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1.
Mating behaviour of the ball-rolling dung beetle Kheper platynotus (Bates), adults of which are active in rainy seasons, was studied in southeastern Kenya. Male mating behaviour changed with the progression of the rainy season. In the early season when females made food balls, males attempted forced copulation with wandering and food-ball-making females on dung mounds. As the season progressed, females made brood balls, and males attempted to pair off with such females, as well as attempting forced copulation with wandering and food-ball-making females. A male who paired off with a brood-ball-making female cooperated with the female to make the ball. The male usually copulated after burying the ball (pre-copulatory mate guarding), but sometimes copulated during ball-making. In the latter case the male usually showed post-copulatory mate guarding until ball burial, but sometimes left soon after copulation. In the late season, when available females decreased because of maternal care in the underground nests, males started to make food balls to secure food resources for survival until the next rainy season. Male mate guarding involving ball-making, -rolling and -burying seemed to function to raise paternity confidence, but such assistance seemed to be less beneficial to females. Fights frequently occurred between guarding and intruding males on brood balls. Both residency and relative body sizes of fighters were important asymmetries influencing contest outcome. This seemed to result in not active but passive mate choice by brood-ball-making females.  相似文献   

2.
During mating, males of Cressida cressida (Lepidoptera, Papilionidae) form a large external mating plug or sphragis that covers the female's copulatory opening and physically prevents remating. The sphragis has lateral and distal projections that make it an obvious structure. We tested experimentally the hypothesis that the sphragis acts as a signal of female mating status. Males pursue mated females with an intact sphragis only briefly and rarely make physical contact with them. When the sphragis of a mated female is removed or reduced in size, males are significantly more likely to physically contact the female and initiate the aerial takedown that preceeds a copulation attempt. These results suggest that the sphragis deters male sexual interest at a distance and thus functions as a signal of female mating status. The discussion focuses on the fitness consequences for females and their mates of the signal function of the sphragis.  相似文献   

3.
《Journal of Natural History》2012,46(17-18):1119-1129
Despite their abundance and diversity, Neotropical spiders have been the subject of relatively few studies of behavioural ecology. The sexual behaviour and maternal care of the spider Aglaoctenus lagotis (Lycosidae) is described here. We performed experimental manipulations to test the hypothesis that males are attracted by female cues in the web. Two predictions were tested: (a) webs used by a virgin female will attract more males than webs used by an inseminated female; (b) the main cue in the web is chemical, so webs recently used by virgin females will attract more males than those that are not recently used. Additionally, we tested the hypothesis that maternal care increases offspring survivorship. Results showed that males are attracted by recently used webs (z = 0.0015; p = 0.037; z-test) and webs of virgin females (z = 0.041; p = 0.036, z-test). Male sexual behaviour presented three different categories: court, pre-mate and mate. After the mating, the females built a cocoon that was transported adhered to the spinnerets and held by the last pair of legs. After the hatching of the eggs, the young migrated to the dorsal region of the mother's body for 5 days. During maternal care the mother eliminates a yellowish drop from its oral cavity, which is collected by the young. During the development of the young until adulthood, the offspring that have their mother present in the first stages of life have greater survival compared with those without maternal care. Our results make it possible to perform comparative analyses between a South American Lycosidae species and other species distributed worldwide.  相似文献   

4.
《Journal of Natural History》2012,46(1-2):107-117
Males of Conops quadrifasciata “claim” females in late morning and then spend the rest of the day exposed as “riders” to attacks by other males. Male riders can respond to an attack by performing an abdomen‐lift which denies the attacker access to the female's genitalia. Attacking males can tailor their behaviour to suit the prevailing conditions. If a rider is engaged in a “repeat” copulation (as he does at regular intervals), the attacker “waits” beside the rider. If the rider is not in genitalic contact with the female, the attacker tries to mate with her immediately. It is proposed that females deliberately expose their riders to takeovers in order to gain the fittest mate.  相似文献   

