Cytogenetics of the genus Parasarcophaga (Sarcophagidae: Diptera)

Somatic chromosome complements of five sympatric species of the genus Parasarcophaga, viz. P. misera, P. albiceps, P. argyrostoma, P. ruficornis and P. knabi, are described. All the species have five pairs of meta/submetacentric autosomes and an XX/XY sex chromosome pair which is highly variable in size and shape. In P. misera and P. albiceps they are tiny dots while in P. knabi the metacentric X and Y chromosomes constitute almost one third of the genome. In P. ruficornis and P. argyrostoma they are telocentric chromosomes of moderate size. A comparative study of the C-banding patterns of P. ruficornis, P. knabi, P. argyrostoma and P. misera shows that autosomes of the former three species possess characteristic C-bands in pericentric regions while in P. misera they are absent. The heterochromatic sex chromosomes are C-band positive in all the species. However, with the exception of the tiny sex chromosomes of P. misera, the X chromosomes of other species show shorter or longer regions which stain rather lightly. These C-banded areas correspond to the heterochromatic areas revealed in orcein stained preparations. The evolutionary implications of these results are discussed.     

The polytene chromosomes of Nilodorum biroi (Kieffer) (Diptera: Chironomidae)

The polytene chromosomes of the salivary glands of Nilodorum biroi (Kieffer) comprise three long metacentric or submetacentric chromosomes. It is considered that this is a derived condition from a diploid number of 8, by the tandem fusion of a small acrocentric element (C) to a metacentric chromosome (AB). A standard chromosome map for the genus is provided and the chromosomal polymorphism of Indian and Australian populations is described.     

肥须亚麻蝇幼虫不同发育阶段气门形态学变化

为了满足实际工作中利用蝇类幼虫日龄推断尸体死后间隔时间的需求,本文采用显微镜观察不同龄期肥须亚麻蝇 Parasarcophaga crassipalpis (Macquart)幼虫气门的形态学变化,通过计算机图像分析系统对幼虫的前、后气门等可用于判断幼虫生长发育的形态学指标进行测量。结果表明：肥须亚麻蝇幼虫前、后气门随时间而发生规律性的变化,幼虫前气门色素管部的平均光密度及其长宽比,以及后气门的平均光密度这 3 项指标是推算幼虫日龄较理想的指标,对法医学中尸体死亡时间的推测具有重要的指示意义。此外,叠龄期作为幼虫发育的必经阶段,可为特殊时间点的推测提供可靠依据。     

Interspecific competition among larvae ofHemipyrellia ligurriens (Calliphoridae) andBoettcherisca formosensis (Sarcophagidae) (Diptera)

1. The effects of larval rearing density and species relative proportions on life-history parameters of two necrophagous Diptera, Hemipyrellia ligurriens (Wiedemann) (Calliphoridae) and Boettcherisca formosensis Kirner and Lopes (Sarcophagidae), were investigated in mixed cultures. Larval rearing density had a significant effect on larval to adult survivorship, duration of immature development, adult size and relative performance (measured by the composite index of performance, r′) of both species. However, species relative proportions affected adult size of both flies and the duration of immature development of B. formosensis only.
2. B. formosensis had a higher survivorship than H. ligurriens in all mixed cultures and showed a similar survivorship pattern to that in pure cultures. By contrast, survivorship of H. ligurriens was lower in mixed than in pure cultures.
3. H. ligurriens adults reared from mixed cultures were smaller than those from pure cultures of comparable density, but B. formosensis adults from pure and mixed cultures were of similar size.
4. The results suggest that competition between B. formosensis and H. ligurriens larvae was asymmetric and the former was the superior competior.
5. At low larval densities in mixed cultures, the presence of H. ligurriens enhanced the performance (as measured by r′) of B. formosensis, a consequence of suspected interspecific facilitation of larval growth.

