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.     

Strong phenological differences between two populations of a Neotropical funnel-web wolf spider

Comparisons of phenological patterns among populations within a species are uncommon in arachnids. Aglaoctenus lagotis is a wolf spider that lives in funnel-webs across South America. The aim of this study was to describe the phenological patterns of two distant populations of A. lagotis (central Argentina, CA, and southern Uruguay, SU). Individuals of each population were sighted along transects, every month for two years. The CA and SU populations differed in their phenological patterns (Wald χ² = 966.94, df = 66; p <0.001). The CA population showed a spring–summer unified reproductive season and immature individuals overwintered. SU showed the sexual period during autumn, the maternal period during spring–summer and the females, mostly mated, overwintered. These strong differences imply temporal isolation in mating possibilities between both populations. The differences encountered could be due to phenotypic plasticity or have a phylogenetic basis. Interpopulation studies of other features of A. lagotis would show whether they also vary, suggesting speciation.     

Ecology and conservation of the endangered quillwort Isoetes sinensis in China

Isoetes sinensis Palmer is an East Asia endemic fern that faces impending extirpation from the expansive area of Mainland China. Presently, only two natural populations are known to exist in this vast region. Both populations have decreased by about 50% within the last 4 years. This reduction is most probably related to the decline in the size of the wetlands since reproductive activity, spore production, and recruitment were noticeably lower at the microsites occurring in smaller ponds. The decline in population size seems to be associated with succession from marsh to dry land at the habitats of both populations. The study revealed that individuals in both populations produced copious numbers of spores suggesting adequate fecundity, furthermore high levels of spore germination were obtained in laboratory experiments. However, inefficient spore dispersal appears to have contributed to the limited spread of the species. The sex ratio in both populations was male‐biased. Several factors are identified here as posing a threat to Isoetes sinensis populations in China, chiefly the loss of habitat due to infrastructure construction and competition with adventive weed species for establishment on available sites. Disturbance by introduced mammals during browsing and trampling by livestock farm workers, as well as tourists, further contribute to the diminishing numbers of Isoetes sinensis at the study sites.     

Comparison of natural histories and karyotypes of two closely related ant‐eating spiders,Zodarion hamatum and Z. italicum (Araneae,Zodariidae)

Based on morphological characters, two species of the genus Zodarion, Z. hamatum and Z. italicum, were placed into the italicum group. The aim of this study was to evaluate similarity of these two species in respect of various aspects of their natural history and karyotypes. Both species had similar phenological patterns, being univoltine, but some specimens reached adulthood the same year before winter. Both representatives had nocturnal activity and were able to capture various ant species. Zodarion hamatum seems to be specialized on Myrmicinae ants, and Z. italicum on Formicinae ants. Zodarion hamatum showed more agile predatory behaviour than Z. italicum presumably due to specialization on Myrmicinae ants, which have lower population density. Both species are generalized mimics of bicoloured (orange‐dark brown) ants, such as Lasius emarginatus; they performed similar courtship and mating. The two study species exhibited contrasting reproductive strategies. Zodarion hamatum spiders had higher fecundity than Z. italicum as a result of larger body size but Z. italicum had larger eggs than Z. hamatum. This is presumably an adaptation to different availability of prey ants. Both species had the same diploid chromosome number, sex chromosome system and pattern of X chromosome heteropycnosis in testes. Results support a very close relationship between these two Zodarion species.     

Spatial and temporal distributions of juvenile horseshoe crabs (Arthropoda: Chelicerata) approaching extirpation along the northwestern shoreline of the New Territories of Hong Kong SAR,China

