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.     

The species of the parasitic bee genus Osirinus (Hymenoptera,Apidae)

The species in the genus Osirinus Roig-Alsina are revised. Seven species are recognized, including O. ruficrus, new species, from south-eastern Brazil and O. tarsalis, new species, from western Brazil and Peru. Osiris parvicollis Ducke and O. santiagoi Almeida are transferred for the first time to Osirinus. An identification key based mainly on females is provided.     

Polymorphism in the deutonymph and adult of Sennertia alfkeni (Acari: Chaetodactylidae) associated with the large carpenter bee,Xylocopa appendiculata circumvolans (Hymenoptera: Apidae)

Phoretic deutonymphs of Sennertia alfkeni and S. japonica, both associated with the Japanese large carpenter bee, Xylocopa appendiculata, were distinguished by Fain (1974 Fain, A. 1974. The hypopi of the genus Sennertia Oudemans, 1905, described by Oudemans (Acarina, Sarcoptiformes).. Zool Meded., 48: 219–231.  [Google Scholar]) by body size and the presence or absence of a spine proximal to the pretarsal claw. Despite these morphological differences, rearing of iso‐female lines yielded both morphological forms, thus revealing that both were the same species but functionally different during phoresy. Adults also expressed variation in the form of the dorsal setae, ranging from narrow to broad. We hypothesized that deutonymphal morphology was controlled environmentally, but that the adult setal morphology was at least partially controlled genetically. Both types of deutonymphs disembarked from a female bee during the host tunnelling through provisioning of nests in spring, but there seemed to be no behavioural difference between the two morphs at the time of disembarkation.     

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.     

Temperature responses and habitat sharing in two sympatric species of Okanagana (Homoptera: Cicadoidea)

Okanagana striatipes and O. utahensis are species synchronous in location of activity and utilization of host plants. They possess similar acoustic behavior. Analysis of calling songs shows that calls overlap in frequency but differ in temporal pattern. Based on characteristics of the cicada auditory system and the species recognition mechanism, the potential for acoustic interference exists. Both species are ectothermic behavioral thermoregulators. Measurements of thermal preference and body temperature during singing show that although thermal preferences are similar, O. utahensis sings at a significantly higher body temperature. Differences in body temperature required to coordinate singing in the 2 species provide a partial temporal separation of acoustic signaling. We suggest the physiological mechanisms that permit synchronous utilization of a habitat by the 2 species are the production of calling songs of different temporal patterns and the presence of different thermal requirements, which may permit and/or facilitate temporal separation of the acoustic environment during the day.     

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.     

New species of the bee genus Augochlorodes Moure (Hymenoptera,Apidae s. l., Halictinae)

Five new species of the bee genus Augochlorodes from Brazil are described and the type species, A. turrifaciens Moure, 1958 Moure, J. S. 1958. Augochlorodes, a new genus of Halictinae from Brasil (Hymenoptera, Apoidea).. J Kansas Entomol Soc., 31(1): 53–55.  [Google Scholar], is redescribed. The new species are: A. clementis sp. nov. (from the states of Paraná, Santa Catarina and Rio Grande do Sul), A. incomitatus sp. nov. (Rio Grande do Sul), A. politus sp. nov. (Paraná), A. rostratus sp. nov. (Rio Grande do Sul) and A. vachali sp. nov. (Paraná, Santa Catarina, São Paulo). A discriminant function analysis using head measurements is presented to help distinguish the species. An identification key for the species is provided.     

