Modelling age‐ and density‐structured reproductive biology and seasonal survival of Apanteles galleriae Wilkinson (Hym., Braconidae)

Abstract: The biology of Apanteles galleriae Wilkinson, an important biological control agent of wax moths, is well described in the literature. We developed models simulating the functional response of fecundity and female progeny proportion of adult females as a function of age, host and/or parasitoid density to integrate current knowledge. Daily pattern of age‐related fecundity and female progeny proportion of different parasitoids was also examined. We investigated the effect of sex, mating status and seasonal time on adult longevity. We derived survival data of females in two different seasonal periods. We found that 50% of adult life span is important for an efficient fecundity. The patterns of host and/or parasitoid density‐dependent fecundity and sex ratio varied considerably. The highest fecundity and female progeny proportion occurred with one parasitoid and one female equivalent host. Longevity of adults was affected by sex and month periods, but mating status did not affect their longevity. Female survival was greater between December and May relative to June and November. Our results indicated that age, host and parasitoid density, and the timing of rearing influenced the life processes of parasitoids.     

短时高温暴露对Q型烟粉虱存活和生殖适应性的影响

在室内将Q型烟粉虱Bemisia tabaci Q-biotype成虫在44℃下暴露1 h后观察成虫的存活率、产卵量、雌雄寿命和后代存活能力,以研究短时高温暴露对Q型烟粉虱生物学特性的影响。结果表明,Q型烟粉虱成虫在44℃下暴露1 h后的存活率为43.5%,暴露热激后的单头雌虫的产卵量为77.2粒,低于常温下(26℃)的产卵量(100.1粒);短时高温可显著缩短Q型烟粉虱成虫的寿命,在44℃下暴露1 h后Q型烟粉虱雌雄虫寿命分别为14.5 d和10.2 d,显著低于常温下(26℃)雌虫20.4 d和雄虫18.2 d;短时高温对Q型烟粉虱后代存活率和雌雄性比无显著影响,但其产卵高峰期延迟,产卵持续期缩短。以上结果表明,短时高温热激可影响Q型烟粉虱的生殖情况,造成Q型烟粉虱产卵量降低和寿命缩短,Q型烟粉虱雌虫耐热性强于雄虫。     

饲养黄曲条菜跳甲实验种群的一种新方法

介绍一种简便可行的饲养黄曲条菜跳甲Phyllotretastriolata(F.)的新方法———整苗大瓶罩养法。用5种植物根部饲养越冬代,黄曲条菜跳甲均可成功地完成其生活周期,未成熟期最高存活率为63.3%,成虫平均寿命最长为219.2d,平均产卵量最大为192.4粒雌。     

一种珍稀蝴蝶大帛斑蝶Idea leuconoe(Eriehson)的人工饲养方法

【目的】针对现有大帛斑蝶Idea leuconoe(Eriehson)饲养方法中无法有效回避高温造成的成虫大量死亡,卵空壳或干瘪失水的问题,本研究发明了一种新的繁殖网纹室来规模化人工饲养大帛斑蝶的方法。【方法】本研究测定了在新发明和普通繁殖网纹室的饲养下,大帛斑蝶的存活、交配成功率、产卵量和卵孵化率,并对新发明和普通繁殖网纹室之间的参数进行了对比。【结果】采用新发明繁殖网纹室饲养的大帛斑蝶幼虫化蛹率为90.75%±1.12%,蛹羽化率为91.36%±2.43%,均维持在90%以上,均极显著高于普通繁殖网纹室;从幼虫发育到成虫的存活率为82.93%±2.55%,也极显著高于普通繁殖网纹室;在15日龄内,相对于普通繁殖网纹室,新发明繁殖网纹室饲养的存活的成虫,取食频率较高,活跃性较高,虫体比较健壮,且此时成虫存活率显著较高,为81.22%±2.07%;利用新发明繁殖网纹室饲养的成虫,其雌蝶交配成功率为81.67%±4.77%,每雌产卵量为(269.32±9.85)粒,卵孵化率为85.88%±1.93%,均极显著高于普通繁殖网纹室;本研究新发明的繁殖网纹室,可以有效的营造一个温度显著低于空气温度的小环境,供大帛斑蝶躲避高温灼伤。【结论】通过在本研究新发明繁殖网纹室的饲养,大帛斑蝶存活率、交配成功率和繁殖力均维持在较高的水平上,显著高于普通繁殖网纹室,能够保证为市场提供充足的大帛斑蝶虫源,避免农民养殖户的损失。     

