No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
Setting the records straight II: “single spermatheca” of Braula coeca (Diptera: Braulidae) is really the ventral receptacle
Abstract
Braula coeca has been reported repeatedly, but incorrectly, to have only a single spermatheca—an extremely rare condition in the higher flies. This error is based on the misinterpretation of the ventral receptacle as a single spermatheca combined with the failure to detect the two present but largely reduced dorsal spermathecae. This misconception is of importance, e. g., for correct character coding in phylogenetic analyses and in the context of studies regarding recurrent trends in the evolution of the spermathecae and the ventral receptacle. The ventral receptacle of B. coeca is described and illustrated in detail together with other aspects of the female reproductive tract.
... Cryptochetidae, globose metallic flies that parasitise scale insects, and Braulidae, wingless bee parasites, are strongly supported to be close relatives of Drosophilidae. Both were previously proposed to be nested in Carnoidea in classifications derived from morphological synapomorphy [19], though the reliability of these traits has recently been called into question [49]. ...
Background
The most species-rich radiation of animal life in the 66 million years following the Cretaceous extinction event is that of schizophoran flies: a third of fly diversity including Drosophila fruit fly model organisms, house flies, forensic blow flies, agricultural pest flies, and many other well and poorly known true flies. Rapid diversification has hindered previous attempts to elucidate the phylogenetic relationships among major schizophoran clades. A robust phylogenetic hypothesis for the major lineages containing these 55,000 described species would be critical to understand the processes that contributed to the diversity of these flies. We use protein encoding sequence data from transcriptomes, including 3145 genes from 70 species, representing all superfamilies, to improve the resolution of this previously intractable phylogenetic challenge.
Results
Our results support a paraphyletic acalyptrate grade including a monophyletic Calyptratae and the monophyly of half of the acalyptrate superfamilies. The primary branching framework of Schizophora is well supported for the first time, revealing the primarily parasitic Pipunculidae and Sciomyzoidea stat. rev. as successive sister groups to the remaining Schizophora. Ephydroidea, Drosophila ’s superfamily, is the sister group of Calyptratae. Sphaeroceroidea has modest support as the sister to all non-sciomyzoid Schizophora. We define two novel lineages corroborated by morphological traits, the ‘Modified Oviscapt Clade’ containing Tephritoidea, Nerioidea, and other families, and the ‘Cleft Pedicel Clade’ containing Calyptratae, Ephydroidea, and other families. Support values remain low among a challenging subset of lineages, including Diopsidae. The placement of these families remained uncertain in both concatenated maximum likelihood and multispecies coalescent approaches. Rogue taxon removal was effective in increasing support values compared with strategies that maximise gene coverage or minimise missing data.
Conclusions
Dividing most acalyptrate fly groups into four major lineages is supported consistently across analyses. Understanding the fundamental branching patterns of schizophoran flies provides a foundation for future comparative research on the genetics, ecology, and biocontrol.
The species-specificity of male genitalia has been well documented in many insect groups and sexual selection has been proposed as the evolutionary force driving the often rapid, morphological divergence. The internal female genitalia, in sharp contrast, remain poorly studied. Here, we present the first comparative study of the internal reproductive system of Sepsidae. We test the species-specificity of the female genitalia by comparing recently diverged sister taxa. We also compare the rate of change in female morphological characters with the rate of fast-evolving, molecular and behavioral characters.
We describe the ectodermal parts of the female reproductive tract for 41 species representing 21 of the 37 described genera and define 19 morphological characters with discontinuous variation found in eight structures that are part of the reproductive tract. Using a well-resolved molecular phylogeny based on 10 genes, we reconstruct the evolution of these characters across the family [120 steps; Consistency Index (CI): 0.41]. Two structures, in particular, evolve faster than the rest. The first is the ventral receptacle, which is a secondary sperm storage organ. It accounts for more than half of all the evolutionary changes observed (7 characters; 61 steps; CI: 0.46). It is morphologically diverse across genera, can be bi-lobed or multi-chambered (up to 80 chambers), and is strongly sclerotized in one clade. The second structure is the dorsal sclerite, which is present in all sepsids except Orygma luctuosum and Ortalischema albitarse. It is associated with the opening of the spermathecal ducts and is often distinct even among sister species (4 characters; 16 steps; CI: 0.56).
We find the internal female genitalia are diverse in Sepsidae and diagnostic for all species. In particular, fast-evolving structures like the ventral receptacle and dorsal sclerite are likely involved in post-copulatory sexual selection. In comparison to behavioral and molecular data, the female structures are evolving 2/3 as fast as the non-constant third positions of the COI barcoding gene. They display less convergent evolution in characters (CI = 0.54) than the third positions or sepsid mating behavior (CICOI = 0.36; CIBEHAV = 0.45).
