Abstract: Recent debate has highlighted the importance of estimating both the strength of sexual selection on phenotypic traits, and the opportunity for sexual selection. We describe seasonal fluctuations in mating dynamics of Leptinotarsa undecimlineata (Coleoptera: Chrysomelidae). We compared several estimates of the opportunity for, and the strength of, sexual selection and male precopulatory competition over the reproductive season. First, using a null model, we suggest that the ratio between observed values of the opportunity for sexual selections and their expected value under random mating results in unbiased estimates of the actual nonrandom mating behavior of the population. Second, we found that estimates for the whole reproductive season often misrepresent the actual value at any given time period. Third, mating differentials on male size and mobility, frequency of male fighting and three estimates of the opportunity for sexual selection provide contrasting but complementary information. More intense sexual selection associated to male mobility, but not to male size, was observed in periods with high opportunity for sexual selection and high frequency of male fights. Fourth, based on parameters of spatial and temporal aggregation of female receptivity, we describe the mating system of L. undecimlineata as a scramble mating polygyny in which the opportunity for sexual selection varies widely throughout the season, but the strength of sexual selection on male size remains fairly weak, while male mobility inversely covaries with mating success. We suggest that different estimates for the opportunity for, and intensity of, sexual selection should be applied in order to discriminate how different behavioral and demographic factors shape the reproductive dynamic of populations.
Abstract: Phylogenetic relationships within the Sclerosomatidae, the largest family of harvestmen, are
explored using molecular data from four nuclear genes (28S and 18S rRNA, Histone 3 and Elongation factor-1α) and two mitochondrial gene regions (COI-COII, 16S and 12S rRNA). The taxon sample includes representative species from all families in Phalangioidea and all subfamilies of Sclerosomatidae (Gagrellinae, Gyinae, Leiobuninae, Sclerosomatinae). Our results solve several major taxonomic problems, including placement of Gyinae sensu stricto in Phalangiidae, the monophyly of the Metopilio group and its exclusion from Sclerosomatidae, and reaffirmation of the familial rank of Protolophidae. However, most major groups of sclerosomatids (Leiobuninae, Gagrellinae, Leiobunum, Nelima) are recovered as polyphyletic, although with a phylogenetic structure suggesting a strong association between geography and monophyly as well as notable morphological convergence in traditional diagnostic characters. Phylogenetic affinities between biotas of the New World and Asian tropics, as well as between temperate North American and East Asia, suggest that sclerosmatid historical biogeography may conform with the Boreotropic Concept. Finally, we discuss how the many problems that remain in sclerosomatid systematics might be addressed.
Abstract: Theory predicts that asymmetry between contenders influences their ability to defend resources. More recently, some theoretical approaches have also examined the circumstances that might promote sharing of the disputed resources. We tested these hypotheses in males of the ball roller beetle Canthon cyanellus cyanellus . Males fight for possession of a food ball, which is a vital resource used for nesting. We evaluated the role of food resource ownership, body size and reproductive status on the outcome of contests (win, lose or share) between males that rolled a food ball (owners or finders) either alone or with a female partner, when faced with male intruders (or joiners). Large owners of a food ball had a higher probability of victory than small intruders, and small owners had a high probability of losing when faced with large intruders. The reproductive status of both contenders also influenced their chances of winning: previously mated owners of a food ball had a higher probability of winning than virgin owners. Males of a similar size tended to split the food ball, thereby sharing the resource. Our results suggest that competitors may adjust the intensity of their aggression depending at least on their own resource holding power (RHP), the value of the resource in dispute and perhaps even the RHP of their opponents. Sharing the food ball emerges as a fresh solution between similarly matched contestants.
