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W. V. Harris 《Insectes Sociaux》1956,3(2):261-268
Termite mounds present a convenient record of the behaviour of their builders which can be studied at leisure. More usually, insect behaviour has results of a transitory nature, difficult to record and subject in their interpretation to the personal idiosyncrasies of the observer. A behaviour pattern which is specific to a particular termite may, however, result in mounds which appear superficially different under different environments, while two different species may produce mounds which appear to be similar in the same environment. It follows that the use of termite mounds as indications of species behaviour must be considered with care if there are wide differences in environmental factors in the areas being dealt with. The following remarks arise mainly from observations made in Eastern Africa on the large mounds constructed by three species of the genusMacrotermes. Of these,Macrotermes bellicosus (Smeath) is the most widely distributed, occuring from Eritrea (and Aden) in the north to the borders of the Union of South Africa in the south, from sea-level to 1 800 metres, under most conditions other than tropical rain forest and desert sand.Macrotermes natalensis (Hav.) andMacrotermes goliath (Sjost.) have more restricted distributions within the range ofbellicosus. 相似文献
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Christine A. Nalepa 《Evolutionary biology》2011,38(3):243-257
Termites are a monophyletic lineage within the paraphyletic Blattaria, with xylophagous cockroaches in the genus Cryptocercus as sister group. Given this ancestry, termite divergence involved a substantial leap in body plans, as they are pale, fragile,
and miniaturized relative to most cockroaches. Here I suggest that the evolutionary transition to an altricial morphotype
in termites is grounded in the economics of utilizing a wood diet, and occurred via a series of sequential steps associated
with modifications in social behavior. The chief benefit of an altricial morphotype is suggested to be nitrogen made available
by decreasing individual body size and by dispensing with a heavy, melanized cuticle. The primary costs lie in increased vulnerability
to environment hazards, including predators, pathogens, and desiccation. Termites tipped the evolutionary scale via cooperative
behaviors that mitigate the cost or amplify the benefit of a small, fragile morphotype, and were present in rudimentary form
in their cockroach relatives. These include building behavior, cooperative feeding, allogrooming, and most notably, trophallaxis.
It was the directed circulation of nitrogenous reserves via trophallactic feeding among units of the superorganism rather
than their progressive storage in a large, heavily armored body that was the foundation of termite evolutionary success. 相似文献
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Corina E. Tarnita 《Current biology : CB》2018,28(24):R1394-R1396
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Tadahiko Kajiwara Jiro Sekiya Akikazu Hatanaka 《Bioscience, biotechnology, and biochemistry》2013,77(6):1293-1294
The effect of tripropyltin chloride (TPT) on some functional reactions in E. coli was investigated. The inhibition on respiration and protein, DNA and RNA syntheses were examined in vivo. Oxygen consumption by E. coli cells was scarcely inhibited even at the concentration of 30 µg/ml TPT. The incorporations of 14C-labeled amino acids into protein fraction were inhibited. Especially, in the case of l-leucine, it was inhibited 60% even at 10 µg/ml TPT. Both incorporations of 14C-adenine into DNA and RNA fraction were inhibited 50–60% at 20 µg/ml TPT. RNA polymerase was prepared from E. coli cells and the effect of organotin compounds on the enzyme activity was examined. Organotin compounds inhibited the enzyme activity only at high concentrations (5-10mm). and dialkyltin chlorides which possess no antimicrobial action showed the inhibition more intensely than trialkyltin chlorides. The effect on membrane-bound ATPase was also examined in vitro. We found that TPT has high inhibitory action on membrane-bound ATPase. However, it slightly inhibited the activity of ATPase separated from membrane. 相似文献
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Termite feeding deterrent from Japanese larch wood 总被引:1,自引:0,他引:1
Extraction of flavonoids from Japanese larch (Larix leptolepis) wood with water was carried out to prepare a termite feeding deterrent. A two-stage procedure for the extraction was adopted. The first extraction step was performed at ambient temperature (22 degrees C) and the second at elevated temperatures ranging 50-100 degrees C. The first step mainly gave a mixture of polysaccharides together with small amount of flavonoids. At the second step, the yield of extract and its chemical composition were greatly affected by the temperature. The yield of solubilised carbohydrates steadily increased with a rise in the temperature, while the overall yield of flavonoids reached its optimum at 70 degrees C. An additional increase in the temperature resulted in a decrease in the yield. Model experiments using dihydroflavonols confirmed the occurrence of oxidative dehydrogenation and/or intramolecular rearrangement during the hydrothermal treatment at higher temperatures. The crude water extracts showed strong feeding deterrent activities against the subterranean termite, Coptotermes formosanus, in a choice paper disc assay. The extracts containing flavonoids in large quantities exhibited potent termite feeding deterrent activities. 相似文献
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Abstract
Many termite species rely on intestinal protozoan symbionts to digest their cellulosic foods. We examined cellulose acquisition
by the symbionts of the Eastern subterranean termite Reticulitermes flavipes Kollar (Isoptera; Rhinotermitidae) by following their phagocytosis of red paper fed to the termite host. The effects of termite
host starvation and environmental temperature on feeding activity were studied in the zooflagellates Trichonympha agilis Leidy (Trichonymphidae), Pyrsonympha vertens Leidy, Dinenympha fimbriata Kirby, and D. gracilis Leidy (Pyrsonymphidae), which are among the largest residents in R. flavipes' hindguts. Protozoans in termites starved for 24 h ingested red paper significantly sooner than protozoans in termites with
continuous access to food. Trichonympha, Pyrsonympha, and Dinenympha all ingested red paper particles at approximately the same rate. Red paper appeared significantly sooner in protozoans in
termites maintained at 32°C than in those maintained at 22°C or 26°C. At 32°C, numbers of Trichonympha per gut remained constant over 96 h. Pyrsonympha and Dinenympha cells were absent or significantly reduced in number by 72 h at that temperature. These results provide insight into the
environmental factors that shape the termite–protozoan symbiosis. They may aid in the development of protozoicides used to
control pest termites.
