Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “DIPTERA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20Linked to original sources

Effects of cadmium and tributyltin on development and reproduction of the non-biting midge Chironomus riparius (Diptera): baseline experiments for future multi-generation studies.

In this study the effects of tributyltin (TBT) and cadmium (Cd) were tested on the freshwater arthropod Chironomus riparius (Diptera) in life-cycle experiments. To this end, the OECD guideline 218 was extended with reproduction relevant parameters (e.g. number of fertile egg masses per female). Based on these reproduction data the number of larvae for next generation and the population growth rate were calculated. Experiments were performed using environmentally relevant concentrations of the test substances in the sediment (nominal ranges: 50-200 micro g Sn/kg and 0.2-2.1 mg Cd/kg, on a dry weight basis). Quartz sand was used as sediment in order to develop a test system for a following research project, focusing on the effects of TBT and Cd as model stressors on C. riparius populations in multi-generation studies. Both model stressors caused significant effects on development and reproduction of C. riparius. Larval mortality proved to be a sensitive parameter and a clear concentration-response relationship was observed with a significant increase (P < 0.001) at the highest TBT concentration and at a Cd concentration of 1.17 mg Cd/kg dw (P < 0.05). The two highest TBT concentrations emergence was significantly (P < 0.05) delayed compared to the solvent control. For Cd a clear prolonged average main emergence interval was observed, but not for TBT. TBT and Cd inhibited also oviposition. These effects resulted in a concentration-depended reduction of the population growth rate.

Animals↗

Walk-through trap for control of horn flies (Diptera: Muscidae) on pastured cattle.

A walk-through fly trap designed in 1938 by W. G. Bruce was tested for two field seasons in Missouri. Screened elements along both sides of the device functioned as cone traps, thereby catching horn flies, Haematobia irritans (L.), as they were swept from cattle by strips of carpet hung from the roof. Horn fly control on pastured cattle averaged 54 and 73% when they were afforded access to the trap. Analyses of Diptera captured in the trap indicated that horn flies comprised the most abundant species; face flies, Musca autumnalis De Geer, stable flies, Stomoxys calcitrans (L.), and others were present in smaller numbers. Cattle were not reluctant to use the trap, and no structural problems were observed during the experiment.

Animals↗

Evaluation of synthetic female attractants against Ceratitis capitata (Diptera: Tephritidae) in sticky coated spheres and McPhail type traps.

In field experiments conducted in a citrus orchard in Chios, Greece, we tested the efficacy of yellow, sticky, plastic, hollow spheres baited with long-lasting dispensers of the food attractants ammonium acetate, 1,4-diaminobutane (putrescine), and trimethylamine (FA-3) to capture adults of the Mediterranean fruit fly, Ceratitis capitato (Wiedemann) (Diptera: Tephritidae). Yellow spheres (7.5 cm in diameter) baited internally or externally with FA-3 were approximately 30 and approximately 12 times more attractive for females and males respectively than unbaited spheres. However, they were approximately 3 times less attractive for both sexes than plastic McPhail type traps baited with the same attractants and provided with water and a drop of a surfactant in their bases (wet traps), and only 1.5 and 2.8 times less attractive for females and males, respectively, than likewise-baited McPhail type traps provided with a killing agent (dimethyl dichlorovinyl phosphate) but not water in their bases (dry trap). Baited spheres were more C. capitata female selective than either wet or dry McPhail traps. The importance of these findings in developing lure and kill devices for the Mediterranean fruit fly is discussed.

Animals↗

Inability of Ceratitis capitata (Diptera: Tephritidae) to overwinter in the Judean hills.

The overwintering potential of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), in cold winter areas within its northern distribution is a key element in understanding its ecology. Recent studies have suggested that although originating in tropical Africa, the fly has become adapted to the cold weather that prevails within its northernmost areas of distribution. We address the question of whether the Mediterranean fruit fly has expanded its overwintering range to include the mountains of central Israel. Doing so would imply that the fly has developed either a behavioral or a physiological mechanism to cope with low temperature and/or damp conditions in combination with cold. We monitored adult populations year round, sampling fruit, calculating expected emergence days for overwintering flies, and studying adults captured within dense and sparse apple orchards. We also performed several manipulative experiments to study preimago ability to survive the winter under natural or seminatural conditions. The study was conducted in the central mountains of Israel at 700-m altitude from 1994 to 2003. Comparison experiments also were conducted at 400 m and at sea level. Our results show 1) no adults captured during the winter and spring, 2) an absence of new infestations during the winter and spring, and 3) inability of preimago stages to overwinter in the central mountains of Israel. Thus, we conclude that the fly does not overwinter in the central mountains of Israel. We discuss the ecological and applied significance of our findings.