Abstract: Intense maleâmale competition for females may drive the evolution of male morphological dimorphism, which is frequently associated with alternative mating tactics. Using modern techniques for the detection of discontinuous allometries, we describe male dimorphism in the Neotropical harvestman Longiperna concolor , the males of which use their elongated, sexually dimorphic legs IV in fights for the possession of territories where females lay eggs. We also tested three predictions related to the existence of alternative mating tactics: (1) if individuals with relatively longer legs IV (majors) are more likely to monopolize access to reproductive resources, they are expected to remain close to stable groups of females more than individuals with relatively shorter legs IV (minors) do; (2) if minors achieve fertilization by moving between territories, they are expected to be less faithful to specific sites; and (3) majors should be observed in aggressive interactions more often. We individually marked all the individuals from a population of Longiperna during the reproductive season and recorded the location of each sighting for males and females as well as the identity of males involved in fights. Majors were more likely to have harems, and large majors were even more likely to do so. Majors were more philopatric and all males involved in fights belonged to this morph. These results strongly suggest that the mating tactic of the majors is based on resource defense whereas that of the minors probably relies on sneaking into the territories of the majors and furtively copulating with females.
Abstract: Alternative male phenotypes may be a source of novel adaptive traits and may evolve under strong sexual selection. We studied interpopulation differences in male mating behavior related to receptive female synchrony in the monandrous pupal-mating butterfly Heliconius charitonia. In the population in which female-receptive pupae were more synchronous, larger males were unable to monopolize mates; variance in male mating success was lower; strength of sexual selection was weak; and all males competed for access to female pupae using the same strategy (pupal mating). In the population where no more than one female was receptive at a time (extreme asynchrony), only large males competed for pupae, and among these, only the largest individuals successfully mated. Thus, variance in mating success was higher, and sexual selection within pupal maters was stronger. In this population, smaller males patrolled large areas as an alternative mating behavior. When unmated females were experimentally released, small male size was associated with higher mating success. We suggest that alternative patrolling behavior may have evolved under strong sexual selection as a consequence of high asynchrony in receptive female availability in some populations.
Abstract: The lines of defense in the harvestman Hoplobunus mexicanus are reported including the complete chemical characterization of defensive secretion, a morphological description of the ozopore, and a spectrogram of stridulating sounds. Aposematic coloration may be regarded as the first line of defense, warning diurnal predators about the unpleasant attributes of the chemical secretion. At night, the aposematic coloration is probably not efficient and, if an individual is seized by a predator, thanatosis or stridulation can be used as second lines of defense. The last line of defense is the use of chemical irritants. The defensive secretion is a mixture of two compounds: 2-methyl-5-ethylphenol and 2,5-dimethylphenol. Whereas the anterior half of the ozopore is ornamented with many sharp projections, the posterior half is smooth and membranous, probably causing the secretion to flow only to the lateroposterior area of the body. The biological meaning of each defensive mechanism and the type of stimuli that triggers each of them is discussed.
Abstract: The tropical damselfly Paraphlebia zoe has two male morphs: a black-winged (BW) male which is associated with territorial defense of oviposition sites; and a hyaline-winged (HW) male similar in appearance to females, and, compared to the black morph, less frequently found defending territories. In a wild population of this species, we first assessed the relationship between phenotypic traits [male morph, size and territorial status (being territorial or non-territorial)], their role on mating success, and the degree to which a particular territory may contribute to male mating success. Second, to relate a physiological basis of being territorial we compared both morphs in terms of muscular fat reserves and thoracic muscle, two key traits related to territory defense ability. Males of both morphs defended territories although the BW males were more commonly found doing this. BW males were larger than HW males and size predicted being territorial but only within HW males (territorial males were larger) but not in BW males. Male mating success was related to territorial status (territorial males achieved a higher mating success), but not to morph or size. Furthermore, territory identity also explained mating success with some territories producing more matings than others. The BW morph stored more fat reserves which may explain why this morph was more likely to secure and defend a place than the HW morph. However, the HW morph showed higher relative muscle mass which we have interpreted as a flexible strategy to enable males to defend a territory. These results are distant to what has been found in another male dimorphic damselfly, Mnais pruinosa , where the advantage of the non-territorial morph relies on its longevity to compensate in mating benefits compared to the territorial morph.
