Temporal distribution,seed damage and notes on the natural history of Acanthoscelides quadridentatus and Acanthoscelides winderi (Coleoptera: Chrysomelidae: Bruchinae) on their host plant,Mimosa setosa var. paludosa (Fabaceae: Mimosoideae), in the Brazilian Cerrado

The seed beetles, Acanthoscelides quadridentatus and Acanthoscelides winderi are here recorded for the first time feeding on seeds of Mimosa setosa var. paludosa in the Brazilian Cerrado. Our main aims were to describe the temporal distribution, seed damage, and notes on the natural history of these two species on their host plant. We hypothesised that: (a) healthy seeds from infested fruits would have worse germination rate than healthy seeds from noninfested fruits, and (b) females of seed beetles would lay more eggs on large fruits. We made field observations and an experimental field study with the presence of seed beetles versus their exclusion on plants. Results revealed that seed beetles are synchronised with fruiting, with a temporal partitioning in occurrence. Attacked seeds did not germinate, whereas healthy seeds from infested fruits had worse germination rate than healthy seeds from noninfested fruits. Females of seed beetles laid more eggs on large fruits. These results suggest that seed beetles avoid competition through a temporal partitioning curcial for their coexistence, and select large fruits to oviposit as these fruits probably provide more food resource for their offspring. Furthermore, plants might perceive seed beetles’ damage and then reduce resource allocation on infested fruits.     

The Biology and Development of Brachygaster minutus Olivier (Hymenoptera: Evaniidae), a parasite of the oothecae of Ectobius spp. (Dictyoptera: Blattidae).

Summary

Brachygaster minutus is a parasite of the oothecae of three species of British field-dwelling cockroaches belonging to the genus Ectobius. This species has previously received very little attention probably due to its restricted occurrence in Britain and the difficulties encountered in its collection. The life cycle and development of the parasite is described. The species is solitary in habit, the single larva overwintering within the ootheca as a final instar. The emergence of the adult the following summer is perfectly synchronized with the occurrence in the field of the particular cockroach species. Aspects of the mating and oviposition behaviour of the parasite are described.     

First record of nest site and egg guarding in the caecilian Ichthyophis bannanicus (Amphibia: Gymnophiona: Ichthyophiidae)

In late July 2010, three clutches of eggs of the caecilian amphibian Ichthyophis bannanicus (Gymnophiona: Ichthyophiidae) were found in the field in the suburbs of Beiliu City, south-east Guangxi Province, South China. This is the first observation of eggs, guarding and characteristics of oviposition sites in the field for this species. Ichthyophis bannanicus is oviparous and there is no post-hatching parental care. The terrestrial oviposition sites were located in underground chambers close to small streams or rice fields. Nest chambers were connected to the surface by two small openings. Clutches contained 24–68 eggs, and were each associated with one or two adult females.     

Reproductive behaviour of the glass frog Hyalinobatrachium cappellei (Anura: Centrolenidae) in the Southern Amazon

Frog species of the Centrolenidae family exhibit a high variation in reproductive behaviours. Herein we describe the reproductive, ecological, acoustic and behavioural features of Hyalinobatrachium cappellei in Southern Amazon. Two hypotheses were also evaluated: (1) are ecological characteristics of the reproductive site related to male size and quantity of eggs and clutches? And (2) do males with one or more existing clutches at reproductive sites accumulate more new clutches than those males initially without them? This study was conducted at two streams, with sampling at 1 km each in Southern Amazon. Species reproduction occurred during the wet season and was considered prolonged breeding. Although male vocalization occurred on both the upper and underside of leaves, clutches were most often deposited on the underside of leaves. Males emitted a courtship call upon female approach. The process of female approach until oviposition lasted approximately eight hours. After oviposition, females left the breeding site while males remained near the clutch, covering it with the belly in ventral brooding behaviour. Thus, egg attendance is reported for the first time for this species. No intraspecific or interspecific aggressive behaviour was recorded. There was no relationship between habitat characteristics of the reproductive sites and male size, number of eggs and clutches. However, after 10 days of monitoring, we found evidences that parental males had a higher number of clutches than those males initially without clutches. Similar to other glass frog species, the behavioural characteristics of H. cappellei make this species an excellent model to use in evaluating the cost-effectiveness of parental care and the importance of egg attendance for offspring survival. Therefore, these data contribute towards a better understanding of the complex phylogenetic and biogeographic relationships between centrolenid lineages.     