Altitude↗

Influence of adding borax and modifying pH on effectiveness of food attractants for melon fly (Diptera: Tephritidae).

The melon fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae), is the most damaging pest of cucurbits in Reunion Island. The influence of adding borax and modifying pH on the effectiveness of different food attractants for both sexes of the melon fly is analyzed by a release-recapture method in field cages. Adding borax to protein hydrolysates Nulure and Buminal strongly reduced their attractiveness for B. cucurbitae. Acidification of 5% Buminal solution (from pH 6 to pH 3) doubled its attractiveness for melon fly. Conversely, Torula yeast at pH 10.5 was significantly more attractive than the standard Torula yeast at pH 9 (28% of captured flies compared with 17%). However, a further pH increase of the yeast solution does not improve its attractiveness. The results are discussed in relation to other studies on pH modification of various baits for Tephritidae.

Animals↗

Mass rearing history negatively affects mating success of male Anastrepha ludens (Diptera: Tephritidae) reared for sterile insect technique programs.

Mating competitiveness and sterility induction into cohorts of wild Anastrepha ludens (Loew) (Diptera: Tephritidae) was compared among wild and laboratory flies reared for use in the sterile insect technique Mexican program. Laboratory flies stemming from an 11-yr-old bisexual strain were either not irradiated, irradiated at 3 krad (low dose), or irradiated at 8 krad. In 30 by 30 by 30-cm Plexiglas cages, where a cohort of laboratory flies (male and female) irradiated at different doses (0, 3, and 8 krad) was introduced with a cohort of wild flies, males and females of each type mated randomly among themselves. Compared with nonirradiated laboratory and wild males, irradiated males, irrespective of dose (3 or 8 krad), induced shorter refractory periods and greater mating frequency in wild females. Nevertheless, laboratory flies irradiated at a low dose induced greater sterility into cohorts of wild flies than laboratory flies irradiated at a high dose. In a 3 by 3 by 3-m walk-in cage, wild males gained significantly more matings with wild females than nonirradiated and irradiated laboratory males a finding that revealed a strong effect of strain on mating performance. Mating incompatibility of the laboratory strain might have obscured the effect of reduced irradiation doses on male mating performance in the walk-in cage. Our results highlight an urgent need to replace the A. ludens strain currently used by the Mexican fruit fly eradication campaign and at least suggest that reducing irradiation doses result in an increase in sterility induction in wild populations.

Animals↗

Temperature influences on functional response of Coenosia attenuata (Diptera: Muscidae) individuals.

The functional response of single Coenosia attenuta Stein (Diptera: Muscidae) adult females to Drosophila melanogaster (Meigen) adults has been investigated at different but constant temperatures and prey densities. The experiments were conducted in cages over a wide range of temperatures between 12 and 42 degrees C. At each experimental temperature, the number of attacks increases with increasing prey density up to a maximum attack rate referred to as demand rate. A ratio-dependent and demand-driven functional response model was appropriate to describe the attack rate at different temperatures. Both the demand and the search rate linearly increased with increasing temperatures throughout the range. Based on these results, a temperature- and prey density-dependent bidimensional attack rate model was developed and parameterized. The resulting response surface shows that C. attenuata is active over a wide range of temperatures (from approximately 12 to 36 degrees C) and attacks occur up to 42 degrees C. Thus, C. attenuata may be a promising biological control agent in Mediterranean greenhouses. To support this conclusion, further studies including the evaluation of spatial scale effects on the search rate and the consideration of the economically relevant whitefly prey are recommended.

Animals↗

Interactive effects of 1-octen-3-ol and carbon dioxide on mosquito (Diptera: Culicidae) surveillance and control.

