Social behaviour in a thrips from Panama

Summary

Anactinothrips gustaviae is an advanced parasocial thrips (Thysanoptera: Phlaeothripidae: Idolothripinae) from Panama which lives in colonies on smooth-barked trees, reproduces communally, cooperatively broods young, and forages in a highly coordinated fashion (with young, if present). Although this species is presumably haplodiploid, we argue that the patchy, but intergenerationally stable, food supply is the primary factor which has promoted the evolution of advanced social behaviours in this species as opposed to most other thrips.     

Diet and feeding behaviour of the leaf-litter frog Ischnocnema henselii (Anura: Brachycephalidae) in Araucaria rain forests on the Serra Geral of Rio Grande do Sul,Brazil†

Abstract

We analysed the diet of Ischnocnema henselii from a subtropical Araucaria forest through stomach flushing. The identified prey items comprised arthropods such as spiders, ants, orthopterans, collembolans and homopterans. We consider I. henselii to be a nocturnal and opportunistic sit-and-wait predator. Small animals are preferred. Because this species lives permanently on the forest floor, we also determined the composition of the habitat's leaf-litter mesofauna. By using Winkler sieve extraction, we obtained a spectrum of small invertebrates that reflected the prey in the stomach contents well. The only exceptions were mites, the most abundant leaf-litter inhabitants, which frogs either avoided or ignored. Our results represent the first information on the diet of I. henselii and are discussed in comparison with data on related species and in relation to the relevance of this predator within the food web of subtropical montane rain forests in southern Brazil.     

Setal diversity,trophic modes and functional morphology of feeding appendages of two callianassid shrimps,Callichirus major and Sergio mirim (Decapoda: Thalassinidea: Callianassidae)

In the present study we investigate the trophic behaviour, stomach content and morphology of the feeding appendages, with emphasis on setae, of two callianassids; a generalist feeder, Callichirus major (Say, 1818) and a strict deposit feeder, Sergio mirim (Rodrigues, 1971). Of the 87 setal types described, only 5% were common to both species. Setal types were clustered in four main categories; plumed, serrate, plumodenticulate and simple. Callichirus major has higher setal diversity than S. mirim. Relative to the amount of setal types present in each species, C. major has a higher ratio of serrate to plumodenticulate setal types and similar percentages of plumed and simple setae. Examining the setae and spatial position of the segments of the feeding appendages, it is possible to infer that the main function of the dactyli, propodi and basal endites is to brush particles, while the meri, ischia and coxal endites retain sediment. The setal diversity found on the feeding appendages reflected the diverse trophic strategies of the callianassid species studied. Exclusive deposit feeders, e.g. S. mirim, appear to have fewer setal types than generalist feeders, e.g. C. major. Apparently, the higher ratio of serrate to plumodenticulate setal types in Callianassidae depends more on the necessity to triturate particles prior to ingestion than on the trophic mechanism used by the species.     

Composition and habitat use of small mammals in old-growth mountain forests

Old-growth mountain forests in the Pyrenees have natural gap dynamics, a well-developed shrub layer and a large amount of dead wood. Small mammal communities in two types of old-growth forests, silver fir and mountain pine, were studied in July and September in 2006 and 2007. Four species were trapped: bank vole (Myodes glareolus), wood mouse (Apodemus sylvaticus), garden dormouse (Eliomys quercinus) and common shrew (Sorex araneus). Bank voles and wood mice were most commonly trapped (78% of all captures). There were no differences in community composition in the two forest types, although the bank vole was more often captured in the silver fir than in the mountain pine forest. Mammals were more frequently captured at trap stations with high shrub cover, high tree regeneration cover and low herbaceous cover. Our results show that forest structure and, to a lesser extent, forest type determine small mammal community structure, and specifically fine-scale occurrence patterns, in these old-growth forests.     

Australian thrips of the Haplothrips lineage (Insecta: Thysanoptera)

