The locomotory activity of Zonocerus variegatus (L.) (Orthoptera: Acrididae) under natural light,temperature, and humidity conditions

Summary

The locomotory activity of adult Zonocerus variegatus (L.) was investigated in an insectary, using an aktograph apparatus. Under natural light, temperature, and humidity conditions, male and female adults were markedly active during the daytime but showed very little activity during the early hours of the night. The males were found to be more active than the females. Individuals of the same sex showed slightly different patterns of activity. There was some correlation between increased activity and a period of bright sunshine accompanied by increased temperature. Starvation for 24 hours before and for 48 hours during experiments affected the normal locomotory activity of the grasshopper.     

A review of red-eye pigmentation and diel activity patterns in skippers (Lepidoptera,Papilionoidea, Hesperiidae)

ABSTRACT

The visual systems and diel activity patterns of butterflies and moths have been studied for decades, yet understanding the underlying mechanisms that are associated with the evolution of these remains a major challenge. The order Lepidoptera is principally composed of nocturnal lineages with extreme morphological and behavioural adaptations to this lifestyle. Although most butterflies are diurnal, some clades are predominantly nocturnal, for instance, the Hedylidae. Skippers are another family that comprises multiple crepuscular and/or nocturnal lineages. Interestingly, many such lineages have red-eye pigmentation, and this morphological feature has been hypothesised to be an adaptation to the night-time lifestyle. Here, we review the occurrence and frequency of red-eye pigmentation as well as diel activity patterns in Hesperiidae. We place these data within a phylogenomic framework and provide hypotheses and predictions relative to the evolution of red-eye pigmentation in skippers with respect to diel activity. We suggest that several types of red-eye pigmentation exist in skippers, with possible structural red-eye pigmentation in some lineages of diurnal skippers. The colouration of eyes in Hesperiidae, the evolutionary mechanisms that drive these traits and the physiological underlying processes require further attention and could bring new insights into our understanding of butterfly vision systems.     

Activity patterns and habitat use of pudu deer (Pudu puda) in a mountain forest of south-central Chile

The pudu (Pudu puda) is a small, endemic deer, and the only native ungulate found in Chilean and Argentinean temperate forests. Its ecology, including its double role as an herbivore and as a prey, is poorly known. Therefore, it is pressing to gain a better understanding of the pudu given that its habitat is being transformed rapidly by anthropogenic causes. On a coastal mountain range in south-central Chile, we conducted a habitat use study and examined the activity patterns of the pudu using camera traps. The study area was a large native forest patch, surrounded by commercial plantations which would not constitute a habitat for this deer. Using a sampling effort of 7559 camera days, we found that this deer was largely nocturnal with little activity during daytime. The pudu selected Araucaria forests, and avoided Nothofagus forests. These behaviours suggest that the pudu traded off habitat use patterns and activity time to avoid predation, mainly by puma which is the top predator in the rich local community of carnivores occurring in the latter habitat.     

Locomotory activity and orientation of Mesobuthus gibbosus (Scorpiones: Buthidae) in central Aegean Archipelago

This study explores the locomotory activity of Mesobuthus gibbosus on Koufonisi Island (central Aegean). We measured orientation of movement, shelter selection and abiotic factors that influence locomotive activity throughout the circadian and lunar cycles. Our results show M. gibbosus is a highly active and negatively phototactic species with sexually dimorphic patterns of movements that are related to maternal protective behaviour. Male scorpions disperse more widely, apparently as a function of mate search, and exhibit much more opportunistic locomotive behaviour. The locomotory activity of the population was influenced by moon phase (negative phototropic) and air temperature, did not differ intersexually, and was directed towards a dry stone-wall where shelter was readily available.     

Elucidating the diel and seasonal calling behaviour of Elachistocleis matogrosso (Anura: Microhylidae)

ABSTRACT

Acoustic monitoring provides the opportunity to study ecological processes that are difficult to assess with traditional surveys. Elachistocleis matogrosso is an anuran species, described in 2010, for which limited biological information is available. This study investigated the calling activity of the species in the north-eastern portion of the Pantanal, Brazil, a wetland area with marked seasonality between the dry and wet seasons. The calling activity of E. matogrosso was monitored using automated digital recorders in combination with automated signal recognition software over two different annual cycles. The species was vocally active only during the wet season (October – April), with a peak in November-December during the 2013–2014 annual cycle and in February-March during the 2015–2016 annual cycle. The peak calling activity occurred at dusk. This species has nocturnal habits and an explosive breeding activity. The detection of the species was intermittent, which suggests that environmental predictors or site-specific conditions might play an important role in species detection. Moreover, this intermittent occupancy indicated that surveys that employ traditional field techniques would likely fail to detect this species. We describe an effective protocol for detecting E. matogrosso with acoustic monitoring, which requires recording during 20 days in February from 17:01 to 05:00. Our procedure would be easy to adapt to other anuran species, and it could be used for investigating new localities and assessing population changes over time.     

