温度和光周期对烟蚜性蚜的诱导

本文研究了温度和光周期对烟蚜性蚜诱导的影响,结果表明：郑州地区的红色和黄绿色烟蚜在１０小时光照和１５、２０℃组合下可产生性雌和雄蚜,而在１２、１４和８小时及２５℃条件下均未有性蚜产生。     

FEMALE REPRODUCTIVE PATTERNS AND FETAL GROWTH OF ATLANTIC WALRUSES (ODOBENUS ROSMARUS ROSMARUS) IN FOXE BASIN,NORTHWEST TERRITORIES,CANADA

We examined the reproductive tracts of 79 female Arlantic walruses (Odohenus rosmarus rosmarus) caught in July and August by Inuit hunters in northern Foxe Basin, NWT, Canada. We found no evidence of past or present ovulation in animals less than 5 yr old, but the poor representation of juvenile and adolescent animals precluded statistical analysis of the average age of maturity. The ovulation frequency of 64 mature females (0.52) indicated biennial ovulation, while the pregnancy rate (0.33) and birth rate (0.30) suggested that females gave birth once every three years. The sex ratio of 17 fetuses was not significantly different from 1:1. Fetuses increased 2.9 mm d^-1 in crown-rump length and 0.12 g^1/3 d^-1 in mass over the range of collection dates. Based on the inverse regressions of fetal growth, implantation occurred in late June early July.     

Honesty of agonistic signalling and effects of size and motivation asymmetry in contests

Game theoretical models predict that the main function of fighting behaviour is to assess the relative fighting ability of opponents. The sequential assessment game has often been used to investigate contests, while honest signalling theory has received much less attention. With the wolf spider Hygrolycosa rubrofasciata we investigated whether male agonistic signalling can reveal honest information about fighting ability, and how size and motivation asymmetries affect male fighting behaviour. We also determined whether male–male competition affects the courtship behaviour of the males. We found that agonistic drumming activity is an honest indicator of male fighting ability, and that relative size asymmetry and motivation to fight both contribute to the fighting ability. We also found that male–male competition decreases the courtship drumming rate of subdominant males, suggesting that male–male competition limits the opportunities for female choice. We conclude that sequential assessment and honest signalling may both be used in settling contests, and that they may be used simultaneously. Received: 10 December 1998 / Received in revised form: 23 June 1999 / Accepted: 5 July 1999     

光照对鱼类生理活动影响的研究进展

在自然界,光的变化具有稳定性和规律性,它的变动能触发动物的一些生理机制［１］。关于光对鱼类生理活动影响的研究,国内的报道极少,而国外的研究相对多一些。近年来,虽然在这方面的工作取得了一些进展,但从整体上看,还仅仅处在初步探索阶段。本文根据国内外的研究报道,综述了光照对鱼类繁殖、代谢和内分泌活动的影响。１　光照周期对鱼类繁殖的影响光是影响动物繁殖的一个重要生态因子。许多热带鱼类全年繁殖,因为热带地区的昼长基本上是稳定的［２］。大量的实验室工作也证明,光照对动物繁殖的影响不仅因种而异,而且还因动物的…     

Individual heterogeneity in fitness in a long‐lived herbivore

Heterogeneity in the intrinsic quality and nutritional condition of individuals affects reproductive success and consequently fitness. Black brant (Branta bernicla nigricans) are long‐lived, migratory, specialist herbivores. Long migratory pathways and short summer breeding seasons constrain the time and energy available for reproduction, thus magnifying life‐history trade‐offs. These constraints, combined with long lifespans and trade‐offs between current and future reproductive value, provide a model system to examine the role of individual heterogeneity in driving life‐history strategies and individual heterogeneity in fitness. We used hierarchical Bayesian models to examine reproductive trade‐offs, modeling the relationships between within‐year measures of reproductive energy allocation and among‐year demographic rates of individual females breeding on the Yukon‐Kuskokwim Delta, Alaska, using capture–recapture and reproductive data from 1988 to 2014. We generally found that annual survival tended to be buffered against variation in reproductive investment, while breeding probability varied considerably over the range of clutch size‐laying date combinations. We provide evidence for relationships between breeding probability and clutch size, breeding probability and nest initiation date, and an interaction between clutch size and initiation date. Average lifetime clutch size also had a weak positive relationship with apparent survival probability. Our results support the use of demographic buffering strategies for black brant. These results also indirectly suggest associations among environmental conditions during growth, fitness, and energy allocation, highlighting the effects of early growth conditions on individual heterogeneity, and subsequently, lifetime reproductive investment.     

