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Full-Text Articles in Life Sciences
Sequence-Characterized Amplified Regions That Differentiate New World Screwworms From Other Potential Wound-Inhabiting Flies, Joan A Christen, Steven R. Skoda, Tiffany Heng-Moss, Donald J. Lee, John E. Foster
Sequence-Characterized Amplified Regions That Differentiate New World Screwworms From Other Potential Wound-Inhabiting Flies, Joan A Christen, Steven R. Skoda, Tiffany Heng-Moss, Donald J. Lee, John E. Foster
Department of Entomology: Faculty Publications
Abstract. New World screwworms, Cochliomyia hominivorax (Coquerel, 1858), were once devastating pests of warmblooded animals in the United States before they were successfully eradicated using the sterile insect technique. Guarding against the introduction of screwworms to North America or any other screwworm-free area relies on rapid, reliable identification of suspected cases. In the current study, the DNA from excised markers generated by randomly amplified polymorphic DNA polymerase chain reaction was used as the basis to generate 2 species-specific sequence-characterized amplified region molecular markers. Resulting primer pairs, named CR92A1 and J1A2 (each with forward and reverse components), produced amplicons of 852 …
Comparison Of Two Gelling Agents For Screwworm (Diptera: Calliphoridae) Larval Diets, David B. Taylor
Comparison Of Two Gelling Agents For Screwworm (Diptera: Calliphoridae) Larval Diets, David B. Taylor
David B. Taylor
A sodium polyacrylamide polyacrylate gelling agent, Water-Lock G-400, and a galactan polysaccharide agent, carrageenan, were compared for solidifying larval diets of the screwworm, Cochliomyia hominivorax (Coquerel). Water-Lock diet produced larger pupae with less larval mortality than did carrageenan diet. Pupae from larvae reared on the Water-Lock diet exhibited higher emergence and produced adults with higher fecundity. Water-Lock diet also produced larger larvae at 56 h after oviposition. Densities in excess of 300 mg of eggs (16,200 eggs) per liter of Water-Lock gelled diet did not increase larval yield but did reduce larval weight and survival.
Identification Of Screwworm Species By Polymerase Chain Reaction-Restriction Fragment Length Polymorphism, David B. Taylor, Allen L. Szalanski, Richard D. Peterson Ii
Identification Of Screwworm Species By Polymerase Chain Reaction-Restriction Fragment Length Polymorphism, David B. Taylor, Allen L. Szalanski, Richard D. Peterson Ii
David B. Taylor
Restriction fragment length polymorphisms in polymerase chain reaction amplified fragments (PCR-RFLP) of mitochondrial DNA were used to differentiate species of New World screwworms (Diptera : Calliphoridae) . Twenty-seven restriction enzymes were screened on five regions of mtDNA . Eleven restriction fragment length patterns differentiated New World screwworm, Cochliomyia hominivorax (Coquerel), from secondary screwworm, Cochliomyia macellaria (F.) . Five restriction fragment length patterns were polymorphic in C. hominivorax while all fragment patterns were fixed in C. macellaria. Diagnostic restriction fragment length patterns were used for species diagnosis, whereas intraspecific variable patterns were used to characterize field samples and laboratory strains . …
Population Genetics And Gene Variation In Primary And Secondary Screwworm (Diptera : Calliphoridae), David B. Taylor, Richard D. Peterson Ii
Population Genetics And Gene Variation In Primary And Secondary Screwworm (Diptera : Calliphoridae), David B. Taylor, Richard D. Peterson Ii