Responses of natural populations of biting Diptera were studied at Everglades National Park, Fla., to three levels (0, 3.0, and 41.1 mg/h) of 1-octen-3-ol (octenol), four levels (0, 20, 200, and 2,000 ml/min) of carbon dioxide (CO2), and their combinations. Catches of mosquitoes (Aedes taeniorhynchus (Wiedemann), Culex [Melanoconion]) spp., Cx. nigripalpus Theobald, and Wyeomyia spp.) and one tabanid (Diachlorus ferrugatus (F.)) were affected significantly by CO2 and octenol. Significantly greater numbers of all taxa were collected as the level of CO2 was increased. The 3.0-mg/h release rate of octenol alone resulted in increased trap catches relative to no bait for all taxa except Cx. (Melanoconion) spp., whereas the 41.1-mg/h release rate alone generally reduced trap catches relative to either no bait or 3.0 mg/h octenol. The effect of CO2 and octenol was additive for Cx. (Melanoconion) spp. and D. ferrugatus and synergistic for Ae. taeniorhynchus. Six octenol-supplemented CO2 treatments produced mixed results for Cx. nigripalpus.

Aedes↗

Morphological and functional classification of the hemocytes of adult female Simulium vittatum (Diptera: Simuliidae).

Morphology and function of the hemocytes of 1-d-old, female Simulium vittatum Zetterstedt were studied using light and scanning electron microscopy. Four types of hemocytes, comparable with those of other medically important Diptera, were identified: prohemocytes, plasmatocytes, granulocytes, and spherulocytes. Plasmatocytes and granulocytes contained neutral red granules, but only granulocytes exhibited significant acid phosphatase activity. Plasmatocytes and granulocytes were identified as the primary phagocytes: plasmatocytes and granulocytes of bacteria in vitro and granulocytes of human red blood cells in vivo. Granulocytes also were observed attached to and degranulating into fat body and hemopoieticlike tissue fragments, perhaps assisting in the mobilization of nutrients for egg development and in the release of immature hemocytes into circulation.

Animals↗

Blood-feeding strategy of Haematobia irritans (Diptera: Muscidae).

The economic impact on livestock production by Haematobia irritans (L.) is estimated to approach $1 billion per year in North America. However, there is little information regarding the blood-feeding strategy used by these insects. Information presented here shows that horn fly saliva interferes with the normal coagulation response as measured by the recalcification time assay. The relative anticoagulant activity on a per-gland basis was more than or equal to that reported for Simulium vittatum Zetterstedt, a common hematophagous black fly that also feeds on cattle. However, unlike S. vittatum, H. irritans salivary factors do not inhibit platelet aggregation using apyrase and have no detectable vasodilative activity. In this regard, the horn fly is strikingly different from blood-feeding species in the lower Diptera and shows a much more limited repertoire of antihemostatic factors.

Animals↗

Mosquito repellent attracts Culicoides imicola (Diptera: Ceratopogonidae).

A plant-derived mosquito repellent, based on the oil of Eucalyptus maculata var. citriodora Hook, was evaluated against the biting midge Culicoides imicola Kieffer. Suction black light-traps covered with repellent-impregnated polyester mesh and deployed near horses attracted large numbers of C. imicola, which were seen near the treated net within a few minutes of the start of the experiment. Initial collections in the traps were approximately 3 times as large as those in control traps with untreated mesh. Numbers collected in treated traps were similar to untreated control traps after 4 h. Traps with mesh treated with DEET or another plant-derived (Meliaceae) proprietary product, AG1000, acted as repellents relative to the control. The differential activity of repellents against blood-feeding Diptera is discussed.

Animals↗

Sugar meal composition of five north central Florida mosquito species (Diptera: Culicidae) as determined by gas chromatography.

