大分舌蜂主要生物学特性研究

大分舌蜂Colleles gigas Cockerell是江西、湖南、广东等地油茶Camellia oleifera Abel花期主要传粉昆虫之一,广泛分布于我国南方油茶林区及周边林区。2011-2014年在江西新余等中国南方地区对该蜂的形态特征、生活史、行为等生物学特性进行了观察研究。结果表明:该蜂在我国南方地区1年1代。成虫11月中旬开始出巢活动,雄蜂早于雌蜂5 d左右出现,完成交尾后数日死亡,雄蜂寿命25 d左右,雌蜂约45 d,卵期约9 d。幼虫期35 d左右,幼虫将花粉球消耗完后变成老熟幼虫并进入滞育期,滞育期约230 d。翌年10月中旬开始化蛹,蛹期约35 d。出土后的雌蜂当天就可以交配,交配后的雌蜂在羽化地点附近选址筑巢,采集油茶的花粉和花蜜于虫室中预先做好的玻璃纸状包膜中并制成糊状蜂粮,每个包膜中的蜂粮上产卵1粒,偶有2粒。     

火红拟孔蜂的生物学特性

首次报道了火红拟孔蜂除雌性成虫以外的各虫态形态特征、生活史、生殖发育及性行为等生物学特性。该蜂在西鄂尔多斯地区一年发生一代。越冬幼虫翌年4月中旬开始化蛹;预蛹约d左右;蛹期约15d。成虫5月上旬陆续羽化出茧;雄蜂早于雌蜂数日出现,雄蜂交尾后不久死去,寿命约为10d左右。雌蜂寿命约30d。卵期约3d左右。老熟幼虫多数在6月中下旬结茧后进入滞育状态,幼虫期长达300d左右。滞育幼虫通过人工控制温度可提前打破滞育或推迟其羽化的时间。     

沙漠石蜂的生物学特性

沙漠石蜂Megachile(Chalicodoma)desertorumMorawitz的成虫活动期与西鄂尔多斯地区多种植物的开花物候相适应,是多种荒漠植物(其中包括一些珍稀濒危植物)的重要传粉昆虫。该文报道了沙漠石蜂除成虫外各虫态的形态特征、生活史及幼虫和成虫的行为等生物学特性。该蜂在西鄂尔多斯地区1年发生1代。越冬成虫翌年4月中旬开始出巢活动;雄蜂早于雌蜂9 d左右出现,完成交尾后数日死亡,雄蜂出巢后寿命20 d左右,雌蜂约35 d。卵期约12 d。幼虫期85 d左右,老熟幼虫多数在6月中旬结茧,7月末开始化蛹,蛹期约18 d。成蜂于8月中旬陆续羽化,羽化后的成虫很快进入滞育状态,并在茧内越冬;滞育期长达235 d。     

中华食蜂郭公虫的生物学特性和行为观察

中华食蜂郭公虫Trichodes sinae Chevrolat是西鄂尔多斯地区重要传粉昆虫火红拟孔蜂Hoplitis pyrrhosoma Wu的寄生性天敌。文章报道中华食蜂郭公虫除成虫外各虫态的形态特征、生活史及幼虫和成虫的行为等生物学特性。该虫在西鄂尔多斯地区1年发生1代,越冬幼虫于4月上旬开始化蛹,5月中旬陆续羽化出巢,成虫取食植物补充营养后,开始交尾、产卵。1龄幼虫能够寻找并钻入火红拟孔蜂的巢室,取食火红拟孔蜂幼虫,直至结茧化蛹。室温条件下,卵期约6~8d,幼虫期约260~280d,蛹期约40~50d;雄虫寿命约28~30d,雌虫寿命约35~40d。     

红腹柄天牛的生物学特性

红腹柄天牛是阔叶树的重要害虫之一。该虫在福建戴云山2a发生1代,当年以幼虫、次年以成虫在被害木虫道内越冬。雌成虫产卵盛期在5月下旬至6月上旬,6月中旬是产卵末期。卵期7—17d。幼虫共8龄,历期约为481d。成虫出孔后即可交配,每雌虫最大产卵量69粒,最少为20粒,在1株树上产卵量4—46粒不等。雌雄性比约为1：1。     

