Mating Events Research Articles

Characterization of HSP70 expression in drones of Apis cerana (Hymenoptera: Apidae)

• The full-length HSP70 gene of the Eastern honeybee Apis cerana was cloned. • The expression patterns of the HSP70 gene in drones at different developmental stages and ages were investigated. • The expression levels of the HSP70 gene in drones at different reproductive statuses were analyzed. Heat shock proteins (HSPs) constitute a superfamily of molecular chaperones that are rapidly biosynthesized in response to various biotic and abiotic factors. In this study, we first cloned the full-length HSP70 gene of the Eastern honeybee Apis cerana . Then, using real-time quantitative PCR, we explored HSP70 expression profiles in drones at different developmental stages, ages, and reproductive statuses (with and without semen). The full-length HSP70 cDNA is 2421 bp, including a 1953-bp open reading frame (ORF) that encodes a polypeptide of 650 amino acids. The HSP70 gene consists of one intron and two exons. The phylogenetic analysis revealed that the HSP70 genes of A. cerana and Apis mellifera are the most closely related. We observed HSP70 expression at all selected developmental stages and detected the highest expression in pupae with an unpigmented body cuticle and brown eyes (Pb) and much lower expression in larvae hatched within 72 h. In adult drones of different ages, the highest expression level of HSP70 was observed in 16-day-old drones; significantly lower accumulation of HSP70 mRNA was detected in 4-day-old drones. There was no significant difference in HSP70 expression between drones with and without semen captured at the entrance, while the HSP70 gene expression level strikingly differed between drones captured at the entrance and the drones collected within the hive. Our study suggests that HSP70 might play a critical role in drone development and during reproductive mating events.

Limited-Distance Pollen Dispersal and Low Paternal Diversity in a Bird-Pollinated Self-Incompatible Tree.

Bird pollination in Asia is regarded as an uncommon phenomenon and, therefore, only a few investigations on mating pattern and paternity in fruits of Asian bird-pollinated plants have been conducted. Here, we examined spatial genetic structure, pollen dispersal, and multiple paternity in a natural population of Bombax ceiba (B. ceiba) (Malvaceae) in Hainan Island, South China, using simple sequence repeat (SSR) markers. A low genetic diversity (He = 0.351 ± 0.0341 and 0.389 ± 0.043, respectively, for adults and offspring) and bottleneck effects were observed. Genetic kinship was significant within 400 m or in 1,800–3,800 m. Both the mating pattern and paternity analysis confirmed obligate xenogamy and a low multiple paternity in B. ceiba. There was a strongly negative relationship between the frequency of matings and the distance between mating pairs. The average pollen dispersal distance was 202.89 ± 41.01 m (mean ± SE) and the farthest distance of > 1 km was recorded. Realized mating events showed an extremely leptokurtic distribution within 1,200 m, suggesting that the pollen dispersal distance was consistent with the optimal foraging theory of generalist birds such as Zosterops spp. and Pycnonotus spp. Paternity per tree ranged from two to six and the average effective number of pollen donors per maternal plant was 3.773, suggesting a low level of paternity diversity as compared to other bird-pollinated plants. We concluded that optimal foraging behavior by generalist birds could explain the leptokurtic pollen dispersal distribution and predominantly near-neighbor matings in B. ceiba. The limited pollen dispersal distance and low multiple paternity were consistent with low fruit setting rate (3.27 ± 0.93%) in this self-incompatible tree, which was caused mainly by the restricted flight distance of birds and human disturbances. Low genetic diversity and significant spatial genetic structure might have largely resulted from logging and human collection of fruits.

YeastMate: neural network-assisted segmentation of mating and budding events in Saccharomyces cerevisiae.

SummaryHere, we introduce YeastMate, a user-friendly deep learning-based application for automated detection and segmentation of Saccharomyces cerevisiae cells and their mating and budding events in microscopy images. We build upon Mask R-CNN with a custom segmentation head for the subclassification of mother and daughter cells during lifecycle transitions. YeastMate can be used directly as a Python library or through a standalone application with a graphical user interface (GUI) and a Fiji plugin as easy-to-use frontends. Availability and implementationThe source code for YeastMate is freely available at https://github.com/hoerlteam/YeastMate under the MIT license. We offer installers for our software stack for Windows, macOS and Linux. A detailed user guide is available at https://yeastmate.readthedocs.io.Supplementary information Supplementary data are available at Bioinformatics online.