Keys are presented to the 11 genera and 50 species, including 21 new species, of Thysanoptera in Australia that are related to the worldwide genus Haplothrips Amyot and Serville. These taxa belong to what, in recent literature, has been called the “Haplothrips‐lineage”, that is, one of the three major radiations among the 2700 species and 350 genera of Thysanoptera Phlaeothripinae. The group is redefined, and the available tribal name Haplothripini shown to be appropriate. The character states on which the definition is based are discussed, and a list given of the 34 genera worldwide that can be included. The Australian species in these genera exhibit a diversity of biologies. Three genera involve species that invade galls induced by other thrips: Androthrips monsterae (Moulton) from New Guinea is newly recorded from Australia; Mesothrips jordani Zimmermann from South‐East Asia is newly recorded from Australia, with two new synonyms; the Asia‐Pacific genus, Euoplothrips Hood, includes two species in northern Australia. Three haplothripine genera are associated with grasses: one widespread genus, Apterygothrips Priesner, considered polyphyletic, includes only one Australian species; the only known species of Dyothrips Kudo is Oriental but extends into tropical Australia; Podothrips Hood, a circum‐tropical genus of thrips predatory on grass‐living coccoids, has 11 Australian species, six newly described. One grass‐associated genus, Bamboosiella Ananthakrishnan, is excluded from the Haplothripini. An Oriental genus of leaf‐ and flower‐living species, Dolichothrips Karny, includes one species in northern Australia, D. reuteri (Karny); Membrothrips Bhatti in which this species has been placed is considered a synonym. Karnyothrips Watson includes two species introduced to Australia, both predators of coccoids. Priesneria Bagnall includes three species from Australia, of which one fungus‐feeding species is newly described. Xylaplothrips Priesner is a widespread but ill‐defined, polyphyletic genus that currently includes three little‐known Australian species. Haplothrips is the main focus of this study, and character state variation among the Australian species is discussed. In total 24 species of Haplothrips from Australia are recognised, 14 being new species. Also included are the following, one new generic synonym, four new species synonyms, and one new combination. The 250 species worldwide in the genus are usually associated with the flowers of Asteraceae and Poaceae. In Australia, several of the species are specific to flowers, particularly of Poaceae and Cyperaceae but not Asteraceae. Almost half of these Australian species are presumed to be predatory on other small arthropods, and two have unusual host associations—with salt marsh Chenopodiaceae, and with the sori of Dicksonia tree ferns.     

Goliath frogs build nests for spawning – the reason for their gigantism?

ABSTRACT

In contrast to its popularity, astonishingly few facts have become known about the biology of the Goliath Frog, Conraua goliath. We herein report the so far unknown construction of nests as spawning sites by this species. On the Mpoula River, Littoral District, West Cameroon we identified 19 nests along a 400 m section. Nests could be classified into three types. Type 1 constitutes rock pools that were cleared by the frogs from detritus and leaf-litter; type 2 constitutes existing washouts at the riverbanks that were cleared from leaf-litter and/or expanded, and type 3 were depressions dug by the frogs into gravel riverbanks. The cleaning and digging activities of the frogs included removal of small to larger items, ranging from sand and leaves to larger stones. In all nest types eggs and tadpoles of C. goliath were detected. All nest types were used for egg deposition several times, and could comprise up to three distinct cohorts of tadpoles. Nests seemed to be clustered. Camera trapping revealed that nests are guarded by adult frogs at night. The breeding nests may allow the frogs to deposit their eggs away from the torrent rivers, and potential egg and tadpole predators. As nest construction, at least in some cases, requires the removal of large and heavy items, we hypothesize that this can only be achieved by decent sized frogs, possibly explaining the unique size of the species.     

Dhanya,a South-east Asian genus of ozaenine ground beetles

The species of the South-east Asian genus Dhanya are reviewed, and three new species are described: mulu from Sarawak; andrewesi from India; and cylindera from Philippines. Dhanya bioculata is designated as the type-species and a lectotype is designated for this species. The variety pallida is synonymized with its species seminigra. The species cavicola Moore is transferred from Pseudozaena to Itamus. Keys to the genera of South-east Asian Ozaenini and to the species of Dhanya are provided. Morphological details of Dhanya are illustrated with scanning electron micrographs and drawings, and include information on the structure of the prothoracic pits, elytral flanges, and on microsculpture. A cladistic analysis of the species is included and the relationship of the genus to its sister group, Eustra, and to the other genera of Ozaenini is discussed. Specimens of Dhanya are found under bark of fallen logs and in rotting tree stumps in lowland and upland tropical rain forest; an association with ants or termites is suggested for at least one species.     

Observations on zygopine weevil behaviour (Coleoptera: Curculionidae: Zygopinae)