Gas chromatography was used to analyze sugars found in individual crops fed on by wild caught adult Anopheles quadrimaculatus s.l. (Say), Coquillettidia perturbans (Walker), Culex nigripalpus Theobald, Culiseta melanura (Coquillett), and Psorophora ferox (von Humboldt) from several north central Florida locations. A wide range of sugars was found, including fructose, glucose, sucrose, maltose, turanose, melezitose, trehalose, raffinose, erlose, and traces of arabinose, rhamnose, and several unknowns. The frequency of individuals testing positive for crop sugars ranged from 9-10% in An. quadrimaculatus and Ps. ferox to 46% in Cq. perturbans. Based on the presence of melezitose or erlose in the crop, honeydew feeding was shown to be an important dietary component in An. quadrimaculatus (57%), Cs. melanura (31%), Cx. nigripalpus (15%), Cq. perturbans (10%), and Ps. ferox (7%). Gas chromatography of crude crop contents is a rapid one-step process that can address important questions such as the source and occurrence of sugar feeding in Diptera. Unique sugar feeding field observations were recorded for several mosquito species.

Animals↗

Mitochondrial markers for molecular identification of Aedes mosquitoes (Diptera: Culicidae) involved in transmission of arboviral disease in West Africa.

Correct classification of the insect vector is central to the study of arboviral disease. A simple molecular method for identification of the main vectors of the mosquito-borne viruses, dengue, yellow fever, and Rift Valley fever in Senegal, West Africa, was developed. We present a system in which the five mosquito species (Diptera: Culicidae) responsible for the majority of flaviviral disease transmission in Senegal can be reliably identified using small amounts of DNA coextracted during flaviviral screening procedures, via an easy amplification of the mitochondrial gene cytochrome oxidase c subunit I or II (COI or COII, respectively). We observed that despite very similar morphology, the two cryptic disease vector species Aedes furcifer Edwards and Aedes taylori Edwards are highly divergent at the molecular level. This sequence variation was used as a basis for the development of a polymerase chain reaction-restriction fragment-length polymorphism system for the differentiation of the two species. We also present the first investigation of the phylogeny of the culicine mosquitoes based on all COI and COII sequences currently available. There seems to be very low intraspecific variation in both genes, whereas interspecific variation is high. As a consequence, COI and COII are ideal candidates for the molecular identification of disease vectors to species level, whereas deeper divergences remain equivocal by using these genes. This system provides a new technique for the accurate identification of culicine disease vectors in West Africa and provides a basis for the expansion of such methods into the study of a range of diseases.

Aedes↗

Survivorship of Anopheles gambiae sensu stricto (Diptera: Culicidae) larvae in western Kenya highland forest.

The western Kenya highland has been experiencing dramatic landuse changes in the past three decades. Landuse change has been hypothesized to be one of the mechanisms for malaria epidemics in African highlands because it can alter the physical and chemical characteristics of mosquito breeding habitats. One important landuse change in western Kenya highland is deforestation. The current study examined the effects of forestation or deforestation on the survivorship of Anopheles gambiae larvae and colonization of other aquatic insects in larval habitats in Kakamega forest (elevation 1,500-1,700 m above sea level), western Kenya. We found that the survivorship of An. gambiae larvae was reduced from 55 to 57% in habitats fully exposed to sunlight (open habitats) to 1-2% in habitats with full forest canopy coverage (forest habitats) and partial canopy coverage (forest edge habitats) in two out of three trials. The average daily water temperature of the open habitats was approximately 3-3.4 degrees C higher than the forest habitats. Insect species in the orders of Diptera, Coleoptera, and Odonata colonized the larval habitats, but the three habitat types differed greatly in the animal assemblage. Canonical correspondence analysis found that water temperature and amount of leaf litter were the significant variables associated with animal assemblages. Redundancy analysis revealed that openness and the presence of predatory animals were significantly related to An. gambiae survivorship. This result suggests that deforestation facilitates the survival of the immature stage of An. gambiae in the highland.

Animals↗

Attraction of Culex pipiens/restuans (Diptera: Culicidae) mosquitoes to bird uropygial gland odors at two elevations in the Niagara region of Ontario.

In an effort to determine whether female Culex pipiens L. and Culex restuans Theobald mosquitoes (Diptera: Culicidae) are attracted to crow, Corvus brachyrhynchus, uropygial gland secretions, CDC miniature light traps (baited with CO2 but with the lights removed) were placed at approximately 1.5- and 5-m elevations, in 10 trees in awoodlot near Niagara Falls, Canada. These traps were assigned either a bird odor or a blank control. Bird odors were created by attaching cotton swabs coated with crow uropygial gland secretions to the trap intake. A significantly greater number of Cx. pipiens/ restuans were found in the 5-m traps compared with 1.5-m traps, with a significant number attracted to the bird odor over the no odor traps at the 5-m elevation, but not at 1.5 m. We also found more Aedes vexans (Meigen) in the 1.5-m traps than the 5-m traps; however, presence or absence of bird odor did not influence the distribution of Ae. vexans.