Axenic interspecies and intraclonal hybrid formation in Leishmania: Successful crossings between visceral and cutaneous strains.

Diseases caused by trypanosomatids are serious public health concerns in low-income endemic countries. Leishmaniasis is presented in two main clinical forms, visceral leishmaniasis—caused by L. infantum and L. donovani—and cutaneous leishmaniasis—caused by many species, including L. major, L. tropica and L. braziliensis. As for certain other trypanosomatids, sexual reproduction has been confirmed in these parasites, and formation of hybrids can contribute to virulence, drug resistance or adaptation to the host immune system. In the present work, the capability of intraclonal and interspecies genetic exchange has been investigated using three parental strains: L. donovani, L. tropica and L. major, which have been engineered to express different fluorescent proteins and antibiotic resistance markers in order to facilitate the phenotypic selection of hybrid parasites after mating events. Stationary and exponential-phase promastigotes of each species were used, in in vitro experiments, some of them containing LULO cells (an embryonic cell line derived from Lutzomyia longipalpis). Several intraclonal hybrids were obtained with L. tropica as crossing progenitor, but not with L. donovani or L. major. In interspecies crossings, three L. donovani x L. major hybrids and two L. donovani x L. tropica hybrids were isolated, thereby demonstrating the feasibility to obtain in vitro hybrids of parental lines causing different tropism of leishmaniasis. Ploidy analysis revealed an increase in DNA content in all hybrids compared to the parental strains, and nuclear analysis showed that interspecies hybrids are complete hybrids, i.e. each of them showing at least one chromosomal set from each parental. Regarding kDNA inheritance, discrepancies were observed between maxi and minicircle heritage. Finally, phenotypic studies showed either intermediate phenotypes in terms of growth profiles, or a decreased in vitro infection capacity compared to the parental cells. To the best of our knowledge, this is the first time that in vitro interspecies outcrossing has been demonstrated between Leishmania species with different tropism, thus contributing to shed light on the mechanisms underlying sexual reproduction in these parasites.

Consequences of nescient mating: Artificial insemination increases cub rejection in the giant panda (Ailuropoda melanoleuca)

Artificial insemination (AI) is a valuable tool for conservation breeding programs as it can promote reproductive success and genetic diversity in species with decreasing populations. However, females that undergo AI do not experience natural mating events, which we term, “nescient mating.” Thus, these females would not be able to assess the quality of their mate through physical, olfactory, or visual cues. Previous research has found that AI can lead to diminished breeding outcomes when compared to natural mating. In this study, we investigated whether fertilization method (natural mating versus AI) affects postpartum behaviors, such as cub rejection and maternal care in female giant pandas. We analyzed data from 202 cubs and 43 mother-cub dyads between 1996 and 2018. We did not find a difference in gestation length, cub weight, or cub survivorship between naturally mated and artificially inseminated females. Compared to naturally inseminated females, artificially mated females were significantly more likely to reject cubs (p = 0.039). Contrary to what we had predicted, maternal care and infant behaviors during the first month did not differ between natural mating and AI groups. Taken together, our results indicate that female giant pandas who experienced nescient mating may have reduced offspring investment, manifest in increased cub rejection. However, the lack of behavioral differences between AI and natural mating groups was encouraging, indicating that once a female accepted a cub to rear, maternal care was adequate to ensure cub survival. Nonetheless, we recommend that conservation breeding programs prioritize natural mating as higher rates of maternal rejection increase the facility and human time cost of cub rearing and also the chances of detrimental downstream effects on offspring adult behaviors in the giant panda.

Sperm Numbers as a Paternity Guard in a Wild Bird.