Assortative mating in soldier beetles (Cantharidae: Chaulignathus ): test of the mate-choice hypothesis

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

Reproductive ecology of the glass frog Espadarana prosoblepon (Anura: Centrolenidae) in an urban forest of the Central Andes of Colombia

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

On the natural history of Leptodactylus syphax with comments on the evolution of reproductive features in the L. pentadactylus species group (Anura,Leptodactylidae)

We describe the reproduction of Leptodactylus syphax from Brazil and attempt to trace the evolution of reproductive traits within the L. pentadactylus species group. We quantified the proportion of eggs/embryos from fresh nests. We test whether L. labyrinthicus and L. syphax tadpoles can prey on eggs from heterospecific foam nests. Egg clutches were found outside the water at the edges of rocky/seasonal streams, usually within excavated basins. Males beat the foam with their legs moving from side to side. Clutches do not have trophic eggs, since most of their eggs develop into tadpoles. Tadpoles cling on rocks in current/shallow waters. Only L. labyrinthicus tadpoles could prey on eggs from heterospecific foam nests. If the L. pentadactylus group is monophyletic, excavated basins and foam‐beating in lateral motions may be possible synapomorphies of this group. However, large adults, carnivorous tadpoles and trophic eggs appear to be associated synapomorphies of a less inclusive group.     

Biology and defensive secretion of myrmecophilous Thiasophila spp. (Coleoptera: Staphylinidae: Aleocharinae) associated with the Formica rufa species group

Various aspects of the biology of the myrmecophilous Thiasophila angulata and T. szujeckii (Staphylinidae; Aleocharinae), mainly associated with the Formica rufa species group, are studied. The composition of defensive gland secretions from adults of T. angulata has been analysed. The complete development (egg-L_1-3-pupa-adult form), including adult overwintering, of both species takes place solely in ant nests. Under laboratory conditions, this lasts for about 22 days in T. angulata, and the period elapsing between the old and new generations of insects is approximately two months. The mean fecundity of adults of this species (28 eggs) was determined, as well as the duration of its reproductive period (mean 28.5 days), and lifespan (mean 67 days). In natural conditions T. angulata, found within nests of Formica polyctena and F. rufa, produces three generations, and the sibling species T. szujeckii one generation per year. These two species differ in their phenologies and abundance dynamics of adults and larvae, which is linked to the size and temperature regime of the host nest. The results of this study uphold the recent separation of T. angulata and T. szujeckii based on morphological features of adults and selected molecular markers. Adults and larvae of T. angulata forage on both live and dead food items accumulated by the host, as well as on the host’s eggs and larvae. Both the beetle larvae and adults remain unmolested among the host workers. The adults use their defensive gland secretions, which contains substantial quantities of toxic quinones, when necessary. According to the current categories of myrmecophiles, T. angulata (and by analogy, T. szujeckii as well) should be classified as a species wholly integrated with the host.     

Maintenance of colour polymorphism in the leaf beetle Chrysophtharta agricola (Chapuis) (Coleoptera: Chrysomelidae: Paropsini)

Intra-specific colour differences in insects may occur as a result of environmental factors such as food type, temperature and humidity, or may be under genetic control. These colour polymorphisms may result in fitness differences through several mechanisms, including mate selection, camouflage from or warning to natural enemies, and heat absorption. Two colour morphs of adult Chrysophtharta agricola (Chapuis) (Coleoptera: Chrysomelidae: Paropsini) are present in the field in mainland Australia and Tasmania: a common green-brown form, and a rare black form. Tasmanian populations were sampled to assess the frequency of each morph at eight localities. The black form represented less than 3% of beetles (N=1724), with the proportion not significantly different between localities. Crossing tests using the two colour morphs of C. agricola showed that the black form was genetically dominant over the common form. To assess whether colour morphs had any fitness differences, we measured pre-oviposition period, fecundity, longevity, adult size and egg hatch rate, which each showed no significant difference between colour morphs. Field sampling of mating pairs and rearing the offspring of field-collected females showed no evidence of non-random mating. Modelling the population over 100 generations confirmed that for this species, melanism is controlled by a dominant but neutral allele, and, thus, is maintained at a constant low level in the population.     

