西花蓟马取食不同豆科蔬菜的实验种群生命表

西花蓟马Frankliniella occidentalis(Pergande)是传入我国的重要入侵害虫,在贵阳地区对豆科蔬菜为害十分严重。在25℃条件下,组建了西花蓟马取食大豆叶片、豇豆叶片、四季豆叶片和四季豆豆荚时的实验种群生命表。结果表明:西花蓟马未成熟期取食四季豆豆荚时存活率最高,取食其它3种豆科蔬菜时存活率相差不大。西花蓟马取食四季豆豆荚时内禀增长力最高为0.1626,取食豇豆叶片时最低为0.0834,净增值率也是取食四季豆豆荚时最高,取食大豆叶片时最低,表明四季豆豆荚最有利于西花蓟马的生长发育和繁殖。在不同豆科蔬菜上的稳定年龄组配中未成熟期所占的比例很大,而成虫期所占的比例相对较小。     

基于MFA的生态工业园区物质代谢研究方法探析

物质流分析(Material Flow Analysis,MFA)是国家尺度物质代谢研究的重要手段。首先对国内外不同地域尺度下MFA的研究现状进行了概述总结;在此基础上,从工业区内的企业及其所形成的工业共生网络(Industrial Symbiosis Networks,ISNs)物质核算入手,针对如何在生态工业园区(Eco-Industrial Parks,EIPs)尺度开展物质代谢研究进行了详细论述,并通过引入部门间实物型投入产出表(Physical Input-Output Table,PIOT)对该尺度MFA的核算方法进行了改进,最终构建了EIPs-MFA模型及指标体系。以期为生态工业园区实践中的规划与管理提供方法指导。     

马尼拉陡胸茧蜂对甜菜夜蛾的控害潜能

为评价幼虫寄生蜂马尼拉陡胸茧蜂对甜菜夜蛾的控害潜能,编制了寄主和寄生蜂的实验种群生命表,测定了马尼拉陡胸茧蜂对甜菜夜蛾幼虫的寄生功能反应。结果表明:甜菜夜蛾年龄特征生命表参数为:净生殖力(种群趋势指数)R0(I)=122.0172,内禀增长率rm=0.1522,世代平均历期T=40.8556(d),周限增长率λ=1.1644;马尼拉陡胸茧蜂寄生甜菜夜蛾幼虫的生殖力表参数为:R0(I)=20.2479,rm=0.3045,T=9.8788,λ=1.3559。马尼拉陡胸茧蜂对甜菜夜蛾幼虫的捕食功能反应符合HollingⅡ型模型,a=0.8952,Th=0.0205,Namax=48.78(头)。通过生命表参数比较和功能反应模型分析,可见马尼拉陡胸茧蜂对甜菜夜蛾幼虫的寄生能力强,繁殖速率高,对甜菜夜蛾种群有较强的控制能力;从世代平均历期T的比较可知,在甜菜夜蛾繁殖1代的时间内,马尼拉陡胸茧蜂可以繁殖4个世代,在时间上天敌对害虫的发生是"超前的"而不是"跟随的"。因此在放蜂技术上应采取相应的对策,才能充分发挥天敌的控害潜能。     

玉米黄尾球跳甲的发生与防治

调查研究玉米黄尾球跳甲Sphaeroderma apicaleBaly的自然种群动态、自然种群生命表并对其药剂防治策略进行探讨。结果表明:玉米黄尾球跳甲在湖北宜昌1年发生1~2代,以成虫和蛹越冬。越冬代成虫4月中旬始现于田边的杂草,5月上旬迁入大田。百株成虫高峰出现在6月15日和8月7日;性比为0.491;卵始现于5月19日,产卵高峰出现在6月18日;平均卵量123.5粒,单雌最大卵量212粒;6月22日出现最高百株幼虫量。自然种群增长指数(I)为16.20。在发生盛期、高峰期、盛末期,玉米黄尾球跳甲被异角短胸姬小蜂Hemiptarsenus variconisGirault的寄生率分别为14.6,33.6和77.0%。马.辛硫磷1 000倍液和毒死蜱1 000倍液是防治玉米黄尾球跳甲比较理想的农药,校正防治效果分别为76.3%和66.5%;卵和1、2龄幼虫对化学药剂敏感性高,3龄幼虫对化学药剂敏感性低。结合以上的研究,提出玉米黄尾球跳甲的防治策略。     