Abstract: Males and females of two syntopic phytophagous fly species (O. nitens and O. ferruginea, Diptera: Richardiidae) compete over small ephemeral feeding territories. We assessed fight frequency of both sexes of two species in the wild, and the simultaneous effects of potential fight asymmetries, sex and species, on the outcome of territorial contests in relation with resident status. Our results showed that residents won most of the fights, although the proportion of fights won by the resident depended on the sex of the resident, the interaction between the sex of the resident and size, and the year. Furthermore, even though some combinations of species and sex categories could be found on the same tree more than expected by chance, this did not imply a significantly high fight frequency for such combinations.
Abstract: The evolution of sexually dimorphic traits has been the focus of much theoretical work, but empirical approaches to this topic have not been equally prolific. Males of the neotropical family Gonyleptidae usually present a strong fourth pair of legs armed with spines, but their functional significance is unknown. We investigated the putative functions of the leg armature in the harvestman Neosadocus maximus. Being a non-visual species, the spines on male legs can only be perceived by females through physical contact. Thus, we could expect females to touch the armature on the legs of their mates if they were to evaluate it. However, we found no support for this hypothesis. We did show that (1) leg armature is used as a weapon in contests between males and (2) spines and associated sensilla are sexually dimorphic structures involved in ânipping behaviorâ, during which a winner emerged in most fights. Finally, we demonstrate that five body structures directly involved in maleâmale fights show positive allometry in males, presenting slopes higher than 1, whereas the same structures show either no or negative allometry in the case of females. In conclusion, leg armature in male harvestmen is clearly used as a device in intrasexual contests.
Abstract: Males of the subfamily Belostomatinae, within the giant waterbugs (Hemiptera: Belostomatidae), brood eggs on their backs from oviposition until egg-hatching. The eggs in the clutch must be kept moistened and exposed to enough oxygen flow for them to develop properly and maximize hatching success. When submerged, males regularly perform different behavioral patterns that promote oxygen flow to the eggs. One of these patterns, brood pumping, consists of âpush-upâ like movements using their hind legs. In this study, we assessed if temperature, oxygen dissolved in the water and the developmental stage of the clutch influence brood pumping rate in Abedus breviceps. In the wild, we found that males covered with bigger eggs showed a higher brood pumping rate than that of males with smaller eggs. An analysis of egg growth curves under laboratory conditions demonstrated that males that did not perform brood pumping were carrying broods that were in the first third of their developmental period. We also found that non-brooded clutches had a much lower hatching success than those brooded by males, even when exposed to controlled and favorable environmental conditions. We discuss the persistence and modulation of paternal care intensity in belostomatines as an aptative character conditioned by environmental and anatomical features.
Abstract: In lekking species, females may become sperm-limited when mating with sexually successful males, and this may be exacerbated by a poor male diet. Polygynous males may also be limited by the amount of accessory gland products (AGPs) they can transmit to females, which in turn may influence the femalesâ refractory period and longevity. Here, we tested the effect of male mating history, larval and adult diet on copula duration, mating intervals, female fecundity, fertilisation success, life span and likelihood to remate using sexually successful males of the lekking tephritid fly Anastrepha obliqua. Flies originated from either a native or exotic host fruit and were protein-fed or deprived. Male diet and larval host influenced copula duration, while the time elapsed between matings was affected by the interaction of mating order and male adult diet. Female fecundity was not influenced by female position in mating order or protein inclusion into the male diet. However, mating order and male larval diet influenced female fertilisation success. Importantly, as males mated successively they were less able to induce a refractory period on females, as the last females to mate with a male were more likely to remate and had slightly longer life spans than the first females to mate with males. These results might be attributed to a decrease in male AGPs with increasing male mating frequency. We discuss the role of conditional expression of male mating frequency with respect to A . obliqua âs life history, the trade-off that females face when mating with a successful male, the effect of larval diet on adult sexual performance and the possibility for sexual conflict to occur due to high male mating rates and fitness costs to females.