Synonymy of Rhynchophorus ferrugineus (Olivier), 1790 and R. vulneratus (Panzer), 1798 (Coleoptera,Curculionidae, Rhynchophorinae)

Morphological, molecular-genetic and breeding data were collected to investigate the species status of the Asian palm weevils, Rhynchophorus ferrugineus (Olivier) and R. vulneratus (Panzer) (Coleoptera: Curculionidae). These weevils are distinguished by characteristic colouring of the pronota and elytra, but naturally occurring colour intermorphs were observed. Contrary to the literature, quantitative measurements of the concavity of subgenal sutures and of pronotal shape indicated no differences between the two species. Larvae did not differ significantly in labral characteristics. Random amplified polymorphic DNA (RAPD) banding patterns were identical for nine of 14 primers, indicating that these weevils are very closely related. Sequences of the cytochrome oxidase gene for 201 base pairs read were identical for R. ferrugineus and R. vulneratus, but the congener R. bilineatus differed from them by 10%, suggesting divergence of these lineages about 5?million years ago. Hybrid F1s were obtained from all heterospecific crosses, and one surviving hybrid F1 female produced viable eggs. Previous studies have revealed no pheromonal differences. On the basis of this evidence, R. ferrugineus and R. vulneratus should be considered colour morphs of the same species and be synonymized under the name Rhynchophorus ferrugineus (Olivier), with the common name Asian palm weevil.     

Resource defence mating system in two flies from Sulawesi: Gymnonerius fuscus Wiedemann and Telostylinus sp. near duplicatus Wiedemann (Diptera: Neriidae)

Gymnonerius fuscus and Telostylinus sp. near duplicatus are two neriid flies which breed in rot-holes (often beetle larval borings) in fallen trees in tropical forests. Males of both species attempt to establish territories beside rot-holes likely to attract females for egg-laying purposes. Monopolization of incoming females and paternity of any eggs laid are therefore assured. Aggression between males of the larger species G. fuscus is largely through ritualized intimidatory signalling, i.e. wing-flicks. Actual physical aggression only occurs when opponents are evenly matched. By contrast, lengthy and hectic wrestling matches on stilted legs is the normal method of establishing site-ownership in the smaller species T. near duplicatus. Males only seek to exclude conspecific males, such that both species may establish simultaneous ownership of a single rot-hole without interacting. Males of G. fuscus who ‘sneak’ matings away from the territories of larger males, or who manage to mate within a territory, gain little or no reproductive benefit. This is because the territory-owner prevents all females, other than his own current mate, from laying eggs within his territory and females seem reluctant to utilize non-territorial rot-holes for oviposition.     

Activity and reproduction in Megalobulimus paranaguensis (Gastropoda,Eupulmonata): implications for conservation in captivity for a South American land snail

ABSTRACT

In South America, Megalobulimus includes a number of threatened species, as well the largest land snails on the continent. The activity patterns and reproductive aspects of this group have not been documented. This work describes the daily and seasonal activity patterns and reproduction of M. paranaguensis. We maintained specimens in the laboratory for one year, and we quantified their behaviour for one hour at four different times of the day (0 h, 6 h, 12 h and 18 h) during three days in four months (August, September, April and May). The number of postures, hatching rate, time of hatching since oviposition and mortality rate among juveniles for each month were also quantified. Megalobulimus paranaguensis was more active in August, and had a egg laying peak one month after. Fifty-one eggs were laid by 12 captive individuals throughout the year, with a mean value of 4.25 eggs per individual. The hatching rate was 80.39%, and the time of hatching since oviposition was 56.7 ± 4.3 days. In two eggs, we observed the presence of twins. The mortality rate among juveniles was low (9.30%) indicating that rearing land snails in captivity has the potential to be an important and viable tool for the management and conservation of these organisms.     