David B. Taylor
Allozyme variation in screwworm, Cochliomyia hominivorax (Coquerel), and secondary screwworm, C. macellaria (F.), populations from northwest Costa Rica was examined . Variability was observed in 11 of 13 enzyme loci and the frequency of the most common allele was <0.95 for 5 loci in screwworm . In secondary screwworm, 12 of 13 loci were variable and the frequency of the most common allele was <0.95 for 6 loci . Expected heterozygosities were 0.149 and 0.160 for screwworm and secondary screwworm, respectively. Goodness-of-fit statistics for Hardy-Weinberg equilibrium and Wrights F statistics indicated that both species are panmictic with no evidence of …
Mitochondrial Dna Variation In Screwworm, David B. Taylor, Allen L. Szalanski, Richard D. Peterson Ii
Mitochondrial Dna Variation In Screwworm, David B. Taylor, Allen L. Szalanski, Richard D. Peterson Ii
David B. Taylor
Polymerase chain reaction-restriction fragment length polymorphism (PCRRFLP) analysis was used to characterize mitochondrial DNA (mtDNA) variation in screwworms, Cochliomyia hominivorax, and secondary screwworm, C. macellaria, from the Caribbean, North America and South America. Four amplicons, totaling 7.1 kb, were analysed with sixteen restriction enzymes. A total of 133 restriction sites was observed in the two species, 104 in C. hominivorax, of which nineteen were variable, and ninety-five in C. macellaria, none of which was variable. Fourteen mtDNA haplotypes were observed among eighteen C. hominivorax examined. Mean divergence between C. hominivorax haplotypes (d) was 0.0064 …
Comparison Of Gelled And Meat Diets For Rearing Screwworm, Cochliomyia Hominivorax (Diptera: Calliphoridae), Larvae, David B. Taylor, Robert L. Mangan
Comparison Of Gelled And Meat Diets For Rearing Screwworm, Cochliomyia Hominivorax (Diptera: Calliphoridae), Larvae, David B. Taylor, Robert L. Mangan
David B. Taylor
A liquid diet solidified with an acrylamide-acrylate polymer gelling agent (Water-Lock) was compared with a standard meat diet for rearing screwworm, Cochliomyia hominivorax (Coquerel), larvae. Size and yield of larvae reared on gel diet were equal to, or greater than, those of larvae reared on meat diet. Duration of larval development was increased by ca. 13 h on gel diet; however, variability of pupal weight and larval survival over generations were reduced when gel diet was used. Larval size was also more uniform over the 3-d period when larvae leave the rearing medium to pupate (crawl-off). Gelled diet was more …
Gelled Diet For Screwworm (Diptera: Calliphoridae) Mass Production, David B. Taylor, Jimmy C. Bruce, Rene Garcia
Gelled Diet For Screwworm (Diptera: Calliphoridae) Mass Production, David B. Taylor, Jimmy C. Bruce, Rene Garcia
David B. Taylor
A rearing system based on a diet gelled with Water-Lock G400, a synthetic superabsorbent (poly(2-propenamide-co-2-propenoic acid, sodium salt))( WL), was compared with the standard rearing system (liquid diet suspended in acetate fibers) for the mass production of screwworms, Cochlomyia hominivorax (Coquerel). The WL rearing system yielded 2% heavier pupae, 32% higher egg to pupa survival, and required 54% less diet and 88% less labor than the standard rearing system. Other advantages of the WL system include reduced susceptibility to suboptimal environmental conditions and labor practices, and characteristics conducive to centralization and mechanization of rearing procedures.
