74 research outputs found

    Rural Flies in the Urban Environment?

    Get PDF
    Because metropolitan areas in the United States have been expanding at a dramatic rate, there has been direct competition between rural and urban interests for land. Also, market pressures often make it most profitable for meat producers to locate as close to urban centers as possible. A resultant growing interface between rural and urban centers, coupled with inadequate understanding of the people between the two centers, provides a potential for problems to develop. This book generally summarizes one area of contention - flies: few people tolerate flies in any setting anymore

    Amplified fragment length polymorphism used for inter- and intraspecific differentiation of screwworms (Diptera: Calliphoridae)

    Get PDF
    Morphologically, early immature stages of the economically important pest called screwworms, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), and non-pest secondary screwworms, Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae), are nearly indistinguishable. Correct identification is crucial to the ongoing eradication and exclusion program protecting the United States, Mexico and Central America from reinvasion of screwworms persistent in South America and the Caribbean. Amplified fragment length polymorphism (AFLP) polymerase chain reaction was used to differentiate populations of C. hominivorax and to discriminate them from C. macellaria. Ten primer pairs screened for interspecific discrimination of C. hominivorax from C. macellaria showed 52 discrete bands, allowing the two species to be readily distinguished; divergent branches on resulting dendrograms showed 100% bootstrap support. C. macellaria populations grouped at the 92% level; C. hominivorax populations grouped at the 68% level. Of the 52 bands, seven were monomorphic for both species, 22 were specific to C. macellaria, ten were present only in C. hominivorax and the remaining 13 bands differentiated C. hominivorax populations. Separate studies using ten strains of C. hominivorax showed a higher level of genetic similarity within than between populations. Analyses using 72 bands (19 monomorphic bands, 53 bands grouped all ten strains at the 58% similarity level) resolved seven mutant strains from Mexico (85% similarity level); all ten strains were resolved at the 72% similarity level. Diagnostic bands were identified for species and strain identification. We conclude that AFLP can be a valuable tool for studies of interspecific and intraspecific genetic variation in screwworm populations

    Genetic variability of the stable fly assessed on a global scale using amplified fragment length polymorphism

    Get PDF
    The stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), is a blood-feeding, economically important pest of animals and humans worldwide. Improved management strategies are essential and their development would benefit from studies on genetic diversity of stable flies. Especially if done on a global scale, such research could generate information necessary for the development and application of more efficient control methods. Herein we report on a genetic study of stable flies using amplified fragment length polymorphism, with samples of 10–40 individuals acquired from a total of 25 locations in the Nearctic, Neotropic, Palearctic, Afrotropic and Australasian biogeographical regions. We hypothesized that genetic differentiation would exist across geographical barriers. Although FST (0.33) was moderately high, the GST (0.05; representing genetic diversity between individuals) was very low; Nm values (representing gene flow) were high (9.36). The mismatch distribution and tests of neutrality suggested population expansion, with no genetic differentiation between locations. The analysis of molecular variance (AMOVA) results showed the majority of genetic diversity was within groups. The mantel test showed no correlation between geographic and genetic distance; this strongly supports theAMOVA results. These results suggest that stable flies did not show genetic differentiation but are panmictic, with no evidence of isolation by distance or across geographical barriers

    Resistance Status of House Flies (Diptera: Muscidae) from Southeastern Nebraska Beef Cattle Feedlots to Selected Insecticides

    Get PDF
    The status of resistance to three insecticides (permethrin, stirofos, and methoxychlor), relative to a laboratory-susceptible colony, was evaluated in Þeld populations of house flies, Musca domestica L., collected from two beef cattle feedlots in southeastern Nebraska. Topical application and residual exposure to treated glass surfaces were suitable methods for determining the resistance status of house flies to permethrin, stirofos, or methoxychlor. However, in most cases, residual exposure was more sensitive in resistance detection (i.e., higher resistance ratios). The field populations tested were moderately resistant to permethrin (RR = 4.9-fold and RR = 7.3-fold, for topical application and residual exposure, respectively) and extremely resistant to stirofos and methoxychlor (not accurately quantifiable be cause of low mortality at the highest possible concentrations or doses). Probable explanations for the resistance status of these house fly populations and implications for global feedlot fly management are discussed

    Morphological and Genetic Analysis of Four Color Morphs of Bean Leaf Beetle

    Get PDF
    Bean leaf beetle (BLB), Cerotoma trifurcata (Forster; Coleoptera: Chrysomelidae), exhibits considerable color variation but little is known about the underlying genetic structure and gene flow among color phenotypes. Genetic and morphological variation among four color phenotypes—green with spots (G+S), green without spots (G-S), red with spots (R+S) and red without spots (R-S)—were analyzed using amplified fragment length polymorphisms (AFLP) and morphometrics, respectively. AFLP generated 175 markers that showed ≄80% polymorphism. Analysis of molecular variance (AMOVA) indicated that genetic variation was greatest within phenotypes (82.6–84.0%); gene flow among the four phenotypes was relatively high (Nm = 3.82). The dendrogram and STRUCTURE analysis indicated some population divergence of G-S from the other phenotypes. Morphological parameters were similar among phenotypes except that R+S showed significant differences in weight and body-length. Canonical variables 1 and 2, based on average morphometric characters, accounted for 98% of the total variation; some divergence was indicated between G+S and R+S from each other and from the G-S/R-S BLB color morphs. The pattern of genetic variation indicated potential divergence of G-S and G+S from each other and from R-S and R+S. Although these results indicate that the four different color morphs are not genetically or reproductively isolated, there is some genetic differentiation/structure and morphological dissimilarity suggesting weak/incomplete isolation

