Entomology Commons^™

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.

Mitochondrial Dna Variation Among Muscidifurax Spp. (Hymenoptera: Pteromalidae), Pupal Parasitoids Of Filth Flies (Diptera), David B. Taylor, Richard D. Peterson Ii, Allen L. Szalanski, James J. Petersen

David B. Taylor

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing analyses were used to characterize an amplicon of ~625 bp in 4 of the 5 nominate species of Muscidifurax Girault & Sanders, pupal parasitoids of muscoid flies. A single polymorphic nucleotide site was observed among 2 samples of M. raptor Girault & Sanders. No sequence variation was observed among 3 samples of M. raptorellus Kogan & Legner. The sequence of M. uniraptor Kogan & Legner was identical to that of M. raptorellus. Nucleotide divergence among the Muscidifurax spp. ranged from 0.14 to 0.18 substitutions per nucleotide. Muscidifurax zaraptor Kogan & Legner …

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

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 …

Genetic And Morphological Comparisons Of New And Old World Populations Of Spalangia Species (Hymenoptera: Pteromalidae), David B. Taylor, Roger Moon, Gary Gibson, Allen L. Szalanski

David B. Taylor

The genetic similarity of New and Old World samples of Spalangia spp. (Hymenoptera: Pteromalidae) was examined using two ribosomalDNAregions. The species examined were Spalangia cameroni Perkins, Spalangia endius Walker, Spalangia gemina Bouček, Spalangia nigra Latreille, Spalangia nigroaenea Curtis, and Spalangia slovaca Bouček. Two species of Muscidifurax, Muscidifurax raptor Girault & Sanders and Muscidifurax zaraptor Kogan & Legner (Hymenoptera: Pteromalidae) were included as outgroup taxa. The internal transcribed spacer (ITS)-1 region was highly variable among Spalangia species with many insertions/deletions making alignment of the sequences difÞcult. The D2-D3 region of the 28s ribosomal gene and the nuclear rDNA 18s gene were …

Assessing Nuclear And Mitochondrial Dna Sequence Variation Within Steinernema (Rhabditida: Steinernematidae), Allen L. Szalanski, David B. Taylor, Peter G. Mullin

David B. Taylor

DNA sequence analysis was used to characterize the nuclear ribosomal DNA ITS1 region and a portion of the COII and 16S rDNA genes of the mitochondrial genome from Steinernema entomopathogenic nematodes. Nuclear ITS1 nucleotide divergence among seven Steinernema spp. ranged from 6 to 22%, and mtDNA divergence among five species ranged from 12 to 20%. No intraspecific variation was observed among three S. feltiae strains. Phylogenetic analysis of both nuclear and mitochondrial DNA sequences confirms the existing morphological relationships of several Steinernema species. Both the rDNA ITS1 and mtDNA sequences were useful for resolving relationships among Steinernema taxa.

Identification Of Muscidifurax Spp. By Polymerase Chain Reaction-Restriction Fragment Length Polymorphism, David Taylor, Allen Szalanski

David B. Taylor

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the nuclear ribosomal ITS1 region was used to differentiate Muscidifurax (Hymenoptera: Pteromalidae) species which are parasitoids of filth fly pupae. Three restriction enzymes, Dpn 11, Mse I, and Taq I, produced restriction patterns which were diagnostic for the four species analyzed, M. raptor, M. raptorellus, M. uniraptor, and M. zaraptor. Seven other restriction enzymes were able to differentiate one or more of the species and can be used alone, or in combination with other enzymes, to verify identifications. No intraspecific variation was observed among the populations examined. The utility of the …

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 …

Population Genetics And Gene Variation Of Stable Fly Populations (Diptera: Muscidae) In Nebraska, Allen L. Szalanski, David B. Taylor, Richard D. Peterson Ii

David B. Taylor

Genetic variation in stable fly, Stomoxys calcitrans (L.),populations from Nebraska, Canada, and Texas was sampled. Four of 12 allozyme loci were polymorphic, with an average of 1.7 alleles per locus. Observed and expected heterozygosities were 0.086 and 0.070,respectively. Nei's genetic distance between populations averaged 0.001 and ranged from 0.000 to 0.005. Wright's F statistics revealed greater variation within than among populations. Allele frequencies were homogeneous among temporal samples from a single population. Polymerasechain reaction—restriction fragment length polymorphism (PCR—RFLP) analysis of 6.4 kb of the mitochondrial DNA genome with 16 restriction enzymes revealed no variation in stable fly populations from Canada, …

