Female Calls Research Articles

Mating‐Associated Changes in the Behaviour of Leptothorax gredleri Ant Queens

AbstractThroughout their lives, animals adapt their behaviour to environmental fluctuations and to their own requirements. In social insects, behavioural changes are often particularly conspicuous. For example, in many ant species, reproductive sexuals leave their maternal nests and engage in risky mating and dispersal activities. Female sexuals experience, during a short period of time, dramatic changes in terms of behaviour and environmental conditions. But because sexual activities of ants are not easily observed, few studies have quantified in detail how behaviour alters with maturation and mating. We studied how various behavioural traits of Leptothorax gredleri female sexuals, a species in which female sexuals attract males by ‘female calling’, change before and after mating. We tested the hypothesis that behavioural variation reflects the altered requirements of queens to adapt to a particular situation. To this end, we compared geotactic, phototactic and locomotor behaviour across a wide range of life stages from lightly coloured, unmated female sexuals to old, mated queens. The results showed that female sexuals of L. gredleri change conspicuously their geotactic, phototactic and locomotor behavioural traits over their life stages. Three different behavioural states were evident (1) from light to dark female sexuals, individuals have negative phototaxis and reduced locomotor activity; (2) mature female sexuals during the daily period of sexual activity have strong phototaxis, negative geotaxis and an important locomotor activity; and (3) freshly mated and old mated queens avoid light and decrease their locomotor activity. These sharp differences in behaviour between stages match the transition from the relative safety of the nest chamber to the adversary world outside the nest, and back.

The women's quota in conflict ridden Sudan: Ideological battles for and against gender equality

Synopsis This article explores women's substantive representation in Sudan's National Assembly. It examines the extent to which female legislators in the National Assembly represent women's interests, paying special attention to legislative initiatives and accomplishments following the signing of the peace agreement in 2005. The article highlights polarization rather than cooperation between women activists and women in the government as an important factor in explaining the lack of legislative accomplishments. There are competing gender ideologies between women activists demanding gender equality (musawah) and female legislators calling for gender equity (insaf). They are operating from isolated islands. The article argues that this limits the possibilities for a reform of Sudan's laws. Further, the increasingly polarized political landscape, limits the possibilities for even minor reforms on women's issues in the few areas where there is in fact a broad agreement between women activist and women in government on what constitutes acting in the interest of Sudanese women. Particularly after the International Criminal Court issued an arrest order for President Bashir in 2009, he has on more occasion than one turned to the religiously conservatives for support. While the religiously conservatives have the president's ear, the reformist voices within the government are marginalized, including the women.

Vocal cooperation between the sexes in Little Spotted Kiwi Apteryx owenii

Sexual call dimorphism in birds is usually associated with sexual size dimorphism. Departures from this relationship can be used to infer call function, but research into inter‐sexual call differences, as with song function in general, has been restricted by a bias towards male passerines. The nocturnal and flightless New Zealand kiwi (Apterygidae) are acoustically similar but taxonomically and ecologically very different from other birds, so provide a contrast in exploring avian call function and evolution. However, kiwi acoustic ecology is poorly understood, with the calls of only one of the five kiwi species spectrally described, and acoustic differences between the sexes virtually unknown. We conducted the first bioacoustic study of Little Spotted Kiwi Apteryx owenii, and assessed sexual call dimorphism in this species. There were significant inter‐sexual differences in call temporal and frequency characteristics that were not related to size dimorphism. Contribution to duets and variation in temporal structure with call context also differed between the sexes. We suggest that these differences indicate divergent call function, with male calls more suited for territory defence, and female calls for pair contact. There was a striking lack of overlap in the frequency spectrum distributions of male and female calls, which was also unrelated to size and was further emphasized by the presence of formants in female calls. We propose that this provides evidence for inter‐sexual acoustic cooperation in call frequency, of a type which to our knowledge has not previously been described in birds. This may result from selection for enhanced joint resource defence in kiwi.

