Life cycles and host–parasitoid relationships of five species of Leucospis wasps in Argentina (Hymenoptera: Leucospidae)

The genus Leucospis Fabricius is comprised of parasitoid wasps relatively uncommon in nature. Their immature stages develop on aculeate Hymenoptera, in particular solitary bees, but hosts are known for only around 25 Leucospis species (about 20% of 115–120 world species), so the true relationship of this family with bees is largely unknown. Here we report on individuals of five species of Leucospis wasps which emerged from nests of different bee and wasp species during distinct sampling periods during a trap-nesting programme, in two contrasting areas: agro-ecosystems and natural habitats in the Pampean region. Some of these nests were parasitised by L. cayennensis Westwood, L. coxalis Kirby, L. egaia Walker, L. pulchriceps Cameron and L. signifera Bou?ek. Our results expand the available information of host species for L. cayennensis, L. coxalis, L. egaia and L. pulchriceps and represent the first record of hosts associated with L. signifera. The hosts were only bee species of the genera Centris, Tetrapedia (family Apidae) and Megachile (Megachilidae). These species were more abundant in the natural reserve than in agro-ecosystems, suggesting that anthropogenic activities could negatively affect their populations. Most nests were attacked in one (43.7%) or two (40.7%) cells, but the remaining nests (16.5%) had more (up to seven cells). However, the position of the attacked cells was variable, suggesting that females of Leucospis species oviposit in recently built cells, and that the hatching of larvae is delayed, or that the first larval stage waits until the host larva reaches a sufficient size to attack.     

Morphology of oil-collecting pilosity of female Rediviva bees (Hymenoptera: Apoidea: Melittidae) reflects host plant use

The oil-collecting hair morphology and pilosity on female foretarsi for all 26 species of the southern African endemic bee genus Rediviva was studied and related to host plant use based on about 2700 flower visitation records. Four different types of tarsal pilosity and six principal hair types are identified. Rediviva bees collect floral oil from 12 plant genera representing the families Iridaceae, Orchidaceae, Scrophulariaceae and Stilbaceae, with Diascia being the most frequently used host. Differences in foretarsal pilosity reflect the availability of floral oil and elaiophore morphology of the principal host flowers. Rediviva species with short female forelegs exhibit a greater diversity of tarsal oil-collecting pilosity than long-legged species. This contradicts an earlier hypothesis that the pilosity of species with shorter legs might be less complex than in Rediviva with elongate forelegs.     

Satellite flies (Leucophora personata,Diptera: Anthomyiidae) and other dipteran parasites of the communal bee Andrena agilissima (Hymenoptera: Andrenidae) on the island of Elba,Italy

Solitary and presocial aculueate Hymenoptera are parasitized by a range of dipteran species in the families Anthomyiidae, Bombyliidae, Conopidae, Phoridae, and Sarcophagidae that are likely to impact on their hosts. We undertook a study over several years of a univoltine and communal bee, Andrena agilissima, and its main dipteran parasites, in particular the satellite fly Leucophora personata (Diptera: Anthomyiidae). Behavioural and ecological data were collected from one nesting aggregation of the host bee on the island of Elba, Italy, from 1993 to 2003, and from a foraging site of the bee, ca 5?km from the nesting aggregation. Other Diptera associated with A. agilissima at the field site were the bee fly Bombylius fimbriatus (Bombyliidae), the conopid fly Zodion cinereum (Conopidae), and the scuttle fly Megaselia andrenae (Phoridae). The phenology of the Diptera broadly overlapped with that of their host across the season of activity (end of April and all of May). Diurnal activity patterns differed slightly; L. personata in particular was active at the host's nesting site before A. agilissima. Female satellite flies also showed a range of behaviours in gaining entry to a host nest. We summarize published data on this and other Leucophora species that parasitize Andrena host bees. Host bees returning to their nests occasionally undertook zig‐zag flight manoeuvres if followed by a satellite fly that were generally successful in evading the fly. Satellite flies that entered a nest, presumably to oviposit, were less likely to remain therein if another host bee entered the same nest, suggesting that one advantage to communal nesting for this host is a reduction in brood cell parasitism by L. personata. We provide the first clear evidence for parasitism by a Zodion of any Andrena host. Both L. personata and M. andrenae concentrated their parasitic activities in the zone of the host nesting aggregation with highest nest densities. Three of the Diptera, L. personata, B. fimbriatus, and Z. cinereum, seemed to have extremely low rates of parasitism whilst that of M. andrenae appeared low. Though they have refined parasitic behaviour that allows them to gain entry into host nests (L. personata, B. fimbriatus, and M. andrenae) or to parasitize adults (Z. cinereum), these parasites seem not to impact upon the dynamics of the host A. agilissima at the nesting aggregation, and the host possesses traits to reduce parasitism.     

