Megaselia Scalaris Research Articles

Does GM wheat affect saprophagous Diptera species (Drosophilidae, Phoridae)?

Summary Genetically modified (GM) plants might affect ecosystem functioning through effects on non-target decomposer organisms, which play an important role in the decomposition of organic matter and nutrient release. These organisms can be affected directly by the transgene products, or indirectly by pleiotropic effects, which may influence the composition of plant compounds, such as the lignin content or the C/N ratio that could even modify matter flux. Therefore, an ecological risk assessment for GM plants also has to include decomposers. In a laboratory diet experiment, we investigated possible effects of transgenic antifungal wheat on two saprophagous Diptera species, the drosophilid Drosophila melanogaster and the phorid Megaselia scalaris . We used several experimental transgenic wheat varieties with a specific antifungal powdery mildew resistance (Pm3b) and varieties with a broad antifungal resistance, which is based on the expression of chitinase and glucanase. We determined if important fitness parameters, such as fertility, development time and sex ratio differed when the two saprophagous Diptera species were fed with either leaves of transgenic or non-transgenic wheat. To include potential long-term effects, we performed our experiments over four fly generations. Additionally, we analysed the C/N ratio, and the cellulose, hemicellulose and lignin contents of the different wheat lines to investigate any changes in the diet composition, which may alter food quality through potential pleiotropic effects. We found occasional differences in development time or the number of offspring for both dipteran species in several investigated diet comparisons but we found no consistent pattern of GM wheat effects on the tested dipteran species. Though some wheat lines showed an altered chemical composition, possibly indicating a pleiotropic effect, we found no correlation between diet quality of the wheat lines and fitness parameters. Our study shows also that dipterans represent useful model species with M. scalaris being the most suitable species, and that our experimental approach is an appropriate laboratory method to investigate the decomposition of GM material by insect larvae.

First records of two species of Oriental scuttle flies (Diptera: Phoridae) from forensic cases

In Penang, Malaysia, the Oriental and Afrotropical Megaselia curtineura (Brues) and the Oriental and Japanese Megaselia spiracularis Schmitz are reported from human corpses, these being the first reports of these species in such forensic cases.

The scuttle fly (Diptera: Phoridae) assemblages of pine plantations of the Biała Forest (Poland)

Scuttle fly diversity in disturbed habitats was evaluated on plots in pine plantations of Poland’s Biała Forest. The assemblages present in the two years were assessed for the abundance of species, dominance structure, similarity and species richness, as well as in regard to indices of species diversity, evenness and fidelity. Megaselia brevicostalis was the first dominant on each of the three plots and in both study years. The number of species and their abundance was greatest on the turn of August and September. Most of the dominants and characteristic species are multivoltine, showing spring and late summer/autumn activity.

The True Identity of Copeland's Aquatic Scuttle Fly (Diptera: Phoridae) from Indiana and Recognition of a Sibling Species from Texas

Among the insects reported by Copeland (1989) breeding in the waters retained by treeholes in Indiana was a scuttle fly identified by W. H. Robinson as Megaselia scalaris (Loew). It is here reported that in fact this fly, along with fresh material from Illinois and Missouri, is M. imitatrix Borgmeier, whose type series was from Puerto Rico. An aquatic species reported from Texas is recognized as a sibling species of M. imitatrix and is named M. hansonix Disney, sp. nov. A single female from Brazil represents a third species of this complex, thus raising doubts about the identity of specimens from Brazil attributed to M. imitatrix by Benton and Claugher (2000).