Juvenile horseshoe crabs, Tachypleus tridentatus and Carcinoscorpius rotundicauda, with prosomal widths of between 11.5 and 102.5 mm, occur along Hong Kong's northwestern shoreline abutting Deep Bay where dissolved oxygen (DO) has been identified as the principal factor determining distribution and survival. Unreported upon hitherto, however, Tachypleus tridentatus occurred consistently in association with sea-grass (Halophila beccarii) beds, with DO concentrations of 8–14 mg·L^?1, a median grain size of >180 μm, interstitial water contents of <36% (sediment wet weight) and organic contents of <3.2% (sediment dry weight). Most individuals occurred between 60 and 120 m down from the shoreline although there appeared to be a trend of down-shore migration in summer, possibly to alleviate thermal stress. No individuals were found at sediment temperatures ≤20°C, i.e. in sub-tropical Hong Kong's winter, when they adopt buried repose. Abundances of emerged T. tridentatus, peaking in November, were synchronized with interstitial salinities of 22–26‰ and averaged 1–2 individuals per 100 m². Mean population density of T. tridentatus was 4–9 individuals per 100 m². Only four individuals of C. rotundicauda were found in August and September, suggesting a recent dramatic decline in numbers. The natal crèche environment for juvenile horseshoe crabs in Hong Kong is deteriorating and threatening their survival.     

Description and ecology of a new species of sun spider (Arachnida: Solifugae) from the Brazilian Cerrado

A new species of solifuge from São Paulo State, south-eastern Brazil, is described, together with its phenology, habitat use, activity pattern and the effect of fire on the population. Mummucia coaraciandu n. sp. differs from other Mummuciidae in cheliceral dentition and pleurite coloration. Over a one-year period, 649 individuals of M. coaraciandu were captured in 72 pitfall traps distributed in three Cerrado physiognomies: borders of gallery forest (N=53), campo sujo (N=561) and campo cerrado (N=35). The species is diurnal and showed two peaks of surface activity during the year: the highest peak occurred in the cold–dry season (June to July) and the smaller peak in the middle of the warm–wet season (December to February). The number of individuals per trap was negatively correlated with the mean monthly temperature, but showed no correlation with the monthly precipitation. The sex ratio was male-biased (7:1) and the number of males trapped was positively correlated with the number of reproductive females. More individuals were trapped in burned areas when compared with unburned areas 1 month after the fire. This difference between the two areas was not observed 1 month before and 3–4 months after the passage of the fire (when the vegetation had recovered). Mummucia coaraciandu is the second solifuge described from the Brazilian Cerrado and its ecology is very similar to that of Mummucia mauryi from Caatinga vegetation.     

Ecology and field biology of two dominant Camponotus ants (Hymenoptera: Formicidae) in the Brazilian savannah

Camponotus renggeri and C. rufipes are very abundant in Brazilian cerrado savannah, where they feed extensively on liquid rewards and commonly associate with plants bearing extrafloral nectaries and honeydew-producing insects. Here, we provide a qualitative and quantitative field account on the natural history and ecology of these two ant species. The study was carried out in a cerrado reserve in south-eastern Brazil across a rainy/hot season (summer) and a dry/cold season (winter). The ants were found in two vegetation physiognomies: all nests of C. rufipes were located in the cerrado sensu stricto (scrub of shrubs and trees, 3–8 m tall), whereas C. renggeri occurred mostly in the cerradão (forest with more or less merging canopy, 10–12 m tall). Both species nested in fallen or erect dead trunks, as well as underground. In addition, C. rufipes built nests using dead plant material arranged or not around shrub bases. Colonies of C. rufipes were generally more populous than those of C. renggeri, and both species had colonies with more than one dealated queen. Both species were active mainly at night and foraged for resources near their nests, mainly extrafloral nectar and hemipteran honeydew (aphids and mealybugs). The average size of the home ranges of C. renggeri in cerrado sensu stricto and cerradão varied from ≈ 2.8 to 4.0 m² and apparently were not affected by season. In C. rufipes, however, foraging grounds in cerrado sensu stricto showed a twofold increase from dry/cold (≈ 4.5 m²) to rainy/hot season (≈ 9.8 m²). Our study highlights the importance of natural history data to understand the foraging ecology and role of these ants in cerrado savannah.     