日本佳盾蜾蠃的生物学特性观察

日本佳盾蜾蠃Euodynerus nipanicus（Schulthess）是一种重要的独栖捕食性天敌昆虫,对我国南方林区鳞翅目蛾类害虫的控制具有一定作用。本文报道了日本佳盾蜾蠃的形态特征、生活史及幼虫和成虫的行为等生物学特性。该蜂在江西赣州地区 1 年发生 4 代,以滞育的老熟幼虫在巢管虫室内越冬,滞育期约 190 d。翌年的4月下旬成虫开始外出活动,主要包括交配、筑巢、产卵、捕食等行为。通过野外收集筑巢巢管,室内饲养观察等,发现该蜂的卵近似微弯的长圆柱形,长 2.912 ± 0.127 mm,卵期2-4 d,平均 2.5 ± 0.99 d;非越冬幼虫期 8. 1 ± 0. 99 d;预蛹期4.3 ± 0. 48 d;蛹期7. 4 ± 0.84 d;雌雄比约为 2. 95:1。本研究丰富了日本佳盾蜾蠃的生物学基础知识,为进一步利用该蜂防治南方林区鳞翅目蛾类害虫提供了依据。     

绿缘扁角叶甲生活史、交配及繁殖的观察

【目的】探明绿缘扁角叶甲Platycorynus parryi Baly年生活史、交配及繁殖情况。【方法】越冬代成虫在室内自然条件下连续繁殖,及在不同温度下,详细观察记录了成虫的交配、繁殖力和寿命。【结果】绿缘扁角叶甲是络石Trachelospermum jasminoides的重要害虫,以老熟幼虫在3~5 cm深的土层中越冬,在江西南昌一年发生1代。越冬幼虫于次年4月中旬开始陆续化蛹,4月下旬成虫开始羽化。自然条件下各虫态发育历期:卵期(11.81±0.17)d,幼虫期300~330 d,蛹期(13.62±0.13)d,成虫寿命(47.99±0.65)d。成虫羽化3~4 d后开始交配,日平均交配(3.55±0.11)次,交配持续时间最短5 min,最长可达140 min,平均交配持续时间(28.11±0.89)min,日龄大的成虫交配持续时间显著短于日龄小的成虫;相邻两次交配之间的间隔时间最短3 min,最长426 min,平均交配间隔时间(74.75±3.19)min,日龄大的成虫交配间隔时间显著短于日龄小的成虫。交配后2~3 d开始产卵,平均每雌产卵量为169粒。在22、25和28℃条件下,温度对雌虫寿命具有显著影响,随着温度升高,雌虫寿命显著缩短,而雄虫寿命和每雌产卵量却差异不显著。【结论】绿缘扁角叶甲在江西南昌一年发生1代,以老熟幼虫在土中越冬,成虫可进行多次交配,成虫日龄对其交配行为有显著影响,温度对该虫的繁殖力无显著影响。     

白斑切叶蜂的生物学特性观察

白斑切叶蜂Megachile strupigera是我国南方野生植物及部分农林作物的有效传粉昆虫之一。本文利用人工巢管完成白斑切叶蜂的野外收集和观察,结合室内人工饲养和相关数据的采集,系统研究了该蜂除成虫外各虫态的形态特征、生活史、筑巢习性和访花行为以及寄生性天敌等相关生物学特性。结果表明:白斑切叶蜂在江西赣州地区1年2代,以滞育状态下的老熟幼虫在虫室中越冬,滞育期约270 d。成虫翌年5月下旬开始出巢活动,主要包括羽化、交配、产卵、筑巢、访花等行为。室内观察和测量发现该蜂的卵近似微弯的长圆柱形,长3.15±0.14 mm。卵期2-3 d;幼虫期6-8 d;蛹期10-12 d。该蜂雄性个体多于雌性个体且同年2代雌雄比有一定的差异。该蜂成虫主要到访黄荆Vites negundo和藤金合欢Acacia sinuate等多种植物。该蜂偏好选择内径在0.614-0.948 cm,长度在8.1-20.1 cm的巢管筑巢。该蜂幼虫期寄生性天敌主要有Melittobia australica和波赤腹蜂Euaspis polynesia。本研究通过对白斑切叶蜂基础生物学进行研究,旨在为该蜂人工管理、驯化、工厂化繁殖等技术提供基础,同时也为制定该蜂保护策略和适宜栖息地环境的构建提供重要理论依据。     