Sialoglycoconjugates inHerpetomonas megaseliae: role in the adhesion to insect host epithelial cells

Herpetomonas megaseliae is a monoxenic trypanosomatid isolated from the phorid fly Megaselia scalaris. In the present report, the expression of cell surface sialoglycoconjugates in this parasite was analyzed by Western blotting, flow cytometry and fluorescence microscopy analyses using lectins that specifically recognize sialic acid residues. A strong reaction was detected when parasites were treated with Limax flavus, Maackia amurensis and Sambucus nigra lectins. Analysis of crude protein extracts by Western blotting revealed that bands with molecular masses ranging from 19 to 80 kDa were reactive to these lectins, which showed a sugar-inhibited recognition with the parasite extract. These results indicated that molecules containing alpha2,3- and alpha2,6-sialylgalactosyl sequences are present in this protozoan. The role of the surface sialomolecules in the interaction with explanted guts from Aedes aegypti was assessed. The interaction of H. megaseliae with the insect gut was strongly inhibited in the presence of mucin (71%), fetuin (68%) and sialyllactose (68%). Collectively, our results suggest a possible involvement of sialomolecules in the interaction between this insect trypanosomatid and the invertebrate host.

Chronic exposure to elevated levels of manganese and nickel is not harmful to a cosmopolitan detritivore, Megaselia scalaris (Diptera: Phoridae)

AbstractEnvironmental contamination with metals such as manganese (Mn) and nickel (Ni) often results in elevated concentrations of these metals in plant tissues. At high concentrations, these metals are known to have detrimental effects on certain insect herbivores. Using laboratory bioassays and artificial diet, we investigated the development and survival of a cosmopolitan insect detritivore, Megaselia scalaris (Diptera: Phoridae), exposed to concentrations of Mn and Ni reaching 2600 mg Mn/kg and 5200 mg Ni/kg dry mass (dm) in artificial diet. Surprisingly, Ni and Mn at the concentrations tested did not harm this fly. Treatment groups from diets with 260–2600 mg Mn/kg dm and 1300–5200 mg Ni/kg dm had significantly shorter larval development times, overall times to adult emergence, and both pupariation and pupal eclosion times compared to a control group. Wing length of females, a correlate of adult fitness, was also greater in metal treatment groups. Other measures including rate of egg hatch, percentage of emerging flies that were female, and wing length of male flies, were not significantly different in metal treatment groups. We conclude that Megaselia scalaris is tolerant of exceptionally high levels of Mn and Ni.

A review of termitophilous and other termite-associated scuttle flies worldwide (Diptera: Phoridae)

AbstractA review is provided of the morphological and behavioural observations known for the 190 recorded termitophilous and other termite-associated species of Phoridae (scuttle flies) known worldwide. A full list of these termite-associated phorids is provided, together with their recorded termite hosts, as an Appendix. The influence of batch size, egg size, developmental cycle, wing reduction and winglessness, egg-laying and morphological adaptations of a termite-associated lifestyle is discussed, based on differences observed among termite-associated phorids. A high number of termitophilous phorid species with batch sizes of four eggs or less are noted, probably reflecting the stable environment termitophilous phorids experience, and the high percentage of species with parasitoid or predatory larvae. Minimising the free-living larval stage by a reduction of the number of instars, by larval instar curtailment, or by endoparasitism is here hypothesised to be an advantageous life history strategy for many termite-associated phorids. Termite-associated phorids can be divided into four main types, according to their biology and morphology. The exploitive- and generalistic-types include both obligate and non-obligate termite associates that take advantage of the more vulnerable stages of the termites. The protective- and guest-types are obligate associates, spending full larval and pupal stages with their hosts. The guest-type is described as being socially integrated, communicating with the host and being involved in worker/nymph interactions.

What can you do with 0.1× genome coverage? A case study based on a genome survey of the scuttle fly Megaselia scalaris (Phoridae)

BackgroundThe declining cost of DNA sequencing is making genome sequencing a feasible option for more organisms, including many of interest to ecologists and evolutionary biologists. While obtaining high-depth, completely assembled genome sequences for most non-model organisms remains challenging, low-coverage genome survey sequences (GSS) can provide a wealth of biologically useful information at low cost. Here, using a random pyrosequencing approach, we sequence the genome of the scuttle fly Megaselia scalaris and evaluate the utility of our low-coverage GSS approach.ResultsRandom pyrosequencing of the M. scalaris genome provided a depth of coverage (0.05-0.1x) much lower than typical GSS studies. We demonstrate that, even with extremely low-coverage sequencing, bioinformatics approaches can yield extensive information about functional and repetitive elements. We also use our GSS data to develop genomic resources such as a nearly complete mitochondrial genome sequence and microsatellite markers for M. scalaris.ConclusionWe conclude that low-coverage genome surveys are effective at generating useful information about organisms currently lacking genomic sequence data.

