杭州悬铃木方翅网蝽的捕食性天敌种类及日本通草蛉幼虫捕食作用   总被引：1，自引：0，他引：1  

纪锐  王宝辉  娄永根 《中国生物防治》2011,27(1):32-37

本文调查发现杭州悬铃木方翅网蝽Corythucha ciliata(Say)的捕食性天敌有5科7种,主要是日本通草蛉Chrysoperla nipponensis(Okamoto)、普通草蛉Chrysoperla carnea(Stephens)和小花蝽属Orius spp..日本通草蛉幼虫对悬铃木方翅网蝽成虫、若虫的捕食功能反应均符合Holling Ⅱ型方程,捕食作用强弱为:日本通草蛉3龄幼虫捕食若虫＞日本通草蛉2龄幼虫捕食若虫＞日本通草蛉3龄幼虫捕食成虫,其对应的搜寻效率α与处理时间Th值分别为1.0141、0.5687、0.3757和0.0075、0.0121、0.0267.成虫和若虫共存时,日本通草蛉3龄幼虫喜好捕食若虫.日本通草蛉幼虫的搜寻效应随猎物密度的增加而降低.在悬铃木方翅网蝽若虫密度相同的条件下,日本通草蛉2龄、3龄幼虫随着自身密度的增大,其平均捕食量逐渐减少,捕食作用率也相应降低,其捕食作用率E与自身密度P的关系分别为:E=0.3164 P-0.4700和E=0.3411 P-0.4762.日本通草蛉幼虫间存在分摊竞争.  相似文献   

Predation of artificial nests in a fragmented landscape in the tropical region of Los Tuxtlas, Mexico     

Alejandro Estrada  Andrómeda RiveraRosamond Coates-Estrada 《Biological conservation》2002,106(2):199-209

Predation rates of artificial nests were investigated in a fragmented landscape in the lowlands of Los Tuxtlas in southern Mexico. Hen and plasticine eggs were used to assess predation pressure in four habitats: the interior of forest fragments, the forest-pasture edge, corridors of residual forest vegetation and linear strips of live fences across pastures. Three sites per habitat were used in three experimental trials. Hen and plasticine ground nests with three eggs each were alternated every 50 m along transects at each site. Predation rates on each type of nest were monitored for 9 days. Survey of potential avian and mammalian potential nest predators were conducted at each site prior to the experimental trails. Readings of amount of light illuminating the ground were taken by each nest at each site to assess exposure of nests. In general, average predation rates were significantly higher for both hen and plasticine nests in the forest-pasture edge and in the corridors than in the interior of the forest fragments. While birds and mammals were the principal predators on hen eggs in the forests, mammals were responsible for the majority (?70%) of eggs damaged at the other habitats. Surveys of potential nest predators showed that avian and mammalian potential nest predators were significantly more common at the forest-pasture edges and at the other habitats than in the forests. Readings of light reaching the ground suggest that concealment of nests by the vegetation may play an important role in predation risk. Our results are consistent with reports from other Neotropical rainforests indicating an increase of artificial nest predation pressures from forest interior to open habitats. Restoration of forest fragments, allowing the vegetation to grow along the forest-pasture edge and the planting of arboreal crops at the forest-pasture edges may be measures that could increase cover and nest protection.  相似文献   

Intensive beach management as an improved sea turtle conservation strategy in Mexico     

Andrés Garc?&#x;a  Gerardo Ceballos  Ricardo Adaya 《Biological conservation》2003,111(2):253-261

We evaluate the role of intensive beach management, meaning intense patrolling and nest reburial to a central hatchery, as a strategy for improving the success of sea turtle conservation at nesting sites in Mexico. We report the results of an experimental program at Playa Cuixmala, Jalisco, western Mexico. Sea turtle conservation efforts in Mexico have, in general, poor results because of lack of funds, which leads to insufficient beach protection and severe negative effects of nest removal on hatching success and sex ratios. Alternative strategies are needed to optimize limited resources. We predicted that intensive beach management, which included intense patrolling and careful nest reburial, could be an effective way to maximize nest survival and hatchling release under limited financial and human resources. The results of our 9-year study were very positive. Survival rate increased several fold during the study period. Hatching success and sex ratios were not significantly different between in-situ and removed nests. Survival in removed nests was, however, much higher that in-situ nests, because of predation and beach erosion. In total, the small (3 km length) Playa Cuixmala became the second most productive sea turtle nesting beach in the region because of these concentrated efforts. Intense beach management can be an important technique for sea turtle conservation, and can be properly applied to small beaches or the most productive sections of large beaches.  相似文献   

What do artificial nests tells us about nest predation?     