The morphology and biology of the entomophilic Thripinema fuscum (Tylenchida: Allantonematidae), and the histopathological effects of parasitism on the host Frankliniella fusca (Thysanoptera: Thripidae)

We used light and electron microscopy to detail the in vivo life cycle of the nematode Thripinema fuscum and to determine the effects of parasitism on tissues of the thrips host Frankliniella fusca. The parasitic T. fuscum female produced eggs within 4–5 days after ingress and the host haemocoele became packed with eggs and developing juvenile nematodes. Mature juveniles migrated to the hindgut and fully developed juveniles first emerged from the posterior end of the male or female F. fusca 9 days after parasitization. Parasitization induced a displacement of the host alimentary tract, an atrophy of the ovaries and fat body, and an alteration of energy and waste reserves in host tissues. Our observations reveal a specialized relationship showing that this parasite is well adapted to exploit the host digestive, reproductive and excretory systems.     

A new Stelis (Dolichostelis) from northern Colombia (Hymenoptera: Megachilidae): first records for South America and a synopsis of the bee fauna from the Caribbean region of Colombia

The cleptoparasitic anthidiine bee genus Stelis Panzer is primarily Holarctic in distribution, extending as far south as Costa Rica. A new species of Stelis subgenus Dolichostelis Parker and Bohart is described and illustrated based on females collected in dry forests of the Caribbean region of Colombia. Stelis (Dolichostelis) costaricensis Friese is also recorded from dry forests but in western Colombia. These are the first records of the genus, as currently recognized, for South America. An updated key to the species of Dolichostelis and a synopsis of the diversity and biogeography of the bee fauna from the Caribbean region of Colombia are provided. Based on reports from the literature and data from collections, we provide a checklist consisting of 125 species in 48 genera of five families. The complex composition of this bee fauna parallels that of the flora, with taxa having the following origins or distributions: West Indian, North or Central American, Andean, xeric or temperate South American, and Neotropical widespread. A brief account on the contribution of George Salt to the knowledge of the biology of this Colombian bee fauna is also provided.     

First host records for the rogadine genera Rogasodes Chen and He and Canalirogas van Achterberg and Chen (Hymenoptera: Braconidae) with description of a new species and survey of mummy types within Rogadinae s. str.

The parasitic wasp genus Rogasodes is recorded for the first time outside mainland China, based on a new species, R. scytaloptericola Quicke and Shaw sp. nov., from Java. Rearing data and host remains associated with the type specimen show that it is a parasitoid of the palm‐feeding drepanid moth, Scytalopteryx elongata (Snellen). Canalirogas sp. aff. balgooyi van Achterberg and Chen is recorded from an unidentified lymantriid on clove trees in Indonesia (Sumatra) and illustrated. Both of these are the first host records for the genera. Rogas spilonotus Cameron is transferred to Canalirogas. A survey of mummy sclerotization and adult emergence holes in the subfamily Rogadinae sensu stricto is presented. The data suggest an early shift to a posterior emergence position, with a strictly dorsal position being largely characteristic of the common genus Aleiodes. Only Aleiodes and a few apparently closely related taxa, including Hemigyroneuron, typically form heavily sclerotized mummies.     

New species of Hygiella Mesnil (Diptera: Tachinidae), parasitoids of leaf insects (Phasmatodea: Phylliidae)

The Oriental genus Hygiella Mesnil is revised: three species are described as new, Hygiella angustifrons sp. nov., Hygiella luteipes sp. nov. and Hygiella proclinata sp. nov., and two known species are re-described, Hygiella nigripes Mesnil and Hygiella pygidialis Mesnil. A key to these five species is provided. The host of H. proclinata, Phyllium siccifolium (Linnaeus) (Phasmatodea: Phylliidae), is recorded for the first time as a host of the Tachinidae. The systematic position of Hygiella is discussed and the genus is placed in the tribe Acemyini (Exoristinae) based on the structure of the male terminalia.     

A new species of bethylid wasp (Hymenoptera) from New Zealand,with comments on its life history and host

A new species of parasitoid wasp Chilepyris platythelys (Chrysidoidea: Bethylidae), from New Zealand, is described and illustrated. Its life history is described and its host, an anobiid (Coleoptera) larva, Hadrobregmus (Megabregmus) magnus is mentioned as the first host record for the genus Chilepyris.     

