Using short-term surveys and mark–recapture to estimate diversity and population size of orchid bees in forest formations of the Brazilian savanna

Studies on the diversity and population dynamics of euglossine bees in forest formations of the Brazilian savanna can be notably informative considering that most species are forest-dependent. The current study aimed to estimate the diversity and population size of euglossine bees using short-term surveys and the mark–recapture method. We also compared short-term surveys with monthly surveys over a 1-year period (long-term surveys) to assess the species diversity. The study occurred in seven forest formations of the Brazilian savanna. We collected 14 species and marked 375 males but recaptured only 23 (6.1%). The population size of Euglossa bees ranged from 111.1 ± 34.4 to 1384.5 ± 384.6 males. The diversity indices achieved through the short-term surveys were similar to or higher than those obtained from long-term studies. The low recapture rate of euglossine males seems to be the result of their long-distance dispersal capacity. We also proposed that short-term surveys be viewed as a favourable alternative to long-term studies on diversity estimation and that euglossine bees can occur in small populations in some forest formations studied.     

Food niche of Exomalopsis (Exomalopsis) fulvofasciata Smith (Hymenoptera: Apidae) in Brazilian savannah: the importance of oil-producing plant species as pollen sources

Exomalopsis are ground-nesting species, and their food-niche breadth is little known due the difficulty in locating the nests and finding efficient bait plants to attract these bees. Some species of Exomalopsis were recorded as tomato, hot pepper and eggplant pollinators. Information about the food niche could be useful to increase Exomalopsis populations, providing consistent and comparable data for the enrichment of natural and crop areas with adequate plant sources. This study aimed to determine the food niche and the role of pollen size in the diet of E. fulvofasciata. We analysed pollen loads of 28 individuals of E. fulvofasciata collected from bait plants, in two natural areas of the Brazilian savannah. Only five pollen types belonging to the families Malpighiaceae, Solanaceae, Leguminosae, Myrtaceae and Lythraceae were important for this species. This result indicates that E. fulvofasciata is probably a polylectic species. However, we noticed that the Byrsonima used as bait plants contribute significantly for its larval provision, indicating that small pollen grains were more frequently collected.     

Patterns of insect flower visitation in Lavandula buchii Webb (Lamiaceae), an endemic shrub of Tenerife (Canary Islands)

The foraging ecology of insect visitors of the endemic lavender Lavandula buchii (Lamiaceae) was studied in a relict population of the plant in north-west Tenerife (Canary Islands). Timed observations were used to describe this pollination system in terms of the structure of the visitor assemblage, foraging patterns and efficiencies of the main insect species. The visitor pool was dominated by anthophorid solitary bees. Furthermore, it was characterized by a high level of endemicity and a small number of species compared with continental relatives of Lavandula. The main visitors, two anthophorids and a bombyliid fly, clearly differed in their foraging behaviour, i.e. visitation frequency, visit duration, rate of flower probing, and in anatomical traits (body size and proboscis length). In these terms, the bees were by far more efficient foragers than the fly. These results are discussed in the context of insect-flower interactions in insular pollination systems.     

Time-lapse photography reveals the occurrence of unexpected bee-pollination in Calanthe izuinsularis,an endangered orchid endemic to the Izu archipelago

Calanthe izuinsularis is a rare, beautiful and fragrant orchid endemic to the Izu archipelago. Although it is known that mainland populations of closely related Calanthe species are pollinated by medium- to large-sized bees, it is likely that C. izuinsularis has been forced to alter its floral biology to attract alternative pollinators, as large-sized bees are rarely found on the Izu Islands. Indeed, the unusual floral characteristics of C. izuinsularis, which produces pale flowers that emit a strong and fragrant scent during the night, are considered the adaptation to a moth-pollinator syndrome. As expected, our time-lapse photography using a digital camera revealed that the inflorescences of C. izuinsularis were most frequently visited by nocturnal moths such as Noctuidae, Geometridae and Crambidae, which accounted for 50% of all insect visits (in terms of both the number of frames with captured visitors and the number of times visited). However, our study could not provide evidence of a pollinator shift towards moths because none of the moth species was observed with pollinaria. On the other hand, our study found that the pollinaria of C. izuinsularis could become attached to the mesothorax of the small-sized sweat bee Lasioglossum occidens. Therefore, our study suggests that C. izuinsularis is still somewhat dependent on bee pollination, while the orchid has changed its floral colouration and scent. The occurrence of bee-pollination in C. izuinsularis would provide an explanation for how the natural hybridisation between C. aristulifera, C. discolor and C. izuinsularis can occur.     