The nesting habits and flower relationships of the bee Melitoma ameghinoi (Holmberg) (Hymenoptera,Apidae), with notes on its taxonomy and distribution

ABSTRACT

The nesting behaviour of Melitoma ameghinoi was studied in the province of Chaco, Argentina. Contrary to other Melitoma species, which are known to nest on banks or other vertical or sloping surfaces, the nests were found on horizontal ground, in extremely hard clay soil. The nests were shallow, with three to four vertical cells. The short turrets pointed upwards for a short stretch and then were strongly curved, with the entrance directed towards the soil surface. The floral relationships of this species were studied by pollen analysis of faeces from cells, a pollen mass, scopal loads of specimens, and direct observation of floral visits. Pollen counts and field observations indicate that M. ameghinoi collects pollen exclusively from Ipomoea species. A compilation of pollen sources for species of Melitoma is presented. All known species, including M. ameghinoi, fall in the category of narrowly oligolectic. A discussion of the taxonomic relationships of the species is presented, and a lectotype is designated.     

Nesting biology and behavioural ecology of the solitary bee Monoeca haemorrhoidalis (Smith) and its cleptoparasite Protosiris gigas Melo (Hymenoptera: Apidae: Tapinotaspidini; Osirini)

The species Monoeca haemorrhoidalis, the largest species in the genus, occurs in the Atlantic rainforest of southeastern and southern Brazil. The aim of this study was to investigate the nesting ecology of M. haemorrhoidalis and its interactions with natural enemies. Nest aggregations were studied in an area at the transition between Dense and Mixed Temperate Rainforest, south Brazil. The period of nest construction and cell provisioning started in October and stopped in February. Plant species of the families Orchidaceae, Styracaceae and, mainly, Malpighiaceae, were the most important pollen and floral oil resources that were used in brood cell provisioning. During the nest construction activities, 27 insect species were observed at the nesting sites. The cleptoparasitic bee Protosiris gigas was one of the main causes of M. haemorrhoidalis mortality. Some behavioural and biological data of P. gigas are also reported.     

Larval food sources of Centris (Heterocentris) analis (Fabricius, 1804) (Hymenoptera: Apidae), an oil-collecting bee

Pollen analysis of larval food allows identification of plants used as nest provision sources. Considering the importance of Centris analis in pollination, we aimed to identify its plant sources, food niche width in Cerrado, and analyze the use of sources between cool/dry and warm/wet seasons. We sampled 22 nests collected in two areas from February 2008 to October 2009. Heteropterys spp. (Malpighiaceae) were the main pollen sources, but Byrsomia spp. (Malpighiaceae), Banisteriopsis malifolia (Malpighiaceae), Solanum lycocarpum (Solanaceae) and Machaerium spp. (Leguminosae) were also important food sources. There was no difference in the use of the sources between the seasons (F_1,100?=?0.001; p?=?0.979). Despite the high number of pollen types (n?=?14) the food niche widths were low, H?=?0.777 and H?=?0.949, which can be explained by the dominance of some food items. Hence, C. analis use, profusely, a few plants as food sources that could be considered conservation targets.     

Six new species of Microstigmus wasps (Hymenoptera: Sphecidae), with notes on their biology

Six new species of Microstigmus are described and illustrated. Nests and other aspects of their biology, when known, are also described. Microstigmus puncticeps sp. n. (northern Brazil and Peru) and M. xanthosceles sp. n. (Central America and western Colombia) belong to two distinct groups not closely related to previously described species. Microstigmus cooperi sp. n. and M. crucifex sp. n. (both from northern Brazil and Colombia) represent basal lineages within the large group including M. brasiliensis, M. theridii, M. lobifex, etc. Microstigmus flavus sp. n. (southeastern Brazil) is closely related to M. lobifex. Microstigmus simplex sp. n. (northern Brazil) is a basal lineage within the group containing M. guianensis and M. arlei. Reuse of nests of M. nigrophthalmus by M. flavus sp. n. and of M. crucifex sp. n. by a species of the M. theridii complex is reported for the first time for Microstigmus.     

Habitat selection and nest construction behaviour in some Afrotropical species of Ammophila (Hymenoptera: Sphecidae)

Nest construction behaviour and nest site selection are described for seven species of Afrotropical Ammophila.