Influence of adult diet on the reproductive biology and survival of the western corn rootworm,Diabrotica virgifera virgifera

Adult corn rootworm beetles,Diabrotica virgifera virgifera LeConte, were maintained on three dietary regimes which mimicked the progression of corn tissues that would be available in the field for beetles eclosing when corn was in the following growth stages: (A) after tassels had emerged but prior to silking and pollen shed; (B) while plants were silking and shedding pollen; and (C) after pollination was complete and silks had turned brown. A fourth regime (D) was established in which green corn silks, pollen, and leaves were provided throughout the study. The mean number of eggs laid per female over the 12-week duration of the study was 125, 235, 179, and 441 for regimes A, B, C, and D, respectively. Median length of life was 7.2, 7.2, 6.7, and 8.8 weeks for regimes A, B, C, and D respectively. Beetles in regime A laid a greater proportion of their eggs at an older age than did beetles from regimes B and C. To further investigate the influences on survival of changes in food quality of corn as plants and beetles aged, newly-eclosed beetles and beetles that had been maintained in caged plots of corn growing in a greenhouse for various lengths of time were caged on corn at different stages of growth, and the proportion of beetles surviving for 48 h was determined. Survival decreased as plants aged for both groups of beetles, but decreased at a faster rate for old than for young beetles.

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Influence de l'alimenation sur la reproduction et la survíe deDiabrotica virgifera virgifera

Résumé D. virgifera virgifera LeConte a été placé sur des régimes nutritifs mimant l'évolution des tissus du maïs disponsibles dans le champ lorsque les insectes éclosent est aux stades suivants du maïs: 1) après émergence de l'épi mâle, mais avant l'apparition des barbes et l'émission du pollen; 2) lors de la présence de barbes et de l'émission de pollen; 3) après la pollinisation et quand les barbes ont bruni. Un quatrième régime a été fourni pendant toute l'expérience comprenant des barbes vertes, du pollen et des feuilles. Les pontes moyennes des femelles pendant les 12 semaines de l'étude on été 125, 235, 179 et 441 pour les régimes 1, 2, 3 et 4. Les dates de mort de la moitié des adultes a été 7,2, 7,2, 6,7 et 8,8 semaines pour respectivement les mêmes régimes. Les femelles du régime 1 pondent à un âge plus avancé que les femelles des régimes 2 et 3. L'influence des changements de la qualité alimentaire du maïs au fur et à mesure du vieillissement des plantes et deDiabrotica, a été déterminée par la survie au bout de 48 heures d'insectes éclos depuis peu et d'autres maintenus en cage sur des lots de maïs à différents stades poussant en serre depuis des temps plus ou moins longs. Plus les plantes sont âgées, plus la survie des 2 groupes deDiabrotica diminue, mais plus vite chez les lots d'insectes âgés.

     

Reproductive strategy of Labeo senegalensis Valenciennes 1842 (Teleostei: Cyprinidae) in the Ouémé basin,Benin

Aspects of the reproductive biology and population structure of Labeo senegalensis were investigated in the Ouémé River between April 2005 and March 2006. Reproductive strategy was investigated using gonadosomatic index, ovarian structure and fecundity. Average size-at-first-maturity (L ₅₀) was estimated at 29 cm TL for females and 25.7 cm TL for males. The average sex ratio (1:0.96) was not significantly different from unity. Oocyte diameter frequency distribution suggests synchronous development with a single total spawning. Absolute fecundity ranged between 12 948 and 74 832 eggs. Labeo senegalensisis a highly fecund fish that presents a seasonal cycle of reproduction from May to October during the rainy season.     

A key to the Mexican and Central America Genera of Anthonomini (Curculionidae,Curculioninae)

Presently the only keys available for identification of genera of Anthonomini are limited to those of the United States of America and Canada. A dichotomous key is presented to identify all genera of Mexican and Central American Anthonomini. Previous keys do not include the genera Achia, Botanebius, Loncophorus, Loncophorellus and Melexerus. A brief synopsis is given for each genus and photographs of representative species are included.     