Breeding of the Scuttle Fly Megaselia scalaris in a fish Carcass and Implications for the use in Forensic Entomology (Diptera: Phoridae)

The breeding of 138 specimens of the scuttle fly Megaselia scalaris (Loew 1866) in a piece of sardine, Sardinella brasiliensis (Steindachner 1879) (Teleostei: Clupeidae), exposed in a rural site in SE Brazil is reported. Some aspects regarding the exploitation of carcasses of such nature and size by phorids are discussed, aiming to comprehend their potential forensic utility.

A Laboratory-Based Study for First Documented Case of Urinary Myiasis Caused by Larvae of Megaselia scalaris (Diptera: Phoridae) in Saudi Arabia

Megaselia scalaris (Diptera: Phoridae) is one of the medically important insects. Maggots from a urine sample of a 5-year-old Saudi girl were examined microscopically for identification. These maggots were cultured to become adult flies. Larvae and adults were identified using standard keys. Protozoan flagellates were obtained from the gut of the larvae. This is the first report of M. scalaris as a causative agent of urinary human myiasis in Saudi Arabia.

Some Scuttle Flies (Diptera: Phoridae) of the Galápagos Islands

The first scuttle fly (Diptera: Phoridae) recorded from the Galapagos Archipelago (Megaselia scalaris (Loew, 1866)) was collected during the Williams Expedition (1923) (Johnson 1924) and a second species (Dohrniphora cornuta (Bigot, 1857)) was collected during the Norwegian Zoological Expedition (1925) (Curran 1932). Additional material of the latter species was collected on the Templeton Crocker Expedition of 1932 (Van Duzee 1933; Curran 1934). In 1985, Stewart Peck (Carleton University, Ottawa) started the first of five collecting expeditions to the Galapagos, with the aim of generating an invertebrate inventory of the island fauna. There is little doubt that these surveys have had a tremendous impact on the knowledge of the terrestrial invertebrates, producing numerous publications in many and several major monographs (Peck 2001, 2006). BJS participated in the second Peck expedition of 1989. Vast numbers of specimens were collected on these two surveys, which resulted in the listing of four phorid species, all classified as introduced invasive species (Causton et al. 2006). We report here primarily on the collections of scuttle flies made by S. & J. Peck and BJS and identified by RHLD.

Natural History of the Scuttle Fly,Megaselia scalaris

The larvae of Megaselia scalaris (Diptera: Phoridae) exploit a broad spectrum of larval pabula. Consequently, the species features in a range of situations that affect the resources or well-being of humans. Furthermore, M. scalaris is readily cultured in the laboratory and is therefore favored as an experimental species for genetic, developmental, and bioassay studies. However, the extensive but widely scattered literature, reviewed herein, is frequently ignored by specialists, which gives rise to the unwitting repetition of previous work as well as insupportable proposals.

First record of Megaselia scalaris (Loew) (Diptera: Phoridae) infesting laboratory colonies of Triatoma brasiliensis Neiva (Hemiptera: Reduviidae)

Megaselia scalaris (Loew) is a cosmopolitan and synanthropic scuttle fly, eclectic in its feeding habits and acts as detritivore, parasite, facultative parasite, and parasitoid. Here we report for the first time M. scalaris infesting laboratory colonies of Triatoma brasiliensis Neiva, the most important Chagas disease vector in semiarid areas of Brazil. M. scalaris larvae were found feeding inside bugs; pupae were found in the esophagus and intestinal regions of T. brasiliensis through dissection. Other relevant information about this finding is also described in this note, including some preventive measures to avoid laboratory colonies infestations.

