云南古蚤雄性的记述及雌性的形态补充

根据采自云南丽江玉龙雪山和大理苍山背纹鼩鼱(Sorex cylindricauda)等小兽体的蚤类标本,首次对云南古蚤Palaeopsylla yunnanensis Xie et Yang．1982的雄性进行了描述并对雌性的部分形态进行了补充。     

王氏鬃蚤雌性的发现及对两种雄蚤 形态的补充和更正*

我国蠕形蚤科ＶｅｒｍｉｐｓｙｌｉｄａｅＷａｇｎｅｒ,１８８９鬃蚤属ＣｈａｅｔｏｐｓｙｌａＫｏｈａｕｔ,１９０３的蚤类目前有两种缺少配对标本,其中之一是１９９７年根据采自湖北省西北部神农架林区１只雄蚤订立的王氏鬃蚤Ｃｈａｅｔｏｐｓｙｌａ（Ｃｈａｅｔｏｐ...     

裂新蚤的厘订及雄性形态描述（蚤目：多毛蚤科）

本文将裂新蚤Neopsylla schismatosa Li,1980改订为特新蚤裂亚种N.specialis schismatosa Li,1980,并首次记述其雄性,同时对雌性形态作了补充。     

盲鼠蚤属一新种及无窦盲鼠蚤雄蚤的发现(蚤目:细蚤科)

记述盲鼠蚤属Typhlomyopsyllus Li et Huang,1980一新种,刘氏盲鼠蚤Typhlomyopsyllus liui sp.nov.及无窦盲鼠蚤T.esinus Liu,Shi et Liu,1985的雄蚤,前者模式标本采自鄂西南五峰县后河自然保护区与湘西北石门县壶瓶山自然保护区两省交界处的猪尾鼠Typhlomys cinereus体上。     

鼹古蚤雌性的记述

本文根据采自运动漾苍山长毛鼹Ｔａｔｌｐａｌｏｎｇｉｒｏｓｔｒｉｓ体的蚤类标本,首次对鼹古蚤ＰａｌａｅｏｐｓｙｌｌａｔａｌｐａｅＧｏｎｇｅｔＦｅｎｇ,１９９７雌性进行了记述。     

中国西部纤蚤属两新种记述（蚤目：多毛蚤科）

本文报道了采自我国西部纤蚤属Ｒｈａ－ｄｉｎｏｐｓｙｌｌａ Ｊｏｒｄａｎ ｅｔ Ｒｏｔｈｓｃｈｉｌｄ,１９１２两新种;乌兰纤蚤Ｒｈａｄｉｎｏｐｓｙｌｌａ ｕｌａｎｇｅｎｓｉｓ Ｃａｉ ｅｔ Ｗｕ,ｓｐ,ｎｏｖ。和西藏纤蚤Ｒｈａｄｉｎｏｐｓｙｌｌａ ｘｉｚａｎｇｅｎｓｉｓ Ｃａｉ,Ｌｉ ｅｔ Ｚｈｅｎｇ,ｓｐ。ｎｏｖ。模式标本存放在作者单位。     

高黎贡山柳氏蚤属一新种记述（蚤目：多毛蚤科）

本文记述柳氏蚤属Liuopsylla一新种,杆形柳氏蚤L.clavula sp.nov.。新种与锥形柳氏蚤L.conica Zhang,Wu et Liu,1985接近,但有明显区别。标本采自云南高黎贡山多齿鼩鼹(Nasillus gracillis)体上。     

古蚤属一新种记述（蚤目：多毛蚤科）

本文记述采自经省神农架林区古蚤属Ｐａｌａｅｏｐｓｙｌｌａ Ｗａｇｎｅｒ,１９０３－新种,巫山古蚤Ｐａｌａｅｏｐｓｙｌｌａ ｗｕｓｈａｎｅｎｓｉｓ ｓｐ．ｎｏｖ．,模式标本存于湖北省医学科学院寄生虫病研究所。     

青海多毛蚤属一新种记述（蚤目：多毛蚤科）

本文报道多毛蚤属Ｈｙｓｔｒｉｃｈｏｐｓｙｌｌａ的一新种,文贞多毛蚤Ｈ．ｗｅｎｚｈｅｎｉ ｓｐ．ｎｏｖ．,新种与近缘种圆凹多毛蚤Ｈ．ｒｏｔｕｎｄｉｓｉｎｕａｔａ,多刺多毛蚤Ｈ．ｍｕｌｔｉｄｅｎｔａｔａ和尼泊尔的Ｈ．ｓｙｎａｐｔｉｃａ接近而又有明显区别,新种采自青海省同德县的斯氏水麝鼠句Ｃｈｉｍａｒｒｏｇａｌｅ ｓｔｙａｎｉ,标本存青海省地方病防治研究所。     