Four species were atypical in their nest siting. Ammophila beniniensis selected shaded sites in well vegetated habitats, A. vulcania selected small clumps of vegetation in otherwise open habitats. A. insignis nested in vertical banks, old animal burrows and caves. A. braunsi is unique amongst Ammophila in its use of abandoned burrows of other wasps in non-friable clay soils. A. ferrugineipes, A. dolichodera and A. dolichocephala nested mostly in open habitats.

Methods of soil waste disposal, sealing of nests and their final coverage, differed interspecifically, in some cases intraspecifically, but often apparently in response to the habitat.

Temperature conditions, affected by habitat, influenced the depth to which nests were dug by some species. A. insignis switched sites in response to seasonal changes in temperature regimes in vertical banks.

The existence in particular species of both primitive and advanced aspects of nesting behaviour questions their use in assessing the evolutionary status of these species.     

Variation in the incidence of botfly larvae ( Cuterebra ) in two sympatric species of Peromyscus in northern Colorado

Differences in botfly parasitism were observed in the sympatric species Peromyscus maniculatus and P. difficilis in northern Colorado. The overall incidence of infection was 13.7 percent in P. maniculatus and only 0.6 percent in P. difficilis. The incidence of parasitism was affected markedly by trapping locality and by month of capture.     

Reproductive strategies of two sympatric species of Hyalella Smith, 1874 (Amphipoda,Dogielinotidae) in laboratory conditions

This study was performed in order to test theoretical predictions that sympatric species might show different reproductive strategies to facilitate their coexistence. The duration of precopulatory mate‐guarding behaviour, body size of ovigerous females, embryonic and postembryonic development time, fecundity, and viability of the sympatric amphipod species Hyalella pleoacuta and H. castroi were investigated under laboratory conditions (19±1°C and 12 h light/dark photoperiod). Specimens were collected with nets in autumn and spring 2004, and summer and winter 2005 in the Vale das Trutas, São José dos Ausentes County, southern Brazil, and transported to the laboratory. Both species of Hyalella showed similar reproductive strategies, especially in respect to the duration of the precopula, duration of the embryonic period, and fecundity. However, these species differed in body size of ovigerous females, duration of the postembryonic period, viability, and body size of juveniles that remained in the marsupium and those released by females. These differences in the reproductive traits of H. pleoacuta and H. castroi may facilitate their coexistence in nature.     

Abundance variations and life history traits of two sympatric species of Neotropical annual fish (Cyprinodontiformes: Rivulidae) in temporary ponds of southern Brazil

We investigated abundance variations and life history traits (body size, sex ratio, length–weight relationships and condition factor) of two species of annual fish (Austrolebias minuano Costa and Cheffe and Cynopoecilus fulgens Costa) in temporary ponds of southern Brazil. Six samples were taken from small temporary ponds during three annual seasons over 2 years (2008–2009). A total of 104 individuals of A. minuano and 433 individuals of C. fulgens were collected. The abundance of both species tended to decrease from autumn to spring in the 2 years. The overall sex ratio of A. minuano and C. fulgens were 1.0 male to 1.8 females and 1 male to 1.04 females, respectively. Juveniles of both species occurred only in autumn over the two years and no adult was observed during this season. While the length–weight relationship of A. minuano indicated hyperallometric growth, the relationship of C. fulgens indicated values close to isometric growth.     

Breeding biology of the threatened Campo Miner Geositta poeciloptera (Aves: Scleruridae), a Neotropical grassland specialist

