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Full-Text Articles in Entomology

Comparison Of Two Gelling Agents For Screwworm (Diptera: Calliphoridae) Larval Diets, David B. Taylor Feb 2012

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 Feb 2012

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 Feb 2012

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 Feb 2012

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 …


Genetics Of The Screwworm Fly, David B. Taylor, Estela Martinez Cuevas Feb 2012

Genetics Of The Screwworm Fly, David B. Taylor, Estela Martinez Cuevas

David B. Taylor

Three spontaneous eye mutants of Cochliomyia hominivorax, the screwworm fly, are described and characterized. The mutants, yellow eye (ye), orange eye (or), and white eye (wh), segregate independently and are recessive. Yellow eye is recessively epistatlc to orange eye and dominantly epistatic to white eye. All three mutants have complete penetrance, are autosomal, and have little effect on fly viabillty under laboratory conditions.


Comparison Of Gelled And Meat Diets For Rearing Screwworm, Cochliomyia Hominivorax (Diptera: Calliphoridae), Larvae, David B. Taylor, Robert L. Mangan Feb 2012

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 …


Population Genetics And Gene Variation In Secondary Screwworm (Diptera: Calliphoridae), David Taylor, Richard Peterson Ii Feb 2012

Population Genetics And Gene Variation In Secondary Screwworm (Diptera: Calliphoridae), David Taylor, Richard Peterson Ii

David B. Taylor

Allozyme variation in 4 populations of secondary screwworm, Cochliomyia macellaria (F.), representing North, Central, and South America was examined . Variability was observed in 12 of 13 enzyme loci, and the frequency of the most common allele was <0.95 for 6 loci . Observed and expected heterozygosities were 0.149 and 0.154, respectively. Nei's genetic distances were ≤ 0.001. Goodness-of-fit statistics for Hardy-Weinberg equilibrium and Wright's FIS statistics indicated random mating within populations . Wright's FST statistics and chi-square contingency analyses indicated homogeneous gene frequencies among the populations. These data suggest that C. macellaria is a panmictic species with high levels …


Gelled Diet For Screwworm (Diptera: Calliphoridae) Mass Production, David B. Taylor, Jimmy C. Bruce, Rene Garcia Feb 2012

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.


Response Of Screwworms (Diptera: Calliphoridae) To Changes In The Concentration Of Blood, Egg, And Milk In The Larval Diet, David B. Taylor Feb 2012

Response Of Screwworms (Diptera: Calliphoridae) To Changes In The Concentration Of Blood, Egg, And Milk In The Larval Diet, David B. Taylor

David B. Taylor

Larvae of screwworm, Cochliomyia hominivorax (Coquerel), were reared on diets with varying concentrations of whole dried bovine blood, whole dried egg, and nonfat dried milk. Pupal weight, egg to pupal survival, adult emergence, sex ratio, fecundity, and fertility were significantly affected by one or more of the dietary components. Curvilinear models for the effect of dietary component concentration on life history parameters were derived by multiple regression. Most models resulted in bell-shaped curves that were used to calculate optimal diet component concentrations. Biomass, survival, emergence, and fecundity were maximized at 6% blood, 5% egg, and 1.3% milk.


Population Genetics And Gene Variation In Screwworm From Brazil (Diptera: Calliphoridae)., David B. Taylor, Richard D. Peterson Ii, Gonzalo E. Moya-Borja Dec 1995

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.


Rearing Systems For Screwworm Mass Production, David B. Taylor Dec 1991

Rearing Systems For Screwworm Mass Production, David B. Taylor

David B. Taylor

No abstract provided.


Reproductive Compatibility Of New World Screwworms, Cochliomyia Hominivorax, From North Africa And Central America., David B. Taylor, Leslie Hammack, Richard L. Roehrdanz Jan 1991

Reproductive Compatibility Of New World Screwworms, Cochliomyia Hominivorax, From North Africa And Central America., David B. Taylor, Leslie Hammack, Richard L. Roehrdanz

David B Taylor

The reproductive compatibility of New World screwworms, Cochliomyia hominivorax (Coquerel), from North Africa and a strain being mass produced for the Mexican eradication programme was examined to assess the feasibility of using flies from the Mexican screwworm mass production facility for a sterile insect technique eradication programme in North Africa. Males from the production strain mated randomly with females from North Africa and from the production strain when both were present. Neither strain of males discriminated between cuticular extracts of North African and production strain females containing a contact sex pheromone. Interstrain crosses between North African flies and production flies …


Genetics Of Screwworm, New Genetic Markers And Preliminary Linkage Map., David B. Taylor Jan 1989

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 (le), 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.


Genetics Of Screwworm, New Genetic Markers And Preliminary Linkage Map., David B. Taylor Dec 1988

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.


Truncation Of Screwworm (Diptera: Calliphoridae) Development By Irradiation Of Embryos., David B. Taylor, Robert L. Mangan Jan 1988

Truncation Of Screwworm (Diptera: Calliphoridae) Development By Irradiation Of Embryos., David B. Taylor, Robert L. Mangan

David B Taylor

Gamma irradiation of screwworm, Cochliomyia hominivorax (Coquerel), embryos was used to truncate the life cycle at the prepupal stage. Egg hatch and larval survival were not reduced by dosages ≤8 kilorads (kr). Pupariation and adult emergence were inhibited by dosages ≥2.8 and 1.2 kr, respectively. Larvae, irradiated as embryos with dosages ≤8 kr, successfully infested wounded sheep, although larval weight was lower than normal. A dosage of 5.8 kr was sufficient to prevent pupariation, while permitting larval development to the third instar. Truncation of screwworm development permits the use of artificially wounded and infested animals for screwworm population surveillance and …