Application of a powdered artificial diet to promote the establishment of the predatory bug Geocoris varius (Hemiptera: Geocoridae) on strawberry plants

We examined whether the application of a powdered artificial diet on target plants would promote the establishment of Geocoris varius (Uhler) (Hemiptera: Geocoridae). Laboratory trials showed that, after 72 h, 93 % of the G. varius individuals remained on plants to which the artificial diet was applied as opposed to only 30 % of G. varius remaining on untreated strawberry plants. Moreover, application of the powdered diet promoted the development of G. varius from the third to the fifth nymphal stages and extended the average longevity by 12 days. The results suggested that the application of powdered artificial diet promotes the establishment of G. varius released in a greenhouse, even when pest densities are low, increasing the effectiveness of biological control. Furthermore, the increase in predation associated with greater numbers of more developed G. varius would improved the effectiveness of this biocontrol method.     

Comparative immunohistolocalization of carbonic anhydrase isozymes I, II and III in the equine and bovine digestive tract

Summary Immunohistochemical localizations of carbonic anhydrase isozymes (CA-I, CA-II and CA-III) in equine and bovine digestive tracts were studied. In the horse, epithelial cells in both the oesophagus and non-glandular part of the stomach lacked all three isozymes. In contrast, surface epithelial and parietal cells in the glandular region of the stomach showed reactivity for CA-II. In the small intestine, absorptive columnar cells covering the villi in the duodenum were positive for CA-II. The epithelium of the jejunum and ileum lacked all three isozymes. In the large intestine, CA-II was detected in the columnar cells in the upper part of the crypt. In cattle, epithelial cells of the oesophagus showed reactions for CA-I and CA-III but not for CA-II. Although the absorptive epithelial cells of the small intestine lacked CA-I, CA-II and CA-III, those of the upper part of large intestine crypts were heavily stained for all three isozymes.     

Effects of frequency of the tones on auditory event related potentials in monkeys (Macaca fuscata) under various hypobaric hypoxia conditions of simulated high altitudes

Changes in auditory event related potentials (ERPs) as a function of frequency of tones ranging from 500 Hz to 8,000 Hz were examined under various hypobaric hypoxia conditions of simulated high altitudes up to 6,000 m. A sequence of P₁-N₁-P₂ components, corresponding to those of the human subject, was observed with the monkey's ERPs. These component amplitudes changed as a function of frequency of tone. The relationship revealed an inverted U curve with a maximum amplitude at a tone of 2,000 Hz. The following results under hypoxia were noted: marked reduction of amplitude in ERPs induced by hypoxia linked only to a tone's particular frequency, especially for 2,000 Hz. The delay of latency in the respective components of the ERPs was dependent on the degree of hypoxia. These findings seem to suggest the anatomical bases of the neural generators contributing to each component of the ERPs. This work was supported by the Cooperation Research Program, Primate Research Institute, Kyoto University.     

Development and reproduction of Geocoris varius (Hemiptera: Geocoridae) on two types of artificial diet

Biological control using the polyphagous predator big-eyed bug Geocoris varius (Uhler) (Hemiptera: Geocoridae) is currently being investigated in Japan. However, the production costs of G. varius are relatively high because the eggs of Ephestia kuehniella Zeller (Lepidoptera; Pyralidae) are used as the major food source for mass rearing. Development time and reproductive fitness were therefore examined for G. varius fed two types of artificial diet based on liver and ground pork. The diets were administered either by wrapping in Parafilm^® or by presenting the food in lyophilized form. The results were compared with those obtained by rearing G. varius on E. kuehniella eggs. Although development time of Geocoris varius fed the artificial diets was significantly delayed compared with G. varius fed on E. kuehniella eggs, delays are slight and not serious for mass rearing projects. The findings suggested that both artificial diets could be used to reduce the costs associated with mass rearing of G. varius.     

Wind,Waves, and Wing Loading: Morphological Specialization May Limit Range Expansion of Endangered Albatrosses

Among the varied adaptations for avian flight, the morphological traits allowing large-bodied albatrosses to capitalize on wind and wave energy for efficient long-distance flight are unparalleled. Consequently, the biogeographic distribution of most albatrosses is limited to the windiest oceanic regions on earth; however, exceptions exist. Species breeding in the North and Central Pacific Ocean (Phoebastria spp.) inhabit regions of lower wind speed and wave height than southern hemisphere genera, and have large intrageneric variation in body size and aerodynamic performance. Here, we test the hypothesis that regional wind and wave regimes explain observed differences in Phoebastria albatross morphology and we compare their aerodynamic performance to representatives from the other three genera of this globally distributed avian family. In the North and Central Pacific, two species (short-tailed P. albatrus and waved P. irrorata) are markedly larger, yet have the smallest breeding ranges near highly productive coastal upwelling systems. Short-tailed albatrosses, however, have 60% higher wing loading (weight per area of lift) compared to waved albatrosses. Indeed, calculated aerodynamic performance of waved albatrosses, the only tropical albatross species, is more similar to those of their smaller congeners (black-footed P. nigripes and Laysan P. immutabilis), which have relatively low wing loading and much larger foraging ranges that include central oceanic gyres of relatively low productivity. Globally, the aerodynamic performance of short-tailed and waved albatrosses are most anomalous for their body sizes, yet consistent with wind regimes within their breeding season foraging ranges. Our results are the first to integrate global wind and wave patterns with albatross aerodynamics, thereby identifying morphological specialization that may explain limited breeding ranges of two endangered albatross species. These results are further relevant to understanding past and potentially predicting future distributional limits of albatrosses globally, particularly with respect to climate change effects on basin-scale and regional wind fields.     

LOCALIZATION AND MULTIPLE FORMS OF ACETYLCHOLINESTERASE IN SEA URCHIN EMBRYOS

Acetylcholinesterase during the development of the sea urchin Pseudocentrotus depressus was examined by enzyme assay (the colorimetric method of E llman et al. ), histochemistry (a Cu-thiocholine method), polyacrylamide gel electrophoresis and DEAE-Sephadex ion exchange chromatography.
The enzyme activity is detected in the unfertilized egg, remains low during cleavage, elevates slightly through gastrulation, and then increases rapidly thereafter. The intense activity is localized in the mesenchyme cells associated with the larval skeleton of young pluteus larvae, and their cell membranes and nuclear envelops. Soluble enzyme accounts for 60% of the total activity. The additional 34% is extracted by 1% Triton X-100 from particulates. The soluble enzyme consists of two forms. Both are strongly acidic proteins which are similar in electric charge, but dissimilar in size, being 180,000 and 280,000 in molecular weights. The enzyme released from the membrane by the detergent possesses a component which is not present in the soluble complement of the enzyme. It is not a secondary product of the soluble enzyme interacting with the detergent.
Acetylcholinesterase serves as a marker of late differentiation and regional differentiation in the sea urchin embryo.