Abstract: * 1âBody condition (defined as the relative amount of energy reserves in the body) is an animal trait with strong ecological implications. In some animal taxa (e.g. arthropods), the external volume of the body part in which most nutrients are stored (e.g. abdomen) is used interchangeably with body mass to estimate body condition, making the implicit assumption that abdomen residual volume is a good surrogate of residual mass. However, the degree of correlation between these two measures should largely depend on the density of the nutrients stored. * 2We simulated two food-supplemented experimental groups of animals, each storing a slightly different amount of lipids either in their abdomens or in their entire bodies, and explored (i) how different estimates of condition were able to detect fixed differences between the groups; and (ii) how the amount of lipids stored could affect the outcome of non-intrusive measures of condition on a dichotomous variable (e.g. survival, mating success). We found that density body condition (body mass statistically controlled for structural body size and body volume) has much greater power to detect differences between experimental groups or effects on binary response variables than do classic mass/size or volume/size condition indices. * 3Using data on Lycosa tarantula (L.), a burrowing wolf spider, we report dramatic differences among these three indices in their ability to detect sex differences in the effect of feeding treatment on body condition at maturity. In particular, a plot of residual mass against residual volume reflecting nutrient density suggests that poorly fed spiders are nutritionally unbalanced, since well-fed spiders invest in nutrients of very different density. * 4Furthermore, using data on Scathophaga stercoraria (L.), the yellow dung fly, we found that an index of density condition was better at distinguishing condition differences among three populations than were mass or volume condition estimates alone. * 5We propose that including these three surrogates of condition (mass, volume and density) will substantially improve the accuracy of non-intrusive estimates of body condition, thus providing more powerful tools with direct application in a wide range of disciplines.
Abstract: We carried out a captureârecapture multistate modelling approach to estimate survival and recapture probabilities and transition rates between parental and nonparental status in an adult wild population of the water bug Abedus breviceps StÃ¥l, 1862 (Hemiptera: Belostomatidae). The global model included the following parameters: sex, male parental status (brooding or not), and transience (individualâs permanent movement from the site after first capture). Models were selected by means of the information-theory paradigm. The best supported model shows no difference in survival between males and females regardless of male parental status. Thus, the frequently assumed cost of parental care in terms of survival is not supported by our data. Furthermore, during the study, male expected adult life span in the wild was lower than the time needed to brood a batch of eggs from oviposition to hatching. We discuss potential consequences of such a short male expected adult life span in terms of parental behaviour decision rules related to fitness maximization.
Abstract: Golden egg bug Phyllomorpha laciniata (Heteroptera, Coreidae) females oviposit on male and female conspecifics that carry ova until they hatch. Embryos benefit from being carried because of diminished risks of predation. Female carriers are never the parents of carried eggs, and males are only rarely the fathers of any carried eggs. Eggs develop and hatch without being carried in the laboratory. Egg carriers may be viewed as victims, exploited by females that encumber them with eggs. The intensity of selection favouring resistance to egg carrying should be proportional to the costs of this behaviour. One possible cost could be a reduction in mobility caused by carried eggs. We compare movement rates among encumbered and unencumbered golden egg bugs of both sexes. Protracted copulations (often exceeding 20 h) typical of this species and mating may also cause reduction in bugs mobility. Therefore, we also evaluate rates of movement of coupled pairs of bugs. Our results indicate that egg loads do not affect the mobility and speed of either males or females. However, copulating pairs are significantly slowed as compared to single bugs. Thus protracted copulations have a clear cost in rates of movement and possibly risks of predation, but there are no apparent mobility costs for egg carrying.
Abstract: Body size is an essential variable in many behavioural and physiological studies. Previous methods for body size estimation present two conflicting drawbacks. They either (1) consider variation in only one dimension through linear measurements or (2) they are time and resource consuming, hard to apply in field conditions and/or stressful to the animal. We present a method for estimating body size, an ellipsoid approximation, which requires simple linear measurements and incorporates variation in three dimensions. The method is tested on two species of teleost fish and one species of insect. The amount of variance in mass explained by the proposed method exceeds that of previous reported methods, including the most accurate ones, that usually require expensive digitising procedures and/or stressful handling.