Liana Zanette 《Biological conservation》2002,103(3):323-329

Artificial nests are commonly used to evaluate predation, but the assumption that this method mimics predation on natural nests has seldom been tested. Natural and artificial nests of eastern yellow robins (Eopsaltria australis) were monitored in four, 55-ha plots over two breeding seasons. Overall, daily survival rates were higher (P<0.001) for natural (95%/day) than for artificial nests (88%/day). Among plots, daily survival rates for the two types of nests were not correlated with one another (P=0.72) indicating that the spatial pattern of predation on artificial nests did not mimic that for natural nests. Seasonal variation was evident for natural nests in one year, when they were more successful at the beginning and end of the breeding season. No seasonal patterns were observed for artificial nests in either year. Neither natural nor artificial nests showed annual variation in predation. Previous researchers concluded that large birds were important predators on robin nests. In this study, predation by large birds on artificial nests was positively correlated with the numbers of large birds counted on the plots (P=0.04). However, large birds depredated only 16% of artificial nests. Daily survival rates for artificial nests were recalculated using predation by large birds only. These rates were compared with natural nests, but there was still no correspondence in the spatial and temporal patterns of predation for the two types of nests. These results suggest that inferences about predation on natural nests based on artificial nest studies should be avoided.  相似文献   

Predation as a determinant of size structure in populations of crucian carp (Carassius carassius) and tench (Tinea tinea)     

C. Brönmark  C. A. Paszkowski  W. M. Tonn  A. Hargeby 《Ecology of Freshwater Fish》1995,4(2):85-92

Predation is an important structuring force in many fish assemblages and may have large, direct lethal effects on prey fish populations but also may affect growth rate and survival indirectly through shifts in behavioral patterns. Some species appear more sensitive to predation and earlier studies in a limited set of Finnish ponds suggests that crucian carp (Carassius carassius) is very sensitive to predation, which results in changes in population size-structure and density. In this study we tested the effect of piscivore presence or absence on crucian carp populations by using data from a large number (>600) of Swedish lakes across a wide geographical area and ranging in size from small ponds to large lakes (0.02–4400 ha). We also included a second species, tench (Tinea tinea), in our analyses. The population size structures of crucian carp and tench were clearly related to the presence or absence of piscivores. In lakes and ponds without piscivores. populations were dominated by small-bodied individuals. When piscivores were present, populations consisted almost exclusively of large individuals. Densities of crucian carp and tench were much higher in ponds and lakes without piscivores. There were no differences in size structure or relative abundance when catches from electrofishing were compared with gill net catches, suggesting that our results are not an effect of a behavioral shift in the presence of piscivores.  相似文献   

The influence of physical watercourse parameters on the degree of anadromy in different lake populations of Arctic charr (Salvelinus alpinus (L.)) in northern Norway   总被引：1，自引：1，他引：0  

K. Kristoffersen 《Ecology of Freshwater Fish》1994,3(2):80-91

The influence of physical watercourse parameters on the degree of anadromy was studied in 15 lake populations of Arctic charr (Salvelinus alpinus (L.)) in northern Norway. The anadromy of the different populations was scored based on the following criteria; marine parasites. fish length and length at maturity. There were significant negative correlations between the anadromy scores and both the length of the outlet rivers of the different lakes and a migration barrier index for the different watercourses (combining migration distance and water velocity). It is hypothsized that these correlations were due to differences in energy expenditure for charr during upstream migration and/or differences in predation pressure on charr during river migration. Short rivers with relatively high water velocity seem to be the most preferable conditions for the anadromous life-history strategy. There were no correlations between the degree of anadromy and mean river slope or minimum summer water discharge.  相似文献   

红彩真猎蝽对斜纹夜蛾和烟青虫的捕食功能反应   总被引：5，自引：0，他引：5  

邓海滨  王珍  陈永明  吴文斌  彭文松 《广东农业科学》2012,39(13):107-109

在室内条件下研究了红彩真猎蝽雌成虫对斜纹夜蛾和烟青虫2龄幼虫的捕食作用和种内干扰作用。结果表明,红彩真猎蝽雌成虫的捕食量随着斜纹夜蛾和烟青虫幼虫的密度增加而增大,其捕食功能反应符合Holling II型方程,红彩真猎蝽对斜纹夜蛾2龄幼虫的捕食量符合Na=0.4665Nt/(1+0.0036 Nt),对烟青虫2龄幼虫的捕食量符合Na=0.4275Nt/(1+0.0041Nt)。红彩真猎蝽的捕食作用有较强的种内干扰反应,捕食率与个体间相互干扰的关系符合Hassell模型,红彩真猎蝽的捕食量与害虫密度正相关,寻找效应与害虫密度负相关。  相似文献   

Spatial and temporal effects on seed dispersal and seed predation of Musa acuminata in southern Yunnan, China     