Observations on the behaviour and chosen environment are reported of the zygopine weevils Mecopus audinetii, M. bispinosus, M. fausti, M. pulvereus, Phylaitis v-alba and Osphilia sp. Mecopus audinetii and M. bispinosus were not distinguished in the field, but can be separated by details of the male and female genitalia and by the presence in the male of M. bispinosus of long black hairs on the pronotum. All the species studied were found on the bark of fallen or dying trees, the Mecopus species and Phylaitis v-alba being associated with whitish-silvery bark and the Osphilia species with greenish-brown substrates. The small Phylaitis species was found on branches of smaller diameter than those frequented by the larger Mecopus species. All the species are fairly cryptic in coloration, but when moving the larger species are more visible than the smaller, and the ones on pale bark are more visible than those on greenish-brown bark. Potential predators may be confused by jerky movement patterns observed in all species and the distant shadows cast by the long-legged larger Mecopus. The weevils are not believed to be involved in any mimicry, although this has been suggested for other members of the same subfamily. A single contest between males of Mecopus audinetii/bispinosus was observed, in the absence of a female. Each male attempted to dislodge its opponent from the substrate using its rostrum; the thoracic spines were not seen to be used. Contests between males of Osphilia sp. and Phylaitis v-alba were observed in the presence of females of the appropriate species. The males of Osphilia species attempted to dislodge one another from the back of the female in contention, and also engaged in a spiralling flight together. The males of Phylaitis v-alba did not come into physical contact, but responded to the threat of an approach. During copulation in Mecopus audinetii/bispinosus and Osphilia sp. the male repeatedly brushed the head and thorax of the female with his front legs. In the first species the male stood on the substrate and ‘caged’ the female with his legs and rostrum but in the second the male, ‘rode’ the female. Both species oviposit into the bark of their trees, the females using the rostrum to drill a hole for the ovipositor. The length of the rostrum probably determines the thickness of the bark through which eggs are laid, and hence the area of the region of the tree inhabited by the beetles.     

Assembly of Myrmelachista Roger (Formicidae: Formicinae) in twigs fallen on the leaf litter of Brazilian Atlantic Forest

The nests of Myrmelachista are found in tree trunk cavities and branches. The biology of these arboreal ants is still relatively unknown. We investigated the nesting behaviour of this genus in fallen dry twigs in the Atlantic rainforest of southeastern Brazil. Physical characteristics of the nests, colony demographics, presence of breeders and ant worker sizes were recorded. Samples were collected weekly for 12 months, along open, sunny and undisturbed trails within forest remnants. In all, 202 nests were collected and six species were recorded. Myrmelachista ruszkii had the highest population of immatures and the greatest number of nests found. Myrmelachista nodigera had the smallest workers, was the least populous and the colony was housed in the finest branches. These results expand the current knowledge about the diversity and biology of Myrmelachista in the Brazilian Atlantic forest, and describe polydomic nests and competitive behaviour of M. ruszkii.     

Environmental humidity and leaf-litter depth affecting ecological parameters of a leaf-litter frog community in an Atlantic Rainforest area

We studied a leaf-litter frog community from an Atlantic Rainforest area in the state of Espírito Santo, south-eastern Brazil. Frogs were sampled using 4 × 4-m plots. We recorded 348 individuals from 13 species. The estimated overall density of leaf-litter frogs in the study area was 6.6 frogs/100 m² with an estimated overall frog biomass of 0.04 g/ha. Brachycephalus didactylus was the species with the highest estimated density and highest abundance. Five of the litter frog species recorded are considered endemic to the Atlantic Forest and two species are endemic to the state of Espírito Santo, including Euparkerella robusta, which is considered threatened as the result of habitat loss. The overall abundance of leaf litter was positively related to relative humidity and depth of the leaf litter. The relationship between frog body mass and frog abundance was significant, suggesting that a general biological trend in this relationship occurs in our study area.     

Fungal spore-feeding by adult and larval Mecynothrips hardyi (Priesner) (Thysanoptera: Phlaeothripidae: Idolothripinae)

Mecynothrips hardyi (Priesner), a member of the phlaeothripid subfamily Idolothripinae, is demonstrated to feed on whole fungal spores on hanging dead leaves and branches of Acacia harpophylla (brigalow). The diet primarily comprises spores of a recently described species of Dothiorella (Botryosphaeriaceae). The 14μm-wide food canal enclosed by the maxillary stylets is evidently adapted to imbibe whole spores, and the foregut includes a sclerotized proventriculus with internal ridges that presumably aids in the abrasion and thus digestion of the thick-walled spores.     

Rediscovery of the Hawaiian endemic bark beetle Xyleborus pleiades Samuleson, 1981 on Moloka‘i,with records of three new exotic bark beetles for the island (Coleoptera: Curculionidae: Scolytinae: Xyleborini)

ABSTRACT

During the course of a targeted bark beetle survey of the Hawaiian Islands, insect sampling undertaken in native forest biotopes on Moloka‘i island revealed the presence of one native and three exotic species of xyleborine bark beetles (Coleoptera: Curculionidae: Scolytinae: Xyleborini) hitherto not recorded from the island. We present detailed new island records for these species, which include the second record of Xyleborus pleiades Samuelson, 1981, an endemic Hawaiian species not recorded in over 50 years, and previously known only from two specimens from the island of Maui. The three newly recorded introduced species are widespread pantropical beetles of actual or potential pest status: Xyleborus affinis Eichhoff, 1867, Xyleborinus saxesenii (Ratzeburg, 1837), and Xylosandrus crassiusculus (Motschulsky, 1866). The importance of the records is briefly discussed, and all newly recorded species are illustrated in colour photographs.     