Abstract: Sexes and also within sex phenotypes, frequently differ in morphological traits associated with efficiency and performance in foraging and mating behaviours. In butterflies and other flying animals, phenotypic differences in wing size and traits associated with flight are involved in flight performance and individual fitness, but explorations of links among two or more traits and intrasexual differences are scarce. Foraging patterns were studied in a population of Heliconius charitonia butterflies having three phenotypes (females and two male phenotypes) which differ in their wing morphology and reproductive behaviour. As in previous studies, intersexual differences in foraging patterns were found; more interestingly, intrasexual differences were found between alternative male mating strategies. Using morphological and behavioural data, as well as data from previous flight analyses in Heliconius butterflies, we show that intrasexual differences may be explained by the energetic demands of each phenotype. Energetic expenditure is partially related to phenotypic variability in flight morphology and efficiency, and at least in both male phenotypes, differences may also be related to the energetic demands of alternative mating strategies.
Abstract: Selection usually acts differently on males and females during intrasexual competition for resources and/or mates. Nevertheless, agonistic behavior has been examined both theoretically and empirically mostly in males. Our research questions whether males and females follow the same rules of engagement in intrasexual contests as predicted by the sequential assessment model (SAM). The SAM predicts negative correlations between contest intensity and duration and the magnitude of asymmetry in resource holding power (RHP) between the contestants, such that the most escalated contests are those between similarly endowed individuals. We staged male and female intrasexual contests with varying degrees of body size asymmetry under a round robin design using the monogamous Texas cichlid fish (Herichthys cyanoguttatum) as a study case. We used Mantel's matrix analysis to compare how the behavioral content, duration, structure, and outcome of male and female contests were affected by the relative body size of the contestants. In the case of males, relative size in each contest predicted outcome, duration, and frequency of conventional and escalated behaviors according to prevailing theory. Female contest structure and outcome, however, were not predicted by the relative size of contestants. We discuss our results in terms of other asymmetries that might be important in structuring female contests, and we propose potential approaches to study femaleâfemale aggression.
Abstract: Anastrepha fraterculus (Wiedemann) is recognized as a pest of citrus, apples, and blackberries in South America. In Mexico, it is mainly found in fruit of the family Myrtaceae and has never been reported infesting citrus. Here, we sought to determine whether females stemming from Mexican A. fraterculus populations (collected in the state of Veracruz) would lay eggs in `Valencia' oranges and `Ruby Red' grapefruit and, if so, whether larvae would hatch and develop. We worked under laboratory and seminatural conditions (i.e., gravid females released in fruit-bearing, bagged branches in a commercial citrus grove) and used Anastrepha ludens (Loew), a notorious pest of citrus, as a control species. Under laboratory conditions, A. ludens readily accepted both oranges and grapefruit as oviposition substrates, but A. fraterculus rarely oviposited in these fruit (but did so in guavas, a preferred host) and no larvae ever developed. Eggs were deposited in the toxic flavedo (A. fraterculus) and nontoxic albedo (A. ludens) regions. Field studies revealed that, as was the case in the laboratory, A. fraterculus rarely oviposited into oranges or grapefruit and that, when such was the case, either no larvae developed (oranges) or of the few (13) that developed and pupated (grapefruit), only two adults emerged that survived 1 and 3 d, respectively (5-17% of the time necessary to reach sexual maturity). In sharp contrast, grapefruit exposed to A. ludens yielded up to 937 pupae and adults survived for >6 mo. Therefore, the inability of Mexican A. fraterculus to successfully develop in citrus renders the status of Mexican A. fraterculus as a pest of citrus in Mexico as unsubstantiated.