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

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 …

Genetic Similarity Among Pheromone And Voltinism Races Of Ostrinia Nubilalis (Hubner) (Lepidoptera: Crambidae), P. C. R. G. Marcon, David B. Taylor, C. E. Mason, R. L. Hellmich, Blair Siegfried

David B. Taylor

The genetic variability of seven European corn borer populations, Ostrinia nubilalis, from North America and Europe was assessed by polymerase chain reaction- restriction fragment length polymorphism (PCRRFLP) analysis and DNA sequencing. The nuclear ribosomal internal transcribed spacer 1 (ITS-1) region (≈ 500 base pair [bp]) and four mitochondrial (mtDNA) regions (1550 bp total) were examined. The smartweed borer, Ostrinia obumbratalis, and south-Western corn borer, Diatraea grandiosella, were used for comparisons. Of 106 restriction sites identified (80 in mtDNA and 26 in ITS-1), none differentiated geographical populations, pheromone races, or voltine ecotypes of the European corn borer. The lack of variation …

Susceptibility Of House Fly (Diptera: Muscidae) Larvae To Entomopathogenic Nematodes (Rhabditida: Heterorhabditidae, Steinernematidae, David B. Taylor, Allen L. Szalanski, Byron J. Adams, Richard D. Peterson Ii

David B. Taylor

The potential for entomopathogenic nematodes to control flies in cattle feedlots was determined by screening 40 strains representing 8 species of Heterorhabditis Poinar and 5 species of Steinernema Travassos for virulence toward 3rd-instar house flies (maggots), Musca domestica L. None of the 22 strains of Heterorhabditis infecting maggots caused significant levels of mortality in a filter paper assay. Ten strains of Steinernema infected maggots, of which 7 strains--4 S. carpocapsa (Weiser), 2 S. feltiae (Filipjev), and 1 S. scapterisci (Nguyen & Smart) caused significant mortality. Ten Heterorhabditis strains and 10 Steinernema strains successllly reproduced for 22 generations in maggots. No …

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

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.

Sugar Feeding In Adult Stable Flies, David Taylor, Dennis R. Berkebile

David B. Taylor

Adult stable flies (Stomoxys calcitrans L.) are known to feed readily on sugars in the laboratory. However, little is known concerning the extent of stable fly sugar feeding in wild populations. We examined the frequency of sugar feeding in stable flies collected on Alsynite sticky traps in rural and urban environments. In addition, stable flies were visually examined to determine whether blood was present in the gut. In laboratory studies, sugars were detectable with the anthrone technique in stable flies for ~3 d after being imbibed, and blood could be visually detected in the gut for 24-48 h after feeding. …

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.

Economic Impact Of Stable Flies (Diptera: Muscidae) On Cattle Production., David Taylor, Roger Moon, Darrell Mark

David B. Taylor

Stable flies, Stomoxys calcitrans (L.), are among the most damaging arthropod pests of cattle worldwide. The last estimate of their economic impact on United States cattle production was published 20 yr ago and placed losses at $608 million. Subsequently, several studies of effects of stable flies on beef cattle weight gain and feed efficiency have been published, and stable flies have become increasingly recognized as pests of cattle on pasture and range. We analyzed published studies and developed yield-loss functions to relate stable fly infestation levels to cattle productivity, and then estimated the economic impact of stable flies on cattle …

Dispersal Of Stable Flies (Diptera: Muscidae) From Larval Developmental Sites., David B. Taylor, Roger D. Moon, John B. Campbell, Dennis R. Berkebile, Philip J. Scholl, Alberto B. Broce, Jerome A. Hogsette

David B. Taylor

Seven mark-recapture studies were conducted over 3 yr to assess dispersal of newly emerging adult stable flies, Stomoxys calcitrans L., from larval development sites in a mixed agricultural environment in northeastern Nebraska. Infested hay debris piles were marked by dusting their surfaces with fluorescent pigments, adults were captured with surrounding grids of Alsynite sticky traps, and specimens were dissected to determine feeding histories and reproductive age. Distances and directions of 3,889 marked specimens indicated males and females dispersed equally and in all directions. Midguts of males and females were equally likely to contain blood-meal remnants. Percentage with blood remnants and …

Stable Fly Population Dynamics In Eastern Nebraska In Relation To Climatic Variables., David B. Taylor, Dennis R. Berkebile, Philip J. Scholl