Sperm competition is thought to impose strong selection on males to produce competitive ejaculates to outcompete rival males under competitive mating conditions. Our understanding of how different sperm traits influence fertilization success, however, remains limited, especially in wild populations. Recent literature highlights the importance of incorporating multiple ejaculate traits and pre-copulatory sexually selected traits in analyses aimed at understanding how selection acts on sperm traits. However, variation in a male’s ability to gain fertilization success may also depend upon a range of social and ecological factors that determine the opportunity for mating events both within and outside of the social pair-bond. Here, we test for an effect of sperm quantity and sperm size on male reproductive success in the red-back fairy-wren (Malurus melanocephalus) while simultaneously accounting for pre-copulatory sexual selection and potential socio-ecological correlates of male mating success. We found that sperm number (i.e., cloacal protuberance volume), but not sperm morphology, was associated with reproductive success in male red-backed fairy-wrens. Most notably, males with large numbers of sperm available for copulation achieved greater within-pair paternity success. Our results suggest that males use large sperm numbers as a defensive strategy to guard within-pair paternity success in a system where there is a high risk of sperm competition and female control of copulation. Finally, our work highlights the importance of accounting for socio-ecological factors that may influence male mating opportunities when examining the role of sperm traits in determining male reproductive success.

Notes from rusty patched bumble bee (Bombus affinis Cresson) nest observations

Abstract The rusty patched bumble bee, Bombus affinis, is federally endangered in the United States and Canada. Information on natural history is crucial to conservation planning, but little is known about B. affinis nesting biology, habitat, overwintering, and mating behaviours. We report observations on three B. affinis nests in Minnesota and Wisconsin found in 2020. Previous to this report, there were only four published descriptions of B. affinis nests, with the last nest recorded nearly 30 years ago. Here, we share findings on nesting habitat, nest size, mating behaviours, and nest parasites. The nests were located in between the foundation and a layer of insulation in an urban residence, in an urban backyard near a house foundation, and in a degraded semi‐wooded, riparian natural area. Colony size estimates ranged from 251 to 1341 bees. We observed males chasing gynes near a nest entrance and one mating event approximately 5 m from the nest. We documented the chalcid wasp, Melittobia acasta, as a new host association. These observations increased the known colony size range, documented a new host association, and indicate the potential importance of urban and degraded habitats for recovery of the endangered rusty patched bumble bee.

Sperm Storage Costs Determine Survival and Immunocompetence in Newly Mated Queens of the Leaf-Cutting Ant Atta colombica

In the leaf-cutting ant Atta colombica, queens receive ejaculates from multiple males during one single mating event early in their lives. A queen’s fertility and fitness therefore depend on maximizing the number of sperm cells she can store and maintain inside her spermatheca. Previous studies implied significant physiological mating costs, either originating from energetic investments maximizing sperm survival, or from resolving sexual conflicts to terminate male-driven incapacitation of rival sperm via serine proteases found in seminal fluid. Here we conducted an artificial insemination experiment, which allowed us to distinguish between the effects of sperm and seminal fluid within the queen’s sexual tract on her survival and immunocompetence. We found significantly higher mortality in queens that we had inseminated with sperm, independently of whether seminal fluid was present or not. Additionally, after receiving sperm, heavier queens had a higher probability of survival compared to lightweight queens, and immunocompetence decreased disproportionally for queens that had lost weight during the experiment. These findings indicate that queens pay significant physiological costs for maintaining and storing sperm shortly after mating. On the other hand, the presence of seminal fluid within the queens’ sexual tract neither affected their survival nor their immunocompetence. This suggests that the energetic costs that queens incur shortly after mating are primarily due to investments in sperm maintenance and not costs of terminating conflicts between competing ejaculates. This outcome is consistent with the idea that sexually selected traits in social insects with permanent castes can evolve only when they do not affect survival or life-time fitness of queens in any significant way.