Life History of Kampimodromus aberrans as a predator of Phytoptus avellanae (Acari: Phytoseiidae, Phytoptidae)

The biology of Kampimodromus aberrans (Oudemans), a predator of the big bud mite, Phytoptus avellanae Nalepa, was studied under laboratory conditions. All experiments were conducted on hazelnut leaf discs in an incubator at 25 ± 1 °C, with 16:8 h L:D, at an average daily relative air humidity of 76%. Observations were made twice daily for the immature stages and daily for the adults to determine developmental time, survival and fecundity. The mean developmental time for females was 6.90 days and for males was 7.10 days, and mean adult longevity for females was 11.67 days. The mean total and daily egg production were 12.67 and 1.85 eggs, respectively. The net reproduction rate (R₀) was 7.09 females/female, intrinsic rate of increase (r_m) was 0.153 female/female/day and mean generation time (T₀) was 12.80 days. The mortality rate of immature stages was 0.66% and the sex ratio was 0.51 female.     

Biology, life table and predation of Feltiella acarisuga (Diptera: Cecidomyiidae) feeding on Tetranychus cinnabarinus eggs (Acari: Tetranychidae)

Feltiella acarisuga (Vallot) is a common predatory gall midge, which feeds on many species of spider mites. All major life history and life table parameters of F. acarisuga were determined using the carmine spider mite, Tetranychus cinnabarinus (Boisduval) eggs as prey under laboratory conditions [26.7 ± 2 °C, 75 ± 5% RH, and a photoperiod of l4:10 (L:D) h]. Developmental times of F. acarisuga were 2.6, 7.1, and 6.7 d for eggs, larvae, and pupae, respectively, with an average of 16.4 d from egg to adult emergence. Female immatures development took ≈1 d longer than male immatures did. Adult F. acarisuga lived an average of 12.8 d, and the female adults (13.3 d) lived significantly longer than male adults did (11.9 d). After an average of 1.5 d preoviposition period, each female laid an average of 27.3 eggs in its life span with an average of 2.1 eggs per day and an average of 2.8 eggs on each of its oviposition day. The raw data were analyzed using an age-stage, two-sex life table method that takes into consideration of the variable developmental rates among individuals and between sexes. The intrinsic rate of natural population increase (r), net reproductive rates (R_o), gross reproductive rate (∑m_x), generation time (T), and doubling time (DT), and the finite rate of increase (λ) of F. acarisuga were estimated using the age-stage, two-sex (male and female) life table analysis as 0.122 d⁻¹, 16.19 eggs per female, 20.81 eggs per female, 22.81 d, 1.1298 d, and 5.7 d⁻¹, respectively. Each of the first, second, and third instar larvae of F. acarisuga consumed an average of 35.5, 54.0 and 86.9 T. cinnabarinus eggs per day, respectively. Larvae of F. acarisuga could consume an average of 175.4, T. cinnabarinus eggs, and female larvae consumed 14% more spider mite eggs (187.6 eggs) than male larvae (165.1 eggs). The significance of other life table parameters related to the population and the potential of using F. acarisuga as a biological control agent are discussed.     

Reproductive and developmental biology of Gonatocerus ashmeadi (Hymenoptera: Mymaridae), an egg parasitoid of Homalodisca coagulata (Hemiptera: Cicadellidae)