Radiation biology and inherited sterility in false codling moth (Lepidoptera: Tortricidae)

False codling moth, Cryptophlebia leucotreta (Meyrick), male and female mature pupae and newly emerged adults were treated with increasing doses of gamma radiation and either inbred or out-crossed with fertile counterparts. For newly emerged adults, there was no significant relationship between dose of radiation and insect fecundity when untreated females were mated to treated males (N female by T male). However, fecundity of treated females mated to either untreated (T female by N male) or treated males (T female by T male) declined as the dose of radiation increased. A similar trend was observed when mature pupae were treated. The dose at which 100% sterility was achieved in treated females mated to untreated males (T female by N male) for both adults and pupae was 200 Gy. In contrast, newly emerged adult males treated with 350 Gy still had a residual fertility of 5.2% when mated to untreated females, and newly emerged adult males that were treated as pupae had a residual fertility of 3.3%. Inherited effects resulting from irradiation of parental (P1) males with selected doses of radiation were recorded for the F1 generation. Decreased F1 fecundity and fertility, increased F1 mortality during development, and a significant shift in the F1 sex ratio in favor of males was observed when increasing doses of radiation were applied to the P1 males.     

二齿新蚤和方形黄鼠蚤松江亚种侵袭与离开宿主习性的实验研究

本文对二齿新蚤和方形黄鼠蚤松江亚种侵袭与离开宿主的习性进行了实验研究,结果：(1)蚤攻击宿主距离平均在2cm以内,最大攻击距离不超过10cm。在有效侵袭范围内,蚤与宿主距离近时较距离远时吸血蚤数增多。(2)蚤对宿主的侵袭程度雌蚤大于雄蚤,繁殖蚤大于新羽化蚤,二齿新蚤大于方形黄鼠蚤松江亚种,对小白鼠大于对达乌尔黄鼠。(3)宿主死后一定时间内,仍有部份蚤侵袭其尸体。 死亡时间越长侵袭蚤数越少,呈logY=a-blogX型曲线。(4)蚤离开宿主时间呈偏态分布,温度越高偏态分布越明显。蚤离开死鼠和离开活鼠所需时间很接近。 二齿新蚤和方形黄鼠蚤松江亚种离开宿主时间几乎相同。二种蚤离开宿主平均时间与环境温度呈负相关,且呈曲线关系。     

Differential dispersal patterns of male and female masu salmon fry

Behavioural experiments using artificial and natural stream channels were undertaken to determine whether there were differences in dispersal between newly emerged male and female masu salmon. Eyed eggs from a cross with wild spawners were planted in the middle pool of an artificial channel. After emergence, more males than females moved into an upstream trap, while fewer males moved downstream. In a natural stream, eyed eggs were marked with alizarin complexone to distinguish them from naturally spawned eggs and these were planted into artificial redds. More newly emerged male fry remained at the planted site than female fry. In contrast, more females moved downstream than males. These results imply that differences in dispersal patterns between male and female masu salmon fry are genetically controlled.     

First blood meal of Ctenocephalides canis (Siphonaptera: Pulicidae) on dogs: time to initiation of feeding and duration

Two experiments were conducted on dogs to evaluate interval to initiation and duration of the first blood meal of Ctenocephalides canis (Curtis). Percentage of fed male and female fleas was calculated for fleas held on dogs for 5, 15, 30, 60 min, 6, and 24 hr. Duration of first blood meal was also measured for individual fleas confined on dogs. When fleas were free in the hair coat, 21.2% had begun blood feeding within 5 min. After 1 hr, 72.5% of fleas had fed. After 6 hr, 95.2% of males and 100% of females had taken a blood meal, and 24 hr after deposition all fleas had fed. There was no significant difference between the 2 sexes. The mean delay between deposition and biting for fleas that began feeding within 15 min was 2 min 52 sec +/- 3 min 2 sec for female fleas and 3 min 8 sec +/- 2 min 45 sec for males. The mean duration of female and male meals was 5 min 3 sec +/- 3 min 41 sec and 6 min 9 sec +/- 6 min 8 sec, respectively. There was no significant difference between the 2 sexes. The dog flea took its blood meal on dogs more slowly than the cat flea did on cats; this meal was significantly longer for Ctenocephalides felis felis (Bouche) than for C. canis.     