Abstract: We report the results of a 2-yr survey that determined some of the host plant and parasitoid associations of Anastrepha fruit flies (Diptera: Tephritidae) in the âMontes Azulesâ tropical rainforest biosphere reserve (State of Chiapas, Mexico). We collected a total of 57.38 kg of fruit representing 47 native species from 23 plant families. Of these, 13 plant species from eight plant families were found to be native hosts of 9 species of Anastrepha. The following Anastrepha host associations were observed: Bellucia pentamera Naudin (Melastomataceae) with A. coronilli Carrejo y González; Malmea gaumeri (Greenm.) Lundell (Annonaceae) with A. bahiensis Lima; Tabernamontana alba Mill. (Apocynaceae) with A. cordata Aldrich; Quararibea yunckeri Standl. (Bombacaceae) with A. crebra Stone; Ampelocera hottlei (Standl.) Standl. (Ulmaceae) with A. obliqua (Macquart) and A. fraterculus (Wiedemann); Zuelania guidonia Britton and Millsp. and Casearia tremula (Griseb.) Griseb. ex C. Wright (Flacourtaceae) with A. zuelaniae Stone; Psidium sartorianum (O. Berg.) Nied (Myrtaceae) with A. fraterculus; Psidium guajava L. and P. sartorianum (Myrtaceae) with A. striata Schiner; and Manilkara zapota (L.) Van Royen, Pouteria sp., Bumelia sebolana Lundell, and Calocarpum mammosum (L.) Pierre (Sapotaceae) with A. serpentina (Wiedemann). The following are new host plant records: Malmea gaumeri for A. bahiensis; Quararibea yunckeri for A. crebra; Ampelocera hottlei for A. fraterculus and A. obliqua; Bumelia sebolana for A. serpentina; and Casearia tremula for A. zuelaniae. A. coronilli is reported for the first time in Mexico. Infestation levels were variable and ranged between 0 and 1.63 larvae/g of fruit depending on host species. Larvae of eight species of Anastrepha on nine plant species from six plant families were found to be parasitized by Doryctobracon areolatus Szepligeti, D. crawfordi Viereck, D. zeteki Musebeck (new report for Mexico and northernmost record for the species), Opius hirtus Fisher, Utetes anastrephae Viereck (all Hymenoptera: Braconidae), and Aganaspis pelleranoi Brethes (Hymenoptera: Figitidae). Percent parasitism ranged from 0 to 76.5%. We discuss our findings in light of their practical (e.g., biological control) and theoretical (e.g., species radiation) implications and highlight the importance of these types of studies given the rampant deforestation of tropical forests in Latin America and the risk of extinction of rare fruit fly species that could shed light on the evolution of host plant and parasitoid associations within the genus Anastrepha.
Abstract: The reproductive behavior and dispersal patterns of Lethocerus colossicus (Heteroptera: Belostomatidae) were studied in the field and in the laboratory, in Puerto Morelos, State of Quintana Roo, in the Yucatan Peninsula. Afemale skewed sex ratio and sexual dimorphism were found in field populations. Adults migrate short after the final molt, and apparently remain in the same pond throughout their lives once they have started to breed. A field population consisting of around 17 adults bred continuously between April and September. Courtship, mating and exclusive male parental care are described. The male guards the clutch during the complete incubation period, moistening the eggs once or twice a day, and aggressively defending them against "potential predators" (i.e. the·observer). After hatching, larvae disperse and reach adulthood after 3 months. The sexual behavior of L. colossicus is discussed in the context of the evolution of reproductive strategies in belostomatids.
