A comparative study on insemination dependency of circadian activity pattern in mosquitoes

Abstract. Two forms of mosquitoes in the Culex pipiens complex, C.p.pallens and C.p.molestus , were compared for the insemination-dependency of entrained female circadian activity in LD 16:8h. When virgin, Pallens is nocturnal and molestus is, in addition, diurnal. Insemination and injection of extracts of the male accessory gland affects virgin activity in that nocturnality is strengthened in both mosquitoes, and the diurnal activity of molestus is depressed. This was so whether the treatments were intra- or interspecific. These findings are compared with those already published for other mosquitoes. A coherent view is proposed that the mosquito, nocturnal/crepuscular, nocturnal and diurnal, or diurnal, has potentially a similar entrained waveform which is affected by insemination in a common way, and by lighting conditions in species specific ways.     

Importance of Queen Bumble Bees as Pollinators Facilitating Inter-morph Crossing in Primula sieboldii

Abstract Flower-visiting insects, the distribution of pollen on an insect's body, and fruit and seed sets of Primula sieboldiiE. Morren were investigated in a maritime deciduous forest habitat of the Hidaka region in Hokkaido. Queens of Bombus diversus tersatus Smith (Hymenoptera: Apidae), Bombus schrencki albidopleuralis Skorikov, and Bombus deuteronymus deuteronymus Schulz were observed to visit the flowers of the species. Bumblebee claw marks were found on the flower petals of 68% of the flowering ramets of the species. Scanning-electronmicroscopy revealed that pin and thrum pollens of P. sieboldii were deposited in different positions along the proboscis of a B. diversus tersatus queen (n=38400 grains). On the glossa, all the observed pollen was of the pin type, while more than half of the pollen grains observed on the upper part of the proboscis, galea, stipes, and maxillary palpus were of the thrum type. In the field, high fruit and seed sets were recorded for both pin and thrum morphs, indicating the occurrence of sufficient legitimate pollination during the flowering season. In addition to the effectiveness of queen bumblebees as pollinators for P. sieboldii suggested in this study, phenological and morphological matches, i.e., early spring flowering during the queen bee emergence season and the similar lengths of the corolla tube and the bee proboscis, also support the inference that queen bumble bees play an important role in legitimate pollination of P. sieboldii.     

An Algorithm for Estimating Chlorophyll Content in Leaves Using a Video Camera

Plant leaf colour is commonly used as an index for nutrientdiagnosis. We have developed a low-cost diagnostic method thatis easy to use to assess the nutrient status of plants, basedon the estimation of chlorophyll content of leaves using a portablecolour video camera and a personal computer. Relationships betweenchlorophyll content and various functions derived from red,green and blue wavelengths are examined. Although red-blue andgreen-blue wavelengths show the highest correlation with chlorophyllcontent under a limited range of meteorological conditions,the normalized difference (red-blue)/(red+blue) is the mostapplicable function which can use data collected under differentmeteorological conditions. The accuracy in estimating chlorophyllcontent from video images could be improved by correcting withsolar radiation data. It is shown that, for practical purposes,the chlorophyll content of leaves can be estimated with sufficientaccuracy using a portable video camera.Copyright 1998 Annalsof Botany Company Chlorophyll content; leaf colour; video camera; image processing; nutrient diagnosis.     

Ganglioside Expression in Melanomas From Japanese Individuals: Unusual Pattern in Two Patients With Metastatic Lesions of Acral Lentiginous Melanomas

Melanoma among Japanese is rare, and differs in its clinical and histological characteristics from that found in Caucasians. In this study, the ganglioside expression of melanoma specimens obtained from Japanese was determined and compared with previously published data on Caucasians. The ganglioside composition of 25 biopsy melanoma specimens, including 13 primary and 12 metastatic lesions, was studied using thin layer chromatography. Four gangliosides (G_M3, G_D3, G_M2, G_D2) were most commonly expressed in melanomas in Japanese. The expression of gangliosides was quite variable in both primary and metastatic melanomas as seen in previous reports. No significant differences were observed between gangliosides from primary and metastatic sites. A new type of ganglioside expression, in which G_M3 was nearly the only ganglioside (>95%), was found in metastatic tumors from two Japanese patients with acral lentiginous melanoma (ALM), which is the most common clinical and histopathological type of melanoma among Japanese but is very unusual among Caucasians. The patterns of expression were similar to those in Caucasians except for the detection of a “new” pattern.