Nesting habits of the Japanese foliage spider,Cheiracanthium japonicum (Araneae: Miturgidae): host plant preference based on the physical traits of plant leaves

A Japanese foliage spider, Cheiracanthium japonicum, builds nests with plant leaves. The nests are classified into seven types in relation to the seasons and purposes of nesting. We investigated whether the spider selects a plant species according to the nest type and how the physical traits of leaves influence the spider's plant selection. The difference between the composition of the host plant species used for nesting and that of the seasonal vegetation cover was confirmed. This suggests that the spider chooses the host plant species regardless of its abundance in their habitat. Early juveniles use small living or large dead leaves of various plant species to build moulting nests. Females prefer long and large leaves found in Miscanthus sinensis and Phragmites japonica over other plant leaves to build breeding nests.     

Structural comparisons of isomorphic breeding nests between closely allied spiders Cheiracanthium japonicum and Cheiracanthium lascivum (Araneae: Eutichuridae)

Closely allied spider species Cheiracanthium japonicum and Cheiracanthium lascivum make a closed breeding nest for egg laying and parental care. The nest provides the internal climatic stability required for suitable development of eggs and the physical durability required for protection against intruders. Although the breeding nests of these two spiders are quite similar in structure and appearance, their climatic stability and physical durability seem to be empirically different. Such physical features of the nests of these two spiders were compared based on a balance between the inner and outer air temperature and humidity of the nest as well as on the amount and size of spider silks lining the nest. In addition, the female’s relative energy allocation to egg production versus nest construction was examined based on the number or weight of eggs versus the climatic stability and physical durability of the nest. According to the results, the stability of temperature and humidity was maintained better in the breeding nest of C. japonicum than in that of C. lascivum. Furthermore, the nest of C. japonicum was more strongly constructed, with a greater volume and size of silks, than that of C. lascivum. On the other hand, the number or weight of eggs in relation to the female’s body weight in C. japonicum was smaller than that in C. lascivum. These results suggested that the reproductive effort towards nest construction for the purpose of egg and juvenile care in C. japonicum was larger than that in C. lascivum. In contrast, the effort towards egg production in C. japonicum was smaller than that in C. lascivum. Consequently, it is likely that the structural differences in breeding nests between these two spiders are responsible for the discrepancies in the female’s relative energy allocation to nest construction.     

Revision of the spider subfamily Gnaphosinae in Israel (Araneae: Gnaphosidae)

Gnaphosid spiders of 6 genera in Israel are revised presenting a relative richness in species and updated information on the Mediterranean spider fauna. Many inhabit the stony deserts of the south or are psammophiles that were detected by pitfall trapping. Minosia, Minosiella and Gnaphosa have never before been reported from Israel. Minosia simeonica sp. n. and the unknown males of M. spinosissima and Minosiella pharia are described. Gnaphosa barroisi is reinstated as a separate species. Berlandina jovia Denis, 1947 is newly synonymized with B. venatrix Dalmas, 1921, while the following B. chopardi Denis, 1955, B. paludani Denis, 1958, B. afghana Denis, 1958 and its subspecies B. a. spinitarsis Denis, 1958, and B. macrostigma Denis, 1966 are new synonyms of B. plumalis (O. P.-Cambridge, 1872) one of the most widely distributed gnaphosids in the Old World. The matching female of Nomisia excerpta and the matching of N. palaestina, each proving a separate species, have been identified, and N. negebensis sp. n. is described. Nomisia marginata (O. P.-Cambridge, 1874) and N. mauretanica Dalmas, 1921 are new synonyms of N. ausserei (L. Koch, 1872), N. verneaui (Simon, 1889) = N. excerpta (O. P.-Cambridge, 1872), and N. soror Dalmas, 1921 = N. palaestina (O. P.-Cambridge, 1872). In Pterotricha, the largest genus of Gnaphosinae in the Middle East, P. levantina sp. n., P. parasyriaca sp. n., P. engediensis and the unknown female of P. dalmasi are described, and the following new synonyms are recognized: P. aegyptiaca Dalmas, 1921 and P. isiaca Dalmas, 1921 = P. conspersa (O. P.-Cambridge, 1872); P. fanatica Dalmas, 1921 = P. lesserti Dalmas, 1921; P. peregrina Denis, 1948 = P. chazaliae (Simon, 1985); P. lentiginosioides Nosek, 1905 = P. kochii (O. P.-Cambridge, 1872). Illustrations of diagnostic characters, records of distribution and pertaining literature are provided for each species.     