Laboratory Environment Effects On The Reproduction And Mortality Of Adult Screwworm (Diptera: Calliphoridae), Dennis Berkebile, Agustin Sagel, Steven R. Skoda, John E. Foster
Laboratory Environment Effects On The Reproduction And Mortality Of Adult Screwworm (Diptera: Calliphoridae), Dennis Berkebile, Agustin Sagel, Steven R. Skoda, John E. Foster
Department of Entomology: Faculty Publications
The New World screwworm, Cochliomyia hominivorax Coquerel, is mass reared for screwworm eradication initiatives that use the sterile insect technique. New methods for rearing have helped to reduce the cost of the eradication program. We examined the effect and interaction of three temperatures (24.5, 29.5 and 34.5ºC), two diets (2% spray-dried blood plus 0.05% vitamins and corn syrup carrageenan) and three population densities (300, 400, and 500 flies/cage) on egg production, egg hatch, number of observable fertilized eggs, mortality (male and female) and ovarian development. The three population densities did not affect any of the parameters monitored. Using the protein …
Quality Of Transgenic Laboratory Strains Of Cochliomyia Hominivorax (Diptera: Calliphoridae), Margaret L. Allen, Philip J. Scholl
Quality Of Transgenic Laboratory Strains Of Cochliomyia Hominivorax (Diptera: Calliphoridae), Margaret L. Allen, Philip J. Scholl
Department of Entomology: Faculty Publications
Genetically modified, mass reared insects present novel possibilities for the future of insect control. One concern about manipulation of insects is a possible loss of strain quality due to the introduction of a foreign gene of any sort into the insect genome. Eight transgenic strains of screwworm, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), were compared with the wild-type parental laboratory strain in laboratory culture. Measurements of average fertility, fecundity, larval productivity, and longevity were analyzed. Two transgenic strains had significantly lower larval productivity than controls, one of which was explained by a homozygous lethal insertion of the transgene. Another strain produced …
Postlarval Fitness Of Transgenic Strains Of Cochliomyia Hominivorax (Diptera: Calliphoridae), Margaret L. Allen, Dennis Berkebile, Steven R. Skoda
Postlarval Fitness Of Transgenic Strains Of Cochliomyia Hominivorax (Diptera: Calliphoridae), Margaret L. Allen, Dennis Berkebile, Steven R. Skoda
Department of Entomology: Faculty Publications
Eight transgenic strains of Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae) were compared with the wild-type parental laboratory strain (P95) in colony. Measurements of average weight of pupae, percentage of adults emerging from pupae, ratio of males to total emerged adults, and mating competitiveness were analyzed. The parental strain colony was subcultured and exposed to handling procedures equivalent to transgenic strains for valid comparison of overall colony fitness. None of the transgenic colonies exhibited significantly lower fitness characteristics than the control parental colony. One transgenic colony had a higher ratio of adults emerging from pupae, and five colonies had higher average pupal …
Piggybac Transformation Of The New World Screwworm, Cochliomyia Hominivorax, Produces Multiple Distinct Mutant Strains, M.L. Allen, A.M. Handler, Dennis Berkebile, S.R. Skoda
Piggybac Transformation Of The New World Screwworm, Cochliomyia Hominivorax, Produces Multiple Distinct Mutant Strains, M.L. Allen, A.M. Handler, Dennis Berkebile, S.R. Skoda
Department of Entomology: Faculty Publications
Sterile insect technique (SIT) programs are designed to eradicate pest species by releasing mass-reared, sterile insects into an infested area. The first major implementation of SIT was the New World Screwworm Eradication Program, which successfully eliminated the New World screwworm (NWS), Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), from the Continental US, Mexico and much of Central America. Ionizing radiation is currently used for sterilization, but transgenic insect techniques could replace this method, providing a safer, more cost-effective alternative. Genetic transformation methods have been demonstrated in NWS, and verified by Southern blot hybridization, PCR and sequencing of element insertion junctions. A lethal …
Cryopreservation Of Embryos Of The New World Screwworm Cochliomyia Hominivorax (Diptera: Calliphoridae), R.A. Leopold, W.B. Wang, Dennis Berkebile, T.P. Freeman
Cryopreservation Of Embryos Of The New World Screwworm Cochliomyia Hominivorax (Diptera: Calliphoridae), R.A. Leopold, W.B. Wang, Dennis Berkebile, T.P. Freeman
Department of Entomology: Faculty Publications