Abstract: Fruit flies (Diptera: Tephritidae) have been used previously as a model to explore the effect of nutrition on male reproduction. Here we tested the hypothesis that adult feeding history influences male sexual performance in four species of neotropical fruit flies of the genus Anastrepha ( A. ludens, A. obliqua, A. serpentina , and A. striata ), an approach that allowed us to consider species-specific ecological factors independent of phylogenetic constraints. We fed, from the moment of emergence, four experimental groups of males of each species with either (1) dry sucrose, (2) a mixture of dry sucrose and hydrolyzed protein (enzymatic yeast hydrolyzate), (3) a mixture of dry sucrose and bird feces, or (4) an open fruit [ Citrus sinensis (orange), Mangifera indica (mango), Manilkara zapota (chico zapote), and Psidium guajava (guava) for A. ludens, A. obliqua, A. serpentina , and A. striata , respectively]. Cohorts of 12-day-old individuals (28 males [7 of each diet treatment] and 14 females) were released simultaneously into species-specific field cages and the following parameters recorded over a 4-day period (procedure repeated with five different cohorts for each species): number of males involved in âcallingâ activities every hour (i.e., pheromone emissions, wing fanning, wing motions, or extensions of the mouthparts), identity of copulating males, and copula duration. In the case of A. obliqua , we also observed separately cohorts of 20-day-old individuals. In A. obliqua, A. serpentina , and A. striata , males fed on a protein-supplemented diet had higher copulatory success when competing against males fed on other diets. Anastrepha serpentina and A. striata were sensitive to diet on all but two of the parameters analyzed (i.e., males with consecutive copulas and copula duration in the case of A. serpentina and males with multiple and consecutive copulas in the case of A. striata ). In sharp contrast to this, the male mating performance of A. ludens was not affected by diet. Anastrepha obliqua was sensitive to different parameters depending on age. We discuss our findings and their sexual selection implications in light of each species' habits.
Abstract: Golden egg bug ( Phyllomorpha laciniata Vill) females oviposit on the bodies of conspecifics of both sexes. Studies on the golden egg bug have opened a new approach to understanding how forces arising from sexual conflict act in breeding systems (Kaitala, 1998, 1999; Kaitala and Miettinen, 1997; Hardling and Kaitala, in press ), in particular, how females are able to exploit males' sexual interests by dumping eggs on courting or mating individuals. These studies also show that social interactions among individuals may be complicated by sexual conflicts of interest. Many aspects of the peculiar behavior of the golden egg bug are already known, although much of it is still unexplained and theoretically poorly understood.
Here we comment on the paper by Reguera and Gomendio ( 1999) to clarify what really makes the golden egg bug so interesting and unique. The golden egg bug is not unique among insects in the sense that individuals carry eggs (see Smith, 1997), but rather it is unique because no simple explanation can be given for egg carrying. We strongly feel that it is incorrect to assume a priori that the bug's behavior is parental care, as Reguera and Gomendio ( 1999) do, only because eggs are attached on the backs of conspecifics. Below we expand on this claim and emphasize the known aspects of the bug's behavior.
Abstract: Courtship and mating behavior of Brachypelma klausi, heretofore unknown, is described on the basis of three courtship and mating sequences, one in captivity and two in the field. Adult males perform courtship movements (pedipalp drumming, leg drumming, push-up and shaking) when they locate a female's burrow, probably in order to avoid female aggression. After some physical contact, the female raises the prosoma and extends her chelicerae. The male then grasps her chelicerae with his tibial apophyses and the female arches her body backwards leaving the epigyoum exposed. The male starts boxing the female's sternum and presumably inserts his pedipalps and inseminates the female. In two cases the female vigorously attacked the male immediately after mating and probably would have killed him had observers not intervened; the other pair separated more slowly and peacefully. Males appear to use chemical and/or tactile cues from the female's silk around the burrow during short-range searching behavior. Males begin courtship behavior by drumming on the silk to signal to the female that he is present. One male of B. klausi observed in the field laid silk over the female's silk around the burrow, possibly to prevent subsequent matings by other males. A second male did not detect the burrow after this act.
Abstract: The number of copulations by different males and in different territories was evaluated in the field in the butterfly Callophrys xami (Lycaenidae). The total number of copulations per male and per hour was very low (.0027 and .0029 copulations / male / h in 1989 and 1990, respectively). There was high variance among males in the number of copulations. Data from the few males observed copulating more than once suggests a mating advantage for big, long lived males. Variation among territories in the number of resident males, frequency of occupation and number of copulations suggests variation in territory quality. Frequency of occupation was not correlated with the territory variables measured, and there were no differences in any territory variable between territories in which copulations were observed and those in which no copulation was observed. Furthermore, there were no between-years correlations in frequency of occupation and number of copulations in the territories studied in two different years. The location of territories may be important in determining territory quality.
