Distal leg morphology,subgenual organs and host detection in Stephanidae (Insecta,Hymenoptera)

The morphology of the tibia and tarsus of all legs is examined in species of two genera of Stephanidae. The subgenual organ (SGO) is examined in more detail for Megischus spp. The fore leg is the most modified in Schlettererius. In Megischus, the SGO of the hind leg is displaced to the middle of the tibia, which is swollen distad of it; in the female the hind tarsi are three‐segmented, the basitarsomere being a composite of tarsomeres 1–3. Internally, the SGO of Megischus is suspended between a spine and a ridge. In the mid and hind legs, part of the tibial wall is thinner in the region of the SGO. Our observations provide circumstantial evidence that female Stephanidae detect substrate‐borne vibrations when searching for hosts. The absence of antennal modification, as well as information on host stage targeted and general behaviour on the oviposition site indicates that they rely on noise made by the host rather than generate vibrations themselves, in contrast to Orussidae, a parasitoid wasp taxon that has been inferred to employ vibrational sounding. The external receptor elements – membranous pads versus tufts of setae – are not homologous in Orussidae and Stephanidae. A spine and ridge suspensorium of the SGO found in members of both families may represent a derived groundplan feature of the orussid–apocritan clade, with secondary modification or reduction in the latter group. Characters of the distal leg elements and the SGO suggest a basal position of Schlettererius and Stephanus within Stephanidae. Modifications of the hind tibia and tarsus in more derived members of the family indicate a shift in relative importance in vibration detection from the fore leg to the hind leg within the family.     

Constraints on convergence: hydrophobic hind legs allow some male pollinator fig wasps early access to submerged females

Pollinator fig wasps (Hymenoptera: Agaonidae) display numerous adaptations linked to their obligate association with fig trees (Ficus). Ceratosolen fig wasps pollinate figs that often fill temporarily with liquid, and one clade has males with unusually long hind legs. We investigated their morphology and behaviour. Scanning electron microscopy (SEM) revealed that the cuticle of their hind legs is highly modified and covered with numerous hydrophobic setae and microtrichia that can prevent blockage of the wasps’ large propodeal spiracles by liquids. In deep liquid, the males floated on the surface, but when only a thin layer of liquid was present, the legs allowed males to access females without the risk of drowning. Access to females was facilitated by an air bubble that forms between the hind legs and maintains a column of air between the spiracles and the centre of the figs. Sexual selection should favour males that can gain earlier access to mates, and the modified legs represent an adaptation to achieve this. Convergent adaptations are known in some unrelated non-pollinating fig wasps that develop in similar liquid-filled figs, but these species have enlarged hydrophobic peritremata at the ends of their metasoma to protect the spiracles located there. Unlike non-pollinating fig wasps, pollinator males need to insert their metasoma deep into females’ galls during mating. This difference in mating behaviour has constrained the extent of convergence.     

Singing and dancing in the ghost crab Ocypode platytarsus (Crustacea,Decapoda, Ocypodidae)

Male ghost crabs, Ocypode platytarsus, have the most elaborate visual and acoustic/vibrational display so far described in the genus. In common with other species, rapping as a result of hitting the ground with the major cheliped produces rap trains with a variable number of elements. Ocypode platytarsus also produces faster and longer rap trains by drumming with both chelipeds. Additionally, at the approach of a wandering crab, a dance display is also performed. The display begins with the crab rearing up on outstretched legs. Rapid stepping on the spot leads to swift sideways movements that increase in complexity with the longest ones being full circling movements around the wanderer. The display generates an auditory/vibrational sound that is distinct from that produced by the chelipeds. Longer rap trains and drumming events occur in close association with, or following dance displays, but usually when the wanderer is moving away. At other times, rap trains with fewer than ten elements are produced. These observations are discussed in relation to the possible interaction of the three communication channels that are available to the Ocypodinae.     