On three new species of Mesochra Boeck, 1865 (Harpacticoida: Canthocamptidae) from Iceland

Three new species of Mesochra Boeck, 1865, were found during two surveys in south‐western Iceland of the feeding ecology of juvenile lumpsucker Cyclopterus lumpus Linnaeus, 1758, in floating seaweed and the seasonality of harpacticoids in a low intertidal pool. Only two species of the genus, M. lilljeborgi Boeck, 1864 and M. rapiens (Schmeil, 1894), have been found in previous studies in Iceland. The three new species, Mesochra ingolfssoni sp. nov., Mesochra snoppa sp. nov., and Mesochra freyri sp. nov. resemble M. stellfeldi Jakobi, 1954 in the normal (not dwarfed) outer seta of both male and female P5 EXP, but differ in that M. stellfeldi possesses unequal inner baseoendopodal setae on the female P5. The three new species resemble M. pygmaea (Claus, 1863) in the equal inner baseoendopodal setae of the female P5, but differ in the dwarfed outer seta of the male and female P5 EXP present in M. pygmaea, and can be easily separated by shape of the rostrum, female P6, number of pinnate elements on the second antennular segment, general shape of the antenna and shape of the lateral and distal inner spines, among other character states.     

Differentiated use of pollen sources by two sympatric species of oil-collecting bees (Hymenoptera: Apidae)

We identified the food niche breadth of two sympatric species of oil-collecting bees, Centris (Heterocentris) analis (Fabricius, 1804) and Centris (Hemisiella) tarsata Smith, 1874, based on pollen analyses of larval food. We tested differences in the use of pollen sources considering the anther type and pollen size of the flowers. The species presented a low similarity in the use of pollen sources and C. analis had a wider niche breadth than C. tarsata. Centris analis mainly used Heteropterys spp. and other flowers with non-poricidal anthers. In contrast, C. tarsata commonly used Solanum lycocarpum A. St.-Hil., as well as other flowers with poricidal anthers. Despite the differences in pollen composition of larval food, both species predominantly used medium-sized pollen grains. Although C. analis and C. tarsata are sympatric species, belonging to the same functional group and presenting an overlap in nesting periods, they used different pollen sources, which suggests the occurrence of food niche partitioning.     

Foraging ecology and behaviour of the ponerine ant Ectatomma opaciventre Roger in a Brazilian savannah

This study provides a detailed account of the foraging behaviour of the ponerine ant Ectatomma opaciventre in a ‘cerrado’ savannah in south-east Brazil. Our observations suggest that this species has an exclusively diurnal foraging pattern. Feeding habits included both predation and scavenging, with termite workers and leaf-cutting ants as the most important food items. Contrary to all other Ectatomma species studied to date, no liquid food such as hemipteran honeydew or plant nectar was collected. Foragers showed clear individual foraging area fidelity.Workers of E. opaciventre employed a typical individual foraging strategy, i.e. there was no co-operation between foragers in the search for or retrieval of food, neither by tandem running nor by trail laying. Nest density was considerably lower than in other Ectatomma (0.015 nests per m²). The observed mean distance to the nearest neighbouring nest was 5.85 m, with a significant tendency toward over-dispersion. Nests were more frequently found in specific microhabitats, which may suggest active choice of nesting site by founding queens.     