Quantity matters: male sex pheromone signals mate quality in the parasitic wasp Nasonia vitripennis

Sexual selection theory asserts that females are well adapted to sense signals indicating the quality of potential mates. One crucial male quality parameter is functional fertility (i.e. the success of ejaculates in fertilizing eggs). The phenotype-linked fertility hypothesis (PLFH) predicts that functional fertility of males is reflected by phenotypic traits that influence female mate choice. Here, we show for Nasonia vitripennis, a parasitic wasp with haplodiploid sex determination and female-biased sex ratios, that females use olfactory cues to discriminate against sperm-limited males. We found sperm limitation in newly emerged and multiply mated males (seven or more previous matings) as indicated by a higher proportion of sons in the offspring fathered by these males. Sperm limitation correlated with clearly reduced pheromone titres. In behavioural bioassays, females oriented towards higher doses of the synthetic pheromone and were attracted more often to scent marks of males with a full sperm load than to those of sperm-limited males. Our data support the PLFH and suggest that N. vitripennis females are able to decrease the risk of getting constrained to produce suboptimal offspring sex ratios by orienting towards gradients of the male sex pheromone.     

Sex ratio in flea infrapopulations: number of fleas, host gender and host age do not have an effect

This study set out to determine whether the sex ratio of fleas collected from host bodies is a reliable indicator of sex ratio in the entire flea population. To answer this question, previously published data on 18 flea species was used and it was tested to see whether a correlation exists between the sex ratio of fleas collected from host bodies and the sex ratio of fleas collected from host burrows. Across species, the female:male ratio of fleas on hosts correlated strongly with the female:male ratio of fleas in their burrows, with the slope of the regression overlapping 1. Controlling for flea phylogeny by independent contrasts produced similar results. It was also ascertained whether a host individual is a proportional random sampler of male and female fleas and whether the sex ratio in flea infrapopulations depends on the size of infrapopulations and on the gender and age of a host. Using field data, the sex ratio in infrapopulations of 7 flea species parasitic on 4 rodent species was analysed. Populations of 3 species (Nosopsyllus iranus, Parapulex chephrenis and Xenopsylla conformis) were significantly female-biased, whereas male bias was found in 1 species (Synosternus cleopatrae). In general, the sex ratio of fleas collected from an individual rodent did not differ significantly from the sex ratio in the entire flea population. Neither host gender, and age nor number of fleas co-occurring on a host affected (a) the sex ratio in flea infrapopulations and (b) the probability of an infrapopulation to be either female- or male-biased.     

Sexual attractiveness shared by both sexes mediates same‐sex sexual behaviour in the parasitoid wasp Telenomus triptus

The mating behaviour of a quasi‐gregarious egg parasitoid Telenomus triptus Nixon (Hymenoptera: Platygastridae), which exploits egg masses of a stink bug Piezodorus hybneri (Heteroptera: Pentatomidae), is examined in the laboratory. In this parasitoid wasp, male adults that emerge earlier stay at the natal egg mass and mate with subsequently emerging females. In the present study, a male adult that encounters the emergence of another male always waits for it to egress, and then mounts the newly emerging male. To examine why males of T. triptus show same‐sex sexual behaviour, male adults are presented with a parasitized host egg mass or a freshly killed wasp. Male adults are observed to remain at host egg masses from which only male wasp(s) had emerged. In addition, male adults attempt to copulate with freshly killed young male wasps. It is suggested that newly emerging male wasps are targets of same‐sex sexual behaviour because they possess cues for male sexual behaviour similar to the cues of females. Both the sex and age of freshly killed wasps affect the frequency of the sexual behaviour of male adults: females are more attractive than males, although their attractiveness declines with age. When the mating opportunity is restricted to the natal egg mass, the costs of failing to notice newly emerging female adults should be extremely high. Therefore, males are forced not to discriminate the sex, resulting in same‐sex sexual behaviour.     

Superparasitism and sex ratio adjustment in a wasp parasitoid: results at variance with Local Mate Competition?