Soil oribatid mite (Acari: Oribatida) diversity and composition in semi-deciduous forest fragments in eastern Amazonia and comparison with the surrounding savanna matrix

We recorded species abundance and richness of oribatid mites along 16 plots established in semi-deciduous forest fragments in Amazonia. The results were compared with a published dataset consisting of an inventory carried out in 38 plots in the surrounding savanna. Totals of 143 and 91 species were recorded in the forest fragments and savanna, respectively. Sørensen similarity index between both environments was 0.44. Ordination of sites according to oribatid mite species composition showed a clear separation between forest fragments and savanna. Rostrozetes ovulum, Archegozetes longisetosus and Eohypochthonius (Eohypochthonius) becki were abundant and frequent in the forest fragments but exceedingly rare in the savanna. Neoppia (Neoppia) schauenbergi, Pseudoppia sp. C, Microppia sp. A and Cosmochthonius sp. A were limited to the savanna. This study also represents an early step toward knowing which groups of species are exclusive to one or another vegetation type or are sensitive to their inherent environmental conditions.     

Nest-site microhabitat association of red-billed leiothrix in subtropical fragmented forest in central China: evidence for a reverse edge effect on nest predation risk?

Previous studies of nest-site selection on a fine scale may reveal limiting resources within habitat types. The red-billed leiothrix (Leiothrix lutea Scopoli, 1786) is a common bird species that lives in the subtropical forests of Asia. Despite many reports of this species from introduced populations, little information has been obtained from its native range. From 2011 to 2013, we studied nest-site selection of red-billed leiothrix at micro-scales in Daweishan Nature Reserve, Hunan Province, central China. A total of 363 nests were found in five vegetation types. We measured the habitat variables and constructed nest-site selection models for nests found in the forest and scrub-grassland. Among the 18 variables measured in the forest, six variables were selected to construct the nest-site selection model: distance to forest edge (DTE), distance to water (DTW), vegetation comprehensive coverage, tree coverage, bamboo coverage and shrub height. According to Akaike’s information criterion, the best model consisted of five of these variables (excluding vegetation comprehensive coverage), and distance to forest edge, distance to water, tree coverage and bamboo coverage had negative effects on nest-site selection. In scrub-grassland, the DTE, DTW, and bush coverage (BUC) were selected from the 13 variables measured, and, accordingly, the best model consisted of DTE and BUC. Model averaging suggested that BUC had a positive effect on nest-site selection. In contrast, DTE has a reverse effect. In addition, DTE differed significantly between successful and failed nests in forest and scrub-grassland. More successful nests were found near the forest edge. Taken together, these findings emphasise the power of fine-scale habitat selection models in identifying relevant habitat variables with a significant effect on preferred habitat and eventually, breeding success.     

The Australian species of Chromotydaeus Berlese and Penthaleus C. L. Koch (Acarina: Penthaleidae)

The Australian species of Chromotydaeus Berlese and Penthaleus C. L. Koch (Acarina: Penthaleidae) are revised. Chromotydaeus quartus n. sp. and Penthaleus falcatus n. sp. are described, and P. major (Dugés) and P. minor (Canestrini) redescribed. P. major is an agricultural pest, but all the other species appear to have no economic importance.     

Ecological aspects of the pumpkin toadlet,Brachycephalus garbeanus Miranda-Ribeiro, 1920 (Anura: Neobatrachia: Brachycephalidae), in a highland forest of southeastern Brazil

Brachycephalus garbeanus is an aposematic toadlet, endemic to the Atlantic Forest in the mountains of the state of Rio de Janeiro, southeastern Brazil. Information regarding the ecology of species in this genus is scarce, with no information on most species, including B. garbeanus. We provide ecological information about B. garbeanus, in particular regarding microhabitat use, sexual dimorphism in body size, and feeding habits. Our study was conducted in a montane area of the Parque Estadual dos Três Picos, the largest State park in Rio de Janeiro. Most of the B. garbeanus in the study area were found on the forest floor leaf litter. Females were larger on average than males. Brachycephalus garbeanus consumed a wide array of prey, comprising exclusively invertebrates and predominantly arthropods. There were seasonal differences in the diet composition, but mites and ants were important in both wet and dry seasons.     

