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The biological and physical role of mulch in the rehabilitation of crusted soil in the Sahel 总被引:3,自引:0,他引:3
Abstract. During three consecutive years (1993–1995) a split-plot design with three replications was used to study the biological and physical role of mulch in the improvement of crusted soil water balance and its productivity in the north of Burkina Faso. The main treatment was the use of an insecticide, to obtain plots with and without soil fauna (SF and NSF). The subsidiary treatment consisted of four mulch types randomly applied on subplots. These were straw of Pennisetum pedicellatum applied at 3 t ha−1 , woody material of Pterocarpus lucens applied at 6 t ha−1 and composite (woody material and straw) treatments applied at 4 t ha−1 . In addition there was a control, with no mulch (bare plot). Data on soil faunal activity, runoff, sediment accumulation from wind blown soil, vegetation cover and vegetation dry matter yield were collected on all plots.
The biological activity (mainly termites) in mulched plots was the key element in the efficacy of mulching to rehabilitate crusted soil. Water infiltration and dry matter yield were statistically lower on NSF plots than on SF plots and runoff and dry matter yield were not different from the values obtained on bare plots. A significant correlation was found between runoff, all vegetation data and termite-voids. Sediment accumulation due to the physical barrier of the mulch was not found to be a significant factor in the improvement of vegetation performance and the reduction of runoff. 相似文献
The biological activity (mainly termites) in mulched plots was the key element in the efficacy of mulching to rehabilitate crusted soil. Water infiltration and dry matter yield were statistically lower on NSF plots than on SF plots and runoff and dry matter yield were not different from the values obtained on bare plots. A significant correlation was found between runoff, all vegetation data and termite-voids. Sediment accumulation due to the physical barrier of the mulch was not found to be a significant factor in the improvement of vegetation performance and the reduction of runoff. 相似文献
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The effects of hexaflumuron consumption on the mortality of workers of the Western subterranean termite, Reticulitermes hesperus Banks, were observed following various exposures to a substrate treated with 14C-labeled hexaflumuron at 5 g kg(-1). Uptake of hexaflumuron by workers was rapid, peaking at approximately 280 ng hexaflumuron per termite 12 days after exposure. The onset of mortality began at day 8, with cumulative mortality reaching approximately 96% by day 45. Excretion of hexaflumuron from worker termites was rapid following various exposure periods, half-lives ranging from 2.1 to 4.7 days. Trophallaxis among worker termites was efficient, hexaflumuron levels in recipient termites approaching two-thirds of levels present in donor termites feeding continuously on hexaflumuron-treated filter paper. The effect of donor-to-recipient group ratios was negligible on the amounts of hexaflumuron transferred from donors to recipients. In laboratory tests, hexaflumuron diffused from a feeding source within 7 days. The presence of additional food sources appeared to inhibit movement of hexaflumuron. Movement of hexaflumuron by cannibalism and coprophagy occurred, but was significant only when termites were starved. Hexaflumuron also appeared to adversely affect egg development by preventing hatch. Hexaflumuron was readily transferred through termite groups, effectively suppressing laboratory populations of R hesperus. Variable efficacy in field situations employing baiting with hexaflumuron in southern California may be a consequence of sporadic feeding at bait stations, the rapid clearance of hexaflumuron from individual termites, and the difficulties in bait presentation (low foraging activity, poor bait station foraging fidelity) inherent in the foraging characteristics of the Western subterranean termite. 相似文献
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A review of subterranean termite control practices and prospects for integrated pest management programmes 总被引:3,自引:0,他引:3