Spatial niche variation in two sympatric species of Bokermannohyla (Anura: Hylidae) in southeastern Brazil

We studied patterns of microhabitat use by adults of two sympatric Bokermannohyla species at the Reserva Particular do Patrimônio Natural Santuário do Caraça, southeastern Brazil. We selected three streams, one where both species occurred in syntopy and the other two where each one occurred alone. We sampled 150-m transects in each stream throughout 1 year, recording microhabitat features for each frog located (substrate type, height and distance from water). Microhabitat availability varied between dry and wet seasons in all streams, and overall microhabitat diversity changed in two streams. Bokermannohyla nanuzae seemed to have a niche contraction in the presence of Bokermannohyla martinsi, but this only happened during the dry season. Microhabitat requirements during the wet season may be closely linked to similar reproductive needs that probably represent a strong selective pressure, forcing niche overlap.     

Systematics and fossil evidence of host-parasitoid relationships of Calamiscus Borgmeier (Diptera: Phoridae)

The life history and hitherto unknown males of Calamiscus cryptopalpis are described. A second species of this genus, C. inflativenis n. sp. is described from Costa Rica. The species C. cryptopalpis is a gregarious parasitoid of injured stingless bees in Costa Rica. The co-occurrence of a specimen of the genus Calamiscus in a piece of amber with the oldest known fossil bee is hypothesized to be the most ancient host-parasitoid relationship between a pair of insect species documented thus far. The otherwise rarely-seen fly was probably lured to the amber site by the alarm pheromones of the bee, and then trapped in the sticky tree resins.     

Prey choice and raiding behaviour of the Ponerine ant Pachycondyla analis (Hymenoptera: Formicidae)

Termite raiding behaviour of the African poneromorph ant Pachycondyla analis was studied at Mpala, Kenya. In all, 330 raids were observed with the raiding activity showing peaks in the morning and evening. Time spent at the termite source was positively correlated with the numbers of termites taken. The sizes of foraging parties, number of termites taken, distance travelled and time spent at termite sources also showed a positive correlation. Pachycondyla analis preyed significantly more on Microtermes spp. than they did on Odontotermes spp. but no significant differences were found in terms of predator efficiency even though many ants were injured in raids on Odontotermes spp. compared with those on Microtermes spp. Our results indicate that P. analis seems to forage optimally, balancing the costs of energy with prey reward and prey choices were not only influenced by prey abundance, but also by the costs of foraging, as influenced by prey defences, size and foraging behaviour.     

Life cycle of Huarpea fallax (Hymenoptera: Sapygidae) in a xeric forest in Argentina

This study describes the life cycle of Huarpea fallax (Hymenoptera: Sapygidae) in a xeric forest in La Pampa province, Argentina. This cleptoparasitic wasp attacks the nests of two species of leaf-cutter bees: Megachile catamarcensis and Anthidium vigintipunctatum, both belonging to the family Megachilidae. Nests of these bee species were obtained during a trap-nesting programme. Adult emergence showed a unimodal pattern indicating a univoltine life cycle. The period from egg-laying to adult emergence lasted for 10–13 months; however, one female took about 2 years to emerge, suggesting parsivoltinism. Most females attack one cell per host nest, the outermost cells being the ones most parasitized. However, the position of the attacked cells was variable. In this paper, although there were insufficient data to prove a correlation, the data suggest a positive trend between body size of sapygid wasps and their host bees.     

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.     

Foraging behaviour of three sphaerodactylin geckos on Trinidad and Tobago (Sauria: Gekkonomorpha: Sphaerodactylini: Gonatodes)