Meng L  Gao X  Chen J  Martin K 《Integrative zoology》2012,7(1):30-40

Wild bananas are abundant in tropical areas and many ecologists have observed that the succession process is quicker following increased disturbance. This study was conducted to analyze animal-seed interactions and their effects on the seed fate of a wild banana species (Musa acuminata) in tropical southern Yunnan (China) through experiments considering spatial (site and habitat) and temporal (seasons) variation. The largest proportion of fruits (81%) was removed by frugivorous seed dispersers, especially by bats at nighttime. Only 13% of the fruits were removed by climbing seed predators (different species of rats). In the exclosure treatment, rodents accounted for a significantly higher total artificially exposed seed removal number than ants, but with spatial and temporal differences. The highest seed predation rate by rodents (70%) was found in forest with wild banana stands, corresponding with the highest rodent diversity (species numbers and abundance) among the habitat types. In contrast, the seed removal number by ants (57%) was highest in the open land habitats, but there was no close correlation with ant diversity. Seed removal numbers by ants were significantly higher in the dry compared to the rainy season, but rodent activity showed no differences between seasons. The overall results suggest that the largest proportion of seeds produced by wild banana are primarily dispersed by bats. Primary seed dispersal by bats at nighttime is essential for wild banana seeds to escape seed predation.  相似文献   

Evaluation of regeneration potential of Pinus koraiensis in mixed pine-hardwood forests in the Xiao Xing’an Mountains, China     

Yun-bin Li  Pu Mou  Tian-ming Wang  Jianping Ge 《林业研究》2012,23(4):543-551

Large scale harvest of Korean pine(Pinus koraiensis) seeds as a food product in the mixed Korean pine-hardwood forest of northeastern China poses a serious threat to the sustainability and restoration of this endangered regional ecosystem.Seed collection over past decades greatly reduced the seed bank and subsequent seedling and sapling recruitment,and impacting a wide array of granivorous animals that rely on the pine seeds.We surveyed Korean pine seeds,including solid seeds(SS),insect consumed seeds(ICS) and other(animal) consumed(OCS) kernels,of the seed bank(forest floor and the top 10 cm of mineral soil),the seedlings and saplings from 1 m 2 sample plots in five forest types in Liangshui Nature Reserve(LNR) of the southern Xiao Xing’an Mountains in northeastern China to provide accurate information for assessing the Korean pine regeneration potential.The average number of pine seeds in the seed bank were 11.2 seeds/m 2,9.1 seeds/m 2,4.6 seeds/m 2,1.1 seeds/m 2,and 0.2 seeds/m 2 in Korean pine-basswood forest,mixed Korean pine-hardwood forest,mixed conifer-hardwood forest,white birch forests,and oak forests,respectively.In the first three forest types,percentages of SS(potentially viable seeds) were 11.2%,3.5% and 27.8%,respectively.The percentages of ICS(not viable seeds) were consistent at around 35%.The higher but variable percentages of OCS(not viable seeds) indicated high seed predation in these forests.Compared with other studies,we recorded higher percentages of seed damage,probably due to our survey approach and the increased depth of seed bank sampled in our study.Depletion of pine seeds in the seed bank greatly reduced seedling and sapling recruitment.Densities of pine seedlings varied from about 180 trees/ha in the mixed Korean pine-hardwood forest to about 5,400 trees/ha in the mixed conifer-hardwood forests and showed a high degree of spatial variation.Saplings were rare in the mixed Korean pine-hardwood forest,but ranged in the thousands in other forests.Large scale pine seed harvest has seriously threatened the sustainability of the mixed Korean pine-hardwood forest ecosystem.Scaling down the seed harvest or supplemental planting of pine saplings are urgently needed to maintain the health of the existing Korean pine forests and to restore this endangered ecosystem.  相似文献   

The impact of fish and drought on frog breeding in temporary waters in Zimbabwe     

《African Zoology》2013,48(1):124-130

The breeding of frogs in four ponds near Harare, Zimbabwe, was investigated during a wet rainy season (2000/01) and a dry one (2001/02). During 2000/01 eight and nine species bred in two ponds in abandoned gravel pits that never contained fish, but only four species bred in these in 2001/02 and the relative abundance was reduced by about 50%. Pond 3 was a small dam that filled after the rains and was invaded by fish once it overflowed. Five species bred in it in 2000/01, but breeding activity was curtailed once it was invaded by catfish, Clarias gariepinus, some of which were found with frog remains in their stomachs. The pond did not overflow in the following season, and was therefore not invaded by fish; although only four species bred in it their relative abundance was considerably higher. Pond 4 was a permanent pond that always contained fish. Only three species bred in it and the relative abundance of tadpoles was always low. Species belonging to the Ranidae seemed to be most severely affected by drought and this may explain the absence of some species, such as the African bullfrog, Pyxicephalus adspersus, that was once abundant around Harare.  相似文献