Aylax hypecoi Trotter (Hymenoptera,Cynipidae) in Europe: Redescription,with taxonomic and biological notes

Aylax hypecoi (Trotter) (Hymenoptera, Cynipidae, Aylacini), a poorly known cynipid wasp inducing galls on Hypecoum species (Papaveraceae), was described from North Africa and also doubtfully recorded from Greece about a century ago. The species has now been found in Bulgaria and thus its presence in Europe is confirmed for the first time. The species is redescribed and illustrated with SEM pictures of the adult female; galls are also described and illustrated. Data on distribution and biology are given, and its taxonomic and phylogenetic position are discussed. Aylax spirorhynchusii Diakontshuk, , another aylacine species, recorded from Transcaucasus and Middle Asia as a gall‐inducer on Spirorhynchus sabulosus Kar. and Kir. (Brassicaceae) is a synonym of Aylax hypecoi and the host plant record stated is a possible misidentification.     

Nest architecture and use of floral oil in the oil-collecting South African solitary bee Rediviva intermixta (Cockerell) (Hymenoptera: Apoidea: Melittidae)

Nest architecture, use of floral oil for brood cell lining and pollen collecting are described for the first time for the genus Rediviva, using the South African endemic oil-collecting solitary bee species Rediviva intermixta. The nest consists of a dead-end vertical tunnel with a single brood cell located at the end of each of several horizontally branching lateral tunnels. Brood cells are lined with a thin layer of waxy material, presumably derived from chemically modified floral oil. Rediviva intermixta is a pollen generalist but relies on a small number of host plant species for oil-collecting. Brood cells are provisioned with pollen from at least six plant families, but with a preference for non-oil-producing Scrophulariaceae. The nesting biology and Dufour’s gland size of the species are discussed and compared with the closely related genera Melitta and Redivivoides (non-oil-collecting) and Macropis (oil-collecting). The differences between Macropis and Rediviva suggest that oil-collecting in the two genera evolved independently.     

Polymorphism,taxonomy and host plant associations in Alebra leafhoppers (Homoptera: Cicadellidae: Typhlocybinae)

The taxonomy of a complex of morphologically similar Alebra species is clarified, and the number of adult colour pattern morphs of each in Britain, and their host plant associations, established. Morphological characters are figured for the identification of the four species now recognized, including two that are associated with different species of deciduous oaks and which were previously regarded as colour pattern morphs of A. albostriella. Three nymphal colour pattern morphs are described within the A. albostriella sibling species, two of which are shared, thus supplying further evidence for their close relationship. A key is given for the identification of the species and adult morphs of Alebra in Britain.     

LXI.—Exotic Muscaridæ (Diptera).—XXI

Summary

Acuaria subula is recorded for the first time from Passer domesticus domesticus in the British Isles. A list of the definitive hosts is given. Third-stage larvae of A. subula were recovered from the desert locust Schistocerca gregaria after experimentally feeding these insects with eggs of the nematode. Measurements of the third stage are given. An unsuccessful attempt was made to discover the natural intermediate host of A. subula, and the author speculates on the possible nature of the life-history of this worm.     

Indirect and direct acoustic aggression in cicadas: first observations in the Palaearctic genus Tibicina Amyot (Hemiptera: Cicadomorpha: Cicadidae)

Tibicina Amyot is a cicada genus of the Palaearctic biogeographical region with seven taxa (species and subspecies) distributed in France. As in other cicadas, the sound production by tymbal vibration is restricted to males. In Tibicina, males are attracted by conspecific calling songs and tend to form groups of several individuals which maintain a minimal distance between each other. Observations based upon male–male interactions in such aggregations and on some preliminary experiments conducted with males kept in captivity revealed for the first time both indirect and direct aggression. Spacing and chorusing are interpreted as a by-product of indirect aggression mediated through the calling song. Direct aggression occurred when spacing is not respected. It is achieved through a ritualistic sequence that involves mainly the production of the rivalry song, an acoustic signal previously reported in the literature for two cicada species only. In addition, satellite males and male–male courting are reported. These preliminary results suggest that the sound social organization in the genus Tibicina is more elaborate than first suspected and should be reconsidered in terms of lek behaviour and sexual selection.     

The species of four genera of Metopiinae (Hymenoptera: Ichneumonidae) in Britain,with new host records and descriptions of four new species

Two genera of Metopiinae are recorded for the first time from the British Isles, Ischyrocnemis Holmgren and Synosis Townes. An account is also given of a further two genera, Apolophus Townes and Stethoncus Townes, that have been recently recorded from Britain but remain little known. Apolophus and Synosis are shown to be koinobiont endoparasitoids of Lepidoptera larvae of the families Schreckensteiniidae and Yponomeutidae, respectively. Four species are described as new: Stethoncus monopicida sp. nov., Synosis caesiellae sp. nov., Synosis fieldi sp. nov., and Synosis parenthesellae sp. nov. A key to the Western Palaearctic species of Synosis is provided.     