David B. Taylor

Stable flies, Stomoxys calcitrans (L.), are among the most economically important arthropod pests of livestock in North America. In this study, we monitored the seasonal dynamics of a stable fly population in eastern Nebraska for 5 yr. Models based upon temperature and precipitation were developed to determine the affects of these variables on population levels as well as to project population trends. Stable flies appear in eastern Nebraska in late March to early April, and they build to a peak population during the last week of June and first week of July. In most years, the population decreases in midsummer, …

Comparative Efficiency Of Six Stable Fly Traps., David B. Taylor, Dennis R. Berkebile

David B. Taylor

Five adhesive traps and the Nzi cloth-target trap were compared to determine their trapping efficiency and biases for stable flies, Stomoxys calcitrans (L.) (Diptera: Muscidae). Two configurations of the BiteFree prototype trap, constructed of polyethylene terephthalate, were most efficient for trapping stable flies, whereas the EZ trap was least efficient. The two Alsynite traps, Broce and Olson, were intermediate to the BiteFree prototype and EZ traps. All adhesive traps collected a ratio of approximately two males for each female. Approximately 50% of the flies collected on the adhesive traps, both male and female, were blood fed, and 20% were vitellogenic. …

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

David B. Taylor

No abstract provided.

Genetics Of Interspecific Hybridization In The Triseriatus And Zoosophus Groups Of The Aedes (Protomacleaya) (Diptera: Culicidae)., David B. Taylor

David B. Taylor

Interspecific hybridization was used to examine the genetics of species divergence and phylogeny of mosquitoes in the Triseriatus and Zoosophus groups of Aedes (Protomacleaya). Aedes zoosophus Dyar & Knab exhibited a relatively high degree of reproductive compatibility with Triseriatus group species. Crosses between A. zoosophus and A. triseriatus (Say) produced fertile female and sterile, intersex, male progeny. Crosses between A. zoosophus females and A. brelandi Zavortink males were sterile with no egg embryonation observed. Crosses between A. zoosophus males and A. brelandi females and reciprocal crosses between A. zoosophus and A. hendersoni (Cockerell) produced sterile, intersex female and …

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.

Hybridization Of Aedes (Protomacleaya) Zoosophus With Ae. (Pro.) Triseriatus Group Species: Hybrid Morphology, David Taylor

David B. Taylor

Morphology of hybrids between Aedes (Protomacleaya) zoosophus and Ae. (Pro.) triseriatus group species is described. Adult females of hybrids key to Ae. zoosophus. Hybrids are differentiated from Ae. zoosophus by the dark longitudinal medial or submedial lines on the thorax and by the reduced width of the light tarsal and abdominal bands. The transverse band of light scales on the anterior scutum is complete in Ae. hendersoni / Ae. zoosophus hybrids and incomplete in Ae. triseriatus / Ae. zoosophus hybrids. Aedes brelandi / Ae. zoosophus hybrids are similar to Ae. hendersoni / Ae. zoosophus hybrids. However, due to the …

Genetic Compatibility Of Aedes (Protomacleaya) Triseriatus With A. (P.) Brelandi And A. (P.) Hendersoni (Diptera: Culicidae)., David B. Taylor

David B. Taylor

Interspecific hybridization was used to examine reproductive compatibility of Aedes (Protomacleaya) triseriatus (Say) with Aedes (P .) brelandi Zavortink and Aedes (P.) hendersoni Cockerell. Most male progeny were sterile intersexes when A. brelandi or A. hendersoni males were crossed with A. triseriatus females. Female hybrids, and males from the reciprocal crosses, were morphologically normal and fertile. Varying percentages of intersex males were observed among progeny when normal F₁ hybrids were crossed to either parental species or with other hybrids. Egg and female sterility resulting from a partial incompatibility between A. triseriatus cytoplasm and …

Speciation In The Aedes Triseriatus Species Complex., David B. Taylor

David B. Taylor

Interspecific hybridization was used to determine the genetic relationships between the four species of mosquitoes in the Triseriatus and Zoosophus groups of the aedine subgenus Protomacleaya (Diptera : Culicidae) . Four factors were investigated : 1) fertility of intra- and interspecific crosses, 2) morphology of the interspecific hybrids and the genetic bases of morphological characters, 3) modes of postcopulatory reproductive isolation and 4) types of chromosomal changes occurring during and subsequent to the divergence of the species .

Hybrid progeny were produced in 11 of the 12 possible crosses between the four species . Only the Aedes zoosophus female X …