Oviposition site preference and reproductive ecology of Teratohyla midas (Anura: Centrolenidae) in the Colombian Amazon

ABSTRACT

The family Centrolenidae (Glass frogs) includes 157 species of anurans with a Neotropical distribution. Although glass frogs have been the subject of several studies encompassing various aspects of their biology, natural history data on their reproductive ecology is still scarce. One of the important aspects of reproductive ecology is the oviposition site since it can impact the reproductive success of a species. Herein, we provide detailed information on the reproductive ecology of a population of Teratohyla midas from the Colombian Amazon foothills and test whether this species shows a preference on substrate and height of oviposition site. We monitored a population using capture-mark-recapture of individuals identified by a photograph of their unique pattern of dorsal yellow spots. Wild-ID Software was used to corroborate if the dorsal pattern was different between individuals. Additionally, we monitored the presence of egg clutches, amplexus and oviposition behaviour. We observed 110 males and 5 females of T. midas, seen at an average height of 3.1 m ± 2.9 (0–17.8 m) from the ground. Likewise, we recorded the amplexus behaviour of two pairs for approximately 150 min. Once the oviposition happened, the male retreated, and the female covered the egg clutches for approximately 60 min. We observed 25 egg clutches with 60% being deposited in leaves of Selaginella sp and found at an average height of 2.9 ± 1.7 m (1.1–7.0 m). Thus, the selection of oviposition site was not random but mostly specific to one type of substrate. Furthermore, there was an overlap of the re-sampled median height distributions of active individuals and clutches, which suggests that oviposition does not occur at a preferred height within the vertical distribution of individuals. The information presented here is the first detailed record of reproductive ecology for this species and we hope to provide a basis to improve our knowledge on the biology of this species and other glass frogs.     

Two new Encarsia species (Hymenoptera: Aphelinidae) reared from eggs of Cicadellidae (Hemiptera: Auchenorrhyncha) in Argentina: an unusual new host association

Males of two undescribed Encarsia species were reared from eggs of two cicadellid species during a study of egg parasitoids of corn leafhopper, Dalbulus maidis (DeLong and Wolcott) in northwestern Argentina. Samples were collected during the summer of 2004–2007 using sentinel eggs, and several males of a new species of Encarsia (Hymenoptera: Chalcidoidea: Aphelinidae) were obtained. A single male of a closely related Encarsia species, also previously undescribed, was reared from an egg of another cicadellid on maize, Plesiommata mollicella (Fowler). These are the first records of any Encarsia species reared from eggs of Cicadellidae. The two new species are described as Encarsia dalbulae Polaszek and Luft Albarracin sp. nov., and Encarsia mollicellae Polaszek and Luft Albarracin sp. nov.     

Reproductive biology of two species of Hyalella Smith, 1874 (Crustacea: Amphipoda: Hyalellidae) from southern Brazil

Reproduction is a critical event in the life cycle of animals, and a high amount of energy is allocated to it. The aim of this study was to characterize the reproductive biology of two recently described species of Hyalella from the north-east region of state of Rio Grande do Sul in southern Brazil. The specimens were collected during 12 months from a stream source (Hyalella georginae) and from a water reservoir (H. gauchensis), in Palmeira das Missões municipality, state of Rio Grande do Sul. Upon sampling, ovigerous females and pairs in precopulatory behaviour were separated into microtubes. In the laboratory, the cephalothorax length (CL in mm) of all specimens was measured. Male size at onset of sexual maturity was larger than that of the females, in both species. There was a correlation between the size of paired males and females: larger males carried larger females, in both Hyalella species. Precopulatory pairs were found throughout the year; however, H. georginae had a higher frequency in spring, and H. gauchensis in autumn. There was a positive correlation between the CL of ovigerous females and the number of eggs/juveniles. A reduction in the number of eggs throughout the embryonic development was observed in H. georginae. The average fecundity of H. georginae was significantly higher than H. gauchensis. The differences between the reproductive biology of these species may be related to the physical and environmental conditions at which they are exposed in their habitats.     