Sperm and female reproductive tract morphology are among the most rapidly evolving characters known in insects. To investigate whether interspecific variation in these traits results from divergent coevolution we examined testis size, sperm length and female reproductive tract morphology for evidence of correlated evolution using 13 species of diopsid stalk-eyed flies. We found that sperm dimorphism (the simultaneous production of two size classes of sperm by individual males) is ancestral and occurs in four genera while sperm monomorphism evolved once and persists in one genus. The length of 'long-sperm' types, though unrelated to male body or testis size, exhibits correlated evolution with two regions of the female reproductive tract, the spermathecae and ventral receptacle, where sperm are typically stored and used for fertilization, respectively. Two lines of evidence indicate that 'short sperm', which are probably incapable of fertilization, coevolve with spermathecae. First, loss of sperm dimorphism coincides phylogenetically with reduction or loss of spermathecae. Second, evolutionary change in short-sperm length correlates with change in spermathecal size but not spermathecal duct length or ventral receptacle length. Morphological coevolution between sperm and female reproductive tracts is consistent with a history of female-mediated selection on sperm length.
Piophila casei has been reported repeatedly, but incorrectly, to have only a single spermatheca—an extremely rare condition in the higher flies. This error is based on the misinterpretation of the large sclerotized ventral receptacle as a single spermatheca combined with the failure to detect the two present but unsclerotized spermathecae. This misconception is of importance not only in the context of studies regarding recurrent trends in the evolution of the ventral receptacle. It also led to a set of erroneous character codings in a phylogenetic analysis of the family. To set the records straight, previous more accurate literature is revisited and the ventral receptacle of Piophila casei is described and illustrated in detail together with other aspects of the female reproductive tract such as the spermathecae, accessory glands, vagina, and anterior ventral vagina pouch.
The internal female reproductive tract of a Neotropical species of stilt-legged fly (Diptera: Micropezidae: Grallipeza sp. A) is described and illustrated with microphotography. Special emphasis is given to the massively enlarged sclerotized tubular ventral receptacle and an almost complete reduction of the spermathecal capsules, suggesting that sperm storage has been shifted from the spermathecae to the ventral receptacle. This constitutes a remarkable convergence with analogous developments in other dipteran taxa. The published information on the internal female reproductive tract of other Micropezidae is reviewed, and the evolutionary history of the condition in Grallipeza sp. A is reconstructed and related to evolutionary processes likely involving sperm competition and cryptic female choice. The presence of paired accessory glands in Grallipeza sp. A is confirmed.
The systematic position of the Piophilidae sens . lat . within a group of nine schizophorous families with tephritid-like ovipositors (Lonchaeidae, Otitidae, Platystomatidae, Pyrgotidae, Tephritidae, Tachiniscidae, Richardiidae, Pallopteridae, and Piophilidae) is elucidated. It is shown to be a sister-group of the Pallopteridae, and these two families together with the Richardiidae comprise a monophyletic suprafamily unit within the larger group of families. The evolutionary changes that occurred within the Piophilidae are analyzed and the supposed phylogeny of its component taxa is portrayed. The family is redefined to include neottiophilids and thyreophorids and is classified into two subfamilies, Neottiophilinae and Piophilinae; the latter is divided into two tribes, Mycetaulini and Piophilini (with subtribes Piophilina and Thyreophorina ). Twenty-three genera are recognized and taxonomically defined; this includes description of two new genera, Neopiophila and Parapiophila . Clusina Curran is synonymized with Protopiophila Duda (new synonymy), and four nominal species are placed in synonymy for the first time, i . e . Piophila anomala Malloch and Piophila setosa Melander and Spuler = Parapiophila vulgaris (Fallén) (new synonymy), Piophila flavifacies Brunetti = P . casei (Linnaeus) (new synonymy), and Mycetaulus pulchellus Banks = Mycetaulus longipennis Loew (new synonymy). Six new species, Actenoptera avalona (Newfoundland), Neopiophila setaluna (Northwest Territories), Protopiophila atrichosa (Peru and British Honduras), Protopiophila pallida (Peru and British Guiana), Prochyliza azteca (Mexico), and Prochyliza inca (Peru) are described. The following 20 new combinations are made: Mycetaulus lituratus (Melander and Spuler), Allopiophila testacea (Melander), Protopiophila nigriventris (Curran), Prochyliza lundbecki (Duda), nigricornis (Meigen), nigricoxa (Melander and Spuler) and nigrimana (Meigen), Arctopiophila arctica (Holmgren), Parapiophila atrifrons (Melander and Spuler), calceata (Duda), coerulescens (Zetterstedt), dudai (Frey), flavipes (Holmgren), lonchaeoides (Zetterstedt), nitidissima (Melander and Spuler), pectiniventris (Duda), penicillata (Steyskal), vulgaris (Fallén), and xanthopoda (Melander and Spuler). In all, 67 valid species are placed, their geographic distributions are outlined, and the zoogeographic implications are discussed. A lectotype is designated for Piophila flavitarsis Meigen = Madiza glabra Fallén (Milichiidae).A key to subfamilies, tribes, and genera is provided, and keys to world species are given where needed. An annotated world list of all names referred to the family ( sens . lat .) is provided. The paper includes 58 figures, two tables, and 122 literature references.