A method for cryopreserving embryos of the screwworm, Cochliomyia hominivorax (Coquerel), was developed for the long-term storage of strains used in research projects and for colonies maintained as back-up to production strains that are mass-reared for sterile insect release programs. This protocol, when combined with a previous procedure that was designed to render screwworm embryos permeable to water loss and the influx of cryoprotectants, yields rates of ~53% hatching, 22% pupation, and 75% adult emergence. These yields are all lower than control levels, but by the next generation the progeny of the cryopreserved flies are near or equal to control …
Identification Of Screwworm Species By Polymerase Chain Reaction-Restriction Fragment Length Polymorphism, David B. Taylor, Allen L. Szalanski, Richard D. Peterson Ii
Identification Of Screwworm Species By Polymerase Chain Reaction-Restriction Fragment Length Polymorphism, David B. Taylor, Allen L. Szalanski, Richard D. Peterson Ii
Department of Entomology: Faculty Publications
Restriction fragment length polymorphisms in polymerase chain reaction amplified fragments (PCR-RFLP) of mitochondrial DNA were used to differentiate species of New World screwworms (Diptera : Calliphoridae) . Twenty-seven restriction enzymes were screened on five regions of mtDNA . Eleven restriction fragment length patterns differentiated New World screwworm, Cochliomyia hominivorax (Coquerel), from secondary screwworm, Cochliomyia macellaria (F.) . Five restriction fragment length patterns were polymorphic in C. hominivorax while all fragment patterns were fixed in C. macellaria. Diagnostic restriction fragment length patterns were used for species diagnosis, whereas intraspecific variable patterns were used to characterize field samples and laboratory strains …
Mitochondrial Dna Variation In Screwworm, David B. Taylor, Allen L. Szalanski, Richard D. Peterson Ii
Mitochondrial Dna Variation In Screwworm, David B. Taylor, Allen L. Szalanski, Richard D. Peterson Ii
Department of Entomology: Faculty Publications
Polymerase chain reaction-restriction fragment length polymorphism (PCRRFLP) analysis was used to characterize mitochondrial DNA (mtDNA) variation in screwworms, Cochliomyia hominivorax, and secondary screwworm, C. macellaria, from the Caribbean, North America and South America. Four amplicons, totaling 7.1 kb, were analysed with sixteen restriction enzymes. A total of 133 restriction sites was observed in the two species, 104 in C. hominivorax, of which nineteen were variable, and ninety-five in C. macellaria, none of which was variable. Fourteen mtDNA haplotypes were observed among eighteen C. hominivorax examined. Mean divergence between C. hominivorax haplotypes (d) was 0.0064 …
Population Genetics And Gene Variation In Screwworm From Brazil (Diptera: Calliphoridae)., David B. Taylor, Richard D. Peterson Ii, Gonzalo E. Moya-Borja
Population Genetics And Gene Variation In Screwworm From Brazil (Diptera: Calliphoridae)., David B. Taylor, Richard D. Peterson Ii, Gonzalo E. Moya-Borja
David B. Taylor
Allozyme variation in New World screwworm, Cochliomyia hominivorax (Coquerel), populations from Brazil was examined. Variability was observed in 8 of 13 enzyme loci and the frequency of the most common allele was <0.95 for seven loci. Observed and expected heterozygosities were 0.159 and 0.165, respectively. Comparisons of the Brazilian populations with previously studied populations from Costa Rica resulted in Nei's genetic distances of between 0.000 and 0.006, with the greatest distance being between populations within Brazil. Comparisons with Mexican populations using only three loci resulted in genetic distances <0.031. Goodness-of-fit statistics for Hardy–Weinberg equilibrium and Wright's F statistics indicated small deviations from expected equilibrium genotype frequencies and low levels of differentiation between populations within Brazil. Differentiation among screwworm populations from Brazil, Costa Rica, and Mexico was minimal.
Population Genetics And Gene Variation In Primary And Secondary Screwworm (Diptera : Calliphoridae), David B. Taylor, Richard D. Peterson Ii
Population Genetics And Gene Variation In Primary And Secondary Screwworm (Diptera : Calliphoridae), David B. Taylor, Richard D. Peterson Ii
Department of Entomology: Faculty Publications
Allozyme variation in screwworm, Cochliomyia hominivorax (Coquerel), and secondary screwworm, C. macellaria (F.), populations from northwest Costa Rica was examined . Variability was observed in 11 of 13 enzyme loci and the frequency of the most common allele was <0.95 for 5 loci in screwworm . In secondary screwworm, 12 of 13 loci were variable and the frequency of the most common allele was <0.95 for 6 loci . Expected heterozygosities were 0.149 and 0.160 for screwworm and secondary screwworm, respectively. Goodness-of-fit statistics for Hardy-Weinberg equilibrium and Wrights F statistics indicated that both species are panmictic with no evidence of population substructuring. Nei ' s genetic distances were 0.000–0.001 for intraspecific comparisons and 0.899–0.916 for interspecific comparisons. The data indicate a high level of gene flow between populations within each species.
