Is it all death feigning? Case in anurans

Anurans are known to feign death as a way to avoid or minimize the risk of predation. However, information on this defensive strategy is scattered and we believe that there is more than one behaviour type referred to as thanatosis. Here we review the literature, add original data, and propose definitions and new names that complement the present knowledge on the subject. We collected information on 334 individuals of 99 species in 16 families and grouped the recorded displays into two categories of tonic immobility: (1) thanatosis, death-feigning, or playing possum, and (2) shrinking or contracting. These two categories are treated as different behaviour types because of the display pattern (position of fore- and hindlimbs, eye opening), presence of skin toxins (shrinking is mostly displayed by toxic species, whereas thanatosis is mostly displayed by non-toxic species), social context (interaction with predators), and their putative or actual functions.     

Mating behaviour in the bees,Dieunomia heteropoda and Nomia tetrazonata,with a review of courtship in Nomiinae (Hymenoptera: Halictidae)

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

The genus Grammostola Simon 1892 (Araneae: Theraphosidae): a new species from western Argentina,new synonymy and distributional data

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

Field and laboratory observations on reproductive aspects of Pseudopaludicola ameghini (Cope, 1887) (Leptodactylidae: Leiuperinae)

ABSTRACT

The genus Pseudopaludicola includes small-sized anurans, widely distributed throughout South America. Twenty-three out of the 25 species occur in Brazil. Although described more than a century ago, from mid-southern Mato Grosso state, central Brazil, Pseudopaludicola ameghini is poorly known. Here we describe the characteristics of reproductive site, amplexus, egg-laying behaviour, eggs and tadpoles of P. ameghini based on specimens and observations performed in the vicinities of the type locality. Pairs of P. ameghini reproduce in shallow and slow groundwater established on hydromorphic terrains, in open environments amidst the Brazilian Cerrado savanna. Reproductive activity occurred between 17:00 and 21:00 h at two sites studied from December 2013 to April 2014. Amplexus is axillary. Eggs are spherical, with a mean diameter of 5.1 mm (yolk plus jelly envelope). Oviposition occurs in shallow sites at a depth of nearly 2.0 cm. Females deposit their eggs one at a time, directly onto sediment at the bottom of waterbodies or attached to submerged vegetation. The tadpole body is oval in dorsal view and globular/depressed in lateral view; eyes are large and dorsally positioned. Nares are large, round, with a small apophysis on marginal rim, dorsally positioned, near the eyes. The spiracle is short, with posterodorsal opening. The oral disc is anteroventral, emarginated laterally, with one dorsal and two ventral gaps; the tooth row formula is 2(2)/2(1), and the upper jaw sheath is ‘arc’ shaped. Pseudopaludicola ameghini has a unique behaviour of oviposition among members of the genus. The differences in reproductive pattern and larval characteristics of P. mystacalis and P. ameghini reinforce the taxonomic validity of the latter, questioned until recently.     

The puparia of some West African species of Mepachymerus and Steleocerellus (Diptera: Chloropidae)

The puparia of two species of Mepachymerus and three species of Steleocerellus (Diptera: Chloropidae, Chloropinae), reared from wild grasses in West Africa, are described.     

Complex display behaviour during the intraspecific interactions of myrmecomorphic jumping spiders (Araneae,Salticidae)

Jumping spiders (Salticidae) are known for their elaborate vision‐based display behaviour, and a sizeable minority of the species in this large family resemble ants. The display repertoire of two ant‐like salticid species from the Philippines is investigated. Myrmarachne assimilis is a specialist ant mimic, closely matching the appearance of the weaver ant Oecophylla smaragdina. Myrmarachne bakeri is a generalist mimic, which, although ant‐like, is not a close match to any sympatric ant species. Myrmarachne are sexually dimorphic, with males having enlarged chelicerae. The copulatory posture of Myrmarachne is unique among salticids, apparently as an adjustment for the male's elongated chelicerae. Details concerning the intraspecific behaviour of Myrmarachne appear to be adjustments to living in environments populated by numerous other animals with similar appearance (ants). However, the specialist and the generalist that were investigated have display repertoires that are broadly similar to each other and to those of more typical salticids. Generally, the display behaviour of Myrmarachne appears not to have necessitated dramatic deviation from typical salticid display and mating strategies.     