Patterns of prey use in four sympatric species of Philanthus (Hymenoptera: Sphecidae) with a review of prey selection in the genus

Summary

Observations were made on four sympatric species of sphecid wasps of the genus Philanthus that nest in late summer and prey upon Hymenoptera. All four species nest in a restricted locale, but with little overlap in nesting areas. Comparison of nest contents of females demonstrated limited overlap in prey utilization among the four species, but only when both size and taxonomic category of prey were considered. The ultimate cause of this resource partitioning is unknown. Review of 30 populations of 16 species of North American Philanthus reveals varying degrees of specialization on prey types. Although populations of one species, separated in either time or space, tend to have similar niche breadths, this is not always the case. Intra-and inter-populational comparisons of prey records suggest behavioural plasticity allowing response to variations in prey availability. Some of the divergence in prey use among species is due to differences in predator size.     

Reproductive biology of Limnoria chilensis: another boring peracarid species with extended parental care

Several boring peracarid species engage in extended parental care with parents tolerating small juveniles in their burrows, but only anecdotal observations have been reported from boring isopods of the genus Limnoria. The isopod Limnoria chilensis Menzies is frequently found in holdfasts of the macroalgae Macrocystis pyrifera (L.) C. Agardh and Durvillea antarctica (Chamisso) Hariot. In the present study, holdfasts of D. antarctica that harboured L. chilensis were carefully dissected in order to examine the association pattern of reproductive females and small juveniles. In most infested holdfasts, L. chilensis reached very high densities of 43.7 ± 3.9 (mean ± SE) individuals cm^?2 (range: 0–90 individuals cm^?2). The overall sex ratio (females:males) was close to unity (1.2). Male size varied between 1.5 and 2.6 mm body length (BL) and female size between 1.5 and 3.6mm BL. The percentage of reproductive females was low (19.7% of all females), and only the largest females (>2.6 mm BL) were reproductive. Embryo numbers ranged between six and 19 per female and a significant correlation between female BL and the number of embryos was found. Several females were found with small juveniles (0.8–1.2 mm BL) in the terminal end of their burrows. On several occasions, aggregations of similar-sized juveniles (1.0–1.5 mm BL) in their own burrows were found near a female burrow, indicating that these juveniles initiated their first individual burrows from within the maternal burrows. Some females with small juveniles in the terminal end of their burrows were either accompanied by males or they were ovigerous, indicating that they may have been in the process of producing a second brood. The fact that juveniles build their first burrows in the protection of female burrows suggests that such small juveniles have not yet developed full boring capacity. Extended parental care in this (and other boring) peracarid species represents a mechanism facilitating high juvenile survival rates. Given the highly local recruitment, it is suggested that the reproductive biology of this isopod has strong implications for Its population biology.     

Deep-water amphipods from the Catalan Sea slope (western Mediterranean): Bathymetric distribution,assemblage composition and biological characteristics

Deep-water epibenthic/suprabenthic species of Amphipoda were studied in the Catalan Sea (north-western Mediterranean) at depths from 389 to 1859 m. In four cruises 20 samples were effected during 1991–1992, covering four different seasonal periods (March, April, July and December). A minimum total of 82 species was collected. Ampelisca uncinata and Eusirus leptocarpus were newly recorded as components of the Mediterranean fauna while three other species collected (Bathymedon sp. A, Autonoe sp. and Rhachotropis cf. gracilis) had distinct possibilities to be new species. The Gammaridae Carangoliopsis spinulosa and the Oedicerotidae Synchelidium maculatum were the two main dominant species on the upper slope level (389-506 m). On the middle slope (between 549-601 m), dominance by any few species was not apparent; the Eusiridae Rhachotropis glabra and R. caeca together with Bathymedon acutifrons, Scopelocheirus hopei and Andaniexis mimonectes were the most abundant species. On the lower slope, at depth below 1000 m, R. caeca was the largely dominant species. The highest species richness (S_T) was reported at intermediate depths over the middle slope (63 species), decreasing with depth increase, and being particularly low at 1808–1859 m (19 species). Total amphipod densities were also higher at the upper and middle slope levels (1760.2–2613.9 amphipods/1000 m³) than below 1000 m (376.4–679.2 amphipods/1000 m³). The low swimming coefficients (K_t) of bathyal Gammaridea, ranging between 0 and 0.336, indicate their relationship to the water-sediment interface although interespecific differences in K_t in relation to species size were also reported. Almost all the dominant amphipods had recruits (=smallest juveniles) in two or three of the three seasons sampled (mainly in March and December), and the smallest juveniles were often only abundant in two of these seasons. This indicates that most species had more than one generation per year, probably suggesting bivoltinism, a commonly adopted biological strategy among intertidal, littoral and shallow water amphipods, as the commonest strategy adopted by the mid-bathyal amphipods in our study.     