Analysis of VCR images of pre-oviposition and oviposition behaviour of Culex quinquefasciatus (Diptera: Culicidae) females,in the laboratory

The aim of this work was to study the pre-ovipostion and oviposition behaviour of gravid Culex quinquefasciatus females, under laboratory conditions. Preliminary tests showed that oviposition is initiated from the third day after bloodfeeding and occurs in the first two hours and the eighth to the tenth hour of scotophase. Image analysis showed that females presented different types of exploratory flights, and that the most common was touching the hay infusion with their hind legs, while flying. The two main oviposition behaviours observed were: (1) females that land at the container's inner wall, rub one leg against the other and walk towards the interface between the wall and hay infusion surface to lay the egg raft; (2) females that land on the hay infusion surface, keep four or six legs on the surface, and lay the egg raft. Interestingly, females that touched the hay infusion with their proboscis rejected it as an oviposition substrate.     

Resource defence mating system in two flies from Sulawesi: Gymnonerius fuscus Wiedemann and Telostylinus sp. near duplicatus Wiedemann (Diptera: Neriidae)

Gymnonerius fuscus and Telostylinus sp. near duplicatus are two neriid flies which breed in rot-holes (often beetle larval borings) in fallen trees in tropical forests. Males of both species attempt to establish territories beside rot-holes likely to attract females for egg-laying purposes. Monopolization of incoming females and paternity of any eggs laid are therefore assured. Aggression between males of the larger species G. fuscus is largely through ritualized intimidatory signalling, i.e. wing-flicks. Actual physical aggression only occurs when opponents are evenly matched. By contrast, lengthy and hectic wrestling matches on stilted legs is the normal method of establishing site-ownership in the smaller species T. near duplicatus. Males only seek to exclude conspecific males, such that both species may establish simultaneous ownership of a single rot-hole without interacting. Males of G. fuscus who ‘sneak’ matings away from the territories of larger males, or who manage to mate within a territory, gain little or no reproductive benefit. This is because the territory-owner prevents all females, other than his own current mate, from laying eggs within his territory and females seem reluctant to utilize non-territorial rot-holes for oviposition.     

Two new species of asterocherid (Copepoda: Siphonostomatoida) associated with a sponge from the Strait of Messina,Italy: taxonomic and ecological traits

Two new species of asterocherid associated with sponges are described from the Mediterranean Sea. They are Psilomyzon laetitiae sp. nov. and Psilomyzon sarcotragusicola sp. nov. The genus Psilomyzon consists of only one known species, P. pauciseta. The two new species can be easily distinguished from the cogener species by reduction of the endopod of leg 4. In P. pauciseta the leg 4 endopod is 3-segmented, with the third segment reduced; in both new species it is 2-segmented, with the second segment carrying an inner projection, possibly homologous to the third segment of the leg 4 endopod of P. pauciseta. In the two new species, the bifid outer process on male leg 4 second endopodal segment seems to be serially homologous to the similar processes on the same segment in legs 1–3, whereas the inner projection may represent a vestigial element of the third endopodal segment of leg 4.

http://zoobank.org/urn:lsid:zoobank.org:pub:33BF0653-BBA9-426B-B365-5D8C62DFD44A     

Meteorus acerbiavorus sp. nov. (Hymenoptera,Braconidae), a gregarious parasitoid of Acerbia alpina (Quensel) (Lepidoptera,Arctiidae) in North Finland

The new gregarious parasitoid Meteorus acerbiavorus sp. nov. (Hymenoptera, Braconidae) was reared from the cocoons of Acerbia alpina (Quensel) (Lepidoptera, Arctiidae) in north-western Finnish Lapland. This species belongs to Meteorus rubens (Nees) species group and differs from the most related M. rubens in the following features: the eyes densely setose; the median lobe of the mesoscutum, scutellum, mesopleuron, and the hind coxa entirely or at least partly rugulose-granulate or rugose-areolate and sometimes with granulation; the ovipositor subapically with distinct dorsal node; the ventral borders of the first metasomal tergum weakly separated by narrow space in its basal half; the colour of the body and legs mostly or entirely dark; the fore wing more or less darkened. Phylogenetic relationships among several Meteorus species close to M. rubens including new M. acerbiavorus were investigated based on DNA sequence fragments of the mitochondrial COI and the nuclear 28S rDNA genes. The discussions on the species groups of Meteorus, on distribution of Acerbia alpina in the Holarctic and on its known parasitoids are presented.     