A review of deviant phenotypes in bees in relation to brood parasitism,and a gynandromorph of Megalopta genalis (Hymenoptera: Halictidae)

We review the occurrence of gynandromorphy in 64 species of bee, and describe the abnormal traits as deviations from the male or female wild-type. Pheno-deviants occur at approximately equal frequency among the main body regions (head, thorax, metasoma). Cross-sex expression of character states occur more often among females (i.e. deviant expression of male-like traits) than among males (i.e. deviant expression of female-like traits). Such pathologies demonstrate how developmental switch mechanisms might generate novel structural traits similar to those expressed as a syndrome of brood parasitic traits. We also describe the first known gynandromorphic bee in the tribe Augochlorini, a specimen of the nocturnal bee, Megalopta genalis.     

The natural history of the parasitic wasp Trogus pennator (Hymenoptera: Ichneumonidae): Host‐finding behaviour and a possible host countermeasure

The parasitic wasp Trogus pennator (Ichneumonidae) attacks the larvae of swallowtail butterflies (Papilionidae). Female T. pennator were followed in the field as they searched for larvae of the zebra swallowtail butterfly, Eurytides marcellus (Papilionidae), feeding on Asimina (Annonaceae) in central Florida, USA. Predictions of host‐finding theory and interactions with the host were thus investigated in a natural setting. Wasps seldom flew to plants other than Asimina and apparently recognized the plants by visual cues. Plants were attractive regardless of host presence, as the wasps approached plants lacking E. marcellus feeding damage twice as often as they approached damaged plants. However, wasps approached damaged plants at a rate greater than their frequency in the Asimina population, indicating that they can detect host damage before they approach the plants. After approaching within 0.5?m of plants, wasps tended not to land on plants lacking feeding damage. A comparison of the plants they landed on, however, showed no consistent preferences for damaged plants. The weaker trends in the latter data indicate that the presence of feeding damage was not the sole criterion for landing, although it evidently influenced behaviour. After landing, wasps spent more time searching damaged plants than undamaged plants. Butterflies preferred to oviposit on plants shorter than those searched by T. pennator. Possible adaptive consequences of this phenomenon are discussed.     

Bulinus coulboisi of Lake Tanganyika: assessment of its taxonomic position and role as intermediate host for S. haematobium

Summary

The freshwater snail Bulinus coulboisi (Bourguignat) has been reported by previous authors to occur in a large area of central and eastern Africa, and to be a potential intermediate host for Schistosoma haematobium. In order to establish the taxonomic position of B. coulboisi, the present authors made observations on preserved specimens from the type-locality on the western shore of Lake Tanganyika, and on snails collected alive at Kigoma on the eastern shore. Information is presented for the shell, radula, copulatory organ, egg proteins, certain enzymes and chromosome number. The tetraploid chromosome number (2n=72), biochemical features and morphological characteristics of our materials provide evidence that B. coulboisi is a southern form of B. truncatus (Audouin, 1827). The latter species is widespread in northern Africa and is an important intermediate host for S. haematobium, particularly in Egypt and Sudan. The present observations and those of other authors indicate that B. coulboisi lives in small waterbodies, marshes and tributaries associated with Lake Tanganyika, but not in the main body of the lake.

Laboratory-bred B. coulboisi originating from Kigoma gave no patent infections following exposure to a strain of S. haematobium normally carried by a member of the B. africanus group. Only a low degree of compatibility was observed with one of the two tested parasite strains which are normally carried by a member of the B. truncatus group. From the known distribution of urinary schistosomiasis it appears that S. haematobium is represented in western Tanzania by a strain adapted, perhaps exclusively, to the B. africanus group. It is concluded that if B. coulboisi and B. truncatus have any potential importance as intermediate hosts in this region, it will depend upon the introduction of a compatible strain of parasite.     

On new or poorly known Australian Filistatidae spiders (Araneae: Araneomorphae), including a study on the fine morphology of Wandella

I present an update on the taxonomy of the filistatid genera Wandella Gray and Yardiella Gray, both endemic to Australia. Two new species are described: Wandella grayi sp. nov., known from Queensland, and Wandella infernalis sp. nov., known from a single cave in Western Australia. The male of Wandella australiensis (L. Koch) and the females of Wandella stuartensis Gray and Wandella waldockae Gray are described and illustrated for the first time. New records are given for these and other species of Australian filistatids, including the first epigeal records of Yardiella humphreysi Gray, a species so far known only from caves. Updated distribution maps are presented. Additionally, I present novel morphological data for Wandella using light and scanning electron microscopy. The cephalothorax, spinning organs, genitalia and appendages of some species are illustrated in detail. I report the presence of a putative claw extensor muscle in the male palpal cymbium, and describe interesting modifications in the clypeal region of adult males. The phylogenetic significance of these characters is briefly discussed.