Trade‐off between flight capability and reproduction in Acridoidea (Insecta: Orthoptera)

In many insect taxa, there is a well‐established trade‐off between flight capability and reproduction. The wing types of Acridoidea exhibit extremely variability from full length to complete loss in many groups, thus, provide a good model for studying the trade‐off between flight and reproduction. In this study, we completed the sampling of 63 Acridoidea species, measured the body length, wing length, body weight, flight muscle weight, testis and ovary weight, and the relative wing length (RWL), relative flight muscle weight (RFW), and gonadosomatic index (GSI) of different species were statistically analyzed. The results showed that there were significant differences in RWL, RFW, and GSI among Acridoidea species with different wing types. RFW of long‐winged species was significantly higher than that of short‐winged and wingless species (p < .01), while GSI of wingless species was higher than that of long‐winged and short‐winged species. The RWL and RFW had a strong positive correlation in species with different wing types (correlation coefficient r = .8344 for male and .7269 for female, and p < .05), while RFW was strong negatively correlated with GSI (r = −.2649 for male and −.5024 for female, and p < .05). For Acridoidea species with wing dimorphism, males with relatively long wings had higher RFW than that of females with relatively short wings, while females had higher GSI. Phylogenetic comparative analysis showed that RWL, RFW, and GSI all had phylogenetic signals and phylogenetic dependence. These results revealed that long‐winged individuals are flight capable at the expense of reproduction, while short‐winged and wingless individuals cannot fly, but has greater reproductive output. The results support the trade‐off between flight and reproduction in Acridoidea.     

Aliphatic alcohols and aldehydes of the honey bee cocoon induce arrestment behavior in Varroa jacobsoni (Acari: Mesostigmata), an ectoparasite of Apis mellifera

The ectoparasitic mite Varroa jacobsoni reproduces in the capped brood of the honey bees Apis cerana and Apis mellifera. Observations on the reproductive behavior of the mite have shown a well-structured spatial allocation of its activity using the bee or cell wall for different behaviors. The resulting advantages for the parasite of this subdivision of the concealed brood environment suggests an important role for chemostimuli in these substrates. Extracts of the European honey bee cocoons induce a strong arrestment response in the mite, as indicated by prolonged periods of walking on the extracts applied on a semipermeable membrane and by systematically returning to the stimulus after encountering the treatment borders. Two thin-layer chromatography fractions of the cocoon extract eliciting arrestment were found to contain saturated C₁₇ to C₂₂ primary aliphatic alcohols and C₁₉ to C₂₂ aldehydes. We analyzed extracts of the cocoon and different larvae, pupae, and adults of both worker and drone A. mellifera to determine the relative amounts of these chemostimuli in the different substrates employed by Varroa. Both aldehydes and alcohols were more abundant in the cocoon than in the cuticle of adult or developing bees. Mixtures of the aliphatic alcohols and aldehydes at the proportions found in the cocoons acted synergistically on the arrestment response, but this activity disappeared when mixed in equal amounts. When these oxygenated chemostimuli were mixed with C₁₉ to C₂₅ alkanes at the proportions found in the cocoon extract, we observed a significantly lower threshold for the chemostimulant mixture. These results indicate how Varroa may use mixtures of rarer products to differentiate between substrates and host stages during its developmental cycle within honey bee brood cells. Arch. Insect Biochem. Physiol. 37:129–145, 1998. © 1998 Wiley-Liss, Inc.     

Juvenile hormone-mediated reproduction in burying beetles: From behavior to physiology

The burying beetle, Nicrophorus orbicollis, is the first beetle exhibiting parental care for which endocrinological studies have been initiated. Burying beetles bury and prepare small vertebrate carcasses as a breeding resource for their offspring. After emergence as an adult, hemolymph titers of juvenile hormone and ovarian size increase in concert for 2–3 weeks, and both plateau until an appropriate resource is discovered. Upon finding a suitable carcass, titers of juvenile hormone increase extremely rapidly (<20 min), and within 18 h ovarian mass increases threefold and oviposition begins. This rapid reproductive development is hypothesized to be selected by the intense competition for these protein-rich but quickly deteriorating resources. Burying beetle females exhibit an additional juvenile hormone surge at the time young hatch. This peak in juvenile hormone is hypothesized to be associated with either the considerable behavioral demands which accompany care of young larvae or with a female's willingness to oviposit a replacement clutch should brood failure occur early in the care-giving phase. Parental care has evolved in at least 16 additional families within the Coleoptera. Comparative studies of nonparental and parental groups will be important for understanding how the physiology of ancestral groups affects the evolution of complex social behavior. Arch. Insect Biochem. Physiol. 35:479–490, 1997. © 1997 Wiley-Liss, Inc.