Two new deep-sea species of Argestidae and Ameiridae (Copepoda: Harpacticoida) from the Eastern Mexican Pacific and Gulf of California,with proposal of a new genus of the family Argestidae

ABSTRACT

A handful of benthic harpacticoid species are known from the Gulf of California. Here I describe Argestes analongises sp. n. (Argestidae), and Argestigens celibis sp. n. (Ameiridae) from the deep sea of the Tropical Eastern Pacific and Gulf of California. Argestes analongises sp. n. fits in the subfamily Argestinae (Argestidae) and was attributed to the genus Argestes by the presence of small spinules covering the body surface of, at least, the urosome, and by the presence of an extremely elongated distal seta on the sixth segment of the female antennule. This new species seems to be allied to A. angolaensis by the situation of all the caudal setae, and by the ventral position of caudal seta III. They differ in the relative length of the female caudal rami, size, shape and relative position of the sensilla-bearing tubercles associated to the anal somite, armature of the mandibular basis, shape of the exopodal and endopodal segments of swimming legs, and relative length of the setae on the female P5 endopodal lobe and position of the innermost seta of the exopod of the female fifth leg. Argestigens celibis sp. n. was attributed to the family Ameiridae based on the non-argestid maxilla, on the presence of a more or less well-developed endopodal lobe of the male fifth leg and three inner setae on the third endopodal segment of the third leg, and on the presence of the typically modified ameirid-like inner spine on the basis of the male first leg. The new species was attributed to Argestigens based on the non-prehensile endopod of first leg and presence of long inner spinules on the basis of second to fourth legs. Additionally, a new genus, Georgus gen. n., is proposed for Bodinia peterrumi, and some comments are given on the monophyly of that genus.

www.zoobank.org/urn:lsid:zoobank.org:pub:4BD580B0-E856-4FBC-ABA6-B031A9B6E1F9     

A new genus and species of Conchaspididae (Hemiptera: Coccoidea) from Florida,remarkable in lacking legs

A new genus of Conchaspididae, Asceloconchaspis gen. nov., is described for Asceloconchaspis milleri sp. nov., a new species from Florida, USA. Unlike other conchaspidids, the adult female and second instar of the genus lack legs. The presence of legs is one of the important, distinguishing characters at present separating the Conchaspididae from the Diaspididae. However, the new genus also possesses well-developed antennae and has multilocular disc pores on the abdomen in the adult female; these distinctly conchaspidid characters are never found in the Diaspididae. Asceloconchaspis is closely related to Fagisuga Lindinger, a monotypic genus with primitive characters described from South America on Nothofagus. A key to the four known genera of Conchaspididae is provided, and the morphology and distribution of the Conchaspididae are discussed.     

Observations on zygopine weevil behaviour (Coleoptera: Curculionidae: Zygopinae)