The Campo Miner is a threatened grassland passerine endemic to the South American Cerrado, whose life history is almost unknown. In this paper, we studied during three breeding seasons (2014 to 2016) the breeding biology of a colour banded population of the species found in the Upper Rio Grande Grasslands, south-eastern Brazil. We found 98 nests, 81 of which became active and were monitored. The Campo Miner breeds in frequently burnt-and-grazed natural grasslands, successfully nesting in highly disturbed sites, such as dirt banks along roads and even in mine pits. The species is socially monogamous and both parents build the nest, which is a cavity/with-tunnel/simple/platform type. The nest chamber is lined with a platform made of grass fragments, charcoal, hairs, and mammal faeces. The most common clutch size is three eggs (n = 66), with some nests containing one (n = 1), two (n = 12) or four eggs (n = 2). The egg is white and pyriform and the incubation, performed by both parents, lasts 17.5 days. Mean nestling period is 15.5 days, with both parents feeding the young. Breeding season lasted for about 125 days (August to December) and multiple breeding attempts in a single season were common, with a maximum of three attempts recorded. All species of Scleruridae built their nests inside cavities dug in the soil with an access tunnel to it, where they lay a small clutch (usually 2–3 white eggs), but no other species in the family has been studied in detail to date. Further studies are required to understand why a species apparently tolerant to anthropogenic impacts such as G. poeciloptera can be so rare, patchily distributed and threatened throughout its range.     

Egg production of two sympatric species of Hyalella Smith, 1874 (Crustacea,Amphipoda, Dogielinotidae) in aquaculture ponds in southern Brazil

This study tests the hypothesis that sympatric species of Hyalella may show different reproductive strategies that permit their coexistence. Ovigerous females were collected monthly with nets during a 1-year period in two aquaculture trout ponds in Vale das Trutas, São José dos Ausentes County, southern Brazil. In both species there was a decrease in the number of embryos in the brood pouch during embryonic development, and an increase in egg volume. However, the two species differed in the body size of ovigerous females, number of eggs and juveniles per female, brood mortality rate, egg size and hatching size of juveniles. Egg production continued throughout the year, with the highest number of eggs produced during winter and spring by Hyalella pleoacuta, and winter, spring and autumn by Hyalella castroi. These differences in the reproductive traits of species of Hyalella may permit their coexistence in nature.     

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.     

Sperm ultrastructure in two species of Gyraulus (Gastropoda: Pulmonata: Planorbidae)

Sperm morphology offers a rich source of potentially informative characters for gastropod taxonomy and in this study it was used to provide additional information for Gyraulus (Armiger) crista (Linnaeus, 1758), whose taxonomic position within the Planorbidae Rafinesque, 1815 remains uncertain. Sperm morphology in G. (A.) crista and G. (Gyraulus) albus (Müller, 1774), the type species of the genus, was examined using light microscopy, scanning electron microscopy and transmission electron microscopy. The ultrastructure of spermatozoa in the two species was found to conform to the general pattern characteristic of the Hygrophila Férussac, 1822: the spermatozoa had an anterior head containing an acrosomal complex (apical vesicle and acrosomal pedestal) and cone-shaped nucleus, followed by a very long midpiece with glycogen spirals, and then by a glycogen piece and tail. Although the spermatozoa of the two species shared some common features (one nuclear keel and four glycogen spirals), they differed significantly in length, morphology of the annulus and structure of the spiral surface ridges. There were also some differences in the size and structure of the acrosomal pedestal and the shape of the nucleus. The spermatozoa of the two Gyraulus species are compared with those of other Hygrophila and the possible importance of sperm morphology for the taxonomic status of G. (A.) crista is discussed.     

Basking behaviour in two sympatric herbivorous lizards (Liolaemidae: Phymaturus) from the Payunia volcanic region of Argentina

We studied several aspects of the thermal biology of two coexisting saxicolous species of the genus Phymaturus (Liolaemidae) at the Payunia, a volcanic region in Argentina where harsh conditions prevail. We marked individuals in grids and assessed the environmental conditions when the individuals showed their maximum activity (i.e. when more than 50% of marked individuals were active), the time spent basking, and the postural behaviour in relation to different cloudiness conditions. We found that temperatures recorded when the species exhibit their peaks of activity were higher for Phymaturus payuniae, the smaller species, during the summer at one of the three studied sites. Phymaturus roigorum exhibited the longest basking periods, but during these longer periods cloudy conditions prevailed. Both species adopted a head-up posture when conditions were sunny and a head-down posture when under cloudy conditions. This is the first contribution where thermal aspects of two sympatric species of Phymaturus are evaluated.