大猿叶虫龙南种群的生物学特性

系统研究大猿叶虫Colaphellus bowringi Baly江西龙南(24°9′N,114°8′E)种群生物学特性。结果显示,该虫仅在春季和秋季发生为害,以成虫在土中越冬和越夏。由于成虫滞育期的差异,该虫显示出生活史多样性,有些个体隔年繁殖;有些个体是一化性,仅在春季或秋季繁殖1代;有些个体是二化性,在春季和秋季各繁殖1代;有些个体是多化性的,春季1代,秋季2~3代,因此,在田间1年可发生1~4代。春季,滞育成虫于2月中旬至4月初陆续出土繁殖,羽化的成虫于4月上旬至5月中旬陆续入土越夏;秋季,滞育成虫于8月中旬至10月中旬陆续出土,羽化的成虫于9月中旬至12月中旬陆续入土越冬。成虫一生能多次交配,在25℃下,春季世代雌虫产卵期为8~29d,平均产卵量为776粒;秋季世代雌虫产卵期为9~39d,平均产卵量为1003粒。各虫态的发育历期:在18~28℃间,卵为8.66~3.85d,幼虫为19.37~7.92d,蛹为8.57~3.41d。卵、幼虫和蛹的发育起点温度分别为10.5、11.5和11.9℃。滞育成虫的寿命为5~28个月。     

条纹小斑蛾的生物学特性

条纹小斑蛾Thyrassia penangae(Moor)是乌蔹莓(Japanese cayratia)的重要害虫,在南昌1年发生4～5代,以老熟幼虫结茧越冬。由于该虫各世代总有极少部分个体进入滞育,少数进入越夏的个体1年只发生2代或3代。羽化时间多出现在上午7～10时,羽化后当日或次日下午交配,交配时间集中在下午3～6时,交配一般可持续12个h左右。成虫羽化后需取食花蜜做补充营养才能充分产卵。产配后次日即可产卵。第1代成虫常将卵数十粒聚产于幼嫩叶片的背面,以后各代主要聚产于花蕾上,平均每雌产卵量为43粒。幼虫为4龄。第1代主要取食叶芽、幼枝及嫩叶,以后各代主要取食花蕾。在自然条件下各虫态发育历期:卵为4～7d;幼虫为10～14d;非滞育的茧期(指幼虫结茧后的预蛹至成虫羽化的日期)为8～11d,越夏茧期为32～40d,越冬茧期为205～224d。成虫寿命为3～13d。     

Effects of mate removal on the behaviour and reproductive success of Reed Warblers Acrocephalus scirpaceus

The Reed Warbler Acrocephalus scirpaceus is a largely monogamous insectivorous passerine in which males and females provide equal care by day to eggs and chicks. Polygyny occurs occasionally, with males leaving one female unaided. When females were temporarily removed from three recently-completed clutches their males deserted and resumed the high song levels typical of unmated males. Males may desert either because they are physically incapable of incubation or because the energy expenditure needed for a male to return to an equivalent stage in the breeding cycle is much lower than for a female to do so. Widowed females ( n = 7 ), however, continued the breeding attempt alone, with similar incubation levels but higher provisioning rates than those of control females. In three out of four mid-season broods raised by lone females all fertile eggs were reared to healthy fledglings (in the fourth brood the female died), while only one of four late-season nests produced any fledglings (which were underweight). Late-season control nests were as successful as earlier ones. Loss of male help led to starvation of chicks, but caused no adverse effects during incubation. This explains the small changes in widows' sitting levels during incubation, but much greater effects after hatching. Females may need male help to rear late broods (but not early broods) as days are shorter and food is scarcer. Males may normally help at nests, even those in the mid-season, because in stressful spells (even for a few days) such help is vital for successful breeding but in good periods it costs the male little.     

Prolactin and parental behavior in Adélie penguins: effects of absence from nest, incubation length, and nest failure

Adélie penguin (Pygoscelis adeliae) males and females, nesting in Antarctica, alternate attendance at the nest with absences of many days to forage at sea. We investigated the importance of tactile input from egg and chicks on prolactin levels by observing nest attendance patterns and obtaining blood samples (1) during the first nest exchange of the incubation stage, (2) from birds whose incubation period was artificially increased or decreased by about 10 days, and (3) from birds whose nests had failed. Prolactin levels in females after 8 to 11 days of absence from the breeding colony did not differ from those in incubating males and did not change after females resumed incubation. Moving eggs between nests resulted in nests in which chicks hatched after about 26, 36 (normal), or 46 days. Duration of incubation did not affect prolactin levels in the parents measured during incubation, at the pip stage, hatch stage, or early brood stage. Adults first left their chicks unguarded on about the same calendar date, regardless of chick age. However, chicks from long incubation nests averaged 8 days younger when they were left unguarded than chicks from control or short-incubation nests. In females, there was no effect of nest failure on prolactin levels. In males, prolactin levels were slightly lower after nest failure than in males tending nests. Testosterone was significantly higher in males after nest failure than in males still tending nests. Prolactin is elevated in Adélie penguins as part of the program of cyclical hormonal changes that accompany the lengthy reproductive season and is relatively independent of tactile input. Sustained prolactin secretion is probably required for the maintenance of parental behavior in offshore feeding species that must be absent from the nest for many days at a time.     