Observations on the behaviour and chosen environment are reported of the zygopine weevils Mecopus audinetii, M. bispinosus, M. fausti, M. pulvereus, Phylaitis v-alba and Osphilia sp. Mecopus audinetii and M. bispinosus were not distinguished in the field, but can be separated by details of the male and female genitalia and by the presence in the male of M. bispinosus of long black hairs on the pronotum. All the species studied were found on the bark of fallen or dying trees, the Mecopus species and Phylaitis v-alba being associated with whitish-silvery bark and the Osphilia species with greenish-brown substrates. The small Phylaitis species was found on branches of smaller diameter than those frequented by the larger Mecopus species. All the species are fairly cryptic in coloration, but when moving the larger species are more visible than the smaller, and the ones on pale bark are more visible than those on greenish-brown bark. Potential predators may be confused by jerky movement patterns observed in all species and the distant shadows cast by the long-legged larger Mecopus. The weevils are not believed to be involved in any mimicry, although this has been suggested for other members of the same subfamily. A single contest between males of Mecopus audinetii/bispinosus was observed, in the absence of a female. Each male attempted to dislodge its opponent from the substrate using its rostrum; the thoracic spines were not seen to be used. Contests between males of Osphilia sp. and Phylaitis v-alba were observed in the presence of females of the appropriate species. The males of Osphilia species attempted to dislodge one another from the back of the female in contention, and also engaged in a spiralling flight together. The males of Phylaitis v-alba did not come into physical contact, but responded to the threat of an approach. During copulation in Mecopus audinetii/bispinosus and Osphilia sp. the male repeatedly brushed the head and thorax of the female with his front legs. In the first species the male stood on the substrate and ‘caged’ the female with his legs and rostrum but in the second the male, ‘rode’ the female. Both species oviposit into the bark of their trees, the females using the rostrum to drill a hole for the ovipositor. The length of the rostrum probably determines the thickness of the bark through which eggs are laid, and hence the area of the region of the tree inhabited by the beetles.     

Pre-ovipositional and ovipositional behaviour of Lasioseius ometes (Oudemans) and Hypoaspis kargi Costa (Acari: Dermanyssiae: Ascidae,Laelapidae) with notes on egg protection strategies in Mesostigmata

Egg deposition by the soil mites Lasioseius ometes (Oudemans, 1903) and Hypoaspis kargi Costa, 1968 was observed using continuous video-monitoring. The process in both species was found to consist of four distinct phases. In Phase 1, both species engage in pre-ovipositional activity prior to the egg being extruded from the genital opening. In L. ometes, the female often selects a substrate depression for egg laying and examines the depression carefully with the gnathosoma and legs I before oviposition. In H. kargi, egg deposition sites are chosen without regard for substrate depressions. Phase 1 lasted approximately 3 minutes for both species. Phase 2 involved egg extrusion and holding of the egg beneath the gnathosoma. Phase 2 lasted approximately 20 times longer in L. ometes (5 minutes) than in H. kargi. Alteration of the egg surface in the form of thorn-like outgrowths was recorded in L. ometes. Egg deposition occurs in Phase 3, and in L. ometes the egg is generally placed at the deposition site using the chelicerae. Hypoaspis kargi also uses the chelicerae for egg manipulation, but also adjusts orientation of the egg with legs I. The sticky nature of egg surface in H. kargi may provide a means for the female to effectively cover the exposed egg with a protective layer of soil particles. Egg deposition in both species occurred in less than 90 seconds. Phase 4 involves egg covering, but behaviour of the female during this last phase differs markedly between the two species. In L. ometes, the female tends to remain close to the egg, whereas in H. kargi the female moves away from the egg to search for substrate particles appropriate for its covering. The average time for Phase 4 in H. kargi was approximately four times longer (80+ minutes) than in L. ometes.     

Copepoda (Cyclopinidae and Misophriidae) from a deep-sea hydrothermal site in the northeastern Pacific

Two new copepods are described from a depth of 2254m at a hydrothermal site on the Juan de Fuca Ridge, northeastern Pacific. In Barathricola rimensis, gen. nov., sp. nov. (Cyclopoida: Cyclopinidae), the antennule is 13-segmented, the antenna lacks an exopod, the second segment of the endopod of legs 1–4 has 1, 2, 2, 2 setae, and leg 5 is three-segmented in both sexes, the last segment (exopod) having I, I, l, I in the female and I, I, l, I, l in the male. In Misophriopsis longicauda, gen. nov., sp. nov. (Misophrioida: Misophriidae), the antennule is 18-segmented in the female, 13-segmented in the male, the antenna has a six-segmented exopod, legs 1–4 are biramous with three-segmented rami, leg 5 is biramous with a one-segmented endopod and an exopod which is two-segmented in the female, three-segmented in the male.     