Host plants and reproductive behaviour in the African maize stemborer, Busseola fusca (Fuller 1901) (Lepidoptera: Noctuidae)

Summary Busseola fusca Fuller (Lepidoptera: Noctuidae) is the major pest on maize and sorghum crops in sub-Saharan Africa. As a specialised phytophagous insect, survival of B. fusca larvae depends on the presence of the cultivated host plants. Taking into account recent evidence of host-plant presence acting on pheromone perception and production in Lepidoptera, we investigated the effect of different host and non-host plants on reproductive behaviour in B. fusca: female calling behaviour and male attraction by female. Results showed that both behaviours did not change in presence of plants, whether they are larvae host plant or oviposition repellent plant. Native host associated mating remains unknown for this species, but results are likely to favour the hypothesis that mating behaviour is not related to the presence of cultivated or putative native host plants.

六星黑点豹蠹蛾求偶行为与性信息素产生和释放的时辰节律

PDF HTML阅读 XML下载 导出引用 引用提醒 六星黑点豹蠹蛾求偶行为与性信息素产生和释放的时辰节律 DOI: 10.5846/stxb201204200570 作者: 作者单位: 山西农业大学化学生态研究所,山西农业大学化学生态研究所,山西农业大学化学生态研究所,北京林业大学省部共建森林培育与保护教育部重点实验室,北京林业大学省部共建森林培育与保护教育部重点实验室,山西农业大学化学生态研究所,山西农业大学化学生态研究所,山西农业大学化学生态研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 山西省自然科学基金项目(2010011042-2);国家"十二五"科技支撑计划项目 (2012BAD19B07) Circadian rhythm of calling behavior and sexual pheromone production and release of the female Zeuzera leuconotum Butler (Lepidoptera: Cossidae) Author: Affiliation: Institute of Chemical Ecology,Shanxi Agricultural University,Taigu Shanxi,Institute of Chemical Ecology,Shanxi Agricultural University,Taigu Shanxi,Institute of Chemical Ecology,Shanxi Agricultural University,Taigu Shanxi,The Key Laboratory for Silviculture and Conservation of Ministry of Education,Beijing Forestry University,The Key Laboratory for Silviculture and Conservation of Ministry of Education,Beijing Forestry University,Institute of Chemical Ecology,Shanxi Agricultural University,Taigu Shanxi,Institute of Chemical Ecology,Shanxi Agricultural University,Taigu Shanxi,Institute of Chemical Ecology,Shanxi Agricultural University,Taigu Shanxi Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:六星黑点豹蠹蛾Zeuzera leuconotum Butler (Lepidoptera: Cossidae)是一种重要的园林害虫。为研究利用其性信息素防控六星黑点豹蠹蛾,在光周期L∶D = 14∶10、温度19-32℃、相对湿度75%-85%条件下,对雌蛾求偶行为进行了观察;采用腺体提取法和瓶内收集法分别制备了不同日龄在同一时辰、同日龄在不同时辰的雌蛾性信息素粗提物,然后测定雄蛾触角对各种性信息素提取物的触角电位反应;以雄蛾对腺体提取物的EAG值表示性信息素的产生量,对瓶内收集物的EAG值表示释放量,检测性信息素产生与释放的时辰节律。结果表明:雌蛾求偶均发生在暗期;雌蛾求偶率与日龄有关,其中2日龄雌蛾求偶率最高,平均为86.7%;不同日龄雌蛾求偶高峰期均在进入暗期4-6h期间;随着虫龄的增加,求偶高峰期前移。雌蛾羽化当晚体内即可产生性信息素,并且向体外释放,但量较少;2日龄雌蛾产生和释放的性信息素量最大;雌蛾腺体中性信息素含量从进入暗期后逐渐增加,在暗期5h含量最高,随后逐渐减少;雌蛾释放性信息素从暗期4h开始,至暗期6h释放量最大。通过林间处女雌蛾诱捕试验证明了六星黑点豹蠹蛾的求偶行为与性信息素产生和释放在时辰节律上具有一致性。 Abstract:Zeuzera leuconotum Butler(Lepidoptera: Cossidae) is one of the most damaging pests on forestry in northern China in recent years. Because its larvae cause damage by tunneling into tree trunks, it is very difficult to control by cutting off the damaged branches or applying insecticides. In order to find a pollution-free and efficient controlling method,we have already begun a series of studies on the sex pheromone of the pest. It is necessary to know the character of calling behavior and the circadian rhythm of sex pheromone production and release by female Z. leuconotum. In this paper, the female moth calling behavior and characters were investigated through observation in the insectariums under the condition of (19-32)℃,75%-85% RH and 14L∶10D photoperiod. And the circadian rhythm of sex pheromone production and release by the female moth was researched in detail by determining the electrophysiological (EAG) responses. The crude extracts of sexual pheromone were prepared by the two methods. One of the methods was to directly extract pheromone from female sexual gland by hexane, and another was to collect pheromone from air in the bottle which filled with a female moth. The Former reflected the sex pheromone production, and the latter reflected the sex pheromone release. The results showed that the calling behavior of all female moths occurred during the scotophase. Some females (43.3%) called on the first night after eclosion and called mainly during the second half of the scotophase. Calling varied with age of female. The percentage of females calling increased from 1 to 2-d-old and decreased from 3 to 6-d-old gradually. The percentage of 2-d-old females calling was the biggest (86.7%, average), significantly bigger than 1 or 4, 5, 6-d-old females(P＜0.05). The old females (5 to 6-d-old) called earlier than younger in the scotophase. The calling peak occurred in 4-6 h of scotophase. The EAG response of males to different extracts reflected that only a few females could produce and release sex pheromone on the first night after eclosion. The sex pheromone production and release of females varied with age, which regulation was the same as that of calling. The sex pheromone production and release of 2-d-old females were the highest, significantly higher than those of other age females(P＜0.05). The sex pheromone production of the female gland increased with the time into scotophase, but very slowly from the onset to 4 h, and sharply from 4 to 5h, and peaked. After the peak, the production decreased greatly during 6 to 8h. At 4 h into scotophase, sex pheromone release began to increase, and quickly reached the peak. In a word, there was a circadian rhythm in the production and release of sex pheromone by Z. leuconotum. The peak of production occurred on 5 h into scotophase, but that of release occurred on 6 h of entering scotophase. In the field test, it was found that the percentage of males trapped by using 2-d-old virgin females had the same regularity as mentioned above. Therefore, it was confirmed that the calling behavior, sex pheromone production and release of Z. leuconotum were synchronized. 参考文献 相似文献 引证文献