Received: 1 August 1997; Accepted: 26 November 1997 相似文献
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In the coastal zone of central Veracruz, Mexico, we recorded the abundance of orchid plants growing on termite carton trails or directly on the peeling bark of Bursera fagaroides. Although only 19 percent of the surveyed trees contained termite carton trails, trees with termites hosted 92 percent of all orchid individuals. A disproportionate number of orchid seedlings occurred on termite cartons given the relative availability of carton and bark substrate. Our results show for the first time that orchids can establish on termite trails, and we discuss the potential for termite facilitation of orchid populations. 相似文献
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In tropical rainforests, termites constitute an important part of the soil fauna biomass, and as for other soil arthropods, variations in soil composition create opportunities for niche partitioning. The aim of this study was twofold: first, we tested whether soil-feeding termite species differ in the foraging substrate; second, we investigated whether soil-feeding termites select their foraging sites to enhance nutrients intake. To do so, we collected termites and analysed the composition and structure of their feeding substrates. Although Anoplotermes-group members are all considered soil-feeders, our results show that some species specifically feed on abandoned termite nests and very rotten wood, and that this substrate selection is correlated with previous stable isotope analyses, suggesting that one component of niche differentiation among species is substrate selection. Our results show that the composition and structure of bare soils on which different termite species foraged do not differ, suggesting that there is no species specialization for a particular type of bare soil. Finally, the bare soil on which termites forage does not differ from random soil samples. Overall, our results suggest that few species of the Anoplotermes-group are specialized toward substrates rich in organic matter, but that the vast majority forage on soil independently of its structural and chemical composition, being ecologically equivalent for this factor. 相似文献
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Michael A. Yamin 《Applied microbiology》1980,39(4):859-863
The end products of cellulose metabolism by the trichomonad flagellate Trichomitopsis termopsidis from the termite Zootermopsis sp. were investigated by growing axenic flagellates on [14C]cellulose. The growth of T. termopsidis resulted in the release of label into the supernatant fraction of the culture fluid, and > 75% was volatile under acid conditions. The label was analyzed for 14CO2 and for [14C]volatile compounds by vacuum distillation under acid and alkaline conditions in disposable micro-distillation vessels. The distillate and undistilled culture supernatant fluid were chromatographed on cellulose thin layers to identify the labeled end product. T. termopsidis produced 14CO2 and [14C]acetate which accounted for 25 to 30% and 55 to 60% of the labeled end products, respectively. The ratio of label in CO2 to acetate suggests that they are produced in equimolar amounts. No neutral volatile compounds were produced. The remaining unidentified end product (10 to 20%) was not volatile nor extractable into ether. Hydrogen was produced by T. termopsidis, and the cells were killed by the drug metronidazole. Enzymatic activities were found which account for these end products: pyruvate:ferredoxin oxidoreductase and hydrogenase. The results indicate that acetate is the end product of T. termopsidis cellulose metabolism and is available to the termite for energy metabolism and biosynthesis. 相似文献
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Over the course of several million years, the eukaryotic gut symbionts of lower termites have become adapted to a cellulolytic environment. Up to now it has been believed that they produce nutriments using their own cellulolytic enzymes for the benefit of their termite host. However, we have now isolated two endoglucanases with similar apparent molecular masses of approximately 36 kDa from the not yet culturable symbiotic Archaezoa living in the hindgut of the most primitive Australian termite, Mastotermes darwiniensis. The N-terminal sequences of these cellulases exhibited significant homology to cellulases of termite origin, which belong to glycosyl hydrolase family 9. The corresponding genes were detected not in the mRNA pool of the flagellates but in the salivary glands of M. darwiniensis. This showed that cellulases isolated from the flagellate cells originated from the termite host. By use of a PCR-based approach, DNAs encoding cellulases belonging to glycosyl hydrolase family 45 were obtained from micromanipulated nuclei of the flagellates Koruga bonita and Deltotrichonympha nana. These results indicated that the intestinal flagellates of M. darwiniensis take up the termite's cellulases from gut contents. K. bonita and D. nana possess at least their own endoglucanase genes, which are still expressed, but without significant enzyme activity in the nutritive vacuole. These findings give the impression that the gut Archaezoa are heading toward a secondary loss of their own endoglucanases and that they use exclusively termite cellulases. 相似文献
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Degradation of Lignin Compounds by Bacteria from Termite Guts 总被引:3,自引:0,他引:3
By incubating bacteria from the gut of the termite, Nasutitermes takasagoensis, in a culture medium containing a ligninic compound, direct evidence that lignin-biodegradation occurs in the gut of termites was obtained. The bacteria were capable of degrading ligninic compounds. 28% of dealkalized lignin was degraded and lignin dimer compounds, which have a linkage proper to lignin, such as -O-4, -1, phenylcoumarane and biphenyl bonds, were degraded by 60 % to 95 %. 相似文献