Eight species of the S trongylophthalmyiidae are reported from P apua N ew G uinea. Of these, five species ( S trongylophthalmyia gigantica sp. nov., S . papuana sp. nov., S . rubella sp. nov., S . sedlaceki sp. nov. and S . shatalkini sp. nov.) are described as new to science. S trongylophthalmyia puncticollis F rey is recorded for the first time from P apua N ew G uinea. Faunistic remarks, a key to the species of the S trongylophthalmyia in P apua N ew G uinea and a world checklist are provided.
The first mention of this insect was made in 1740 by Reamur (9), who discussed its relation to the honeybee. Nitzsch (1818) described the genus and species, naming the insect Braula coeca; and classified it, on account of its mouth parts, with the Diptera, associating it with the Pupipara. Errors in Nitzsch's description of antennæ and thorax were corrected by Egger (4), thus removing any doubt as to the alliance of Braula with the Diptera. Since Braula did not fit into any insect classification then in use, Egger proposed the special family, Braulidæ. According to Muggenberg (7), the structure of the head vesicle shows a close relationship between Braula and the Hippoboscidæ. Taxonomically, Handlirsch (5) removed the Braula from the Pupipara and placed it in a separate family next to the Phoridæ. It was formerly generally helieved that Braula coeca was pupiparous but, according to Muggenberg (7), Skaife (10), Arnhart (2) and Argo (1), it is oviparous. Skaife and Argo described fairly completely the life cycle of the insect, while Arnhart found the mines and dried out larval skins under honey cappings. Perez (Phillips 8) found that Braula was not a true parasite, as believed by the older workers, but that it was a sort of commensal parasite feeding on the nectar which it steals from the honeybee. Muggenberg (7) described the mouth parts and discovered the eyes of the supposedly blind insect in 1892. Borner (3) gives a detailed account of the external morphological structures. Skaife (10), through microdissection studies, described in a general way the alimentary canal and the male and female reproductive organs. He also worked out the metamorphosis of this insect.
The internal female reproductive tract of Risa is characterized by a pair of short spermathecal ducts with no spermathecae, paired short accessory glands, and a large thimble-shaped strongly sclerotized ventral receptacle. This condition is identical with that in the ground plan of Ephydridae but differs from that of their next relatives, i.e., Camillidae and Diastatidae, regarding the shape of the ventral receptacle. It therefore corroborates the close relationship of Risa with Ephydridae either as its sister taxon or within that family.
Megabraula gen.n. is erected for two new species, M.antecessor and M.onerosa, both found coinhabiting nests of Apis laboriosa in Nepal. Because of their many modifications, the features that distinguish Braula, the other genus in the family, and Braulidae in general are revised. Braulid biology is reviewed, particularly the adaptations involved with the origin of and progressive specialization to commensalism with honey bees.
Studies on the morphology of the bee louse, Braula coeca Nitzsch (Diptera: Braulidae)
- M H Hassanein
- A L El-Salam
Family Cryptochetidae
- E Nartshuk
Family Strongylophthalmyiidae
- M Iwasa
Strongylophthalmyia pengellyi n. sp., a second species of Nearctic Strongylophthalmyiidae (Diptera)
- K N Barber
Beiträge zur Kenntnis der Pupiparen
- J D F Hardenberg
Die Familien und Gattungen der Thierinsekten (Insecta epizoica); als Prodromus einer Naturgeschichte derselben
- C L Nitzsch
Strongylophthalmyiidae
- G C Steyskal
An Australian parasite of Icerya purchasi
- S W Williston
New taxa of the Acalyptrate flies (Diptera: Tunisimyiidae fam. n., Risidae, Ephydridae: Nannodastiinae subfam. n.)
- L Papp
The Anthomyzidae (Diptera) of Israel, with revision of Anagnota Becker
- J Roháček
- A Freidberg
Die Bienenlaus-Arten
- Z Örösi-Pál
One species each of Hyperoscelididae, Pyrgotidae, Odiniidae, Acartophthalmidae and Risa Becker from Mongolia (Diptera). Folia Entomologica Hungarica
- L Papp
Notes on some Becker's types (Diptera, Carnidae and Risidae fam. N.). Annales Historico-Naturales Musei Nationalis Hungarici
- L Papp
Braula hansruttneri sp. n., eine neue Bienenlaus aus Österreich (Braulidae, Diptera). Entomofauna
- E Hüttinger