5.
Sexual dimorphism among crawlers of the scale insect family Eriococcidae is reported for the first time. The general morphology of crawlers of the gall-inducing genus Apiomorpha (Eriococcidae) is presented and sexual dimorphism described. Sexual dimorphism appears to be associated with differential dispersal and settling-site preference of the sexes during the crawler stage. First-instar males of the A. pharetrata and A. munita species-groups settle only on the galls induced by their mothers or, in the case of A. munita, also galls of nearby females, whereas female crawlers disperse. Female crawlers of all species of Apiomorpha, and male crawlers of most species, are well suited for air-borne dispersal. It is suggested that sexual dimorphism among crawlers of Apiomorpha, and some other scale insects, is the result of loss or reduction of those morphological features associated with dispersal. In addition, male crawlers of some species of Apiomorpha have sensory structures which may assist in the detection of sex-specific settling sites.  相似文献   

6.
Males of the thynnine wasp Thynnoturneria sp. attempt to mate with female decoys in the flowers of the elbow orchid Spiculaea ciliata. Experimentally shifted orchids usually attract male wasps quickly, often within 2 minutes of presentation of the ‘bait’ orchids in appropriate habitat. Although the orchid effectively exploits the scramble competition mating system of the wasp, the insect is not totally at the mercy of the deceptive orchid. Fewer than half of all arriving males contact the column of the orchid flower, as required for orchid pollination. Moreover, the number of deceived visitors falls sharply over a short period and the number of wasp visitors does not rebound with the replacement of one bait orchid by another at that location. These observations suggest that patrolling wasp pollinators can discriminate to some extent between orchid decoys and female wasps, especially by learning to avoid particular locations that are associated with unrewarding flower decoys.  相似文献   

7.
While expulsion of male ejaculates by the females after copulation has been reported for various animal groups, expulsion followed by consumption of the expelled ejaculate is a rare behaviour outside spermatophylax-producing orthopterans. Among Diptera, this behaviour has been reported for a few species of Piophilidae, Empididae and Ulidiidae. Here we report on its occurrence among Euxesta eluta and Euxesta mazorca (Diptera: Ulidiidae). We also attempt to characterize the mating system of E. eluta in order to facilitate future hypothesis testing to understand the behavioural factors leading to the evolution of this peculiar behaviour. For this, courtship sequences, copulation duration, frequency of ejaculate expulsion and subsequent consumption, and latency to ejaculate expulsion for both E. eluta and E. mazorca were recorded. The time of sexual maturation, the time window of sexual receptivity during the day, and the mating frequency and variance in mating success for males and females (degree of polygamy) were determined for E. eluta. Both E. eluta and E. mazorca males engaged in elaborate courtship sequences involving visual and tactile displays before copulation. Females of both species almost invariably expelled and consumed ejaculates after copulation. Female E. eluta, required a 6- to 9-day period feeding on protein and sugar before becoming sexually receptive. Reproductive activity occurred continuously over the day with an early morning and late afternoon peak. Both males and females could mate multiply, with multiple partners over a 2-h observational period. Sexual network analysis revealed that some males and females had greater mating success than others. Ejaculate consumption appears to be widespread in the genus Euxesta. It is possible that females obtain nutrients from this behaviour while exerting some control over egg fertilization.  相似文献   