Gelled Diet For Screwworm (Diptera: Calliphoridae) Mass Production, David B. Taylor, Jimmy C. Bruce, Rene Garcia
Gelled Diet For Screwworm (Diptera: Calliphoridae) Mass Production, David B. Taylor, Jimmy C. Bruce, Rene Garcia
Department of Entomology: Faculty Publications
A rearing system based on a diet gelled with Water-Lock G400, a synthetic superabsorbent (poly(2-propenamide-co-2-propenoic acid, sodium salt))( WL), was compared with the standard rearing system (liquid diet suspended in acetate fibers) for the mass production of screwworms, Cochlomyia hominivorax (Coquerel). The WL rearing system yielded 2% heavier pupae, 32% higher egg to pupa survival, and required 54% less diet and 88% less labor than the standard rearing system. Other advantages of the WL system include reduced susceptibility to suboptimal environmental conditions and labor practices, and characteristics conducive to centralization and mechanization of rearing procedures.
Genetics Of Screwworm, New Genetic Markers And Preliminary Linkage Map., David B. Taylor
Genetics Of Screwworm, New Genetic Markers And Preliminary Linkage Map., David B. Taylor
David B. Taylor
Eight new genetic markers for Cochliomyia hominivorax (Diptera: Calliphoridae), the screwworm, are characterized. The markers include three eye mutants, lemon-eye (Ie), cherry-eye (ch), and red-eye (re); one wing mutant, curly-wing (cw); and four allozyme markers, amylase (Amy-1), glycerol-3-phosphate dehydrogenase (Gpd), phosphoglucomutase (Pgm), and octanol dehydrogenase (Odh). The markers are associated into four linkage groups. Radiation-induced translocations were used to correlate the linkage groups with their respective chromosomes. A preliminary genetic linkage map with these and three previously characterized loci is presented.
Comparison Of Two Gelling Agents For Screwworm (Diptera: Calliphoridae) Larval Diets, David B. Taylor
Comparison Of Two Gelling Agents For Screwworm (Diptera: Calliphoridae) Larval Diets, David B. Taylor
Department of Entomology: Faculty Publications
A sodium polyacrylamide polyacrylate gelling agent, Water-Lock G-400, and a galactan polysaccharide agent, carrageenan, were compared for solidifying larval diets of the screwworm, Cochliomyia hominivorax (Coquerel). Water-Lock diet produced larger pupae with less larval mortality than did carrageenan diet. Pupae from larvae reared on the Water-Lock diet exhibited higher emergence and produced adults with higher fecundity. Water-Lock diet also produced larger larvae at 56 h after oviposition. Densities in excess of 300 mg of eggs (16,200 eggs) per liter of Water-Lock gelled diet did not increase larval yield but did reduce larval weight and survival.
Comparison Of Gelled And Meat Diets For Rearing Screwworm, Cochliomyia Hominivorax (Diptera: Calliphoridae), Larvae, David B. Taylor, Robert L. Mangan
Comparison Of Gelled And Meat Diets For Rearing Screwworm, Cochliomyia Hominivorax (Diptera: Calliphoridae), Larvae, David B. Taylor, Robert L. Mangan
Department of Entomology: Faculty Publications
A liquid diet solidified with an acrylamide-acrylate polymer gelling agent (Water-Lock) was compared with a standard meat diet for rearing screwworm, Cochliomyia hominivorax (Coquerel), larvae. Size and yield of larvae reared on gel diet were equal to, or greater than, those of larvae reared on meat diet. Duration of larval development was increased by ca. 13 h on gel diet; however, variability of pupal weight and larval survival over generations were reduced when gel diet was used. Larval size was also more uniform over the 3-d period when larvae leave the rearing medium to pupate (crawl-off). Gelled diet was more …