秦岭地区西藏山溪鲵种群结构及保护

给出了秦岭地区西藏山溪鲵种群的统计学参数,包括年龄锥体、现时生命表、存活曲线,并对各年龄的存活及死亡原因作了分析。结果表明,当年生幼体及三龄变态期个体死亡率升高,这主要与当年生幼体适应急流冲击的能力弱以及三龄变态期个体更换栖息生境有关。径流涵养林的无计划采伐及破坏流溪河道是造成种群数量下降的人为因素。种群保护措施应以保护径流量的稳定为主。     

Effects of prey mite species on life history of the phytoseiid predators Typhlodromalus manihoti and Typhlodromalus aripo

The effects of prey mite suitability on several demographic characteristics of phytoseiid predators and the relationship of these effects to the potential of phytoseiid predators to control herbivorous mite populations are well documented. Evidence has also accumulated in the last 20 years demonstrating that phytoseiid predators utilize herbivorous prey mite-induced plant volatiles as olfactory cues in locating their herbivorous mite prey, but less well established is the predictability of reproductive success from the ability of the predators to utilize olfactory cues to locate their prey, and how these processes are related to the success of the predators as biological control agents of the herbivorous mite. In this study, we determined in laboratory no choice experiments, the development, survivorship and fecundity of the two neotropical phytoseiid predators Typhlodromalus manihoti Moraes and T. aripo DeLeon when feeding on three herbivorous mites, including the key prey species Mononychellus tanajoa (Bondar), and the two alternative prey species Oligonychus gossypii (Zacher) and Tetranychus urticae (Koch). Intrinsic rate of increase (r_m) of T. aripo was 2.1 fold higher on M. tanajoa as prey compared with T. urticae as prey, while it was almost nil on O. gossypii. For T. manihoti, r_m was 2.3 fold higher on M. tanajoa as prey compared with O. gossypii as prey, while reproduction was nil on T. urticae. An independent experiment on odor-related prey preference of the two predator species showed that T. manihoti and T. aripo preferred odors from M. tanajoa-infested leaves to odors from O. gossypii-infested leaves. Moreover, both predator species preferred odors from M. tanajoa-infested leaves over those from T. urticae-infested leaves. As reported here, life history of the two predatory mites matches odor-related prey preference if the key prey species is compared to the two inferior prey species. The implications of our findings for the persistence of T. manihoti and T. aripo and biological control of M. tanajoa in the cassava agroecosystem in Africa are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

动态生命表寿命数收集与处理过程中常见问题的探讨

种群动态生命是研究野生动物存活过程的有用工具,而其可靠性则依赖于生命数据收集与处理过程中的正确性。章就野生动物动态生命表收集和处理过程中常见的右删失数据处理问题、个体死亡时间估计、同生群初始值N0估计以及早期死亡数据的估算问题提出了一点建议和讨论。     

常见寿命数据类型及生命表的编制方法

生命表是描述种群死亡过程的有用工具,介绍了4种常见的寿命数据类型;寿终数据,右删失数据,左删失数据和区间型数据特征及其相应的数据分析处理方法即生命表法,乘积限估计和Turbull估计法,对生命表法和乘积限估计法应用上的特点进行了比较,同时还对特殊的寿命数据类型－－截断数据做了简要介绍。     

棉蚜种群季节性变异的生态条件

研究棉蚜在不同温度下取食不同生育期棉叶后种群的变动情况。通过Weibull函数模拟、生命表分析和高氏距离分析比较表明,无论在苗期和蕾期,随着渐度的升高棉蚜种群的死亡高峰日均提前,世代寿命明显缩短;然而,在20-25℃范围内,相同温度时棉蚜生活在棉花蕾期叶上的繁殖力明显高于苗期叶上的繁殖力。在30℃时繁殖力普遍明显下降,温度20-25℃最适于棉蚜的生长与繁殖。且棉花殖生长期比营养生长期更适于棉蚜的生存和繁殖,温度与棉花生育期都是导致苗蚜与伏蚜生长与繁殖差异的外界因素。     

Semi-field demographic performance of the invasive planthopper,Orosanga japonica (Hemiptera: Ricaniidae) on two host plants

Orosanga japonica Melichar (Hemiptera: Ricaniidae) is an invasive polyphagous pest in Iran. The planthopper damaged host plants by sap-sucking and egg laying on new twigs. This study aimed to determine the life table parameters of O. japonica on Rubus ulmifolius Schoot (elm leaf blackberry) and Melia azedarach L. (chinaberry) under field conditions in Rudsar (North of Iran) during 2019–2020. The collected life history data were analyzed based on age-stage, two-sex life table theory. The results showed that the incubation period of O. japonica was too long (≈ 270 days) on both host plants. The nymphs emerged from mid-May 2020. The planthopper had five nymphal stages under field conditions. The nymphal duration was 41.39 ± 0.56 days and 38.13 ± 0.62 days on R. ulmifolius and M. azedarach, respectively. The total preadult survival rates were 53.2% and 51.7% on R. ulmifolius and M. azedarach, respectively. Based on the results, a significant shorter total developmental time was observed on M. azedarach. When adults emerged in late July, they laid eggs after 26.05 days and 26.75 days on R. ulmifolius and M. azedarach, respectively. The fecundity on M. azedarach (131.69 egg/female) was significantly higher than that on R. ulmifolius. However, the life table parameters were all not significantly different on the two host plants. The intrinsic rate of increase (r) were 0.0097 ± 0.0005 day⁻¹ and 0.0105 ± 0.0006 day⁻¹ on R. ulmifolius and M. azedarach, respectively. Generally, these findings could be helpful to establish an efficient management strategy for this exotic pest.