Anaphes nitens is a solitary parasitoid of the egg capsules of the Eucalyptus snout beetle, Gonipterus scutellatus. Some traits of its natural history suggest that Local Mate Competition (LMC) could account for sex ratio adjustment in this species. We tested whether males emerged early, a prerequisite for fully local mating, and investigated the occurrence and effect of superparasitism on adult size and pre-emergence mortality, factors that might influence sex ratio adjustment. We found in field-collected egg capsules that males emerged first. To investigate the effects of superparasitism on adult size, we compared the sizes of parasitoids that emerged early and late from egg capsules collected in the field, and from egg capsules parasitized and superparasitized in the laboratory. Superparasitism reduced parasitoid size, affecting females more strongly than males, and increased pre-emergence mortality. We estimated A. nitens sex ratio and parasitism rate in the field during 2 years in five localities and during 4 years in a sixth. Following LMC we expected an increase in sex ratio (proportion of males) with increasing parasitism rate (assumed to reflect parasitoid density). We found that sex ratio decreased from 0.38 when the parasitism rate was low (0-20%) to 0.21 when parasitism was high (80-100%). In contrast with field results, a laboratory experiment showed that: (1) at a low parasitism level sex ratio was clearly female biased (0.28+/-0.04), (2) at a high parasitism level sex ratio increased (0.40+/-0.07), (3) male larval survivorship was not lower than female survivorship, and (4) low-quality hosts (i.e. superparasitized) were allocated more males. We conclude that LMC cannot explain the sex ratio adjustment observed in the field, even at low parasitism rates, and alternative explications for highly female-biased sex ratios must be found. One such alternative is female-biased dispersal.     

Transient post-mating inhibition of behavioural and central nervous responses to sex pheromone in an insect

Mating is costly for both male and female insects and should therefore only occur if it is likely to be successful. Within one scotophase, which is the dark period of the light cycle, male moths can only produce one single spermatophore, which is transferred to the female during mating. Remating within the same scotophase would thus be unsuccessful. We tested the hypothesis that newly mated males of the moth Agrotis ipsilon have developed an energy-saving strategy based on the transient inhibition of their sexual behaviour, thus avoiding unsuccessful remating. Agrotis ipsilon males do not copulate more than once during the same scotophase. Moreover, newly mated males do not respond behaviourally to the female sex pheromone although electroantennograms showed that their peripheral olfactory system is fully functional. However, intracellular recordings of antennal lobe neurons showed that the sensitivity for the synthetic sex pheromone blend decreased as compared with that of unmated males. Both the sexual behaviour and the sensitivity of the antennal lobe neurons were restored when tested during the next scotophase. Our results show a fast, transient neuronal plasticity that 'switches off' the olfactory system, which could prevent males from mating unsuccessfully.     

Respiratory gas exchange in the desert flea Xenopsylla ramesis (Siphonaptera: Pulicidae): response to temperature and blood-feeding

Xenopsylla ramesis is a flea species parasitizing gerbilline rodents in the deserts of the Middle East. This study was undertaken to determine metabolic requirements of the different developmental stages of the flea-life cycle as well as to investigate the metabolic response to temperature and starvation after blood feeding. A high resolution respirometry system was used to measure CO2 emission of fleas ranging in size from 0.166+/-0.006 mg (larvae) to 0.263+/-0.009 mg (adults). The free-living stages (larvae and adults) had significantly higher metabolic rates than the cocooned stages (pupae). CO2 emission rates of the larvae exceeded that of the adults by 2.6-fold and the pupae by 7.3 times. In the adults, both temperature and blood feeding significantly affected starvation-level metabolism. Metabolism was temperature dependent with an average Q10 of 2.57 for females and 2.55 for males over the temperature range of 10-30 degrees C. No consistent decline in thermal sensitivity at higher ambient temperatures was evident. Fleas that had a blood meal prior to starvation had significantly higher metabolic rates (0. 86 +/- 0.008 x 10(-3) ml mg(-1) h(-1)) than fleas, which were newly emerged unfed adults (0.56 +/- 0.1 x 10(-3) ml mg(-1) h(-1)). Water content also differed between fed (range approx. 67-69% body mass) and newly emerged adults (range approx. 73-75% of body mass). Feeding may stimulate some as yet undetermined physiological process that causes differential metabolic response in starving, fed and unfed fleas. Characteristics of gas exchange in desert-dwelling fleas are reflective of the off-host life style in the protected microenvironment of the host nest or burrow, rather than as a response to any type of environmental extreme.