucchini yellow mosaic virus or papaya ring spot virus (watermelon strain). In view of these properties, this virus is considered to be a newly described virus and is tentatively named squash yellow leaf curl virus.

BEES OF THE GENUS PALAEORHIZA PERKINS (HYMENOPTERA, COLLETIDAE) IN THE NATIONAL FOREST INSECT COLLECTION OF THE FOREST RESEARCH STATION, BULOLO, PAPUA NEW GUINEA ( I )

BEES OF THE GENUS PALAEORHIZA PERKINS (HYMENOPTERA, COLLETIDAE) IN THE NATIONAL FOREST INSECT COLLECTION OF THE FOREST RESEARCH STATION, BULOLO, PAPUA NEW GUINEA ( I )

Two year observations of a family of the Whooper Swan Cygnus cygnus at Hyoko, Niigata

1. A particular female Whooper Swan and her family, wintering at a well known swan and waterfowl resort, lake Hyoko near Niigata City on Japan Sea coast of Honshu, were kept under observation of behavior in two successive winters. Here the swans (and other waterfowls) are well tamed by artificial feeding.2. This particular female could be identified by a pair of small yellow spots on both sides of the black part of the bill.3. In 1974-75 winter, she formed a family with her mate and four cygnets, but she returned in December 1975 with a male not accompanied by cygnets.4. Continuous observations of 4.6 hours and 6 hours were made on February 14, 1975 and January 30, 1976 respectively.5. Their movements were recorded every 2 minutes and the moving distance/per hour was 680m, on February 14, 1975 (with cygnets), and only 67m, on January 30, 1976 (withont cygnets).6. Although the lake condition partly caused the above difference of moving distance/per hour in 1975 and 76, because most of the lake surface except artificial feeding place was frozen in 1976, but all the surface was free from ice in 1975, the difference of family composition in the two years, with or without cygnets, was apparently correlated as mentioned below.7. The 1976 pair, without cygnets, responded quickly to the artificial feeding and after eating enough could rest on nearly ice not moving to a distance, but the 1975 family, with cygnets, arrived feeding place later than others and could not eat enough, thus moving away to continue feeding on natural food at other parts of the lake.

Description of the Male of Erythrodiplax Maculosa (Hagen) (Odonata: Libellulidae)

Male: Head .—Labium and labrum black; anteclypeus nearly black; postclypeus yellow; frons metallic bluish black with a yellow spot on each side next to compound eye; vertex metallic bluish black; occiput black; rear of head black, with two small yellow spots on each side of occiput, and two yellow crescent-shaped or wedge-shaped areas on each side behind compound eye.

NEW SPECIES OF POLYMERUS (WESTWOOD) FROM THE UNITED STATES (HEMIPTERA, MIRIDAE)

Runs in the couplet with severini in my key (Miridae of Illinois, 1941) but distinguished by black color on apical half of femora, base and apex of tibiae.♂. Length 5.1 mm., width 2.34 mm. Head: width 1.12 mm., vertex .51 mm.; black, a small yellow glabrous spot each side of vertex bordering eye. Rostrum, lengt 1.08 mm., just reaching middle of mesosternum, yellowish, apical half blackish.

Four New Arizona Coleoptera (Cleridae, Corynetidae and Buprestidae)

Brunneus above and below; abdomen lighter; each elytron with three small yellow spots, one at base, a lateral one in front of middle and another back of middle along suture; legs and body with long hairs. Head convex, front confluently punctured, vertex transversely rugose; eyes coarsely granulate, hairy, emarginate; last joint of labial palpae triangular; maxillary palpi with last joint elongate; antennae reaching to humeral angles of elytra when laid along sides of pronotum, eleven jointed, scape stout, second joint short, third joint twice as long as second, joints four to ten inclusive serrate, last joint elongate.

A CANADIAN TRIGONALYS

Male.—Length, 10.5 mm. Black with yellowish markings. Head transverse, as wide as thorax, about twice as wide as long when viewed from above; face above the antennæ, and vertex, polished, impunctate, without apparent sutures and with sparse blackish pubescence; the cheeks and under surface with pubescence more dense; clypeus polished; palpi slender; antennæ as long as head and thorax, rather stout, eighteen-jointed, segments subequal; eyes small but prominent; ocelli small, in a triangle on a line with the posterior margins of the eyes. Thorax rugose with coarse, irregular punctures, those of the pleura and pectus smaller and more numerous; posterior angles of prothorax yellow; legs rather slender, coxa and femora black, remainder yellow, the tips of tibiæ and tarsi somewhat dusky; wings subhyaline, with dark stain covering marginal cell and extending slightly beyond each end of it, stigma and costal nervures black, remaining nervures reddish, second and third submarginal cells subequal; scutellunl abruptly rounded posteriorly, postscutellum yellow, prominent, subpyramidal, notched at apex, in suture on each side several deep shining foveæ; metathorax very short and rounded at sides, without prominent angles, a small yellow spot on each side. Abdomen polished, impunctate, apparently with six segments; second segment as long as all the following and with a yellow central band, or elongated spot on each side; a yellowish spot at lateral base of segments 3 and 4, very faint on the latter; venter slightly pubescent, with double row of yellow spots on segments 1 to 5, largest on 2nd.

THE SECOND ANACRABRO, AND THE SMALLEST AMERICAN OXYBELUS

Anacrabro boerhaviœ, n. sp. or var.—♂ about 7 mm. long; differs from ocellatus by the yellow markings, which are as follows:—Dorsum of prothorax and tubercles yellow, the tubercles with a black central dot. Mesothorax all black, except a small yellow spot on each side at hind border, adjacent to yellow spot of scutellum. Scutellum with a pair of large yellow spots. Postscutellum yellow. Inner side of anterior half of anterior femora yellow. Tibiæ yellow, with more or less black behind. Tarsi yellow, slightly tending to orange. Segments 1-6 of abdomen presenting a yellow spot medially, and a large yellow patch on each side. The median spot on first segment is round, that on 2-3 transversely oval, that on 4 transversely spindle shaped, that on 5 broad with truncate ends, that on 6 nearly square, but slightly constricted on each side. Lateral patches more or less bifid at their inner ends, and produced to a point below on lateral margin of abdomen. Strongly punctured, much more sparsely on pleura. Pubescence of face and cheeks silvery. Eyes very large, at least as near together on middle of face as the two upper ocelli are to one another.