Daily activity of the white-clawed crayfish,Austropotamobius pallipes (Lereboullet): a comparison between field and laboratory studies

The daily activity of the threatened crayfish, Austropotamobius pallipes (Lereboullet), was studied both in the field, through direct counts of active animals along a stream section, and in the laboratory, by means of actographs. In the field, crayfish were mostly found after dawn, with a slight but significant difference among seasons. In winter, only two specimens were seen to be active. Distinguishing among size classes, medium-sized crayfish were more abundant in spring and summer, while large ones mostly occurred in autumn. The former always concentrated their activity at night-time; to the contrary, larger specimens were more active late at night in spring and at dusk in autumn. Sex-ratio, analysed only in summer, was balanced throughout the 24h. Nocturnal activity, although differing among seasons, was similar in size classes, temperatures and sexes. In the laboratory, activity (evaluated as photo-cell interruptions) increased with temperature and occurrence throughout a 24-h cycle (the highest peak shifting from midnight to dusk). Only in the laboratory, a low peak occurred at dawn, but disappeared when a shelter was available. The interaction between the response of A. pallipes to temperature and its nocturnal habit is examined. Questions still remain on the adaptive value of the environmental factors influencing the cycle of freshwater decapods' activity.     

The parasitic copepod Lernaea cyprinacea L. in Britain

Summary

The distribution of phylacites (single-celled dart glands) and pits in the skin of the four British species of Oxychilus is described. These features are peculiar to the genus. The distribution patterns are specific and have been used to compile a key.     

Relationship between environmental conditions and host-seeking activity of Ochlerotatus albifasciatus (Diptera: Culicidae) in an agroecosystem and in an urban area in Chubut,Central Patagonia,Argentina

Ochlerotatus albifasciatus is associated with aquatic environments that are frequently flooded. Awareness of blood hematophagic activity of female mosquitoes is particularly important in species which are vectors of human disease and domestic animals. The study of host-seeking activity allows us to infer the risk of transmission of these parasites. The objective of this work was to study in an agro-ecosystem and urban area of central Argentine Patagonia the relationship between the circadian rhythm of activity of host-seeking of Oc. albifasciatus, and environmental variables. During January 2003, 99 human bait catches were carried out, of which 77.8% registered at least one individual of Oc. albifasciatus. Generalised linear models were used to evaluate the relationship between Oc. albifasciatus biting activity rate and capture time, environmental humidity, air temperature, sunshine degree, wind speed, habitat type and proximity of larval habitat. The model that best explained the variation in biting activity rate included the capture time, environmental humidity, air temperature, sunshine degree and wind speed as predictor variables. Host-seeking activity was higher in the evening than in the morning or afternoon, and it was positively related to mean air temperature and environmental relative humidity (RH), but negatively to sunshine degree and wind speed. The combination of these characteristics (wind speed less than 20 km/h, environmental temperature greater than 26°C, sunshine less than 40% and (RH) greater than 50%) would provide favourable conditions to allow seeking activity and to feed on the host. The dispersion of this mosquito could be among environmental patches that present these characteristics.     

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.     

The occurrence of Podocotyle atomon (Rud., 1802)(Digenea), Bothriocephalus scorpii (Müller, 1776) (Cestoda), Contracaecum clavatum (Rud., 1809) (Nematoda) and Echinorhynchus gadi Zoega,in Müller, 1776 (Acanthocephala) in the five-bearded rockling,Onos mustelus (L.)

Summary

The variation in the incidence and intensity of infestation of the five-bearded rockling, Onos mustelus (L.) with Podocotyle atomon, Bothriocephalus scorpii, Contracaecum clavatum and Echinorhynchus gadi has been studied for a period of one year, on a shore at Mumbles Head, Swansea.

There is a general increase in the incidence and intensity of infestation by P. atomon and C. clavatum with increase in the length (age) of the host. With E. gadi and B. scorpii, however, infestation decreases in the larger fish.

The seasonal variations in the incidence and intensity of infestation with these parasites are influenced by tidal fluctuations, temperature and by the feeding habits and breeding cycle of the fish.

The frequency distribution of parasite specimens is also described and discussed.     

Geckos are milking honeydew-producing planthoppers in Madagascar

In this paper we describe for the first time an extraordinary example of an interspecific trophobiotic relation between reptiles and planthoppers in Madagascar. Day gecko species of the genera Phelsuma and Lygodactylus as well as the nocturnal gecko Homopholis sakalava (Grandidier, 1867) show a particular behaviour that induces planthoppers of the family Flatidae to excrete a drop of honeydew in the course of an interspecific key stimulus reaction. Similar behaviour patterns are well known between ants and green flies or planthoppers, but have not been reported for vertebrates.     

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.     

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.     