     

Studies on polytene chromosomes of Smittia parthenogenetica (Chironomidae,Diptera)

In polytene chromosome II of Smittia parthenogenetica a heterochromatin insertion has been studied which is derived from a germ-line limited chromosome section (Bauer, 1970). This insertion is C-banding positive, late replicating, inactive in RNA synthesis, fluoresces brightly with quinacrine and is polytenized. After N-banding a major part of the heterochromatin insertion is N-banding negative, whereas in the centre of the insertion a N-banding positive body is present. The properties of the N-positive and N-negative parts of the inserted heterochromatin section are compared with the properties of the heterochromatin of Chironomus melanotus and Drosophila melanogaster. It is concluded that the heterochromatin insertion consists of two different heterochromatin types and it is discussed whether the N-banding positive part within the insertion represents a heterochromatin type which is underreplicated during polytenization.Dedicated to Professor Dr. Hans Bauer in honour of his 75th birthday on September 27, 1979     

Malpighian tubule polytene chromosomes of Culex quinquefasciatus (Diptera,Culicinae)

Dipteran polytene chromosomes provide an excellent model for understanding in species complexes, as well as for structural and functional cytogenetics. The status of species in the Culex pipiens complex is controversial and the use of polytene chromosomes for cytogenetic analysis in the subfamily Culicinae has been difficult because of methodological problems. In this study, Malpighian tubule polytene chromosomes were obtained from young (0 to 12 h, 20 C) and old (20 to 42 h, 28 C) laboratory-bred C. pipiens quinquefasciatus pupae. The chromosome maps for this species were constructed and compared with published data for C. pipiens pipiens and C. p. quinquefasciatus. Although the banding patterns were conserved between subspecies, analysis of the structural variations in the bands and interbands revealed differences apparently related to the physiological stage and ecogeographical strain. The organization of the centromeric regions in larval and pupal chromosomes showed greater similarity to each other than did those of pupal and adult chromosomes. The use of pupal polytene chromosomes for in situ hybridization with vector competence probes is discussed.     

DNA replication in polytene chromosomes: Similarity of termination patterns in somatic and germ-line derived polytene chromosomes of Anopheles stephensi liston (Diptera: Culicidae)

DNA replication is initiated in the ovarian follicles of the anautogenous Culicid Anopheles stephensi in response to a blood meal. The chronology of nurse cell polytene chromosome³H-thymidine labelling patterns has been defined and the terminal labelling patterns of the nurse cell and larval salivary gland polytene X-chromosomes have been compared and found to be essentially similar.     

Patterns of incorporation of tritiated thymidine by the dorsal polytene foot-pad nuclei of Sarcophaga bullata (Sarcophagidae: Diptera)

The incorporation of tritiated thymidine into the DNA of the dorsal foot-pad nuclei of Sarcophaga bullata, during pharate adult development, was studied by scintillation counting and autoradiography. Incorporation was maximal on day 4 and showed a progressive temporal decline on days 5 to 8. Autoradiographs of chromosomal arms A¹, A² and D¹, from late stages of the prolonged S period, showed discontinuous incorporation. On days 7 and 8 loci which incorporated the radio-labeled precursor were almost exclusively associated with DNA granules. DNA granules were associated with 8 specific loci in chromosomal arm A¹, 10 in A², and 8 in D¹. The relationship between patterns of incorporation of tritiated thymidine and DNA granules is discussed.Deceased June 15, 1975     

Morphological diversity of centromere regions in polytene chromosomes of blackflies (Diptera, Simulidae)

Karyotypes of more than 120 species of 33 genera of the Palearctic blackflies (Simuliidae) were studied on squashed acetoorcein stained preparations of salivary gland polytene chromosomes in larvae. In the course of evolution of the family, a significant complication was noticed in the morphology of centromere regions of polytene chromosomes. In plesiomorphic species, centromeres are not pronounced morphologically and the general picture does not differ from that of other bands and interbands of the polytene chromosome. In species with apomorphic characters, a distinct precentromeric heterochromatin appears, whose manifestation is responsible for morphological diversity of centromere zones in polytene chromosomes. They are represented either by conspicuous slightly thickened heterochromatic bands or by large amplified blocks of heterochromatin or puff-like structure, being considerably extended as a result of despiralization of precentromeric heterochromatin. There are species, which more commonly lack chromocentre and their chromosomes are separated. Some other species have ectopic contacts between pricentromeric heterochromatin. In some species, this heterochromatin is organized as a compact chromocentre. This has been found only in representatives of southern latitudes, most frequently in evolutionarily young species with narrow specialization.     

