Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) B-and Q-biotypes are exotic insects in Japan and are consequently regarded as insect pests in agricultural fields. Using B-and Q-biotypes, we investigated the hatching rate, survival rate during the larval stage and the total development period from egg to adult. Whiteflies were allowed to lay eggs on several host plants: cabbage, Brassica oleracea var. capitata; cucumber, Cucumis sativus L.; tomato, Solanum lycopersicum L.; eggplant, Solanum melongena L.; bell pepper, Capsicum annuum cv. grossum; and five cultivars of kidney bean, Phaseolus vulgaris (cvs. Kentucky101, Nagauzura, Morocco, Satsukimidori and Honkintoki), and the effects on the above traits were evaluated. Clear differences between the two biotypes were detected. A particularly important difference was that the B-biotype successfully developed to adults on only one of five cultivars of kidney bean, whereas the Q-biotype was able to utilize all the test plants as hosts regardless of the cultivar. This finding suggests that the determination of host plants in B. tabaci is greatly influenced by not only plant species but also by cultivar. In addition, there is a high possibility that the Q-biotype has the ability to adapt to a wider range of plant species and cultivars compared with the B-biotype.
Microwave heating was used to produce aqueous-soluble components from green, oolong, and black tea residues. Heating at 200-230 degrees C for 2 min extracted 40-50% of polysaccharides and 60-70% of the polyphenols. Solubilization of arabinose and galactose by autohydrolysis occurred with heating above 170 degrees C, whereas heating above 200 degrees C was necessary to solubilize xylose. Catechins were soluble in water by heating at low temperature (110 degrees C); however, new polyphenols having strong antioxidant activity were produced above 200 degrees C. The amount of solubilized materials and antioxidant activity increased with increased fermentation of harvested tea leaves (green tea < oolong tea < black tea). Cutin, a plant biopolyester, remained in the residue after heating as did cellulose and lignin/tannin. The predominant cutin monomer that was recovered was 9,10-epoxy-18-hydroxyoctadecanoic acid, followed by dihydroxyhexadecanoic acid and 9,10,18-trihydroxyoctadecanoic acid.
This study investigated why sibling cannibalism is so rare in the second instar of the wolf spider Pardosa pseudoannulata (Araneae: Lycosidae), despite the fact that the spider is cannibalistic and does not discriminate kin from non‐kin. Laboratory experiments revealed that relative size difference between the cannibal and its victim affected the occurrence of nymphal cannibalism, as in other spiders. The degree of the size difference, measured as the coefficient of variation (CV), was smaller within a brood than among broods, but was greater in smaller clutches that might have been produced by less well fed females. Statistical analysis confirmed that intraclutch cannibalism would occur in less than about 1% of encounters among siblings that were randomly selected from the same clutch, because about 99% of intrabrood encounters fell within a 10% size difference, which is the marginal value above which frequent cannibalism occurs. Thus, interclutch cannibalism was expected to occur much more frequently than intraclutch cannibalism. Considering the potential benefit of cannibalism under food stress and high nymphal mortality, even with the sacrifice of their full sibs, the small intraclutch variance in spiderling body size may be understood as a tactic adopted by mother spiders to avoid sibling cannibalism.
Experiments were conducted to investigate whether there is a trade-off between hunting ability and starvation tolerance in spiderlings of a wandering spider, Pardosa pseudoannulata Boes. et Str. The width of the carapace (the cover over the cephalothorax) was used as an index of hunting ability, as a larger carapace was confirmed as being advantageous for capturing prey. Abdomen width was used as an index of starvation tolerance because individuals with larger abdomens survived longer under fasting condition. Effects of carapace width and abdomen width on starvation tolerance were examined using multiple regression analysis. The carapace width was found to have a negative effect but the abdomen width had a positive effect on starvation tolerance. Moreover, the ratio of abdomen width to carapace width was significantly different among clutches. These results suggested that there is a trade-off between carapace width and abdomen width, that is, between hunting ability and starvation tolerance, and also suggested that the tradeoff might be an allocation strategy specific to each clutch.
In many spider species, spiderlings spend several days aggregated in a mass immediately after emerging from the egg sac. During this period, which is called the gregarious phase, spiderlings do not eat. In this study, we conducted two experiments to clarify the benefits of the gregarious phase in a wolf spider, Pardosa pseudoannulata Boes. et Str. In one experiment, we examined the effect of the fasting period on spiderling development (duration until molting to the next instar and increment of carapace width). The fasting period was set at 1 d in one treatment and at 5 d in another treatment. In a second experiment, we examined the effect of aggregation on spiderling development. In one treatment, spiderlings were individually reared from the next day of emerging from the egg sac. In another treatment, spiderlings were allowed to aggregate for 5 d before being reared individually. In both treatments, the fasting period was set at 5 d. Spiderlings that fasted for 5 d molted after a significantly shorter feeding period than those that fasted for 1 d, although we observed no effects of aggregation. The feeding period corresponds to the post-gregarious period when females no longer guard their spiderlings. Our results suggest that the gregarious phase functions to shorten the postgregarious period during which the spiderlings are exposed to natural enemies.
jp) SUMMARY Rhodophyta, Cyanobacteria or other algae contain phycobiliproteins as light-harvesting components for photosynthesis. The bio-regulatory functions of the proteins or their chromophores are introduced. It has been shown that both proteins and chromophores effectively quench various active oxygen species in vivo and in vitro. Phycoerythrobilin and phycocyanobilin, corresponding to the chro mophores of phycoerythrin and phycocyanin, respectively, were mainly responsible for antioxidant ac tivities of the chromoproteins while phycocyanin has anti-inflammatory activity partly due to its specific cyclooxigenase 2 inhibitory property of its apoprotein. Phycocyanobilin also suppressed platelet aggre gation induced by both collagen and ADP.
Juveniles of a nematode belonging to the family Mermithidae were found from wolf spiders, Pardosa pseudoannulata, collected in a paddy field in Kyoto, Japan. Their morphological characteristics are briefly reported along with some ecological notes. This is the first record of a mermithid from P. pseudoannulata.
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