Species and Metabolic Pathways Involved in Bioremediation of Vietnamese Soil From Bien Hoa Airbase Contaminated With Herbicides

Four bacterial strains were isolated from enrichment cultures inoculated with soil from Bien Hoa military base in Vietnam contaminated with the herbicides 2,4-dichlorophenoxyacetate (2,4-D) and 2,4,5-trichlorophenoxyacetate (2,4,5-T). They were classified as Pseudomonas aeruginosa BT1 2.2, Sphingomonas histidinilytica BT1 5.2, Bordetella petrii BT1 9.2, and Achromobacter xylosoxidans BT1 10.2. All four were able to degrade 2,4-D and 2,4,5-T, but only the last three species used them as the sole sources of carbon and energy. Mass balance analyses suggest that between 33 and 46% of the carbon in the herbicides is incorporated into dry weight (DW). We obtained insight into their degradation pathways by the genomic analysis of these strains. A tfdCDEF gene cluster was found in A. xylosoxidans BT1 10.2 with amino acid sequences of their gene products showing high identity to those in B. petrii DSM12804. Bordetella petrii BT1 9.2 has a full complement of the tfdABCDEF genes. Surprisingly, the gene organization along with the amino acid sequences of the gene products are virtually identical to those of Cupriavidus pinatubonensis JMP134, referred to as type I tfd genes, and different from those of A. xylosoxidans BT1 10.2 and B. petrii DSM12804. We hypothesize that some of the genetic potential to degrade the herbicides has been recruited in recent mating events between these species and other members of the proteobacteria. This is the first report showing that B. petrii BT1 9.2 emerges as a key player in the degradation of 2,4-D.

Observations on mating in Mediterranean Sepiola and Sepietta species and review of mating behaviour in Sepiolinae (Cephalopoda: Sepiolidae)

Mating was observed and described in captive individuals of Sepiola affinis, Sepiola intermedia and Sepietta obscura (Cephalopoda: Sepiolidae) collected in the Catalan Sea, western Mediterranean Sea. This is the first report of a mating event in S. intermedia; it is also the first detailed description of the mating behaviour for the other two species. The published literature on mating in Sepiolinae, which includes both cursory reports and in-depth descriptions of mating events, was thoroughly reviewed. In all, copulation has been examined in eight species belonging to four different genera, namely, Eumandya, Euprymna, Sepietta and Sepiola, starting from 1894 to the present. Common traits of the mating behaviour were detected among the studied sepioline species, so that a general five stages succession of actions is established to portray the mating progress in Sepiolinae: (A) female hovers by, male attention (it is discussed whether actual copulation is preceded by any courtship); (B) male approaches female from below; (C) male grasps female at the neck by its third arms, inserts its first arms in the female’s mantle cavity (the hectocotylised left arm is thus aligned with the bursa copulatrix), holds the female’s mantle by its second arms and positions itself and mate in the “parallel position”; (D) copulation and transfer of spermatophores from male to female (this stage may last from 3 min to 3 h); (E) mating dissolution. Mating occurs preferentially during the dark hours; it is described as violent and the female tries to escape the forceful grasp by the male; the male skin coloration turns darker. The similarity of the mating behaviour in all examined sepioline species is an evidence of both its evolution in harmony with their copulatory organs (hectocotylus and bursa copulatrix) and, seemingly, its common derivation to the whole Sepiolinae clade.

Habitat use and behavioral patterns of Cassin's Kingbird (Tyrannus vociferans) in an urban park of Mexico City

Changes in vegetation structure and species composition affect habitat use and behavior in most bird species by altering the distribution and abundance of their resources. We explore how the mating and foraging behavior of Cassin's Kingbirds (Tyrannus vociferans) varies by habitat type within a 2,450 ha urban park in Mexico City. The study site includes primarily water bodies, riparian vegetation, willow and Montezuma cypress stands, maize fields, and grasslands. We recorded kingbird behavior twice a week along 21 transects throughout 2012 and 2015. Courtship and reproductive behaviors were displayed in autumn (Sep) and early winter (Dec). Intraspecific agonistic behaviors were associated with courtship and mating events, particularly in 2015. Cassin's Kingbird generally favored open vegetation. The main foraging strategy in open habitats was flycatching but foliage gleaning became frequent when mistletoe plants produced fruits in infested willow stands. The use of mistletoe fruits, presumably a secondary diet item, coincided with the breeding season. In addition to these observations, our study is the first report of Cassin's Kingbird winter mating at low latitudes.