Songbirds and humans apply different strategies in a sound sequence discrimination task

The abilities of animals and humans to extract rules from sound sequences have previously been compared using observation of spontaneous responses and conditioning techniques. However, the results were inconsistently interpreted across studies possibly due to methodological and/or species differences. Therefore, we examined the strategies for discrimination of sound sequences in Bengalese finches and humans using the same protocol. Birds were trained on a GO/NOGO task to discriminate between two categories of sound stimulus generated based on an “AAB” or “ABB” rule. The sound elements used were taken from a variety of male (M) and female (F) calls, such that the sequences could be represented as MMF and MFF. In test sessions, FFM and FMM sequences, which were never presented in the training sessions but conformed to the rule, were presented as probe stimuli. The results suggested two discriminative strategies were being applied: (1) memorizing sound patterns of either GO or NOGO stimuli and generating the appropriate responses for only those sounds; and (2) using the repeated element as a cue. There was no evidence that the birds successfully extracted the abstract rule (i.e., AAB and ABB); MMF-GO subjects did not produce a GO response for FFM and vice versa. Next we examined whether those strategies were also applicable for human participants on the same task. The results and questionnaires revealed that participants extracted the abstract rule, and most of them employed it to discriminate the sequences. This strategy was never observed in bird subjects, although some participants used strategies similar to the birds when responding to the probe stimuli. Our results showed that the human participants applied the abstract rule in the task even without instruction but Bengalese finches did not, thereby reconfirming that humans have to extract abstract rules from sound sequences that is distinct from non-human animals.

The Evolution of Androconia in Mimetic Tiger Moths (Noctuoidea: Erebidae: Arctiinae: Ctenuchina and Euchromiina)

AbstractTiger moth courtship involves an intricate interplay of female calling and male responses, involving pheromones, ultrasound, or both. A comparative phylogenetic approach is needed to separate proximal (ecological) from ultimate (evolutionary) explanations for observed behaviors. This study focused on mimetic tiger moths (Ctenuchina and Euchromiina) to provide a phylogeny to understand the evolution of male courtship structures (androconia). Genetic data from one mitochondrial gene (1,173 basepairs [bp] of COI) and two nuclear genes (238 bp of 28S rRNA D1 loop; 650 bp of EF1-α) were sampled for 29 species and analyzed using maximum parsimony, maximum likelihood, and Bayesian methods to estimate phylogenetic relationships. The ancestral reconstruction of androconia was optimized using parsimony and Bayesian approaches. Excluding three species, Euchromiina and Ctenuchina were recovered as reciprocally monophyletic, contradicting earlier molecular phylogenies. The genus Cosmosoma was found to be polyphyletic, as was Eucereon. Reconstruction of androconial structures revealed that these structures were acquired once, with subsequent losses in particular species.