Taxonomic families of insectivorous lizards are usually characterized by one of two distinct foraging modes, namely ambush ‘sit-and-wait’ or active ‘widely foraging’. In the Gekkonomorpha the situation has been unclear and in dispute, and among these, that in the Sphaerodactylini is almost unreported. We, therefore, examined the foraging mode of three sphaerodactylin species on Trinidad and Tobago, in May—June 2000 (totalling 72 individuals, observations averaging 23.6 min/individual). In terms of species averages, Gonatodes vittatus, G. humeralis and G. ocellatus all moved for only 1.6–3.55% of observation time (PTM, percent time moving), and switched from sitting to locomoting only 0.18–0.36 times per minute (MPM, moves per minute). The genus thus is a strict sit-and-wait forager. In G. vittatus, the foraging mode was unaffected by sex or habitat structure. In all three species, foraging mode was unaffected by the time of day or air temperature. In G. humeralis, foraging activity (PTM or MPM) correlated with light intensity in the forest within a population (at least MPM) and among populations (at least PTM). Among the three species, too, foraging activity (PTM and MPM) ranked with light intensity during sampling. In all three species, the geckos perched for 68–76% of the time (at any height) with the head pointing down, apparently so as to see better. In conclusion, the three species are strict sit-and-wait' visual hunters that are dependent on light.     

Natural history and ecology of foraging of the Camponotus crassus Mayr, 1862 (Hymenoptera: Formicidae)

ABSTRACT

Ants are abundant in terrestrial ecosystems, especially in the Brazilian Cerrado, where they can play several roles at different levels of the food chain, including protection of plants against herbivores. Although there are many studies that evaluate the ant–plant interaction in the Cerrado, little is known about the natural history of most species of ants. Camponotus crassus Mayr, 1862, for example, is considered one of the main agents of plant biotic defence in Cerrado. But there are no studies specifically focused on this species, which hinders the understanding of how arthropod–plant interactions are structured in Cerrado. Here, we describe the natural history and ecology of the foraging of the C. crassus. We conducted the study from January 2013 to December 2014 in 10 quadrants of 40 m² to measure: the abundance, density and distribution of nests, location of the nests, the internal structure of the nests, the daily foraging of workers out of the nest, the food items they collect and the existence of territoriality and dominance of the workers on the soil and vegetation. We found 18 nests, 13 in the soil and 5 in hollow trunks on the ground with variable internal structures. The distribution of nests is aggregate, with density of 0.045 nests/m² and average distance of 3.73 m between nests. The foraging activity occurs on the daytime during the rainy and dry season. Extrafloral nectar and honeydew were the resources most collected, comprising 83.33% of the resources in the rainy period and 30% in the dry period. Camponotus crassus is a dominant species, especially on vegetation, although it also forages on the soil. This is the first study to evaluate in detail the natural history and foraging ecology of C. crassus, a diurnal, aggressive and territorial ant that mainly forage climbing onto the plants.     

The first Leptanilloides species (Hymenoptera: Formicidae: Leptanilloidinae) from eastern South America

We describe a species of the exclusively Neotropical dorylomorph ant genus Leptanilloides (Leptanilloidinae), Leptanilloides atlantica sp. nov., based on workers collected in the Atlantic Forest, São Paulo, south-eastern Brazil. The 11 species of Leptanilloides described are known from relatively high altitudes in western America (from the Andes foothills in Bolivia to Sierra Morena in Mexico). The discovery of a Leptanilloides species in south-eastern Brazil represents a significant range extension for the genus; this new species shares characters with Leptanilloides biconstricta (Bolivia), Leptanilloides femoralis (Venezuela) and Leptanilloides gracilis (Mexico) and may be distinguished based on a combination of traits. The hypogaeic habits of Leptanilloidinae combined with inefficient collecting techniques may explain the paucity of information and of specimens of this group in most museum collections as well as its present apparent disjunct distribution. We compare Leptanilloides distribution to that of other organisms that show similar disjunct patterns in the Andes and montane sites in the Brazilian Atlantic Forest. http://www.zoobank.org/urn:lsid:zoobank.org:pub:E7E334AA-58C0-455D-A0A6-724D29226DD0     

Morphology of oil-collecting pilosity of female Rediviva bees (Hymenoptera: Apoidea: Melittidae) reflects host plant use

The oil-collecting hair morphology and pilosity on female foretarsi for all 26 species of the southern African endemic bee genus Rediviva was studied and related to host plant use based on about 2700 flower visitation records. Four different types of tarsal pilosity and six principal hair types are identified. Rediviva bees collect floral oil from 12 plant genera representing the families Iridaceae, Orchidaceae, Scrophulariaceae and Stilbaceae, with Diascia being the most frequently used host. Differences in foretarsal pilosity reflect the availability of floral oil and elaiophore morphology of the principal host flowers. Rediviva species with short female forelegs exhibit a greater diversity of tarsal oil-collecting pilosity than long-legged species. This contradicts an earlier hypothesis that the pilosity of species with shorter legs might be less complex than in Rediviva with elongate forelegs.     