Specialization in the choice and use of spider silk in the nest of the chaffinch (Fringilla coelebs) (Aves,Fringillidae)

The chaffinch, Fringilla coelebs, is one of a large number of birds from many families that use silk in the construction of their nests. Thirty-eight chaffinch nests collected from around the UK were examined to determine the nature and role of silk in nest construction. A regular survey of web, retreat and cocoon silk availability was made at a study site close to Glasgow, Scotland, over a 12 month period. The only spider web silk found in the nests was of the type produced by cribellate spiders. The majority of silk in nests, however, was spider cocoons, but there was no correlation between the amount of cocoon and web silk used. Nests with more lichen decoration contained more silk, and cocoon silk was particularly associated with the attachment of lichen. Nest construction at the study site took place from late April to mid-May. When nest building began, the availability of suitable web silk had doubled from its winter (lowest) level; however, its abundance continued to rise sharply until the end of May. The possible influence of silk availability on the timing of chaffinch nesting is discussed.     

Parental care in the dwarf caiman,Paleosuchus palpebrosus Cuvier, 1807 (Reptilia: Crocodilia: Alligatoridae)

Post-hatching parental care is common in crocodilians, but the little information available for Cuvier's dwarf caiman (Paleosuchus palpebrosus) indicates that they show little post-hatching parental care. During surveys undertaken between 2005 and 2011, we counted and captured groups of hatchlings and observed the presence or absence of attending adults in streams around the Pantanal, along the Guaporé-Madeira River and flooded forest in central Amazonia, Brazil. We found 37 groups of hatchlings, of which 29 were accompanied by adults. We captured 13 of these adults and all were females. The groups of hatchlings remained with adults for up to 21 months. We monitored females and hatchlings in streams around the Pantanal using captures and with radiotelemetry and showed that females and hatchlings frequently remained together in burrows, especially during the dry season.     

A revision of the ant-like sac spider genus Apochinomma Pavesi 1881 (Araneae: Corinnidae) in the Afrotropical Region

The genus Apochinomma Pavesi, 1881 is revised in the Afrotropical Region. The male and female of the type species, A. formicaeforme Pavesi, 1881, are redescribed. Five new species are described: A. malkini sp. nov. (♂ ♀) from Nigeria, A. parva sp. nov. (♂) from Guineé, and A. tuberculata sp. nov. (♀) from the Ivory Coast in the A. formicaeforme species group, and A. decepta sp. nov. (♂ ♀) from South Africa and Mozambique, and A. elongata sp. nov. (♂) from Botswana, Malawi and Tanzania in the A. decepta species group. Another undescribed species, known only from juveniles, belongs to the latter species group. Members of the A. formicaeforme species group mimic Polyrhachis ants and are thought to be primarily arboreal, whereas the A. decepta species group has ground-dwelling or grass-dwelling representatives that mimic large ground-dwelling ponerine ants. A single case of A. formicaeforme feeding on its model, Polyrhachis gagates, is noted. http://www.zoobank.org/urn:lsid:zoobank.org:pub:04116235-B195-48B0-B27E-076DAF4F51FD     

Complex display behaviour during the intraspecific interactions of myrmecomorphic jumping spiders (Araneae,Salticidae)

Jumping spiders (Salticidae) are known for their elaborate vision‐based display behaviour, and a sizeable minority of the species in this large family resemble ants. The display repertoire of two ant‐like salticid species from the Philippines is investigated. Myrmarachne assimilis is a specialist ant mimic, closely matching the appearance of the weaver ant Oecophylla smaragdina. Myrmarachne bakeri is a generalist mimic, which, although ant‐like, is not a close match to any sympatric ant species. Myrmarachne are sexually dimorphic, with males having enlarged chelicerae. The copulatory posture of Myrmarachne is unique among salticids, apparently as an adjustment for the male's elongated chelicerae. Details concerning the intraspecific behaviour of Myrmarachne appear to be adjustments to living in environments populated by numerous other animals with similar appearance (ants). However, the specialist and the generalist that were investigated have display repertoires that are broadly similar to each other and to those of more typical salticids. Generally, the display behaviour of Myrmarachne appears not to have necessitated dramatic deviation from typical salticid display and mating strategies.     