Altitude↗

Changes in relative species compositions of biting midges (Diptera: Ceratopogonidae) and an outbreak of Oropouche virus in Iquitos, Peru.

Species compositions of Culicoides paraensis (Goeldi) (Diptera: Ceratopogonidae), the major vector of Oropouche virus to humans in Central and South American urban cycles, and Culicoides insinuatus Ortiz & Leon differed along a northeast-to-southwest transect across Iquitos, Department of Loreto, Peru. The relative distributions of the species were consistent with patterns of human outbreaks along the Amazon River. We resumed collection of biting midges between May 2000 and January 2004 at three sites previously sampled (1996 -1997) to determine whether the known vector was expanding its range relative to the earlier survey. C. paraensis did not replace C. insinuatus across the region surveyed. Instead, C. insinuatus dominated the more southern sites and significantly increased its relative proportion at all three sites. Apparently, microhabitat differences and not range expansion by C. paraensis were responsible for differences in species compositions across the sample sites.

Animals↗

Effects of inorganic nitrogen enrichment on mosquitoes (Diptera: Culicidae) and the associated aquatic community in constructed treatment wetlands.

Ammonium nitrogen (NH4-N) is a significant component of municipal and agricultural wastewaters, and nitrogen reduction is an important use of constructed treatment wetlands. The effects of ammonium nitrogen enrichment on resources of larval mosquitoes, larval mosquito abundance, adult mosquito production, and the abundance of related wetland organisms were examined in 0.1-ha replicate treatment wetlands. The hypothesis of a bottom-up effect induced by ammonium addition was not supported by bacterial abundance, mean bacterial cell size, or algal biomass in the water column. There was, however, a significant negative correlation between bacterial cell length and Culex tarsalis Coquillett (Diptera: Culicidae) larval abundance 1 wk later in wetlands enriched with ammonium nitrogen. Larval mosquito (Culex spp.) abundance in southern California wetlands enriched with NH4-N (mean approximately equal to 3 mg/liter) was significantly greater than in control wetlands at ambient nitrogen levels (8.3 mg NO3-N/liter, 0.1 mg NH4-N/liter). Adult mosquito production was nine-fold greater and chironomid larvae were significantly more abundant in wetlands enriched with NH4-N than in controls but other censused taxa exhibited no significant trends. Mosquitofish, Gambusia affinis (Baird & Girard), abundance was significantly reduced in enriched wetlands, but other potential mosquito predators were not significantly affected by ammonium enrichment.

Analysis of Variance↗

Differentiation of Culicoides obsoletus and Culicoides scoticus (Diptera: Ceratopogonidae) based on mitochondrial cytochrome oxidase subunit I.

Culicoides obsoletus (Meigen) and Culicoides scoticus Downes & Kettle (Diptera: Ceratopogonidae) are sibling species of the Obsoletus group. This group comprises species of biting midges that are suspect vectors of bluetongue virus (family Reoviridae, genus Orbivirus, BTV) and African horse sickness virus (family Reoviridae, genus Orbivirus, AHSV). BTV and AHSV have been isolated several times from females of this group, although it has not been possible to determine the particular species harboring the virus, because of the inability to clearly identify the females of each species based on morphology. Both sexes of C. obsoletus and C. scoticus midges from Catalonia and the Balearics (Spain) were sequenced for the mitochondrial gene cytochrome oxidase subunit I (COI), and these sequences were analyzed to determine intra- and interspecific genetic variability. Species-specific primers for C. obsoletus and C. scoticus were designed and a polymerase chain reaction (PCR)-based diagnostic assay based on the COI gene and using a hemi-nested PCR technique was developed for reliably distinguishing the females of both species. The species-specific PCR diagnostic was compared with morphological discrimination of C. obsoletus and C. scoticus females. The morphologic characters were not fully reliable.

African Horse Sickness↗