Population structure of a native and an alien species of snail in an urban area of the Atlantic Rainforest

Native Megalobulimus paranaguensis was identified on Brazil’s Ilha Porchat promontory, an area that Achatina fulica commonly populates. The population structures of these species were investigated for interactions. Spatial distribution, niche overlap and mark–recapture analysis were conducted. The outer lip of M. paranaguensis and environmental variables were measured. One and two abundance peaks were observed for A. fulica and M. paranaguensis, respectively. Survivorship was higher in A. fulica. Distribution was aggregate for M. paranaguensis, whereas for A. fulica it varied from random to aggregate. Both species aggregate as abundance increases. The lifespan of M. paranaguensis in this location is shorter than its lifespan in a nearby location. Achatina fulica was affected by soil temperature and humidity; M. paranaguensis was influenced by humidity. Niche overlap was random. The results show that M. paranaguensis can keep its natural activity and abundance in the presence of A. fulica, but environmental degradation impacts M. paranaguensis and should be evaluated.     

Breeding season of the hermit crab Dardanus deformis H. Milne Edwards, 1836 (Anomura,Diogenidae) in Maputo Bay,southern Mozambique

The breeding season of the hermit crab Dardanus deformis is studied based on the occurrence of ovigerous females, in relation to temperature and rainfall. Monthly samples were obtained between January and December 2003 at Costa do Sol, Maputo Bay, southern Mozambique. A total of 331 female individuals was analysed of which 164 were non‐ovigerous females and 167 were ovigerous females. Dardanus deformis breeds continuously in the study area with peaks of spawning from August to October and a slight decrease from May to July. Both temperature and rainfall were positively correlated with percentages of ovigerous females. Multiple linear regressions suggest that rainfall is the main factor controlling the breeding activity of D. deformis in Maputo Bay. This species may have a rapid and high reproductive activity in the study area as observed by the higher number of ovigerous females relative to non‐ovigerous females which may contribute to a constant larval supply and recruitment of this species in the study area.     

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.     

Activity and reproductive patterns of lizards in the Chaco of Argentina

We studied the activity and breeding pattern of dominant lizard species in the Arid Chaco, the southernmost subregion of the Chaco ecoregion (Chancaní Reserve, Córdoba province, Argentina). Lizards were captured with pitfall traps over a 4-year period. In total, 1449 individuals belonging to 11 of the 12 lizard species recorded in the area were trapped. Of these, we selected six species for a detailed analysis: Teius teyou and Stenocercus doellojuradoi accounted for 63% of the captures, Tropidurus etheridgei, Liolaemus chacoensis and Homonota fasciata accounted for 32%, and 5% comprised Leiosaurus paronae and the remaining five species. All the studied species were active during the warm–rainy season (September to March). Monthly lizard captures were highly correlated with monthly mean temperature and rainfall. No captures occurred during the remaining months of the year. All reproductive tactics known for the Chaco lizards were observed in Chancaní, including single clutch in a short breeding season in summer or autumn, as well as an extended breeding season with multiple clutches. Stenocercus doellojuradoi and L. paronae showed a singular reproductive timing, suggesting the occurrence of egg retention. Compared with sub-tropical Chaco sites, the Arid Chaco only differs in the lack of winter activity, resulting from the lower temperature and rainfall regime of our study site.     

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.     