Fore Tarsus Attachment Device of the Male Scuttle Fly,Aenigmatias lubbockii

The fore tarsus of the male scuttle fly, Aenigmatias lubbockii (Verrall) (Diptera: Phoridae), is broad and equipped with flattened and apically truncated (FAT) setae on the ventral surface, which are suggested to be involved in the intraspecific phoretic behaviour including airlifting and dispersal of the female. The combination of FAT setae on the male fore tarsi and regularly arranged microtrichia on the female thoracic surfaces is suggested to form a combination of an adhesive structure and possibly a fastener system. Comparisons are made to Puliciphora borinquenensis (Wheeler), which also has apterous females and male-facilitated female dispersal, but where fore tarsal FAT setae are absent.

Forensic entomology cases in Thailand: a review of cases from 2000 to 2006

This paper presents and discusses 30 cases of cadavers that had been transferred for forensic entomology investigations to the Department of Forensic Medicine, Faculty of Medicine, Chiang Mai University, northern Thailand, from 2000 to 2006. Variable death scenes were determined, including forested area and suburban and urban outdoor and indoor environments. The fly specimens found in the corpses obtained were the most commonly of the blow fly of family Calliphoridae, and consisted of Chrysomya megacephala (F.), Chrysomya rufifacies (Macquart) Chrysomya villeneuvi Patton, Chrysomya nigripes Aubertin, Chrysomya bezziana Villeneuve, Chrysomya chani Kurahashi, Lucilia cuprina (Wiedemann), Hemipyrellia ligurriens (Wiedemann), and two unknown species. Flies of the family Muscidae [Hydrotaea spinigera Stein, Synthesiomyia nudiseta (Wulp)], Piophilidae [Piophila casei (L.)], Phoridae [Megaselia scalaris (Loew)], Sarcophagidae [Parasarcophaga ruficornis (F.) and three unknown species], and Stratiomyiidae (Sargus sp.) were also collected from these human remains. Larvae and adults of the beetle, Dermestes maculatus DeGeer (Coleoptera: Dermestidae), were also found in some cases. Chrysomya megacephala and C. rufifacies were the most common species found in the ecologically varied death scene habitats associated with both urban and forested areas, while C. nigripes was commonly discovered in forested places. S. nudiseta was collected only from corpses found in an indoor death scene.

A checklist of arthropods associated with rat carrion in a montane locality of northern Venezuela

This is the first report of arthropods associated with carrion in Venezuela, using laboratory bred rats ( Rattus norvegicus). Rat carcasses were exposed to colonization by arthropods in neighboring montane savanna and cloud forest habitats in the state of Miranda. The taxonomic composition of the arthropods varied between both ecosystems. Scarabaeidae, Silphidae, Micropezidae, Phoridae, Vespidae and one species of ant, were collected only in the cloud forest. Dermestes maculatus, Chrysomya albiceps, Termitidae and most species of ants, were found only in the savanna. Fourteen species were considered to be of primary forensic importance: D. maculatus, Oxelytrum discicolle, Calliphora sp., Cochliomyia macellaria, Compsomyiops sp., C. albiceps, Phaenicia cuprina, P. sericata, P. eximia, Fannia sp., Puliciphora sp., Megaselia scalaris, Ravina sp. and Sarcophaga sp.

First records of Megaselia scalaris (Loew) and M. spiracularis Schmitz (Diptera: Phoridae) from New Zealand, with additional information on other worldwide species

First records are given for the phorid flies Megaselia scalaris (Loew) and M. spiracularis Schmitz in New Zealand. Both are of potential medical significance, being agents of myiasis elsewhere in the world. Further, more detailed records are given for M. halterata (Wood) and M. rufipes (Meigen) in New Zealand. All of these species are widely distributed throughout the world.