Vocal behaviour of Orange River Francolin Scleroptila levaillantoides based on visual and sound-playback surveys

Fieldwork to study the vocal behaviour of Orange River Francolin Scleroptilia levaillantoides was conducted on a farm in the Heidelberg district, Gauteng province, South Africa, during August 2009 to March 2011. Orange River Francolins possess a basic repertoire of seven calls and one mechanical sound. From 83 francolins tested with playback calls only 33 (39.7%) responded with call backs over the course of the study period. This low response rate in the population is ascribed to habituation because most of the coveys were tested repeatedly on a weekly basis. From a management point of view, call backs can be used to locate coveys in the grass that could then be approached, flushed and counted. Alternatively, it is possible to locate coveys with interactive sound equipment and then multiply the number of call-back localities with an average covey size (about two to three francolins) to determine the size of the population. A ‘ke-ri ke-chi’ playback call enticed three different calls from Orange River Francolins that can be used for management purposes, including the ‘ke-ri ke-chi’, cacophony and female calls. These three calls can be used to locate Orange River Francolins, determine dispersion, habitat preferences, breeding cycle and to identify subadults, males and females.

Bat echolocation calls facilitate social communication

Bat echolocation is primarily used for orientation and foraging but also holds great potential for social communication. The communicative function of echolocation calls is still largely unstudied, especially in the wild. Eavesdropping on vocal signatures encoding social information in echolocation calls has not, to our knowledge, been studied in free-living bats so far. We analysed echolocation calls of the polygynous bat Saccopteryx bilineata and found pronounced vocal signatures encoding sex and individual identity. We showed experimentally that free-living males discriminate approaching male and female conspecifics solely based on their echolocation calls. Males always produced aggressive vocalizations when hearing male echolocation calls and courtship vocalizations when hearing female echolocation calls; hence, they responded with complex social vocalizations in the appropriate social context. Our study demonstrates that social information encoded in bat echolocation calls plays a crucial and hitherto underestimated role for eavesdropping conspecifics and thus facilitates social communication in a highly mobile nocturnal mammal.

Does hatching failure breed infidelity?

In socially monogamous species, the reasons for female infidelity are still controversial. It has been suggested that females could seek extra-pair copulations as an insurance against hatching failure caused by male infertility or incompatibility. In species where couples breed repeatedly, females could use previous hatching success as a cue to assess their partner’s infertility (or incompatibility). Hence, it has been predicted that females should increase their infidelity after experiencing hatching failures, but to our knowledge this hypothesis has never been tested experimentally. We manipulated hatching success of pairs in a captive population of zebra finches (Taeniopygia guttata), a species that forms lifelong pair bonds, and measured female willingness to engage in extra-pair copulation. By experimentally cross-fostering fertile and infertile eggs, couples either experienced 100% or about 35% hatching success in each of three consecutive clutches. Contrary to our prediction, females that experienced repeated hatching failure did not increase their responsiveness toward extra-pair males relative to those females with 100% hatching success. Moreover, there was no difference in female calling rate for the partner after male removal and no occurrence of divorce when the opportunity was given. These findings seem to contradict the common view that reproductive failure weakens the pair bond. Furthermore, a critical review of the literature suggests that there is no convincing evidence supporting this hypothesis in other species either. We therefore highlight that this fundamental area of behavioral ecology research is still much in need of specific experimental work that controls for confounding factors. Key words: divorce, extra-pair mating, fertility insurance, hatching failure, pair bond, zebra finch [Behav Ecol]

Silky sifaka (Propithecus candidus) “zzuss” vocalizations: Sexual dimorphism, individuality, and function in the alarm call of a monomorphic lemur