C banding in polytene chromosomes of Simulium ornatipes and S. melatum (Diptera: Simuliidae)

Polytene and mitotic chromosomes of Simulium ornatipes and S. melatum were subjected to C banding procedures. In both species polytene chromosomes consistently show C banding of centromere regions, telomeres, nucleolar organiser and, unexpectedly, numerous interstitial sites. The interstitial C banding sites correspond to morphologically single polytene bands. Their response is graded and independent of band size. Interstitial C bands in S. ornatipes are scattered throughout the complement, whereas in S. melatum they are clustered. Supernumerary heterochromatic segments in S. ornatipes also exhibit strong C banding and inverted segments can differ from standard in C banding pattern. — Mitotic chromosomes of both species show a single centric C band with indications of two weak interstitial bands in S. ornatipes, suggesting that many C band regions, detectable in polytene chromosomes, are not resolved by present techniques in mitotic chromosomes. — Contrary to current opinion that C banding is diagnostic for constitutive heterochromatin, the interstitial C band sites of polytene chromosomes are regarded as euchromatic. Conversely, the heterochromatic pericentric regions of S. ornatipes are not C banded. — It appears that polytene chromosomes offer a promising system for the elucidation of C banding mechanisms.     

A cytogenetic analysis of the polytene chromosomes of Anopheles triannulatus (Diptera: Culicidae) from western Venezuela

The larval polytene chromosomes of Anopheles triannulatus are described for the first time in this report. The population from western Venezuela was chosen arbitrarily as the chromosome standard and is the basis for the photomap presented here. Anopheles trannulatus displays whole-arm associations distinct from other members of the subgenus Nyssorhynchus that have been examined cytogenetically. The association pattern for An. triannulatus is 2R-3R and 2L-3L, rather than the more common 2R-2L and 3R-3L. The possible role of whole-arm translocations in speciation is briefly discussed.     

The Sarcophagidae (Diptera) of the Middle East

A list of 285 species of Sarcophagidaе in the Middle East countries is presented with distributional data, including Bahrain (3 species), Cyprus (46), Egypt (both African and Asian parts) (114), Iran (83), Iraq (17), Israel (113), Jordan (14), Kuwait (3), Lebanon (13), Oman (2), Gaza Strip (5), Palestinian Authority (42), Quatar (1), Saudi Arabia (37), Syria (42), Turkey (both European and Asian parts) (157), United Arab Emirates (14) and Yemen (15). Three new synonyms are established: Blaesoxipha delilah Lehrer, 2006 = Agriella setosa Salem, 1938, syn. n.; Blaesoxipha nahaliana Lehrer, 2008 = Blaesoxipha popovi Rohdendorf, 1937, syn. n.; and Liosarcophaga daccanella Lehrer, 2008 = Liosarcophaga (s. str.) dux (Thomson, 1869), syn. n. Four new combinations for species names are proposed: Liopygia (Engelisca) adhamae (Lehrer & Abou-Ziad, 2008), comb. n.; Liosarcophaga (s. str.) pedestris (Villeneuve, 1910), comb. n.; Liosarcophaga (Pandelleisca) theodori (Lehrer, 1998), comb. n., and Liosarcophaga (Pharaonops) tewfiki (Salem, 1940), comb. n.     

A technique for preparing polytene chromosomes from Aedes aegypti (Diptera,Culicinae)

Polytene chromosome preparations were obtained from larval, pupal and adult female Malpighian tubules of Aedes aegypti. The Malpighian tubules of the pupae (0-4 h old) from larvae reared at 20 C provided the best cytogenetic analysis. The interaction of nucleic acids and proteins that influence the spreading of the chromosomes could be reduced with the preparation technique of the sheets submitted to a stronger treatment starting with the hypotony of tissue and successive bathings with acetic acid. A simple technique should facilitate molecular cytogenetics used in the location of resistance and vector competence genes.     

Synanthropy of Sarcophagidae (Diptera) in southeastern Brazil

Sarcophagidae (Diptera) are potential vectors of several pathogens. They are also very important in forensic entomology, providing basic information on the circumstances of death. The objective of this study was to determine the synanthropic index of adult Sarcophagidae collected in Rio Claro, state of São Paulo, southeastern Brazil. Sampling occurred between September 2009 and August 2010. Traps baited with sardines, beef liver, or minced meat were set for five consecutive days per month in three distinct ecological areas representing urban, rural, and forest environments. A total of 440 specimens of sarcophagids were collected. The most abundant species was Peckia (Sarcodexia) lambens (Wiedemann), followed by Oxysarcodexia thornax (Walker), Peckia (Euboettcheria) collusor (Curran & Walley), Peckia (Euboettcheria) sp., and Peckia (Pattonella) intermutans (Walker). The only species with positive synanthropic index values were O. thornax and P. (S.) lambens, which demonstrated a greater preference for inhabited areas. Peckia (Euboettcheria) florencioi (Prado & Fonseca), P. (P.) intermutans, and Peckia (Euboettcheria) australis (Townsend) were only found in the forested area, which demonstrates their importance in forensic entomology because of their preference for a particular type of environment. The greatest number of sarcophagids was found in the forest environment; however, only the forest and rural areas were significantly different in Sarcophagidae abundance.     