The reproductive and developmental biology of Gonatocerus ashmeadi Girault, a parasitoid of the glassy-winged sharpshooter Homalodisca coagulata (Say), was determined at five constant temperatures in the laboratory: 15; 20; 25; 30; 33 °C. At 30 °C, G. ashmeadi maintained the highest successful parasitism rates with 46.1% of parasitoid larvae surviving to adulthood. Lifetime fecundity was greatest at 25 °C and fell sharply as temperature either increased or decreased around 25 °C. Temperature had no effect on sex ratio of parasitoid offspring. Mean adult longevity was inversely related to temperature with a maximum of 20 days at 15 °C to a minimum of eight days at 33 °C. Developmental rates increased nonlinearly with increasing temperatures. Developmental rate data were fitted with the modified Logan model for oviposition to adult development times across each of the five experimental temperatures to determine optimal and upper lethal temperature thresholds. The lower developmental threshold estimated by the Logan model and linear regression were 1.10 and 7.16 °C, respectively. Linear regression of developmental rate for temperatures 15–30 °C indicated that 222 degree-days were required above a minimum threshold of 7.16 °C to complete development. A temperature of 37.6 °C was determined to be the upper development threshold with optimal development occurring at 30.5 °C. Demographic parameters were calculated and pseudo-replicates for intrinsic rate of increase (r_m), net reproductive rates (R_o), generation time (T_c), population doubling time (T_d), and finite rate of increase (λ) were generated using the bootstrap method. Mean bootstrap estimates of demographic parameters were compared across temperatures using ANOVA and nonlinear regression.     

Bigger is better: age class-specific survival rates in long-lived turtles increase with size

Vital rates for small, non-breeding individuals are important components of population dynamics for many species, but often individuals of these sizes are difficult to locate, capture, and track. As such, biologists frequently lack reliable estimates of juvenile survival because sample sizes and recapture rates for this life stage are low. Long-lived animals often take many years to reach sexual maturity and spend much of this time in the smaller size classes, making them sensitive to changes in survival rates. We estimated the survival rates of all size classes for the northern map turtle (Graptemys geographica) using a mark-recapture dataset with >3,500 captures from 2019–2021 and 210 nests from 2018–2021. As turtle size increased, annual survival probability increased regardless of sex. Estimated annual survival probability for turtles >18 cm long (i.e., adult females >15 years) was about 0.95, over 4 times higher than turtles that were 3 cm long (i.e., hatchlings <1 year; 0.22 annual survival probability). Although we did not observe a difference in survival probability between sexes of any size class, adult females are nearly twice the size of adult males, leading to an increased annual survival probability for females of 0.95, compared to 0.80 for males. Changes in adult survival had the greatest influence on population estimates over time, with temporary decreases, such as those due to poaching or an environmental disaster, potentially leading to unrecoverable decreases in the overall population size. Our study provides detailed survival rates for all size classes in a long-lived turtle, which are necessary to assess population stability and can be used to determine the most effective conservation or management practices.     

Experimental observations on maternal reproductive rate and offspring characteristics

Starting from a clone of Philodina roseola (Rotifera, Bdelloidea) six homogeneous animals have been reared. From them three different age cohorts have been studied in order to determine their life tables. Cohorts and parental life schedules are compared and discussed. A sort of correlation between offspring fecundity and life span and maternal rate of egg production could be established.     

Fecundity and life table parameters of Campoletis sonorensis (Hymenoptera: Ichneumonidae), an endoparasitoid of the Cabbage Looper Trichoplusia ni Hübner (Lepidoptera: Noctuidae), under laboratory conditions

The fecundity and life table parameters of Campoletis sonorensis females were measured using thirty 4-day-old Trichoplusia ni larvae daily at 24°C, 60% RH and a photoperiod of 12 h L:12 h D. The mean longevity was 34.5±2.8 days, the mean oviposition period was 22.7±1.9 days, and the mean constant oviposition period and the mean post-oviposition period were 15.9±1.3 and 11.9±2.2 days, respectively. The mean realised fecundity and the mean fertility differed significantly at 66.9±7.8 and 60.4±7.8 parasitoids per female, respectively. The mean sex ratio for the mean oviposition period (23 days) was 0.13±0.07, indicating a highly female biased ratio. The life table parameters were: intrinsic rate of natural increase (r _m), 0.135 female/day; gross reproductive rate (GRR), 50.30; net reproductive rate (R _o), 49.96; finite capacity for increase (λ), 1.14 female/day; mean generation time (T), 28.97 days; doubling time (DT), 5.13; capacity for increase (r _c), 0.33; and cohort generation time (T _c), 11.69. Campoletis sonorensis may be a suitable candidate for a biocontrol program of T. ni populations mostly because the primary selection criterion, r_m , obtained for this parasitoid can be similar to or larger than the rate obtained for T. ni.