Habitat use and behavioral patterns of Cassin's Kingbird (Tyrannus vociferans) in an urban park of Mexico City

Changes in vegetation structure and species composition affect habitat use and behavior in most bird species by altering the distribution and abundance of their resources. We explore how the mating and foraging behavior of Cassin's Kingbirds (Tyrannus vociferans) varies by habitat type within a 2,450 ha urban park in Mexico City. The study site includes primarily water bodies, riparian vegetation, willow and Montezuma cypress stands, maize fields, and grasslands. We recorded kingbird behavior twice a week along 21 transects throughout 2012 and 2015. Courtship and reproductive behaviors were displayed in autumn (Sep) and early winter (Dec). Intraspecific agonistic behaviors were associated with courtship and mating events, particularly in 2015. Cassin's Kingbird generally favored open vegetation. The main foraging strategy in open habitats was flycatching but foliage gleaning became frequent when mistletoe plants produced fruits in infested willow stands. The use of mistletoe fruits, presumably a secondary diet item, coincided with the breeding season. In addition to these observations, our study is the first report of Cassin's Kingbird winter mating at low latitudes.

Courtship and underwater communication in the Sunda gharial (Tomistoma schlegelii)

ABSTRACT Many threatened crocodilians are shy and difficult to observe in the wild, limiting the current knowledge of their behaviour and ecology. Although acoustic communication is commonly used by adults during courtship and territory defence, the signals produced vary between taxa. Here we provide the first classification of adult vocalisations in Tomistoma schlegelii – a rare gavialid inhabiting swamp forests in Southeast Asia – and describe the behaviour produced during courtship. Using video and passive underwater acoustic monitoring we recorded a breeding captive pair of T. schlegelii housed indoors, as well as monitored 12 captive adults kept in a semi-natural outdoor enclosure over a period of two months. Courtship behaviour during 18 recorded mating events followed that observed in other crocodilians, but acoustic signals were restricted to mating activity and were only recorded in the two animals housed indoors. We identified seven signal types produced by T. schlegelii, which differed in duration, dominant frequency, and the presence of harmonic structure. These results suggest the species uses short-range, underwater acoustic signals during courtship and mating, with little vocal activity outside of those events, and provide foundation for future studies of this rare crocodilian.

First Observation of Pregnancy and Parturition in a Captive Pantropical Spotted Dolphin (Stenella attenuata)

A female pantropical spotted dolphin (Stenella attenuata) successfully mated with a mature male in captivity on April 13, 2017. This mating event was followed by an evaluation of the plasma progesterone concentration, appetite, and rectum temperature of the dolphin during pregnancy. We recorded the progesterone profiles during pregnancy, the gestation period, and the parturition events. The progesterone level (ng/mL) ranged between 0.7 and 133.4 (n = 27), and the average was 45.1 (SD = 38.5). Immediately after mating, extremely high progesterone levels were observed, which showed a decreasing trend towards the parturition day. The gestation period was 352 days. On the morning of the parturition day on March 31, the female displayed symptoms such as a drop in rectal temperature by approximately 1°C and reduced appetite. The time from the first observation of vaginal discharge to the fluke's appearance was 5.5 hr, while the subsequent period until birth was 4 hr in length. The time from parturition to the first successful nursing was approximately 4 hr, while the time from the nursing to the placental passage was less than 1 hr. To the best of our knowledge, this is the first report on the pregnancy period of pantropical spotted dolphins in captivity.