Soil insecticide barriers have been the single most important tool for subterranean termite control in the last half century, but limitations with current soil termiticides have provided the impetus to look for alternatives in recent years. One such alternative is the monitoring--baiting programme. Monitoring stations to detect termites are placed in the soil surrounding a structure. Once termites are found in the stations, monitoring devices are replaced with slow-acting baits such as the chitin synthesis inhibitor, hexaflumuron. Field studies have indicated that termite colonies were eliminated using less than 1 g of hexaflumuron. After the elimination, monitoring resumes and bait is applied if new termite activity is detected. The monitoring and baiting procedure form the basis for an ongoing programme to protect structures from subterranean termite infestation. Although the cost--benefit model developed for agricultural integrated pest management cannot be applied directly to termite control, the underlying concept for using a cost-effective approach remains the same. The benefits of the monitoring--baiting programme over conventional soil treatment are a reduction in pesticide applied per unit and the elimination of termite populations near structures, resulting in the reduction of liability and damage potential. It is expected that the data management system when used in conjunction with the monitoring--baiting programme will provide a database to improve its cost-effectiveness continuously. 相似文献
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海南南湾自然保护区共记录等翅目昆虫—白蚁3科5属10种,其中天涯锯白蚁、海南土白蚁为优势种。南湾白蚁的Simpson指数λ=0.414,PIE指数PIE=0.586,Shanon-Wiener指数H1=1.290,Pielou指数J1=0.560,Whitaker指数βWS=3.13。南湾白蚁物种组成分为二种类型:第一类型是天涯锯白蚁和细颚士白蚁,这一类型占调查样方的42.1%;第二类型中有恒春新白蚁、台湾乳白蚁、异头乳白蚁、黄翅大白蚁、黑翅土白蚁、海南土白蚁以及天涯锯白蚁和细颚土白蚁等,这一类型占调查样方的52.6%;第二类型仅出现在1个样方,有海南大白蚁、平行土白蚁、海南土白蚁、台湾乳白蚁、细颚土白蚁等。天涯锯白蚁、台湾乳白蚁、海南土白蚁和细颚土白蚁是影响白蚁物种组成类型的主要种类 相似文献
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R.H. Scheffrahn H.H. Hochmair W.H. Kern Jr J. Warner J. Krecek B. Maharajh 《国际虫害防治杂志》2014,60(1):9-21
Populations of the arboreal termite, Nasutitermes corniger, discovered in Dania Beach, Florida in 2001 were surveyed and treated for eradication, beginning in 2003. Most N. corniger nest locations were cryptic and some nests contained over 1 million termites. Field efficacy of fipronil (Termidor® SC) and imidacloprid (Premise® 2) were compared in initial treatments, and fipronil was selected for termite-active sites through 2010. In 2006, expanded survey work was discontinued. By 2010 all sites within the original survey area were termite-free. In 2011, a new population of N. corniger was discovered beyond the original 2003 infested tracts. A new (2011–2012) survey revealed a total of four areas outside the original tracts that were infested with N. corniger. No tract treated with fipronil between 2003 and 2010 showed evidence of renewed termite activity in 2011–2012. New application procedures using nest-only and fipronil dust treatments were instituted in May 2012. Live termites were still found within the 2011–2012 treatment area as of November 2013. Very slow but continued spread of N. corniger in tropical urban Florida will have economic consequences as a result of nuisance and structural damage. 相似文献
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D. López-Hernández M. Niño P. Nannipieri J. C. Fardeau 《Biology and Fertility of Soils》1989,7(2):134-137
Summary The relationship between phosphatase activity and soil was studied in 14 mounds and adjacent control soils of plant debris-feeding termites from a Venezuelan savanna. The soils were assayed for acid phosphatase activity with p-nitrophenyl phosphate as substrate and for the effect of inorganic P (300 g P g–1). The proportion of organic matter in the mounds was four times that found in topsoils, indicating strong selection by the termites for organic-rich soil fractions. A comparison of phosphatase activities found no difference between mounds and adjacent soils. It seems possible that the expected increase of enzyme activity in mounds, due to a higher C content, was counteracted by enzyme inhibition due to higher levels of available inorganic P in the mounds. Addition of inorganic P to soil and mound material reduced enzyme activities by 10%–45%, but after a 2-day incubation period differences between the treated soil and the control tended to disappear. 相似文献
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Termites represent one of the most abundant belowground animal taxa in tropical rainforests, where their species richness is much higher than in any other ecosystem. This high diversity in soil ecosystems is however difficult to explain by classical Hutchinsonian niche theory, as there is little evidence for spatial or temporal separation between species. Using δ13C and δ15N isotopic ratios, we tested if resource partitioning along the humification gradient occurs in neotropical soldierless termites of the Anoplotermes-group. Two distinct sites were investigated to check if interspecific differences are transposable between sites. Significant differences in δ15N were found between species of the Anoplotermes-group. Although some species displayed higher intersite δ15N variation than others, species-average δ15N values for both sites were highly correlated, showing that sympatric soldierless soil-feeding termites feed on distinct components of the soil. Our data also suggest that some species are more likely to shift along this gradient than others, in response to overall habitat conditions or to the presence of competitors. Feeding niche differentiation can therefore account for the high species richness and diversity of soldierless soil-feeding termites in neotropical rainforests. 相似文献