8.
Collections, observations and experiments were used to investigate the behavioural ecology of gall thrips (Thysanoptera: Phlaeothripidae) in New South Wales and Queensland, Australia. Data are presented on aspects of gall morphology, male and female morphology, behaviour, life cycles, and sex ratios for six gall-forming species, five species of inquilines (invaders that do not form galls), and one genus that uses secretions to glue phyllodes (modified petioles) together. During gall foundation on phyllodes of Acacia pendula, females of Kladothrips rugosus Froggatt fight other females to the death, males fight other males to the death, and one female or one adult of each sex remains alive within the gall to breed. In addition to the live adults, half of newly found galls contained dead bodies of from one to 13 males and females, which were apparently killed in fights. In Oncothrips tepperi Karny, which forms galls on Acacia oswaldii, single females found new galls, and females engage in lethal fighting during the period from gall initiation until closure. First-generation broods of Oncothrips tepperi comprise winged males and winged females with a sex ratio of about 1:6 female biased. Each gall also contains several wing-reduced adults with larger forelegs than winged adults, which probably either fight among themselves or defend their siblings from gall invaders. Adults of Oncothrips tepperi breed in the galls for two or more generations, whereas in all of the other species studied on Acacia only one generation occurs in a gall. Females of the inquiline Koptothrips flavicornis invade young, first-generation galls of Oncothrips tepperi, kill the foundling female, and produce their own offspring. Single females of Oncothrips antennatus (Moulton) form galls on Acacia aneura, and apparently do not fight. Winged females of Oncothrips antennatus have smaller forelegs, relative to their body size, than do winged females of Oncothrips tepperi. In Onychothrips arotrum Mound and Onychothrips tepperi (Uzel), single females from galls on Acacia aneura. In each species, females engage in lethal fighting during gall initiation. The sex ratio of Onychothrips arotrum broods is about 1:18 female biased. The inquiline Csirothrips watsoni Mound invades galls of Onychothrips arotrum, apparently after most or all of the offspring have left, and breeds inside. Females of this inquiline will kill live Onychothrips arotrum inside the galls, and they apparently plug gall entrances with cast O. arotrum exuviae. Iotatubothrips crozieri Mound and Crespi is involved in the formation of large, woody galls on stems of Casuarina, perhaps in association with a microorganism. They breed in these galls for many generations. Galls contain several to thousands of individuals, and the adult sex ratio is about 1:4 female biased. Adults of the inquilines Thaumatothrips froggatti and Phallothrips houstoni Mound and Crespi invade these galls, kill the Iotatubothrips adults, and breed therein. The Iotatubothrips occasionally attempt, ineffectually, to fight off the invaders, and they apparently make partitions within the gall to protect themselves from takeover. Adults of Lichanothrips spp. glue phyllodes of Acacia harpophylla together using eggs and patches of secretion, and they breed in the resultant narrow space. Xanothrips xantes Mound breed in these spaces after the Lichanothrips have left. Fighting in Kladothrips rugosus, Oncothrips tepperi and Onychothrips tepperi involves two adults rearing up head to head, sparring with their enlarged, armed forelegs raised, and attempting to grasp and hold their opponent with their forelegs and drive their sharply pointed fore-tarsal teeth into their opponent's body. Females of Onychothrips arotrum also grasp, stab and kill with their forelegs, but they have not been observed to rear up head to head. Three of the inquiline species, Csirothrips watsoni, Thaumatothrips froggatti and Phallothrips houstoni, kill the original gall inhabitants by extending their forelegs directly in front of their bodies, tilting their heads back, remaining in this position for variable periods of time, and sharply pulling their armed fore tibiae towards the fore femora when their victim is near. Inquilinism in gall thrips may have evolved from lethal intraspecific fighting. Certain aspects of behaviour and morphology in Australian gall thrips, such as high prevalence of lethal fighting, gall ‘plugging’ in Csirothrips watsoni, attempted gall defence and apparent formation of partitions in Iotatubothrips crozieri, and the presence of wing-reduced adults in Oncothrips tepperi, indicate that these species exhibit some of the most complex behaviour thus far discovered in Thysanoptera.  相似文献   

9.
《Journal of Natural History》2012,46(22):2035-2045
Observations on the courtship behaviour, mating behaviour and mating success of a leaf‐frog, Phyllomedusa rohdei, population were conducted in a temporary flooded site of the Atlantic Forest, south‐eastern Brazil. We did not find any influence of size and body weight on male mating success across three scales: seasonal, nightly chorus and local groups (males found within 1?m of a mated pair). In addition, no evidence was found that female Phyllomedusa rohdei exhibit overt mate choice. The formation of mated pairs in P. rohdei occurred because males moved toward the females, rather than reverse. The only variable that was significantly related to male mating success was the number of nights of participation in chorus activity. Besides calling tactics, males showed active searching behaviour. There was no evidence of size‐ and mass‐assortative mating, and a high percentage of fertilization at all size and mass ratios of males and females was observed. Clutches in this species are produced in the same manner found in others members of Phyllomedusa; a purse‐like nest is made over water by folding a leaf around the egg mass (embryos and fluid‐filled capsules). Finally, we supply a list of several studies that examined the relationship between size or mass ratios of males and females in amplexus and its influence on fertilization rate, and show that size‐assortative mating in anurans is inconsistent (present in some species but not in other).  相似文献   