Lernanthropus antofagastensis sp. nov. (Copepoda: Lernanthropidae) parasitic on Anisotremus scapularis in Chilean waters,and new records of Lernanthropus trachure (Brian, 1903)

Lernanthropus antofagastensis sp. nov., parasitic on Anisotremus scapularis, and inshore fish of Antofagasta, Chile, is described and illustrated. It resembles five other species of Lernanthropus in its dorsal plate and third leg, but can be distinguished from them by a combination of characters. L. trachuri Brian, 1903, is recorded, its male described and illustrated from specimens collected from Seriolella violacea and Trachurus murphy, taken in the same locality.     

Two new species of Siphonostomatoida (Copepoda) found on cnidarians in Tokara Islands,Southern Japan

ABSTRACT

Two new species of siphonostomatoid copepods are described based on specimens collected off Tokara Islands located in the northern part of the Ryukyu Islands, Southern Japan. Cholomyzon multisetum sp. nov. (Coralliomyzontidae) found from the orange cup coral Tubastraea coccinea Lesson, 1829 (Hexacorallia: Scleractinia: Dendrophylliidae) has the following characters: armature formula of the antennule of the female; the outer lobe of the maxillule; and numbers of elements on the legs 1 to 3. Another species, Entomopsyllus takara sp. nov. (Entomolepididae), was found from both the Indo-Pacific blue coral Heliopora coerulea (Pallas, 1766) (Octocorallia: Helioporacea: Helioporidae) and the race coral Distichopora violacea (Pallas, 1766) (Hydrozoa: Anthoathecata: Stylasteridae). This new species of the male specimen is characterized by the antennule with shortest sixth segment, the endopod of leg 2 bearing two inner setae on the second segment and five setae on the third segment, the third exopodal and endopodal segments of leg 3 bearing three spines and three setae, respectively, and the third exopodal segment of leg 4 bearing four setae. These two species represented the first records of the families Coralliomyzontidae and Entomolepididae from Japanese waters.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:7C8DED0A-9CEB-405D-9BBF-FAF2043B0858     

A new Arietellidae (Copepoda: Calanoida) from the Red Sea

A new species of the calanoid copepod genus Paramisophria T. Scott, 1897 is described from the Egyptian sublittoral zone of the Red Sea. Paramisophria aegypti sp. nov. appears to be closely related to the species Paramisophria ammophila and Paramisophria platysoma. Paramisophria aegypti differs from P. ammophila in having two unequal lateral setae plus one long terminal process and two tiny equal lateral setae plus one long terminal process on the third exopodal segment on the male right and left fifth legs (vs three terminal processes increasing in size inward on both male fifth legs). Paramisophria aegypti can be distinguished from P. platysoma in the following characters: prosome symmetrical (vs extreme asymmetry); third exopod segment of the right leg completely separated from the second segment and bears two unequal lateral setae plus one long terminal process (vs partially fused to the second segment and bears four terminal processes increasing in size inward); third exopod segment of the left leg with two lateral setules and one long terminal process (vs two lateral setules, one short outer medial process and one long terminal process); endopodal lobes of the female legs 5 bear one long plumose seta (vs setae are lacking).http://www.zoobank.org/urn:lsid:zoobank.org:pub:C0A92BF9-2306-4A35-AA39-CE3B5865A396     

A revision of Eumedonus H. Milne Edwards, 1834 and Gonatonotus White, 1847 (Crustacea: Decapoda: Brachyura: Eumedonidae), two genera of crabs symbiotic with sea urchins

The eumedonid genera Eumedonus H. Milne Edwards, 1834 and Gonatonotus White, 1847, are revised. Members of both genera are obligate symbionts with sea urchins. Eumedonus is separated from Gonatonotus mainly by the presence or absence of crests on the merus of the ambulatory legs. Eumedonus, as here defined, contains five species, viz. E. niger H. Milne Edwards, 1834 (type species), E. vicinus Rathbun, 1918, E. zebra Alcock, 1895, E. brevirhynchus n. sp., and E. intermedius n. sp. Gonatonotus, as here re-diagnosed, includes three species, viz. G. pentagonus White, 1847 (type species), G. granulosus (MacGilchrist, 1905), n. comb. and G. nasutus n. sp.     