Female teneral mating in a monandrous species

Schultesia nitor is a gregarious species living in Cacicus and Psarocolius ssp. pouch-like nests. Due to gregariousness, opportunities for multiple copulations in both sexes are not supposed to be restricted. Females produce only one brood during their life and die within a few days following the birth of their nymphs, but this unique brood could be the result of either single or multiple mating events (i.e., monandry vs. polyandry). In this study, we first determined the age of sexual receptivity of both males and females. Larval development in this species is shorter in males than in females and thus, this species is protandric. Males were not able to copulate the day after emergence. Contrary to males, teneral females (i.e., females achieving their imaginal molt but not yet fully sclerotised and colored) were attractive and were able to mate with males. In the second experiment, we tested the existence of multiple matings in both sexes. Our results showed that females were monandrous whereas males were polygynous. Since we had observed that females were monoandrous, we expected them to be choosy and we determined their ability to discriminate between virgin and nonvirgin males. When given the choice, females preferred virgin males and overall, they were more successful at mating than experienced ones. Our results suggest that monandry may be primarily driven by the female's short life-span fecundity. The occurrence of teneral mating in this species calls into question the existence of a male strategy for monopolizing females, and as well as the implication of female choice. Although further work is required, this species provides an interesting model for understanding sexual conflicts.     

Male behaviour and female choice: Mate selection in the wren?

The European wren is frequently polygynous. Males occupy exclusive territories within which they spend much time displaying and building nests. They lead females to their nests in courtship. Males building the most nests during a season also make the most breeding attempts. Data collected in one of two years suggested that individual females may show a preference for males with the largest number of complete but vacant nests. There was no consistent correlation between male display behaviour and female mate choice. Data on breeding success may suggest why polygyny is adaptive for both males and females in this species.     

Double nesting of the Red-legged Partridge Alectoris rufa

Some Red-legged Partridge females lay two clutches in separate nests, one immediately after the other, which are incubated separately by the male and female of the pair. Pairs remained together during the laying of both clutches so that there were delays between the end of laving and incubation at the first nests. Incubation of the two nests began at approximately the same time but discrepancies of up to ten days occurred. Males incubated first clutches and females usually the second, but probably the first if the second was destroyed during laying. The proportion of surviving eggs which hatched was similar in first and second clutches but declined if the delay between laying and hatching was exceptionally long.
Yearling females began laying late and few seemed to attempt two clutches compared with older females of which 60–80% showed the double nesting habit. A model predicting reproductive success for both sexes in relation to the rate of nest predation during laying, suggested that attempting two clutches rather than one would be disadvantageous at high predation rates. Females would produce more young if their mates incubated their first clutch immediately it was complete rather than accompanying them during the laying of the second. However, males may benefit by this delay, even though it exposes the nest to predators for a longer time, because they are able to guard their mate and prevent other males from mating with her and fertilizing eggs of her second clutch.     

Female cowbirds have more accurate spatial memory than males

Brown-headed cowbirds (Molothrus ater) are obligate brood parasites. Only females search for host nests and they find host nests one or more days before placing eggs in them. Past work has shown that females have a larger hippocampus than males, but sex differences in spatial cognition have not been extensively investigated. We tested cowbirds for sex and seasonal differences in spatial memory on a foraging task with an ecologically relevant retention interval. Birds were trained to find one rewarded location among 25 after 24 h. Females made significantly fewer errors than males and took more direct paths to the rewarded location than males. Females and males showed similar search times, indicating there was no sex difference in motivation. This sex difference in spatial cognition is the reverse of that observed in some polygynous mammals and is consistent with the hypothesis that spatial cognition is adaptively specialized in this brood-parasitic species.     