Mitochondrial genetic variation within and between Holbrookia lacerata lacerata and Holbrookia lacerata subcaudalis,the spot-tailed earless lizards of Texas

ABSTRACT

We examined genetic relationships among individuals and populations of the species Holbrookia lacerata, the spot-tailed earless lizard, using whole mitochondrial genomes. Lizards were collected from south, central and west Texas. We found significant amounts of genetic structure among populations and evidence of two major reciprocally monophyletic groups of spot-tailed earless lizards in Texas. Holbrookia lacerata lacerata occurs on the Edwards Plateau and adjacent regions of West Texas north of the Balcones Escarpment, while Holbrookia lacerata subcaudalis occurs in South Texas and adjacent Mexico south of the Balcones Escarpment. These two recognised subspecies correspond to the two clades we discovered. Holbrookia l. lacerata occupies much of its historical range at sometimes high population densities, while populations of H. l. subcaudalis appear to be highly fragmented based on recent observations compared to their historical range.     

The armoured scale insects (Homoptera: Diaspididae) of avocado trees in Israel

Summary

Seven species of armoured scale insects infest avocado in Israel. Hemiberlesia lataniae (Signoret) and Abgrallaspis cyanophylli (Signoret) are the most abundant. Avocado seedlings become infested in the nurseries, thus serving as important sources for commercial grove contamination. Because larger diaspidid populations develop at the inside of the trees (as compared to their outside), and at height levels of 1·5–2·0 m (compared to 5·0–6·0 m), these regions were regularly sampled. Equal-area examinations of bark and leaf revealed that H. lataniae prefers the bark, A. cyanophylli the leaves. The populations of both scales undergo similar annual cycles on leaves, peaking during winter, ebbing in early summer. The specific settling pattern of most diaspidids on avocado leaves were figured. The somewhat-different settling sites of H. lataniae and A. cyanophylli apparently preclude competition when low numbers are present, but the former may be partially inhibited when large populations develop. Several predators and hymenopterous parasitoids attack the diaspidids, the parasitoids being most active in early summer. No economic injury to local avocado fruit by armoured scale insects has been reported in recent years. The reasons for this are discussed, and it is recommended that the present situation, in which no insecticides are used in avocado groves, be maintained.     

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.     

A new species of the genus Liopeltis Fitzinger, 1843 from Vietnam (Squamata: Colubridae)

ABSTRACT

A new species of Liopeltis from central Vietnam is described based on morphological and molecular differences. Liopeltis pallidonuchalis sp. nov. is distinguished from its congeners by a combination of the following characters: one single (or missing) loreal; one single nasal shield; dorsal scales in 15–15-15 rows, all smooth; 1 preocular, 2 postoculars and 1 + 2 temporals; 7 supralabials, of which 3^rd and 4^th in contact with the eye; 8 infralabials; nasal contacting internasal; prefrontal touching or separated from supralabials; ventral scales 126–138; subcaudal scales 67–73, paired; relative tail length about 0.274–0.301; an uniform bronze body colouration; a thin postocular stripe extending from eye to end of the neck becoming indistinct posteriorly. The new species differs from the morphologically closest species Liopeltis frenata by the lower number of ventrals and subcaudals, by characteristic colouration and significant divergence in cytochrome b mtDNA gene sequences (p = 15.3–15.6%). The new species is currently known from northen and central parts of the Annamite (Truong Son) Mountains, central Vietnam, and was recorded from montane evergreen tropical forests of Kon Tum–Gia Lai Plateau (Gia Lai and Thua Thien–Hue provinces, Da Nang City) at elevations of 950–1010 m asl to karst tropical forests in Quang Binh Province in the north at elevation 150 asl. We suggest the new species should be considered as Vulnerable (VU) following the IUCN’s Red List categories. An updated taxonomic key to the Liopeltis species is provided.     

Two new species of the genus Sinella Brook, 1882 (Collembola: Entomobryidae) from East China

Two new species, Sinella hexaseta sp. nov. and Sinella pauciseta sp. nov., collected from East China, Anhui and Zhejiang provinces, respectively, were described. Both are easily discriminated from each other and all known Sinella species by their unique dorsocentral chaetotaxic patterns on Abd. IV. In S. pauciseta sp. nov., postlabial setae H_1–4 are ciliate, which are smooth in all other known species of the genus.