10.
《Journal of Natural History》2012,46(47-48):2961-2967
Explosive breeding is a common reproductive strategy, especially in anurans. In some cases of explosive breeding in anurans, intense aggressive interactions occur among males attempting to gain access to females, and for terrestrial species that mate in water, females may die by drowning during long mating struggles. Such occurrences are obviously detrimental to females, and may also cause a decrease in the reproductive success of males through depletion of energy without obtaining access to a live female. However, the males of the small Amazonian frog Rhinella proboscidea can promote the ejection of oocytes from the abdominal cavities of dead females and fertilize them. This behaviour can minimize losses to both partners during explosive reproduction events. The existence of such a “functional necrophile strategy” shows that there may be possible selection in favour of stronger and more persistent males in explosive breeders.  相似文献   

11.
Population and reproductive behaviour aspects of the glass frog Espadarana prosoblepon are well known for populations from Central America, but similar information is lacking for populations from South America. We recorded the reproductive ecology of a population of the glass frog E. prosoblepon in the city of Armenia, Central Andes of Colombia. With weekly surveys with mark-recapture between December 2013 and November 2015, we monitored activity patterns and evaluated if the probability of males mating is associated to their body size or to chorus tenure (i.e. the number of nights a same individual is calling for attracting a mate). In addition, upon observing an amplexus, we recorded the behaviour of the individuals until oviposition and noted characteristics of egg clutch. We recorded 47 males and 32 females, nine amplexus events, eight ovipositions, and 21 egg clutches (35.4 ± 4.79 eggs per clutch, = 29). Activity of males and females and the number of egg clutches were positively correlated to rainfall. Mating success of males was not associated to their body size, but it was positively associated to longer chorus tenure; clutches from large females had a higher number of eggs than clutches from small females. Oviposition occurred on average 3.76 ± 1.74 hours after we first observed the amplexus, occurring 93.1% of the time in fronds of Selaginella geniculata at an average height of 1.58 ± 0.44 m. After the oviposition, the male left the site, while the female remained between 30 and 45 min, partially covering the eggs. The reproductive behaviour of E. prosoblepon did not vary widely between a population in Costa Rica and our population in time to oviposition, and mating success of males associated to chorus tenure; however, in our study population we recorded a larger clutch size and the preference for S. geniculata fronds as oviposition substrate.  相似文献   

12.
《Journal of Natural History》2012,46(31-32):2125-2134
Anurans can be classified as explosive or prolonged breeders. In species with short breeding periods, intensive competition for females is expected. We analyse the temporal breeding pattern of Melanophryniscus aff. montevidensis, a bufonid inhabiting grasslands of Argentina, whose breeding is concentrated in events of short duration. Males are active during more than one breeding event per season, whereas most females take part in a single event per season. Active males outnumbered females by up to 14 times at one event, operational sex ratio (OSR) ranged from 0.07 to 0.75 and intensity of sexual selection (I s) from 0.69 to 24. We found a negative association between I s and OSR, but no correlation between number of active males per event and OSR or I s. The OSR is the key that regulates the intensity of sexual selection, nevertheless, and in spite of being explosive breeders, females would potentially have chances to select their mate.  相似文献   