Male short-tailed field voles (Microtus agrestis) build better insulated nests than females

Nest construction is an extremely widespread behaviour. In small endotherms the nest serves primarily to provide insulation, and thereby retard heat loss of the constructor, or its offspring. In arctic and temperate regions many small mammals build nests to protect themselves from low ambient temperatures. We measured the physical properties of nests built by short-tailed field voles Microtus agrestis that were kept in captivity under cold conditions. The most important factor influencing nest insulation was nest wall thickness; however, nests with thick walls also contained more nesting material. Insulative capacity of the nest did not reach an asymptote up to nests containing 20 g of material. Nest insulation was not correlated with resting metabolic rate, body mass or body composition of the vole that constructed the nest. However, nests built by males had greater insulation than those made by females; males also had significantly lower food intake rates when compared to females with nests. No significant difference was observed in either fat mass or whole animal thermal conductance between males and females. Thermal conductance did increase significantly with increasing body mass, although not with resting metabolic rate. Voles with nests for prolonged periods had lower food intakes than voles without nests. The absolute saving averaged 1.9 g and was independent of body mass. This was a 28% saving on intake for a 22-g vole but only an 18% saving for a 40-g individual. When voles had nests for short periods they used the energy they saved to reduce food intake and increase body mass. Accepted: 2 September 1999     

Decision-making conditions for intra- or inter-nest mating of winged males in the male-dimorphic ant <Emphasis Type="Italic">Cardiocondyla minutior</Emphasis>

Only winged male and female ants generally mate through nuptial flight during the reproductive season. In the ants of Cardiocondyla, the males show wing dimorphism and their reproductive strategies differ depending on the differences in wing morphology. It has been suggested that wingless “ergatoid” males bearing very similar external morphologies to workers mate within natal nests, whereas winged males bearing typical ant male morphology disperse from their nests to mate. However, some behavioral observations suggest that the winged males of some Cardiocondyla ants such as C. obscurior and C. minutior may mate within natal nests before dispersion. We evaluated the factors affecting the mating behaviors of the winged males of C. minutior under laboratory conditions. We found that (1) the winged males remained and mated with virgin females in natal nests when either virgin winged females or the relatively mature pupae of winged females (i.e., at least 10 days) were present in the nest, (2) the winged males dispersed to adjacent nests with virgin winged females when only mated queens and the relatively young pupae of winged females (i.e., <9 days) were present in the nest, and (3) all winged males were accepted by the workers of non-natal nests irrespective of the distance from the natal nests in the field. Although most ergatoid males were accepted by the workers of close non-natal nests, they were all attacked and killed by the workers of distant non-natal nests. These results suggest that intra-nest mating and the dispersion of the winged males of C. minutior are facultatively determined by the condition of winged females (virginity and relative pupal age) in natal nests. Furthermore, our results suggest that winged males are likely to seek mating partners chemically and to mate with virgin winged females.     

Provisioning behaviour at the nest in single-parent versus biparental nests and male versus female parents in the common redstart (<Emphasis Type="Italic">Phoenicurus phoenicurus</Emphasis>)

We analysed video-sequences of undisturbed parental provisioning behaviour on 12 nests of common redstart (Phoenicurus phoenicurus). In 4 of the 12 nests, chicks were fed by a single parent only. We compared provisioning rate of chicks, time spent on the nest and food allocation rules between nests with uniparental and biparental care and between male and female parents in biparental nests. In nests with a single parent, the frequency of feeding visits per parent was higher than in biparental nests. As a result, the rate of food provisioning of chicks was similar in uniparental and biparental nests. The food allocation rules did not differ between uniparental and biparental nests. In biparental nests, male and female provisioning behaviour was similar though with two exceptions: males had a strong preference for feeding chicks in front positions in the nest and females spent a longer time on the nest after feeding. We conclude that single common redstart parents are able to compensate fully for the absence of the other parent through increased provisioning efforts, and that in biparental nests, males and females contribute equally to the provisioning of the young.     

Alternative male mating tactics of the substrate brooding cichlid Telmatochromis temporalis in Lake Tanganyika

Telmatochromis temporalis is a bi-parental substrate brooding cichlid endemic to Lake Tanganyika. Paired males were always larger than their mates and had territories around nests against conspecific males. However, males smaller than the paired females were found in 18% of the nests. Here we report a reproductive tactic of these small males. The small males had as heavy gonads as paired males, and the gonad somatic index (GSI) of the small males was much higher than that of the latter. The examinations of the paternity and maternity using microsatellite-DNA as a genetic marker revealed that the small males were not genetically related to the pair members, and sired some young in 3 of 5 nests. These small males did not guard the broods, suggesting that they are likely to perform reproductive parasitism as sneakers. Paired males could not enter their spawning nests due to their large size, which made it difficult to chase out sneakers once they entered the nest. Some males as small as the sneakers were found outside the territories of paired males, and their gonads were quite small. Circumstantial evidence suggests that small males have two alternative investment patterns: investing in gonad to be sneakers, and investing in growth to probably be territorial males.