The impact of declining dairy fertility on calving patterns and farm systems: A case study from northern Victoria, Australia

CONTEXTFertility is crucial for pasture-based seasonal calving dairy herds, where cows are expected to calve in a single cohort at a time when peak milk production coincides with maximum pasture availability. However, dairy fertility has declined globally, and many Australian herds now use a split calving system, where non-pregnant cows are given additional opportunities to conceive by having two mating periods per year. Other factors prompting a move to split calving may include financial incentives for producing out-of-season milk, increasing levels of concentrate feeding, and pressure due to extreme seasonal conditions – all of which are particularly apparent in the northern Victorian irrigation region. OBJECTIVEThe aim of our study was to describe the fertility and herd characteristics of the study population and to examine changes in reproductive performance and calving systems that have occurred over the same period. METHODSOur study population included 38 herds from the northern Victorian irrigation region in Australia. We collected individual cow records from each herd from the date on which they started herd recording (with a median start year of 2000 for mating event data) up until December 2016, comprising both fertility-related data such as insemination records, calving dates, and pregnancy test results, and systems-related data such as production, herd size and calving pattern. RESULTS AND CONCLUSIONSFrom a relatively small number of herds, we were able to obtain a dataset comprising 438,578 mating and pregnancy test records for 86,974 cows. From 2003 to 2016, 6-week in-calf rate and first service conception rate declined in the study population for both Holstein-Friesians and Jerseys, while 3-week submission rate remained unchanged. At the same time, the proportion of split calving herds in our cohort markedly increased, with a significant expansion in herd size compared to their seasonal counterparts. The proportion of first parity heifers in herds also increased, which may be a function of increasing herd size, or involuntary culling due to poor fertility. SIGNIFICANCESplit calving represents a significant system change for herd managers, with concomitant effects on labour management, input costs, and the lifestyle they experience. However, if this change has been implemented due to poor fertility without considering whether the increased income outweighs increased input costs, then a suboptimal decision may have been made. Finally, high quality data remains underutilised on individual farms, with significant benefits to the Australian dairy industry if we can overcome the numerous challenges to access it.

Sexual selection in a tropical toad: Do female toads choose brighter males in a species with rapid colour change?

AbstractConspicuous visual signals play an important role in animal communication, both within and between species. Bright, colourful signals allow animals to discriminate between individuals and can inform behavioural decisions and social interactions. In many instances, conspicuous colouration appears to have evolved through sexual selection via female mate choice or male–male competition. Male Neotropical yellow toads, Incilius luetkenii, display bright‐yellow colouration during their brief explosive mating events and then revert to a cryptic, female‐like, brown colour following amplexus and fertilization. Recent research has revealed that the yellow colouration of males may serve as a sex identification signal and that males remain yellow in the presence of both males and females but darken without conspecific stimulus. However, there is considerable variation in the brightness of yellow colouration in courting males, ranging from dull olive‐green to vibrant lemon‐yellow. The function of this variation remains unknown. In this study, we conducted two‐choice model presentation trials to test one mechanism of sexual selection that may drive this variation: intersexual selection. Specifically, we set out to determine whether females differentiate between males based on their colouration. We presented females with two hyper‐realistic robotic model toads, with one model painted to match a bright‐yellow male and the other a dull‐yellow male. Using several metrics of choice, we found that females did not show a preference for bright or dull colouration. Our research suggests that variation in the intensity of male breeding colouration is not driven by female choice in this species. Our study is consistent with the idea that there may be limited opportunity for female choice to influence male‐trait expression in explosive breeders. Future research will address whether intrasexual selection may influence colour variation in male yellow toads.

Close-range cues used by males of Polistes dominula in sex discrimination.

Sexual pheromones are chemical molecules responsible for mediating sex recognition and mating events. Long- and close-range sexual pheromones act differently. The first type is released to attract potential partners, whereas the second coordinates the interactions after potential mating partners encounter each other. Cuticular hydrocarbons (CHCs) have been suggested to be important cues in the mating systems of several Hymenoptera species, although empirical data are still lacking for many species. Here, we evaluated whether males of the model species Polistes dominula can differentiate the sex of individuals based on their CHC composition. In August 2019, several post-worker emergent nests (n = 19) were collected in the vicinity of Leuven (Belgium) and taken to the lab (KU Leuven), where newly emerged females and males were sampled, marked individually, and kept in plastic boxes for at least a week before being used in the mating trials. Focal males were paired with females and males from different nests and subjected to five different conditions: (I) alive, (II) dead, (III) CHCs washed, (IV) CHCs partially returned, and (V) CHCs from the opposite sex. We videotaped the interactions for 10min and analysed the duration and different behavioural interactions of the focal male. Our results indicate that CHCs may be used by males as cues to recognise a potential mating partner in P. dominula, since the focal males displayed specific courtship behaviours exclusively toward females. Although we cannot exclude that visual cues could also be used in combination with the chemical ones, we empirically demonstrate that CHCs may be important to convey sexual information at close range in mating systems, allowing fast decisions toward potential sexual partners or rivals.