New Neotropical Haplothripini (Thysanoptera: Phlaeothripidae) with a key to Central and South American genera

The tribe Haplothripini includes a large diversity of Thysanoptera–Phlaeothripinae, comprising more than 550 species in about 35 genera. They are characterised by having a maxillary bridge in the head, prosternal basantra well developed and fore wings with a median constriction. Members of this group are present in all geographical regions, but are particularly poorly studied in Central and South America. In this study, we describe a new genus and species, Myrciathrips variabilis gen. et. sp. nov., and a new Haplothrips species; and propose two new combinations: Karnyothrips grassoi (De Santis), and Mirothrips vespicola (De Santis). A key to the nine Haplothripini genera now recognised from Central and South America is provided, together with an updated key to Haplothrips and Mirothrips species. A total of 45 species of Haplothripini are now recognised from Central and South America, and a list of these and their distributions is given. The genera Karnyothrips, Haplothrips and Leptothrips are the most commonly encountered, and some exotic species such as Androthrips ramachandrai and Dolichothrips indicus are now widespread in the Americas.     

Diet and feeding behaviour of the Neotropical parrot snake (Leptophis ahaetulla) in northern Brazil

Specimens (289) of Leptophis ahaetulla from northern Brazil and western Maranhão were examined for the composition of stomach contents. Most prey items were tree frogs, especially those of the family Hylidae (90%). Most of the anurans identified belong to the Scinax ruber species group (27%) and Scinax sp. (25%). Prey size was significantly related to snake length but not to head length. There was no significant difference related to sex in either case. Both sexes preyed on small to medium‐sized items (3–10% of snake snout–vent length). Leptophis ahaetulla seems to manipulate captured prey before ingestion since most of the prey items (83.6%) were swallowed head‐first. Leptophis ahaetulla is primarily diurnal and semi‐arboreal, inhabits disturbed and undisturbed forest, and forages primarily on the ground and in fallen vegetation, where its prey items are likely to be found at rest.     

The Thysanoptera Haplothripini (Insecta: Phlaeothripidae) of Iran

In Iran, 4 genera and 27 species are recorded of the Thysanoptera tribe Haplothripini (Phlaeothripidae, Phlaeothripinae): Dolicholepta Priesner with 1 species, Haplothrips Amyot and Serville with 23 species, Neoheegeria Schmutz with 2 species, and Plicothrips Bhatti with 1 species. Identification keys are provided to these taxa. Three new synonyms are established: H. inoptatus Priesner is a junior synonym of H. globiceps Bagnall, H. iraniensis Priesner is a junior synonym of H. maroccanus Priesner, and H. scythicus Knechtel is a junior synonym of H. leucanthemi (Schrank). Reports of H. cerealis Priesner from Iran are considered to be misidentifications of H. tritici Kurdjumov, and comments are made on the identity of several predatory species related to H. subtilissimus (Haliday) and H. globiceps Bagnall. Several character states used for recognizing taxa in Haplothrips are discussed, and available biological data for each species are presented.     

Orchid bees (Apidae: Euglossini) in Cerrado remnants in northeast Brazil

There is a general lack of information concerning the diversity of bees belonging to the Euglossini tribe in Cerrado areas closest to the Brazilian Amazon. The state of Maranhão is situated in the northeast Brazilian Cerrado and has become the agricultural frontier of the country due to the advancement of monoculture and cattle farming. These activities have suppressed animal and plant populations in large areas of the Cerrado remnants, for which we have not yet obtained adequate scientific knowledge of local species. The objective of this study was to conduct a survey of Euglossini fauna in the northeast Cerrado. We evaluated the variation in species richness, composition and abundance between two distinct vegetation types: Cerrado sensu stricto (s.s.) and gallery forest. Male bees were captured from 7:00 a.m. to 5:00 p.m. over two consecutive days. Captures were carried out once per month from July 2012 to December 2013, using a combination of passive and active collection techniques, including baited traps, as well as a collector with an entomological net to collect bees near traps. We collected a total of 766 Euglossini males belonging to 24 species and five genera. The most abundant species were Eulaema bombiformis, Eulaema nigrita and Eulaema cingulata for the gallery forest site, whereas Eulaema nigrita, Euglossa melanotricha and Euglossa cordata were more abundant in the Cerrado s.s. The gallery forest yielded a higher number of male Euglossini (n = 503, 21 species) compared with the Cerrado s.s. (n = 263, 16 species). The presence of seven exclusive species in the gallery forest and three in the Cerrado s.s. indicated that both environments are important for the maintenance of Euglossini species in this region and highlight the increasing need for conservation programmes for the protection of Cerrado environments.