A checklist of suctorian epibiont ciliates (Ciliophora) found on meiobenthic marine nematodes

ABSTRACT

A compilation of the ciliated suctorian species found on marine meiobenthic nematodes as epibiont has been carried out based on published records. It included the taxonomic position of each species of ciliate epibiont, the species of basibiont nematodes, the geographic zones where they have been found and the different records of these species together with the corresponding bibliographic references. Altogether 12 suctorian species were listed. Among registered suctorian species, Thecacineta oregonensis, T. urceolata, Trematosoma rotunda, Loricophrya bosporica, L. mediterranea, L. scanica, L. sivertseni, L. spitinae and L. stresemanni are likely specific to nematodes. The species as Thecacineta calix and Limnoricus ceter were found on a variety of hosts. Representatives of the genus Thecacineta reproduce by vermigemmic budding, swarmers of which are unable to swim, and often attached close to the cloaca of the nematodes. Any regularity in localization were not observed in the representatives of genera Trematosoma and Loricophrya, which form ciliary, swimming swarmers.     

Miscellanea Nematodologica. VI. Echinonema australis sp. nov. from Sminthopsis crassicaudata in South Australia

Summary

Echinonema australis sp. nov. is described from Sminthopsis crassicaudata, and differs most markedly from the only other species of the genus, E. cinctum, in lacking a swollen region with intermediate sized spines immediately posterior to the three circles of large spines which occur on the extreme anterior end of the body.     

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

ABSTRACT

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

LX.—Studies on the Onychophora.—VI. The life-history of Peripatopsis

Summary

Specimens of Notoscolex camdenensis, the type-species of Notoscolex are described for the first time since erection of the genus. The type-species is shown to have stomate megameronephridia median to micromeronephridia in posterior segments, a condition indicating that its affinities lie with a Dichogaster-Megascolides group of genera and not, as has previously been held, with a Megascolex group. Only four other species appear to be congeneric with N. camdenensis. These are endemic in New South Wales, like the type-species, or in Queensland.     

Arboreality predicts Batrachochytrium dendrobatidis infection level in tropical direct-developing frogs

Pathogen-mediated changes in host behaviour can result from hosts altering their habitat preferences. Although infection risk with pathogenic fungus Batrachochytrium dendrobatidis in amphibians is associated with environments favouring its growth, the relationship with microhabitat use has not been examined. Here, we aim to determine if microhabitats used by frogs during their nocturnal activity predict B. dendrobatidis prevalence and infection intensity. Our focal host, Eleutherodactylus coqui, is a habitat generalist that uses multiple habitats from the forest floor to the canopy. We analysed data on B. dendrobatidis occurrence in 157 adults and 122 juveniles at El Yunque National forest in Puerto Rico. We categorized each individual’s nocturnal microhabitat as forest floor, curled palm fronds in the floor, arboreal bromeliads and foliage or tree trunks 50 cm to 2.5 m above ground. We found that frogs on the forest floor had the greatest B. dendrobatidis prevalence (73%), compared with those active in vegetation above ground (55%). Overall, the probability of B. dendrobatidis infection in frogs using microhabitats on the forest floor was twice as great as for those on arboreal substrates. Differences in B. dendrobatidis prevalence and intensity in E. coqui may be explained by specific abiotic conditions of microenvironments (temperature and humidity) affecting both pathogen and host, and by the age-specific ecological requirements of hosts. Adults were found to be most active in microhabitats where individuals had lower infection burdens, suggesting pathogen-modulated habitat choice. This work has important implications for the evolutionary dynamics of enzootic diseases and provides data that may inform potential mitigation strategies against a generalist amphibian pathogen.     

A new species of the dentipes-subgroup of Triconia and a redescription of T. giesbrechti and T. elongata (Copepoda: Cyclopoida: Oncaeidae) from the tropical Pacific and the Korea Strait

A new species of Triconia in the family Oncaeidae, Triconia pacifica sp. nov., and a new form variant each of Triconia giesbrechti Böttger-Schnack and Triconia elongata Böttger-Schnack are described from two sites in the Pacific. Triconia pacifica can be distinguished from its sibling Triconia dentipes (Giesbrecht) by (1) morphometric characters, including the proportional lengths of distal endopod spines of swimming leg 4, and the relative length of the outer basal seta on P5, and by (2) a number of micro-structures on the appendages. The Pacific specimens of T. elongata and T. giesbrechti resemble the typical forms in morphometric characters, with some minor differences in proportional spine lengths on the swimming legs, and differ in a few micro-structures. The hitherto unknown male of T. giesbrechti is newly described. For all species/forms described, the intraspecific variability of proportional spine lengths on the endopods of P2–P4 is examined and discussed. http://www.zoobank.org/urn:lsid:zoobank.org:pub:6B41B0E2-0A5C-458B-8F9C-25000F208E24     

Astigmatic mites of the genera Schwiebea Oudms. and nanacarus oudms. from S. E. Ireland

Summary

Schwiebea hibernica sp. nov. (Acaridae) and Nanacarus manus sp. nov. (Saproglyphidae) are described and figured. Species relationships within the genus Nanacarus Ouds., are considered and a key is given for the identification of females. Nanacaroides Volgin and Mironov 1979 is synonymized with Nanacarus Oudemans 1903.