Vocalizations of Madagascar's lemurs have generally been less investigated than those of other primate groups, with virtually no information available about calling in the silky sifaka (Propithecus candidus), a large rainforest species. Current work examined the "zzuss" vocalization, one of the most common and loudest sounds produced by this monomorphic species, and included 160 calls from nine adults (five males, four females) in three groups. Analyses focused on overall acoustic features, individual and sex differences, call usage, and likely function. Acoustically, the calls included separable turbulent noise and tonal components, with the later often marked by frequency jumps and dramatic frequency modulation. Male and female zzuss calls differed most in F0- and amplitude-related features, characteristics that are relatively unconstrained by overall body size. All measures differed among individual callers, with F0-related variables again playing the largest role. Based on usage, these calls most likely function both as generalized alarm and group-coordination signals. The sounds were thus of interest in several regards, including showing sexual differentiation in the absence of other dimorphisms, exhibiting primarily F0-based differentiation in both sex- and individual-based comparisons, and combining apparent alarm and coordination functions across a variety of contexts.

Evolution and Diversity of Vibrational Signals in Mantophasmatodea (Insecta)

Vibrational communication for species identification and mate location is widespread among insects. We investigated the vibrational communication signals of 13 species of the insect order Mantophasmatodea (Heelwalkers). Males and females produce percussive signals by tapping their abdomens on the substrate to locate conspecific mates. We show that male and female calls are of similar general structure but differ in temporal characteristics. Using a principal component analysis, we demonstrate that most species can be distinguished by their calls only. Mapping the calls onto an existing molecular phylogenetic tree reveals a slow diverging drift of male call pattern but no specific trend. For females, a trend from faster towards slower pulse repetition times is indicated. Two sympatric species, Karoophasma biedouwense and Viridiphasma clanwilliamense (Austrophasmatidae), exhibit very different call parameters. The latter species produces calls rather different from all other investigated species, which might hint at reproductive character displacement.

The Structure and Usage of Female and Male Mouse Ultrasonic Vocalizations Reveal only Minor Differences

Ultrasonic vocalizations (USV) of mice are increasingly recognized as informative dependent variables in studies using mouse models of human diseases. While pup vocalizations primarily serve to re-establish contact with the mother, adult male “songs” were considered to be courtship signals. Alternatively, mouse USVs may generally function as territorial signals. To distinguish between these two hypotheses, we compared the structure and usage of adult male and female USVs in staged resident-intruder encounters. If calls function primarily as courtship signals, males should respond stronger than females, specifically when presented with a female intruder. Refuting this hypothesis, we found that in response to female intruders, females called more than males (228±32 calls/min vs. 71±15 calls/min), and males called more to female than to male intruders (14±7.5 calls/min). There were no significant differences in the acoustic characteristics of the calls given by females and males. To control for the influence of the intruder's behavior on calling, we repeated the experiments using anaesthetized intruders. Again, females produced more calls to female than male intruders (173±17 calls/min vs. 71±15 calls/min), while males called more in response to female than male intruders (39±17 calls/min), and there were no acoustic differences in female and male calls. The vocal activity did not differ significantly with regard to intruder state (awake or anaesthetized), while the acoustic structure exhibited significant differences. Taken together, our findings support the view that calls do not mainly function as courtship signals, although they might serve both a territorial (sex-independent) and a courtship function. The comparison of responses to awake vs. anaesthetized intruders suggests that the latter are sufficient to elicit vocal activity. The subtle acoustic differences, however, indicate that the subject differentiates between intruder states.

Song tutoring in presinging zebra finch juveniles biases a small population of higher-order song-selective neurons toward the tutor song.