    A Century and a Half of Research on the Stable Fly, \u3ci\u3eStomoxys calcitrans\u3c/i\u3e (L.) (Diptera: Muscidae), 1862-2011: An Annotated Bibliography

    Get PDF
    The stable fly, Stomoxys calcitrans, is a cosmopolitan pest of livestock, wild animals, pets, and humans. It is a primary pest of cattle in the United States, estimated to cause more than $1 billion in economic losses annually. It also causes dissension at the rural-urban interface and is a problem in recreation areas such as Florida beaches and the Great Lakes. Due to its pestiferous nature and painful bite, methods to control stable flies have been investigated for over a century. A large amount of research has been reported on stable fly biology, ecology, genetics, physiology, and vector competence. For this bibliography, literature has been gathered from journals and other resources available to the authors, and a selected number of articles have been annotated. This bibliography represents an update of literature published since 1980; literature from pre-1980 was included if copy could be ascertained

    A Century and a Half of Research on the Stable Fly, \u3ci\u3eStomoxys calcitrans\u3c/i\u3e (L.) (Diptera: Muscidae), 1862-2011: An Annotated Bibliography

    Get PDF
    The stable fly, Stomoxys calcitrans, is a cosmopolitan pest of livestock, wild animals, pets, and humans. It is a primary pest of cattle in the United States, estimated to cause more than $1 billion in economic losses annually. It also causes dissension at the rural-urban interface and is a problem in recreation areas such as Florida beaches and the Great Lakes. Due to its pestiferous nature and painful bite, methods to control stable flies have been investigated for over a century. A large amount of research has been reported on stable fly biology, ecology, genetics, physiology, and vector competence. For this bibliography, literature has been gathered from journals and other resources available to the authors, and a selected number of articles have been annotated. This bibliography represents an update of literature published since 1980; literature from pre-1980 was included if copy could be ascertained

    Genetic Variability of the European Corn Borer, Ostrinia nubilalis, Suggests Gene Flow Between Populations in the Midwestern United States

    Get PDF
    The European corn borer, Ostrinia nubilalis (HĂŒbner) (Lepidoptera: Crambidae), is a widely distributed and serious economic pest to corn production in the U.S. Genetic variability of O. nubilalis was studied in 18 sub-populations in the upper Midwestern United States using amplified fragment length polymorphism. The relatively low GST values indicate that more variation exists within populations than between populations. High gene flow (Nm) values were indicated across the entire O. nubilalis population; the lowest degree of gene flow was in the northern samples (Nm = 1.96) and the highest degree of gene flow was in the southern samples (Nm = 2.77). The differences observed in the respective regions (north vs. south) may be explained by the voltinism patterns (univoltine vs. multivoltine, respectively) of O. nubilalis: southern multivoltine populations have opportunities for multiple matings for the duration of the year, further mix alleles. AMOVA results also indicated that most of the genetic variation was within sub-populations (≈ 81% of total variation); less variation (≈ 13%) was detected among populations within each of the three regions as designated for this study. However, the most striking and unexpected result was the low percentage of variation between all groups (≈ 6%), further supporting implications of a high degree of gene flow. These results provide support for current requirements of refugia corn planting in Bt-corn management. These results also indicate that if resistance to Bt were to evolve in O. nubilalis, quick action would be necessary to deter the rapid spread of the gene for resistance

    Use of the entomopathogenic fungi \u3ci\u3eMetarhizium anisopliae, Cordyceps bassiana\u3c/i\u3e and \u3ci\u3eIsaria fumosorosea\u3c/i\u3e to control \u3ci\u3eDiaphorina citri\u3c/i\u3e (Hemiptera: Psyllidae) in Persian lime under field conditions

    Get PDF
    The Asian citrus psyllid Diaphorina citri Kuwayama is a destructive insect pest in citriculture, because it is an efficient vector of the proteobacteria ‘Candidatus Liberibacter asiaticus’ (Las), ‘Ca. L. africanus’ (Laf) and ‘Ca. L. americanus’ (Lam). These bacteria cause the ‘huanglongbing’ disease or ‘greening’ or ‘yellow dragon’ disease. The disease kills the plant and reduces fruit production. This insect pest is susceptible to entomopathogenic fungi, and we report the use of different strains of Metarhizium anisopliae, Cordyceps bassiana and Isaria fumosorosea against the nymphs and adults of D. citri under field conditions. The fungi were applied four times using a concentration of 2 £ 1013 conidia/ha with a time interval of 15 days between applications. The percentage of control of Cb 108, Ma 65, Ma 14 and Ifr 4 was 60, 50, 40 and 35% in nymphs, and 50, 50, 42 and 22% in adults, respectively. Metarhizium anisopliae, C. bassiana and I. fumosorosea applied on Persian lime groves are more effective in reducing higher density of nymphs than adults of D. citri
    • 

    corecore