Climatic adaptations and distributions in the Drosophila takahashii species subgroup (Diptera: Drosophilidae)

Among subtropical species of the Drosophila takahashii species subgroup, temperature adaptations were related to altitudinal distribution; D. trilutea was adapted to lower temperature and occurred at high altitudes in September in Taiwan, D. takahashii was adapted to higher temperature and occurred mainly at low altitudes, and D. prostipennis was adapted to an intermediate range of temperature and occurred at mid to high altitudes. A temperate species, D. lutescens, was adapted to a wider range of temperature than the subtropical species: it was more cold-hardy than all three subtropical species and more heat-tolerant than D. prostipennis and D. trilutea. The temperature ranges encountered in the temperate region far exceed the range in subtropical areas, and this is likely to be reflected in the temperature adaptations of these temperate and subtropical species. D. lutescens has a photoperiodically controlled reproductive diapause. No latitudinal cline was observed on cold-hardiness of D. takahashii. By contrast, cold-hardiness and photoperiodic response differed between northern and southern populations of D. lutescens.     

Plant consumption in coastal populations of the lizard Tropidurus torquatus (Reptilia: Squamata: Tropiduridae): how do herbivory rates vary along their geographic range?

Tropidurus torquatus lizards commonly consume vegetal matter as part of their diet. However, it is not known to what extent the rate of consumption of plant material varies among populations. We investigated the consumption of plant material in 10 populations of T. torquatus in eastern Brazil. In all populations, lizards consumed plant matter (especially fruits and flowers). The proportion of plant volume in the diet varied from 2.1% to 58.0% of the total volume consumed. Differences in volumetric proportion of plant material consumed did not result from lizard body size or population latitude. The volumetric proportion of plant material did not differ between sexes at each locality; however, there was a slight trend for larger lizards to consume more plant parts. The data obtained indicate that the observed interpopulational variation in plant consumption by T. torquatus results from local environmental factors, mainly the availability of plant matter.     

“Riding” behaviour by males of Conops quadrifasciata (Diptera: Conopidae): Do females set up “riders” as targets for takeovers by larger males?

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

Temperature-dependent geographic variation in the flashes of the firefly Luciola cruciata (Coleoptera: Lampyridae)

This study examined the regression of male interflash intervals of Luciola cruciata on ambient air temperatures at five sites in central Japan. The result indicated a significant negative correlation between these two variables at any of the sites. The regression lines varied from site to site and, therefore, the five local populations were classified into three types; the fast-flash, slow-flash, and intermediate types. This classification was supported by molecular biological studies, but contradicted the results of previous ecological studies based on interflash intervals only. My result suggests that first the slow-flash type and then the intermediate type evolved from an ancestral fast-flash type. The geographic variation in flashes of this firefly may have arisen from shifts in the response of male flashes to ambient temperature.     

Aspects of the natural history of Leptodactylus knudseni Heyer, 1972 (Anura: Leptodactylidae) in a pristine forest in Central Amazonia,Brazil, with comments on ontogenetic variation of its tadpoles

The Leptodactylus pentadactylus species group is comprised of medium to large species of Neotropical frogs. Leptodactylus knudseni, a member of this species group, has a wide distribution throughout the Amazon Basin. Herein we describe aspects of the reproductive biology of L. knudseni and provide notes about the ontogenetic variation of its tadpoles based on a population in a non-flooded forest near Manaus, Amazonian Brazil. Amplectant pairs of L. knudseni lay foam nests in excavated basins on the edge of temporary ponds located on clay soil and at least 50 m from a stream. The tadpole development happens initially in the foam nests with access to the pond after the rain flooding the basins. Studied clutches lacked trophic eggs and tadpoles did not produce foam. Ontogenetic variations in L. knudseni tadpoles are related to size, teeth formulae and body colour. The use of excavated basins for the deposition of foam nests has been reported in several species of the L. pentadactylus group. The absence of trophic eggs and production of foam by the tadpoles differ from other species of the L. pentadactylus group. The tadpole morphology is similar to that described for other species of the group.     