Foraging mode of Australolacerta rupicola (FitzSimons, 1933) (Sauria: Lacertidae): evidence of seasonal variation in an extremely active predator?

Foraging mode of the endemic Soutpansberg rock lizard (Australolacerta rupicola) was determined by (1) measuring the number of movements per minute (MPM) and the percentage time spent moving (PTM); and (2) analysing faecal samples. Furthermore, these criteria were related to diet composition, proportion of attacks initiated while moving and foraging substrate. The results are discussed in comparison to the foraging modes of 20 other lacertid species. Values for MPM and PTM as well as faecal analysis indicate an active foraging strategy for A. rupicola. Although rock living, this species mostly forages in leaf litter where it is well camouflaged while actively searching for sedentary prey. Even in comparison to other active foragers of the family Lacertidae, A. rupicola displays the prototypic behaviour of a widely foraging lizard with very high PTM and very low MPM.     

Secondary sexual characters in Celaenorrhinus and the delimitation of the genus (Lepidoptera,Hesperiidae)

Summary

Scent producing organs involving parts of the thorax as well as of the abdomen in males of Calaenorrhinus and some related genera are described. The unique character of abdominal pouches with scent hairs is applied to delimit the genus Celaenorrhinus Hübner, 1819, the only pantropical genus of the Hesperiidae. As a consequence, the genera Orneates Godman and Salvin, 1894, and Charmion de Nicéville, 1894, are placed in synonymy. Two species without secondary sexual characters are also considered to belong to Celaenorrhinus, viz., Plesioneura aurivittata Moore, 1865, and Plesioneura jao Mabille, 1889, the latter being placed in Celaenorrhinus for the first time. The evolution of the described scent organs is discussed in relation to their geographic distribution.     

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.     

Diet of tropical insectivorous birds in lowland Malaysian rainforest

ABSTRACT

Despite the importance of diet in avian ecology, knowledge of bird diet in tropical regions, particularly South-East Asia, is limited. Assessing predator–prey relationships of how energy flows across ecosystems provides insight into niche segregation of sympatric species. We examined induced-regurgitation samples from 15 species of insectivorous birds – 12 babblers and three flycatcher-like species – from the Krau Wildlife Reserve, central Peninsular Malaysia. The main objective of this study was to compare and characterise the diet of similar trophically insectivorous birds so as to examine the occurrence of dietary overlap or segregation. The majority of identified prey items belong to the following arthropod taxa: Coleoptera (53%), Hymenoptera (19%), Blattodea (11%), and Araneae (11%). The diet of all bird species slightly overlapped (p = 0.070) but network analysis yielded a relatively low value (R_o = 0.53), indicating dietary divergence may have occurred among the studied bird species, possibly reflected by the variation in proportion of arthropod groups. A high proportion of Coleoptera and three other arthropod groups (i.e. Hymenoptera, Blattodea and Araneae) in the diet of studied birds could be related to their richness and abundance in aerial leaf-litter, the substrate preferred by most babblers. Dietary differences may further be explained by variations in bill shapes and sizes, likely corresponding to prey size. Unique foraging strategies (utilising different vertical strata, microhabitats, and attack manoeuvres) could also lead to dietary separation among sympatric species. Flycatcher-like species were expected to flycatch different prey items (families or lower taxa) versus the gleaning birds (most babblers). This study successfully discerned more details on the diets of insectivorous birds inhabiting Malaysian forests, providing a foundation for future studies on the ecology and biology of understorey birds.