Mating behaviour,territoriality and natural history notes of Phyllomedusa ayeaye Lutz, 1966 (Hylidae: Phyllomedusinae) in south-eastern Brazil

The mating (male courtship, amplexus and oviposition) and male territorial behaviours of Phyllomedusa ayeaye are described from a high-altitude site in the state of Minas Gerais, south-eastern Brazil. Information related to male breeding success and territoriality, as well as egg clutch parameters, is provided, together with qualitative information regarding tadpole phenology and juvenile recruitment. In addition, estimations of sexual dimorphism and numbers of marked individuals are available through capture-mark-recapture sampling. Females bred with males within spatially clustered oviposition sites (broadleaf plants). In some cases, the amplectant couple actively searched for the oviposition site. Males defended territories from other males, employing both acoustic and physical interactions. Some males successfully maintained their calling sites over successive nights, and others seemed to switch among nearby sites during successive nights and tried to disrupt ongoing ovipositions. No significant relationship was found between physical attributes (snout vent length or body mass) of males with breeding success. Also, no influence of the number of nights a male was active in chorus and its breeding success was detected. Therefore, it is proposed that the mating system in P. ayeaye may be opportunistic. Additional information related to reproduction (egg clutch parameters and breeding behaviours) is also discussed for other species of the Phyllomedusa hypochondrialis group and compared with the results of the present study.     

Mating behaviour in two closely related sympatric species of Philonthus (Coleoptera: Staphylinidae)

Summary

The intra-specific mating behaviour of two closely related sympatric staphylinid beetles, Philonthus cephalotes (Grav.) and P. sordidus (Grav.) is described in detail. Mating is essentially similar in the two species, although differing in the duration of copulation (1·7 min in cephalotes, 44·6 min in sordidus), and consists of four phases (A)-(D); (A) pre-copulatory phase, (1) examination of female abdominal apex by male, (2) examination of male abdominal apex by female, (3) prolonged examination of female by male, (4) mounting by male (5) extrusion of male genitalia; (B) copulatory phase; (C) terminal phase; and (D) post-copulatory phase.

An attempt to test the role of species specific patterns of peg setae, occurring on the genitalia of males, as a tactile signalling system was made by observation of inter-specific interactions between males and females of the two species. Under the trial conditions inter-specific intromission did not occur and behaviour was predominantly aggressive. Evidence suggests that signals during the early stages of an encounter between the sexes of different species are generally sufficient to deter further courtship. In two instances courtship reached a more advanced stage and here the patterns of peg setae on the male genitalia may have come into play, operating as a signalling device.     

Molecular phylogenetic analysis of three groups of Asian epilachnine ladybird beetles recognized by the female internal reproductive organs and modes of sperm transfer

We determined partial sequences of the nuclear 28S ribosomal RNA gene (717 base pairs) and mitochondrial DNA NADH-dehydrogenase subunit 2 gene (535 base pairs) of 25 species of phytophagous ladybird beetles from Asia that comprise 16 species of the genus Henosepilachna and nine species of the genus Epilachna, and reconstructed the phylogenetic trees for each gene by the maximum parsimony and maximum likelihood methods. The estimated phylogenetic relationships were consistent with those obtained by the mode of sperm transfer and female internal reproductive system, and supported an earlier assumption that very similar elytral spot patterns of some sympatric members of epilachnine beetles evolved independently.     

Reproductive patterns of Trachycephalus venulosus (Laurenti, 1768) and Scinax fuscovarius (Lutz, 1925) from the Cerrado,Central Brazil

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

The behaviour of Cotinis nitida Linnaeus,the green June beetle (Coleoptera: Scarabaeidae), on mowed lawns makes them especially vulnerable to bird predators

ABSTRACT

Males of the green June beetle Cotinis nitida are regularly attacked by birds as they search for females on lawns but which bird species feeds on the beetle changes from year to year. In 2018 for the first time on a farm in northern Virginia, brown thrashers (Toxostomum rufum) joined blue jays (Cyanocitta cristata) as major predators of the beetles. The two species employed very different tactics when hunting for June beetles, with the thrashers searching while walking forward on the mowed lawn while the jays scanned for beetles when perched in trees about the lawn. The beetles became very scarce at the lawn in early July in 2017 and 2018 and their predators apparently moved elsewhere. Subsequently, male beetles were occasionally observed patrolling a nearby hayfield in search of mates with rare copulations recorded after July 15. Because predatory birds could not exploit the beetles in the tall grass of the hayfield it seems likely that the mowed lawn constituted an evolutionarily novel ecological trap which made searching beetles conspicuous and easily captured by beetle-hunting birds.