13.
《Journal of Natural History》2012,46(7):1069-1086
The sensillar field on tarsus I of Halarachne (Halarachnidae: Gamasida), a respiratory tract endoparasite of seals (Pinnipedia) is associated with 12 hair- or peg-like receptor sensilla in the larva and 13 or 14 in the adult. These include thermo-hygroreceptors, each with a double wall traversed by 3 or 4 slit-like pores (dw/WP-sensilla), olfactory chemoreceptors of small inorganic molecules, each with a single wall spanned by several small and simple pores (sw/WP-sensilla), gustatory chemoreceptors with a single terminal pore (TP-sensilla), and aporous NP-sensilla which have thermoreceptive and/or other unknown functions. Some sensilla are sessile and others socketed, the latter having a possible additional/alternative mechanoreceptive function. One mechanoreceptor is a probable trichobothrium-like vibration receptor which has not been previously described in the Anactinotrichida. This range of sensilla combined with the absence of sw/WP-sensilla, i.e. olfactory chemoreceptors covered with numerous, large centrally-plugged pores, suggests that although Halarachne spp. can locate large endothermic animals, they lack the ability to discriminate between different species.  相似文献   

14.
Mating system variation in anuran amphibians of the Arizona - Sonoran Desert was reviewed. Male density and breeding period duration were negatively correlated in seven bufonids and pelobatids. Variation in male mating behavior and ability of females to freely select their mates unhindered by active - searching males also was related directly to male density. These observations support hypotheses relating ecological factors to mating system organization. It is suggested that male calling behavior, and anuran lek mating systems in general, may be significantly influenced by predation on vocalizing males.        相似文献   

15.
Pollinator fig wasps (Hymenoptera: Agaonidae) display numerous adaptations linked to their obligate association with fig trees (Ficus). Ceratosolen fig wasps pollinate figs that often fill temporarily with liquid, and one clade has males with unusually long hind legs. We investigated their morphology and behaviour. Scanning electron microscopy (SEM) revealed that the cuticle of their hind legs is highly modified and covered with numerous hydrophobic setae and microtrichia that can prevent blockage of the wasps’ large propodeal spiracles by liquids. In deep liquid, the males floated on the surface, but when only a thin layer of liquid was present, the legs allowed males to access females without the risk of drowning. Access to females was facilitated by an air bubble that forms between the hind legs and maintains a column of air between the spiracles and the centre of the figs. Sexual selection should favour males that can gain earlier access to mates, and the modified legs represent an adaptation to achieve this. Convergent adaptations are known in some unrelated non-pollinating fig wasps that develop in similar liquid-filled figs, but these species have enlarged hydrophobic peritremata at the ends of their metasoma to protect the spiracles located there. Unlike non-pollinating fig wasps, pollinator males need to insert their metasoma deep into females’ galls during mating. This difference in mating behaviour has constrained the extent of convergence.  相似文献   

16.
《Journal of Natural History》2012,46(35):3217-3226
Animal mating systems are moulded by ecological factors, mainly the temporal patterns of reproduction. We report the reproductive period, use of microhabitats, clutch and egg sizes, reproductive efforts, occurrence of sexual size dimorphism, and the relation between body size and fecundity in the gravid females of Trachycephalus venulosus and Scinax fuscovarius at Serra da Bodoquena, Central Brazil. The reproduction of both species was correlated with the rainy season. Females of T. venulosus produced more eggs and their eggs were larger than those of S. fuscovarius. The females of both species were larger and heavier than males. The reproductive effort was measured as the ratio of gonad mass in relation to body mass. Females of both species presented similar reproductive efforts, but males of S. fuscovarius invested more in gonads compared to males of T. venulosus. Trachycephalus venulosus presented significant correlation between snout–vent length versus number of mature eggs and body mass versus number of mature eggs and ovarian mass. Scinax fuscovarius showed significant correlation between body mass versus ovarian mass. Trachycephalus venulosus is an explosive breeder, whereas S. fuscovarius has prolonged reproduction. These species are able to adapt to several types of habitat, due to behavioural and physiological plasticity.  相似文献   