We explored physiological changes correlated with song tutoring by recording the responses of caudal nidopallium neurons of zebra finches aged P21-P24 (days post hatching) to a broad spectrum of natural and synthetic stimuli. Those birds raised with their fathers tended to show behavioral evidence of song memorization but not of singing; thus auditory responses were not confounded by the birds' own vocalizations. In study 1, 37 of 158 neurons (23%) in 17 of 22 tutored and untutored birds were selective for only 1 of 10 stimuli comprising broadband signals, early juvenile songs and calls, female calls, and adult songs. Approximately 30% of the selective neurons (12/37 neurons in 9 birds) were selective for adult conspecific songs. All these were found in the song system nuclei HVC and paraHVC. Of 122 neurons (17 birds) in tutored birds, all of the conspecific song-selective neurons (8 neurons in 6 birds) were selective for the adult tutor song; none was selective for unfamiliar song. In study 2 with a different sampling strategy, we found that 11 of 12 song-selective neurons in 6 of 7 birds preferred the tutor song; none preferred unfamiliar or familiar conspecific songs. Most of these neurons were found in caudal lateral nidopallium (NCL) below HVC. Thus by the time a bird begins to sing, there are small numbers of tutor song-selective neurons distributed in several forebrain regions. We hypothesize that a small population of higher-order auditory neurons is innately selective for complex features of behaviorally relevant stimuli and these responses are modified by specific perceptual/social experience during development.

Males use time whereas females prefer harmony: individual call recognition in the dimorphic blue-footed booby

In breeding birds, acoustic signalling is often an important cue for reunion between sexual partners. However, in spite of its potential interest, mate recognition has rarely been examined by comparing the two sexes. We studied the blue-footed booby, Sula nebouxii, a socially monogamous seabird, with a dramatic call sexual dimorphism suggesting two different strategies for identity coding: the female call is an amplitude-modulated sound with a harmonic series slowly modulated in frequency, while the male call is a noisy whistle strongly modulated in frequency. To compare acoustic strategies between the sexes, we (1) recorded calls of both males and females, (2) searched for an individual signature and characterized it, and (3) tested, using a playback experiment, whether the calls of males and females were equally efficient for mate recognition. Results showed that an individual signature was present in the calls of both sexes. However, the acoustic parameters involved differed: female individual identification was principally achieved by a spectral analysis of the call whereas males' identity relied mostly on temporal cues. More than 70% of both females and males tested in playback experiments successfully recognized their mate. This suggests that the coding strategies are equally efficient in terms of individual recognition between mates. From a broader point of view, our results underline the importance of assessing both males and females within the same investigative framework.

Inconsistent geographic variation in the calls and duets of Barred Owls (Strix varia) across an area of genetic introgression

ABSTRACT. Much of our understanding of vocal geographic variation in birds is based on the dialects of oscine songbirds that learn their songs. Recent studies have revealed that nonoscine vocal behavior is more complex than previously thought, yet we still have a rudimentary understanding of how vocalizations of suboscine and nonpasserine birds are influenced by genetic and geographic variation. We examined geographic variation in male calls, female calls, and duets of Barred Owls (Strix varia) among 10 locations across the southeastern United States. Recent molecular work revealed two genetically distinct clades of Barred Owl at either end of our transect, with substantial introgression in between. We predicted that calls would vary with genetic distance in a clinal pattern, but that duets and duetting behavior might exhibit dialects similar to that of learned bird song. Discriminant analysis did not reveal any components of vocalizations or vocal behavior that could be used to assign vocalizations to th...

Horseshoe Bats Recognise the Sex of Conspecifics from Their Echolocation Calls

Echolocation calls produced by bats contain information on the emitter that could be used in social interactions. Nevertheless, little is known about the whether such information actually is being used by bats. Here we tested the ability of two horseshoe bat species (Rhinolophus mehelyi and R. euryale; n = 20 each) to discriminate conspecific male from conspecific female echolocation calls and vice versa. Behavioural data from a habituation-discrimination paradigm revealed that both species were able to recognize the sex of conspecifics from their calls, providing evidence that cues on the sex of the emitter are encoded in echolocation signals. While our data support that the sex-specific acoustic cues are not (just) the horseshoe bats' constant-frequency call part, their nature remains enigmatic. This is the second study to show that bats can recognize the caller's gender from echolocation calls and the first to do so for ‘high-duty-cycle bats’; those that use calls with a prominent constant-frequency (CF) component.