Frecuencia y distribución temporal de moscas cadavéricas (Diptera) en la ciudad de Buenos Aires

Frequency and temporal distribution of cadaveric flies (Diptera) in the city of Buenos Aires. Forensic entomology is used to estimate the post-mortem interval (PMI) by determination of the species of insects found on a corpse and their stage of development. The later varies according to environtmental conditions; in temperate climates the occurrence of each species varies seasonally. The Order Diptera is the most important in the early stages of decomposition. Only fragmentary data on temporal distibution in Buenos Aires have been published, and these were only based on trapping and rearing. This paper is based on records of forensic ntomology expertises performed in the year period 1995-2005. The occurrences of Calliphora vicina, e Phaenicia sericata, Cochliomyia macellaria and Chrysomya albiceps (Calliphoridae), Sarcophaga spp (Sarcophagidae), Hydrotaea argentina and Muscina stabulans (Muscidae) and Megaselia scalaris (Phoridae), indoors and outdoors, is recorded. The predominance of C. vicina from autumn to spring and of P. sericata in summer is confirmed. The autochthonous C. macellaria was recorded the whole year, with a peak in the summer months; it proved rare outdoors. A species which may function as primary or secondary is C. albiceps; it is active in summer and early autumn. The species of Sarcophaga are active mainly in summer but they appear along the rest f the year associated with advanced decomposition. No marked seasonal variation was shown by H. argentina, M. stabulans, and M. scalaris.

Survey for Hymenopteran and Dipteran Parasitoids of the Fall Armyworm (Lepidoptera: Noctuidae) in Chiapas, Mexico

Abstract A survey of hymenopteran and dipteran parasitoids of the fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) larvae was conducted to determine their occurrence and parasitism rates in Western Chiapas, Mexico. 1247 FAW larvae were collected from whorl-stage corn cornfields in 21 locations in the region called “La Frailesca” in Chiapas, Mexico during the summer of 2002; 251 larvae produced parasitoids for an overall parasitism rate of 20.1%. Five braconids were recovered from FAW larvae, Rogas vaughani Muesebeck, R. laphygmae Viereck, Chelonus insularis Cresson, C. cautus Cresson, and Glyptapanteles militaris Walsh. Two ichneumonids, Neotheronia sp., and Ophion flavidus Brulle, and one eulophid, Euplectrus plathypenae Howard were recovered. Dipteran parasitoids were also recovered from last instars. These were the tachinids Archytas marmoratus Towsend, Lespesia archippivora Riley, Archytas sp., and Winthemia sp. Megaselia scalaris Low was a unique phorid recovered. Dipteran parasitoids produced...

Behaviour and activity patterns of the scuttle fly Megaselia oxybelorum Schmitz (Diptera: Phoridae) at nest aggregations of two host digger wasps (Hymenoptera: Crabronidae)

We report on a field study of the behavioural ecology of Megaselia oxybelorum Schmitz at nest aggregations of its hosts, the digger wasps Philanthus triangulum F. and Cerceris arenaria L. (Hymenoptera: Crabronidae). The flies flew across the P. triangulum nesting site both as single individuals and as females and males paired in copula, and the former case was recorded more than twice as often as the latter, while only single individuals were recorded at the C. arenaria site. Individuals both alone and in copula were seen at the P. triangulum site during the day roughly coinciding with the host provisioning activity, while at the C. arenaria site the fly's daily activity followed a bimodal trend in contrast to the normal distribution of the host provisioning. Visits of host nests were frequent at the P. triangulum site and null at the C. arenaria site. Single individuals spent less than 1 min inside a nest, while a female entering while still in copula spent generally 1–3 min inside, males exiting after 1–5 s, showing that only in this second case was an oviposition possible. The number of Megaselia oxybelorum increased with increasing host nest density and decreasing nearest neighbour distances of nests. Behavioural patterns of M. oxybelorum, when compared to other Megaselia spp. associated with fossorial Hymenoptera, showed differences possibly related to the biology of the hosts. In addition, some morphological variation within and between host sites are discussed.