Revision of Neotropical Metopia Meigen (Diptera: Sarcophagidae)

ABSTRACT. The Neotropical species of Metopia Meigen are revised, and a total of fifteen species recorded from the region. Five species are described as new; M.aurigans sp.n., M.pulverulenta sp.n., M.hispidimana sp.n., M.flava sp.n., and M.cubitosetigera sp.n. Three species are recorded for the first time from the Neotropical region; M.inermis Allen, 1926, M.krombeini Sabrosky, 1953, and M.sinipalpis Allen, 1926. Four new synonyms are proposed; M.tessellata Allen, 1926, syn.n. of M.perpendicularis Wulp, 1890, M.macrocera Dodge, 1968, syn.n. of M.brasiliana (Townsend, 1929), M.astuta Dodge, 1968, syn.n. of M.brasiliana (Town-send, 1929), and M.lucipeda Reinhard, 1961, syn.n. of M.campestris (Fallen, 1810). Males of M.polita (Townsend, 1935) and M.juquiana (Townsend, 1934) are recorded for the first time. A key to all American species of Metopia is provided, and the phylogenetic affinities of the Neotropical species are briefly discussed.     

Mitotic and polytene chromosomes analysis of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

The Oriental fruit fly, Batrocera dorsalis s.s. (Hendel) is one of the most destructive agricultural pests, belonging to a large group of difficult to distinguish morphologically species, referred as the B. dorsalis complex. We report here a cytogenetic analysis of two laboratory strains of the species and provide a photographic polytene chromosome map from larval salivary glands. The mitotic complement consists of six chromosome pairs including a heteromorphic sex (XX/XY) chromosome pair. Analysis of the polytene complement has shown a total of five polytene chromosomes (10 polytene arms) that correspond to the five autosomes. The most important landmarks of each polytene chromosome and characteristic asynapsis at a specific chromosomal region are presented and discussed. Chromosomal homology between B. dorsalis and Ceratitis capitata has been determined by comparing chromosome banding patterns. The detection of chromosome inversions in both B. dorsalis strains is shown and discussed. Our results show that the polytene maps presented here are suitable for cytogenetic analysis of this species and can be used for comparative studies among species of the Tephritidae family. They also provide a diagnostic tool that could accelerate species identification within the B. dorsalis complex and could shed light on the ongoing speciation in this complex. Polytene chromosome maps can facilitate the development of biological control methods and support the genome mapping project of the species that is currently in progress.     

Effects of gamma-radiation on the organisation of polytene chromosomes ofGlyptotendipes salinus Michailova (Chironomidae,Diptera)

A series of laboratory experiments onGlyptotendipes salinus were carried out in order to assess cytogenetic effects of different doses of gamma-radiation on polytene chromosomes, isolated from salivary glands. Chrinonomid larvae (III–IV larval stage) were irradiated with doses varying from 0.05 to 1.00 Gy (5–100 rad) and were bred under laboratory conditions until the fourth larval stage. Cytogenetic slides were analyzed for an estimation of occurrence of changes in the organization of the polytene chromosomes caused by gamma-radiation. A specific heterochromatin effect was found in certain chromosomes of the investigated species after 1.00 Gy irradiation. Decondensation of the centromeric heterochromatin and increased functional activity of Balbiany ring 2 were observed in the fourth (G) chromosome. Regression of the nucleolus of the first (AB) chromosome was detected.     

Wing morphometric analysis of Australian Sarcophaginae (Diptera: Sarcophagidae)

Phenetic affinities of thirty-two species of Australian Sarcophaginae are described. A set of wing morphometric characters was analysed using canonical variate analysis and clustering of generalized distances. The results were compared to classifications of Roback (1954) and to that of Souza Lopes (1954, 1958a, b, 1959). There was substantially more agreement with the classification of Roback than with that of Souza Lopes. Thus the subfamily appears to consist of a reduced number of minor genera (Heteronychia, Blaesoxipha, Tricharaea and possibly Sarcosolomonia/Fergusonimyia) and a large complex consisting of species of Sarcophaga sensu lato.