Inheritance of progeny sex ratio in Urtica dioica

Seed samples collected from female Urtica dioica plants in the field showed considerable inter-family variation in the sex ratio (faction of males). To investigate the inheritance pattern of the sex ratio trait, crosses were performed between individual male and female plants from different sex ratio families. Our results suggest, at least for the families studied here, that maternal parents strongly contribute to the variation in the primary sex ratio. Furthermore, progeny sex ratios from reciprocal crosses were significantly different and resembled the sex ratios produced by their maternal parents. We discuss the possible mechanisms underlying maternal control.     

环境颜色对韭菜迟眼蕈蚊生物学特性的影响

【目的】明确环境颜色对韭菜迟眼蕈蚊Bradysia odoriphaga Yang et Zhang生长发育及繁殖能力等生物学特征的影响。【方法】在室内条件下,利用黑、棕、绿、红和橙5种颜色卡纸模拟自然环境颜色,比较研究了其对韭菜迟眼蕈蚊生长发育和繁殖的影响。【结果】韭菜迟眼蕈蚊发育历期在橙色环境下最长,为26.15 d,黑色环境下最短,为22.35 d;世代存活率在黑色环境下最高,为43.88%,橙色环境下最低,为28.88%;性比在各颜色环境下无显著差异;雌雄成虫寿命均在棕色环境下最长,分别为2.06 d和2.99 d,橙色环境下最短,分别为1.58 d和2.57 d;单雌产卵量在棕色环境下最多,为62.99粒,橙色环境下最少,为45.64粒;种群趋势指数由高到低依次为:黑色(15.90)棕色(15.07)透明色对照(12.93)红色(11.69)绿色(11.67)橙色(8.50)。【结论】环境颜色影响韭菜迟眼蕈蚊生物学特性,黑色及棕色环境有利于其生长发育及繁殖,橙色环境可抑制其生长发育及繁殖。     

Effect of host availability on reproduction and survival of the parasitoid wasp Trichogramma minutum

Abstract.

• 1 We tested the hypothesis that females of the egg parasitoid, Trichogramma minutum Riley (Hymenoptera: Trichogrammatidae), could adjust their fecundity schedule according to host availability and that there was a negative correlation between reproduction and survival in these wasps.
• 2 Newly-emerged females were provided with an unlimited or limited number of hosts in the first trial and with either unlimited, limited or zero hosts in the second trial.
• 3 When hosts were unlimited, wasps had the highest rate of reproduction in the first day, which decreased dramatically thereafter. When hosts were limited, wasps from the two trials differed in their response. In Trial I, females with limited hosts had lower first-day fecundity than, and the same subsequent-day fecundity as, those with unlimited hosts. However, in Trial II, females with limited host had a lower first-day but a higher subsequent-day fecundity than those with unlimited hosts. This indicates variation in Trichogramma's ability to shift its fecundity schedule in response to host availability.
• 4 There was a positive (rather than a negative) correlation between reproduction and survival. Wasps that oviposited (in host-unlimited treatment) had greater longevity than those that could not (in host-unavailable treatment).
• 5 The sex ratio of the progeny produced by wasps in both host-unlimited and limited treatments shifted gradually from a female to a male bias as the wasps aged.
• 6 We consider the ability of parasitoids to adjust their fecundity schedule as an adaptation to changing host resources and discuss our findings with regard to theories of life history evolution.

     

Population structure and reproductive biology of Schilbe intermedius (Teleostei: Schilbeidae) in the Pendjari River,Benin

This study, the first on fish reproduction in the Pendjari River, investigated aspects of the reproductive biology of Schilbe intermedius. A total of 429 females and 239 males were collected from March 2007 to February 2008. Females were larger than males and the sex ratio was 1:1.8 in favour of females. Size at first maturity was estimated to be 14.9 cm and 16.1 cm for males and females, respectively. Absolute fecundity ranged from 1 006 to 83 980 (22 421 ± 16 083) oocytes, and mean relative fecundity was 201 ± 162 oocytes g^?1 of total body mass. Frequency distributions of oocyte diameter suggested synchronous development, with total spawning. Spawning lasted from June to November, coinciding with peaks in rainfall and flooding. Larger females began spawning about two months before smaller ones.     