17.
Soldier beetles of 2 species, Chauliognathus basalis and C. deceptus , were examined to test the Crespi hypothesis that positive assortative mating by size is caused by mate choices. Specifically, we tested the prediction that if mate choice involves choosing the largest mate available, then mating individuals will be larger than nonmating individuals. Four samples were taken, at different times during the mating season, from each of 2 sites. Each sample consisted of mating pairs, nonmanting males, and nonmating females. Some of the samples contained beetles of both species; others contained beetles of a single species. For each gender elytron lengths of mating individuals were compared with elytron lengths of nonmating individuals. We found no effect of mating status (mating vs. nonmating) on elytron lengths in samples that exhibited assertive mating (which occurs where 2 species coexist). Surprisingly, we found a consistent effect of mating status on elytron lengths in samples that did not exhibit assortative mating (which occurs where only 1 species exists). Our results do not support the mate-choice hypothesis. Instead, mate choice and assortative mating appear to be alternative mating patterns in which mate choice occurs where a single species exists and assortative mating occurs where 2 species coexist.  相似文献   

18.
《Journal of Natural History》2012,46(5):1109-1117
In this report we describe some aspects of the reproductive biology of a population of the chalcedon checkerspot, Euphydryas chalcedona, in central Arizona. Successful courtship in this species lasts about a minute and has a form similar to that of other nymphalids. During copulation the male forms a spermatophore within the female's bursa copulatrix that represents about 7% of the male's body weight. After copulation females may remate and older females may have mated as many as three times. The spermatophore deflates as time since deposition passes. Females oviposit every other day on average and lay their eggs in clusters. These data confirm previous brief reports of courtship structure and spermatophore size for E. chalcedona. Questions are raised about the control of receptivity in this species and the function of the mating plug.  相似文献   

19.
《Journal of Natural History》2012,46(4):1015-1027
Males of many bees in the subfamily Nomiinae (Halictidae) have numerous secondary sexual characters, which provide much systematic information. Similarly, the use of these structures by males during sexual behaviour may provide useful characters, but the courtship and copulatory behaviour of most of these bees is not known. Structures and behaviour used for courtship and mating are described for two species of nomiine bees, Dieunomia heteropoda and Nomia tetrazonata, along with brief observations of mating in a parasitic bee, Triepeolus verbesinae (Apidae: Nomadinae). A review of mating behaviour within the Nomiinae shows no obvious phyletic patterns, based upon present limited knowledge. The species-specific nature of the male secondary sexual characters suggests they may have evolved in the context of sexual selection, but behavioural data from populations of additional species are needed to evaluate the hypothesis adequately.  相似文献   

20.
Adults of both sexes of Cheimas opalinus (Staudinger), a Satyrinae butterfly occurring in the cloud forests of the Venezuelan Cordillera de Mérida, have simple wing colour patterns, dark brown dorsa marked by one conspicuous element, large greenish-blue patches in the discal area of the hind wing. It was observed that in young, freshly emerged females these patches are frequently absent. They fade away and eventually disappear during mating and nuptial flights when brushed out by lateral movements of the male’s hind wing put between folded female hind wings. The falling off of the scales is made easy because they do not adhere to the wing as firmly as brown background scales due to their particular folded extremities. We speculate that this process is related to the fitness of the females. Prior to mating, blue-green patches are advantageous because they attract the attention of the opposite sex and enhance the chances of successful mating. After mating they lose their sexual role. Females without the blue-green patches become cryptic. Thus, they are less apparent not only for the males, which helps them avoid sexual harassment, but also for potential bird predators. Additionally, the loss of blue reflecting scales may speed up the warming up of the abdomen and egg maturation. In the males, positive role of the patches (signalling), and negative (bird attraction), is balanced during their entire life span, and they fade gradually due to regular usage of wings scaling in flight. Our hypothesis is supported by morphological, optical, experimental and statistical analysis in which we used 509 individuals of both sexes. A similar ratio of young (with undamaged wing) females with or without blue patch was recorded, whereas in the males no individuals without any trace of blue patch were reported, and a correlation of age (wing damage) and gradual fading off of the patch was demonstrated. Such an adaptation involving an active change of the appearance of adults, i.e. colour patterns related to sexual selection, has not been reported previously in Lepidoptera.  相似文献   

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