Behavioral changes in the brown planthopper, Nilaparvata lugens, mediated by melatonin

BackgroundMelatonin has been proved to exist and play importance roles in rice plant, such as biosynthesis and resistance. However, little is known about the function of melatonin in its monophagous pest, the brown planthopper.MethodsIn this study, we examined the effects of melatonin on the copulatory and locomotor behaviors of brachypterous and macropterous adult planthoppers by exposing them to melatonin, luzindole (a melatonin receptor antagonist), or a combination of melatonin and luzindole.ResultsA total of 68.7% of copulation events occurred at night in the control, while 31.2% occurred at night in the melatonin treatment, which led to a decrease in offspring. Brachypterous males were involved in mating events in the melatonin treatment but not in the other two treatments or the control. The daily locomotor pattern in the melatonin treatment was markedly different from that in the luzindole and melatonin and luzindole treatments. The total locomotor activities of the macropterous and brachypterous males exposed with melatonin were suppressed compared to those in the control. Melatonin significantly decreased the daytime and nighttime locomotor activities of macropterous females. In comparison, the activity of brachypterous females decreased slightly in the daytime but was more than double that of the control females at night.ConclusionsOur results reveal that melatonin plays a role in the behaviors of brown planthoppers.

Body scarring as an indicator of social function of dugong (Dugong dugon) tusks

AbstractThe fully aquatic lifestyle of dugongs means that direct observation of social tusk use is not usually possible. This study used body scarring as an indicator of tusk function by males. Tusk rake scars on 298 live wild dugongs, of both sexes and all sizes, were categorized and counted in over 1,000 photographs, and examined in relation to maturity and reproductive activity over seasons. All dugongs had tusk scars, but adults were the main recipients. Sexually active adults acquired the greatest number of fresh tusk wounds during the mating season. Subadults received fresh rakes at similar numbers year‐round. Adult males had more scars on the mid and posterior dorsum, indicating that males direct combative force to these regions of the male body when competing for females. Adult females had heaviest scarring and more tusk puncture wounds on the anterior‐mid dorsum and head, suggesting that male dugongs use tusks in sexual coercion. Heavy scarring sustained by solitary calves compared to dependent ones, suggests that mothers afford some protection. Body scarring caused by tusks may serve as an indicator of reproductive contribution of the recipients, providing that successful males are involved in more reproductive competitions, and successful females in more mating events.

Sexual behavior of Diplura macrura and Ischnothele annulata (Araneae: Mygalomorphae): further evidence of diplurid polyphyly

The Dipluridae (Araneae: Mygalomorphae) is a recently redefined spider family of funnel-web spinners. Diplurid biology is poorly studied, especially regarding their sexual behavior, which is largely unknown for neotropical species. Diplura macrura (C.L. Koch, 1841) (Dipluridae) and Ischnothele annulata Tullgren, 1905 (Ischnothelidae) are medium-sized traditional diplurids from Brazil. We describe the courtship and mating behavior of these two species in detail, based on seven mating events under laboratory conditions observed for D. macrura and 10 for I. annulata. Both sexes of both species present courtship behaviors, and two novel spider sexual behaviors are described for I. annulata males (insertion lifting and post-brushing). Evidence for copulatory courtship is further observed for I. annulata. These sexual behaviors are analyzed and their importance is discussed in a phylogenetic context. Observed behaviors support the hypothesis of diplurid polyphyly, with Dipluridae closely related to Crassitarsae (Theraphosidae, Barychelidae, Nemesiidae, Cyrtaucheniidae and Microstigmatidae) and phylogenetically distant from Ischnothelidae. Additional biological information on both species is provided.