Diurnal mating behaviour of a Nisitrus sp. cricket (Orthoptera: Gryllidae) from Sumatra

The sexual behaviour of a diurnally active cricket in the genus Nisitrus is described from observations made in its natural habitat. Courtship consists of both auditory and visual elements. The male transfers up to five spermatophores to an individual female during a single reproductive sequence lasting more than 3 h. Males guard females during the intervals between successive production of spermatophores. The visual signal-one or more hind-leg waves-given by the male to indicate to the female that she can eat the old spermatophore, and that a new one is now ready, appears to be unique among gryllids studied so far. Females are very co-operative, as they stand to receive and then eat as many as five spermatophores in relatively quick succession. Inter-male rivalry does not occur in the absence of females, but possible 'spoiling' behaviour may occasionally interrupt mating sequences.     

Stridulatory organs of the elm bark beetles Scolytus multistriatus Marsham and Scolytus scolytus Fabricius

Summary

In Scolytidae, stridulatory organs are not usually found in the sex which selects the breeding site and begins the gallery. Exceptions in the literature refer to the genera Dendroctonus and Scolytus. The presence of stridulatory organs in both sexes of the elm bark beetles S. multistriatus and S. scolytus is reported here. The structure of the stridulatory apparatus is described, and the possible role of stridulation in the behaviour of these species is discussed.     

Trolling for water striders: active searching for prey and the evolution of reduced webs in the spider Wendilgarda sp. (Araneae,Theridiosomatidae)

Wendilgarda sp. builds unusually simple webs attached to the surface of water. The simplest design consists of a single vertical line with sticky material near the bottom that is attached at the top to a single horizontal line and at the bottom to the water surface. The spider usually sits immobile waiting for prey as the sticky line skates erratically across the surface of the water, but some spiders actively dragged their webs back and forth across the water. The web's simplicity is apparently derived with respect to the webs of other Wendilgarda species, as spiders sometimes made more complex webs similar to typical Wendilgarda webs. The simplicity of W. sp. webs may be causally related to two other unusual traits: extreme variability in web design and construction behaviour and web manipulation behaviour; and construction of prey capture webs with sticky lines by mature males, confirmed here for the first time in a confirmed member of an orb-weaving family. Some behavioural innovations in Wendilgarda, such as the attachment of a short segment of non-sticky silk to the water surface just prior to laying each segment of sticky line, may represent blocks of behaviour that have been shifted temporally in the web construction sequence.     

Mating behaviour of Staminodeus vectoris (Coleoptera: Curculionidae), and the value of systematics in behavioural studies

The mating behaviour of Staminodeus vectoris Franz (Curculionidae: Curculioninae: Derelomini) is described and discussed in light of a phylogeny of Staminodeus Franz. At La Selva, Costa Rica, S. vectoris is associated with the staminodes of the inflorescences of Asplundia uncinata Harling and several other species of Cyclanthaceae. The males have a row of 6–10 teeth along the margin of the protibia, whereas the females have a small, curved spine on the frons. The adults arrive in numbers at the inflorescences during the pistillate phase of the anthesis of A. uncinata, feeding on the staminodes. Eventually, a female detaches a staminode with her mandibles, falls to the ground, and transports it to the site of oviposition in the leaf litter. First, she crawls underneath the staminode, then moves it posteriorly with her legs, and finally returns to its distal end before repeating the process. The female turns on her back and maintains her original position during the movement of the staminode, using her frontal spine as a point of resistance against the substrate. Meanwhile, a male associates with the staminode. The males fight with their prothoracic legs, executing fast blows until their protibial teeth cling and dislodge competitors from the staminode. The positive and negative allometries of the lengths of the male protibia and female spine, are consistent with their functions in the contexts of sexual and natural selection, respectively. The phylogeny of all seven species of Staminodeus hypothesises that female transporting behaviour evolved before male fighting behaviour.