Adaptability and efficacy of transgenic and wild-type Metaseiulus occidentalis (Acari: Phytoseiidae) compared as part of a risk assessment

Comparisons between transgenic (T) and wild-type Metaseiulus occidentalis colonies (COS) were made under laboratory conditions as part of a risk assessment effort prior to proposed field releases. There were no differences between the transgenic T18 colony and the COS strain in the daily egg production, hatchability at three temperatures and four relative humidity (RH) conditions, diapause incidence, or proportion of female progeny produced. Metaseiulus occidentalis eggs do not hatch at 38°C under any RH tested, nor at 33.5°C under 100% RH, indicating that high temperature and extreme RH affect egg hatch negatively. At 28.5 and 33.5°C, fewer eggs hatched at 32.5% than at 75.5 and 93% RH. Metaseiulus occidentalis cannot survive on any plant tested without prey nor on a diet of pollen alone; adult female mites cannot prey or survive on a diet of eggs and larvae of two lepidopteran species, indicating that the suitability of food sources has not been altered in the transgenic strain. Two subcolonies, derived from two transgenic strains using single females, differed in the rate of egg hatch at 28.5°C under 32.5 and 100% RH, indicating that reduced genetic variation and/or random genetic drift in the two lines may have led to differences in some biological characters. Since we did not find any significant differences between the T18 and COS colonies in the traits tested, the T18 colony is not expected to exhibit any new biological attributes in a proposed short-term field release.     

Survivorship and fecundity of Argulus bengalensis (Crustacea; Branchiura) under laboratory conditions

The Life table features and the fecundity schedule of the fish louse Argulus bengalensis (Branchiura: Argulidae) were estimated under laboratory conditions using Cirrhinus mrigala as the model host. The cohort-based Life table revealed that survival of A. bengalensis declines as a function of age. Life expectancy was observed to be 34?days for a newly emerged adult. The mean number of eggs produced per egg strip was 86 (±8.89 S.E.). The sex ratio 2:1 was biased towards males. The net reproductive rate (R₀) varied between 50 and 487 while the cohort generation time (T_c) ranged between 24 and 26?days. The intrinsic rate of increase (r) was 0.14–0.23, while the finite rate of increase (λ) remained between 1.16 and 1.28. The Life table features and the fecundity schedule of A. bengalensis are comparable with congenerics of temperate regions. Early reproduction (between 21 and 23?days) and an extended postreproductive phase (47?days) of females are characteristic of A. bengalensis and a reflection for survival under uncertain conditions and a parasitic mode of life.     

贡嘎钩蝠蛾交配及生殖力的研究

为明确交配时长、性比、密度及温度对贡嘎钩蝠蛾Thitarodes gonggaensis交配、产卵、孵化的影响,研究了不同交配时长、不同性比、不同成虫密度、不同交配温度对成虫交配、生殖力的影响.结果表明,成虫正常交配时长差异较大,交配时长为22～270 min,平均交配时长为90.85 min,均能够完成正常的产卵,平...     

Environmental influences on fecundity, egg viability and egg cannibalism in the scale insect predator, Chilocorus nigritus

The effects of temperature on age-specific fecundity, egg viability and egg cannibalism were examined in the coccidophagous coccinellid, Chilocorus nigritus being fed on the cyanophyllum scale, Abgrallaspis cyanophylli. There were no significant differences in lifetime fecundity or oviposition rate at constant temperatures in the range of 20 to 30°C although there was a trend for both parameters to increase with increasing temperatures. Total fecundity ranged from five to 1890 eggs per female whilst the oviposition rate varied from 0.2–12.1 eggs day^-1. Egg viability was significantly greater at 26 and 30°C (63 and 74%, respectively) than at lower temperatures (18 to 30%) whilst egg cannibalism was highest at 24 and 26°C (being the mid range of the temperatures tested). Mean pre-oviposition periods varied from 54 days at 20°C to 8.2 days at 30°C. The effect of relative humidities in the range of 33% to 75% on oviposition rate, egg viability and egg cannibalism was measured and found to have no significant effect on either parameter.