Mating behaviour and maternal care in the tropical savanna funnel-web spider Aglaoctenus lagotis Holmberg (Araneae: Lycosidae)

Despite their abundance and diversity, Neotropical spiders have been the subject of relatively few studies of behavioural ecology. The sexual behaviour and maternal care of the spider Aglaoctenus lagotis (Lycosidae) is described here. We performed experimental manipulations to test the hypothesis that males are attracted by female cues in the web. Two predictions were tested: (a) webs used by a virgin female will attract more males than webs used by an inseminated female; (b) the main cue in the web is chemical, so webs recently used by virgin females will attract more males than those that are not recently used. Additionally, we tested the hypothesis that maternal care increases offspring survivorship. Results showed that males are attracted by recently used webs (z = 0.0015; p = 0.037; z-test) and webs of virgin females (z = 0.041; p = 0.036, z-test). Male sexual behaviour presented three different categories: court, pre-mate and mate. After the mating, the females built a cocoon that was transported adhered to the spinnerets and held by the last pair of legs. After the hatching of the eggs, the young migrated to the dorsal region of the mother's body for 5 days. During maternal care the mother eliminates a yellowish drop from its oral cavity, which is collected by the young. During the development of the young until adulthood, the offspring that have their mother present in the first stages of life have greater survival compared with those without maternal care. Our results make it possible to perform comparative analyses between a South American Lycosidae species and other species distributed worldwide.     

The structure,possible function and origin of the remarkable ladder-web built by a New Guinea orb-web spider (Araneae: Araneidae)

Summary

The remarkable, perpendicularly-elongate web of a New Guinea araneid spider is described and illustrated. Its siting and construction are described and the possible origins and functions of the structure are discussed.     

Another migid in the wall: natural history of the endemic and rare spider Calathotarsus simoni (Mygalomorphae: Migidae) from a hill slope in central Argentina

A population of Calathotarsus simoni Schiapelli and Gerschman (1975) was discovered on a hillside in the Ventania system, Argentina. Our objectives were to quantify burrow density, record burrow morphology and door characteristics and describe the micro-habitat. We counted 57 burrows and report a density of 0.01 burrows/m². Aggregation indices suggest that burrows are aggregated under some area plots but more evenly distributed on others. The trapdoor is thick and rigid with bevelled edges connected to the entrance rim by a narrow articulated hinge. Two egg sacs from females were obtained and data on eggs and spiderlings are presented. We registered six burrows of an undetermined species of Actinopus. While a few specimens of Actinopus sp. were found inhabiting this hillside, the highest proportion of burrows belonged to C. simoni. Spider diversity on the hillside shows the predominance of Linyphiidae, Nemesiidae and Gnaphosidae. One juvenile of C. simoni was captured using pitfall traps.     

Observations on the nesting behaviour of the spider wasp Eragenia congrua (Hymenoptera: Pompilidae), with the first record of the host

We describe, for the first time, the nesting behaviour of an Eragenia spider wasp, Eragenia congrua, based on field observations in the Brazilian Amazon. This species was observed nesting in holes at the base of the trunk of a Jacaranda copaia tree and provisioning nests with both amputated and non-amputated species of undetermined Corinna sp. (Corinnidae) spiders. The spiders are carried forward and grasped at the base of the chelicerae. Nesting is gregarious with females nesting in the same small area on successive days.     