Unusual geographic pattern of interpopulation variation in a spring snail Bythinella (Gastropoda: Prosobranchia)

Allozyme polymorphism, mean gene diversity, and a variety of pairwise genetic distances, theta and Nm were analysed for 20 populations of the spring snail Bythinella from Central Europe. Pairwise Mahalanobis' distances for morphological characters and geographic distances were also computed. Contrary to prior assumptions, the level of polymorphism was considerable, and correlations were found to be statistically significant between the genetic and geographic distances, as well as between Mahalanobis' and geographic distances. The present high level of isolation of local populations of the previously amphibious and continuously distributed snail is postulated to be due to a shift in climate and in the snail's habitat preference.     

Mating behaviour of Staminodeus vectoris (Coleoptera: Curculionidae), and the value of systematics in behavioural studies

The mating behaviour of Staminodeus vectoris Franz (Curculionidae: Curculioninae: Derelomini) is described and discussed in light of a phylogeny of Staminodeus Franz. At La Selva, Costa Rica, S. vectoris is associated with the staminodes of the inflorescences of Asplundia uncinata Harling and several other species of Cyclanthaceae. The males have a row of 6–10 teeth along the margin of the protibia, whereas the females have a small, curved spine on the frons. The adults arrive in numbers at the inflorescences during the pistillate phase of the anthesis of A. uncinata, feeding on the staminodes. Eventually, a female detaches a staminode with her mandibles, falls to the ground, and transports it to the site of oviposition in the leaf litter. First, she crawls underneath the staminode, then moves it posteriorly with her legs, and finally returns to its distal end before repeating the process. The female turns on her back and maintains her original position during the movement of the staminode, using her frontal spine as a point of resistance against the substrate. Meanwhile, a male associates with the staminode. The males fight with their prothoracic legs, executing fast blows until their protibial teeth cling and dislodge competitors from the staminode. The positive and negative allometries of the lengths of the male protibia and female spine, are consistent with their functions in the contexts of sexual and natural selection, respectively. The phylogeny of all seven species of Staminodeus hypothesises that female transporting behaviour evolved before male fighting behaviour.     

Reproductive characteristics of Elaphe quadrivirgata (Serpentes: Colubridae) from ecologically dissimilar main island and island populations

We compared reproductive characteristics of a snake (Elaphe quadrivirgata) from two geographically distinct populations, which differ considerably in habitat use and diet. Snakes in Shiga Prefecture, in the central western area of the main island of Japan, occupy open rice fields and predominantly eat frogs. Snakes on Yakushima Island, in southwestern Japan, occupy a forest environment and mainly eat lizards. Maternal body size of snakes from Yakushima was significantly smaller than that of snakes from Shiga. Oviposition date was significantly later in snakes from Yakushima than in those from Shiga, and the former laid a smaller number of considerably elongated eggs than the latter. Relative clutch mass was significantly higher in the Shiga than in the Yakushima population, but egg mass in relation to maternal body mass of the latter was larger than that of the former. Hatchlings of Yakushima were larger than those of Shiga. This size difference in hatchlings was not fully explained by differences in egg size. These differences in reproductive characteristics between the two populations do not seem to be a consequence of morphological constraints of dam snakes. Instead, we presume that the differences in reproductive characteristics reflect local adaptations.     

Anurans of a seasonally dry tropical forest: Morro do Diabo State Park,São Paulo state,Brazil

We studied the richness and composition of the anuran assemblage of Morro do Diabo State Park, the major remnant of Mesophytic Semideciduous Forest in the state of São Paulo, Brazil, through hypothesis tests. From September 2005 to March 2007 we recorded 28 anuran species, comprising a mix of Atlantic, Cerrado and South American widespread species, usually considered tolerant to anthropic modifications. The low richness of species and reproductive modes, the predominance of habitat generalist species, and the high similarity with Cerrado areas can be explained by the climatic seasonality of the studied area (a pronounced dry season), as well as its large distance from centres of anuran diversification, such as the coastal mountains of the wet Atlantic Forest.     

The Neotropical Psylloidea (Homoptera: Insecta): an annotated check list

Summary

The 242 species of jumping plant lice (Homoptera: Psylloidea) recorded from the Neotropical region are listed under their respective genera. Information is given on synonymy, host plant range and distribution. The taxonomic position of the problematical groups is discussed. The check list is supplemented by a taxonomic list of host plants and their associated psyllids.