Female calling and male flight orientation and searching behaviors in Callisphyris apicicornis: evidence for a female-produced sex attractant pheromone

T. Curkovic, and C. Ferrera. 2012. Female calling and male flight orientation and searching behaviors in Callisphyris apicicornis: evidence for a female-produced sex attractant pheromone. Cien. Inv. Agr. 39(1): 147-158. Callisphyris apicicornis is a fruit pest of increasing concern in Chile. To aid in the identification of its sex pheromone for use in the management of this insect, “calling” (pheromone release) of females and “orientation and searching” behaviors of males to calling females were video recorded. Light intensity, wind speed, temperature, time of the day, and the frequency of individuals performing each step within both behavioral sequences were recorded as well. Drawings of the behavioral steps and ethograms (routes and returns) are also provided, including transition frequencies between behavioral steps. The calling behavior of females included diagnostic movements of the abdomen, legs, elytra, and wings, showing similarities to the descriptions of other cerambycid species in which females call. The orientation and searching behavior of males included zigzagging flights (characteristic steps observed in insects responding to airborne pheromone plumes) and landing on and searching for females in cages. Females called and males responded mainly between 9 AM and 1 PM. Both behaviors were performed in a non-random fashion and were stereotyped. Calling behavior was significantly affected by light (apparently triggering the behavior) but not by wind speed, ambient temperature, or female age. Males tended to respond most strongly to younger females, although these called significantly less frequently than older ones. These results strongly support the existence of a female-produced sex pheromone in C. apicicornis and provide the background information to aid in attempts of pheromone collection and identification. Male behavior characterization also provides a base-line to compare with tests to evaluate the activity of putative pheromones for this species. This study is one of the first reports of a cerambycid species in which the female calls and the male consequently responds to her and the first one on the characterization of the calling and oriented searching behaviors for a Necydalinae.

Differential Interactions of Sex Pheromone and Plant Odour in the Olfactory Pathway of a Male Moth

Most animals rely on olfaction to find sexual partners, food or a habitat. The olfactory system faces the challenge of extracting meaningful information from a noisy odorous environment. In most moth species, males respond to sex pheromone emitted by females in an environment with abundant plant volatiles. Plant odours could either facilitate the localization of females (females calling on host plants), mask the female pheromone or they could be neutral without any effect on the pheromone. Here we studied how mixtures of a behaviourally-attractive floral odour, heptanal, and the sex pheromone are encoded at different levels of the olfactory pathway in males of the noctuid moth Agrotis ipsilon. In addition, we asked how interactions between the two odorants change as a function of the males' mating status. We investigated mixture detection in both the pheromone-specific and in the general odorant pathway. We used a) recordings from individual sensilla to study responses of olfactory receptor neurons, b) in vivo calcium imaging with a bath-applied dye to characterize the global input response in the primary olfactory centre, the antennal lobe and c) intracellular recordings of antennal lobe output neurons, projection neurons, in virgin and newly-mated males. Our results show that heptanal reduces pheromone sensitivity at the peripheral and central olfactory level independently of the mating status. Contrarily, heptanal-responding olfactory receptor neurons are not influenced by pheromone in a mixture, although some post-mating modulation occurs at the input of the sexually isomorphic ordinary glomeruli, where general odours are processed within the antennal lobe. The results are discussed in the context of mate localization.

The acoustic expression of stress in a songbird: Does corticosterone drive isolation-induced modifications of zebra finch calls?

Animal vocalizations convey multiple pieces of information about the sender. Some of them are stable, such as identity or sex, but others are labile like the emotional or motivational state. Only a few studies have examined the acoustic expression of emotional state in non-human animals and related vocal cues to physiological parameters. In this paper, we examined the vocal expression of isolation-induced stress in a songbird, the zebra finch (Taeniopygia guttata). Although songbirds use acoustic communication extensively, nothing is known to date on how they might encode physiological states in their vocalizations. We tested the hypothesis that social isolation in zebra finches induces a rise of plasma corticosterone that modifies the vocal behavior. We monitored plasma corticosterone, as well as call rate and acoustic structure of calls of males in response to the playback of female calls of varied saliences (familiar versus stranger) in two situations: social isolation and social housing. Social isolation induced both a rise in plasma corticosterone, and a range of modifications in males' vocal behavior. Isolated birds showed a lower vocal activity, an abolition of the difference of response between the two stimuli, and evoked calls with longer duration and higher pitch. Because some of these effects were mimicked after oral administration of corticosterone in socially housed subjects, we conclude that corticosterone could be partly responsible for the isolation-related modifications of calls in male zebra finches. To our knowledge, this is the first demonstration of the direct implication of glucocorticoids in the modulation of the structure of vocal sounds.