The influence of ants on the mating strategy of a myrmecophilic jumping spider (Araneae,Salticidae)

Phintella piatensis is an unusual jumping spider because, despite being neither myrmecophagic nor myrmecomorphic, it associates with ants, including dangerous weaver ants. Although salticids typically spin cocoon‐like nests for use as shelters, the nests of Phintella are unusually dense. These play an important role in how Phintella adapts to living with ants. In experiments, intraspecific interaction and mating increased the risk of being killed by ants when there was no accessible nest, while access to a nest eliminated this risk. Additionally, while outside nests, seeing ants made Phintella reluctant to mate, this being an unusual example of a small animal with exceptional eyesight compensating for predation risk when making vision‐based mating decisions. On the whole, the behaviour of Phintella during intraspecific interaction had broad similarity to the pattern that is common in salticids, but with some of the details of courtship suggesting further adaptation to interacting in the presence of dangerous ants.     

Occurrence of the trapdoor spider genus Moggridgea in Australia with descriptions of two new species (Araneae: Mygalomorphae: Migidae)

The occurrence of the trapdoor spider genus Moggridgea (Migidae) in Australia is reported, and two new species described: M. tingle n. sp. from southwest Western Australia and M. australis n. sp. from Kangaroo Island, South Australia. This is the first record of the subfamily Paramiginae from Australia. The historical biogeographic implications are discussed.     

Distributional and taxonomic notes on the crab spider genus Epidius with descriptions of five new species (Araneae: Thomisidae)

Distributional and taxonomic data are provided for six species of crab spiders of the genus Epidius Thorell, 1877 of which five species, E. coloratus sp. nov., E. elongatus sp. nov. (male), E. floreni sp. nov. (male/female), E. longimanus sp. nov. (male/female) and E. mahavira sp. nov. (male/female), are newly described. Evidence is provided to demonstrate that Pothaeus Thorell, 1895 (type species Pothaeus armatu is a junior synonym of Epidius. Epidius bazarus is shown to be a junior synonym of E. armatus comb. nov.

http://zoobank.org/urn:lsid:zoobank.org:pub:15B56D3E-69FB-46CD-8AFE-34919B844D14     

Origins and diversification of subsociality in leaf beetles (Coleoptera: Chrysomelidae: Cassidinae: Chrysomelinae)

Leaf beetles (Chrysomelidae; ~40,000 species) are commonly solitary animals but subsociality, maternal care of broods, is known in Cassidinae and Chrysomelinae. We report 11 novel records from Brazil and Peru, bringing the number of subsocial chrysomelids to 35 species in 10 genera. Two evolutionary models of chrysomelid subsociality have been proposed. One proposed three independent origins within Chrysomelinae, based on the potential phylogenetic positions of subsocial genera. The other hypothesised that an evolutionary arms race between chrysomelid prey and their predators, parasites, and parasitoids has led to an escalation of defences. Using our phylogenies, we propose that subsociality originated independently in Cassidinae and Chrysomelinae, and several times within each subfamily. Subsociality was preceded by particular behaviours. In Cassidinae, exophagous larvae with chemically offensive faecal weaponry preceded aggregated living, group defences (e.g. cycloalexy), and maternal guarding. In Chrysomelinae, offensive glandular compounds preceded ovi- and viviparity before subsociality.     

A revision of the genus Qianleptoneta (Araneae: Leptonetidae)

Southwest China is one of three famous karst areas of the world but research on cave spiders of the area is sparse. A Chinese endemic midget spider genus and species, Qianleptoneta quinquespinata (Leptonetidae) was erected by Chen and Zhu, 2008 Chen, HM and Zhu, MS. 2008. One new genus and species of troglobite spiders (Araneae, Leptonetidae) from Guizhou, China. J Dali Univ., 7(12): 11–14.  [Google Scholar]. Here, based on numerous materials collected from Guizhou Province, the mainly karst area of southwest China, Qianleptoneta is revised. Ten new species are described and illustrated: Q. triangula, Q. nuda, Q. identica, Q. lycotropa, Q. multiseta, Q. lophacantha, Q. robustispina, Q. palmata, Q. sublunata and Q. megaloda. The natural history of each species is presented.