Microsatellite loci in the house fly,Musca domestica L. (Diptera: Muscidae)

Genomic libraries from house flies enriched for (CA)₁₅ and (CAG)₁₀ repeats were constructed by using biotinylated probes. Twenty‐five loci were isolated and evaluated for polymorphisms in wild flies representing two geographically diverse populations. Fourteen of 19 dinucleotide loci, and one of six trinucleotide loci were polymorphic. One hundred and twenty‐seven alleles were detected, 39 of which were private. Average number of alleles per polymorphic locus was 8.4 ± 2.5 and average heterozygosity was 72 ± 4%. F_ST by the private allele method was 0.73. Three of 15 loci showed significant heterozygote deficiencies, attributed to null alleles. Five of 15 loci were amplified in the face fly, Musca autumnalis.     

Characterization of microsatellite loci in the house fly,Musca domestica L. (Diptera: Muscidae)

The house fly, Musca domestica L., is a cosmopolitan species with a capacity to transmit human pathogens. Here, we report on the development of polymorphic microsatellite loci for house flies and present preliminary results from four house fly subpopulations from Manhattan, Kansas. Twenty‐four microsatellite loci were isolated and characterized using DNA enriched for repeat sequences. Forty individuals from four locations in Kansas were assayed to identify for polymorphic loci. Eight loci were polymorphic with the number of alleles ranging from three to six.     

Linkage analysis of an acetylcholinesterase gene in the house fly Musca domestica (Diptera: Muscidae)

Linkage of an acetylcholinesterase (AChE) gene was detected in the house fly, Musca domestica L., by using the backcross method between a strain, aabys, that had a morphological multichromosomal marker on each of the five autosomes and a wild strain, LPR. Both strains were homozygous in this gene, and we used eight single nucleotide polymorphisms (SNPs) between them to distinguish the parental sequences in the backcrossed progeny, two of which resulted in the amino acid substitiutions common to the Drosophila and Aedes AChEs insensitive to organophosphates and carbamates. F, appeared to be a wild phenotype, and the AChE gene was heterozyous of aabys and LPR. In the backcross progeny, 32 (2(5)) phenotypes appeared, and 10 phenotypes with one wild or morphological marker were picked up for genotyping by the SNPs of AChE gene. A combination of the morphological markers and the SNPs revealed that the AChE structural gene is linked to autosome 2 in the house fly.     

细菌诱导家蝇蛹抗菌物质的分离纯化

家蝇生境中充满病原菌,其有效的防防机制成为研究的热点.通过三氟乙酸缓冲液浸提、热处理、固相萃取以及两次RP-HPLC等方法,从混合细菌液诱导的家蝇蛹中分离纯化出4种具有抗菌活性的物质.结果表明,提取的家蝇蛹粗提液抗菌谱较广,对多种微生物具有不同程度的抗菌作用,且抗菌效果好于天然肽类防腐剂和一些化学防腐保鲜剂.4种抗菌物...     

Role of prestomal teeth in feeding of the house fly, Musca domestica (Diptera; Muscidae)

Ultrastructural studies of the mouthparts of Musca domestica L. show that the fly's prestomal teeth are more damaging to host tissues than considered previously. When fed on tissue culture or pig cornea, SEM revealed that M. domestica were able to tear and suck up cells. This process occurs so rapidly, and so few cells are involved, that the damage is not perceptible to the naked eye. Except for the prestomal teeth, the mouthparts have few other structures which can inflict the damage observed.     

The use of visual information by house flies,Musca domestica (Diptera: Muscidae), foraging in resource patches

Summary House flies, Musca domestica, respond to visual contrasts on the substrate if a resource is associated with the contrasting patterns. Visible resource patch boundaries serve as a signal to flies that they are about to leave a rewarding patch. Searching flies respond to such visual information by walking along the resource patch boundary and turning back into the patch at its edge. This edge detection and response serve as a mechanism for flies with visual cues to stay in a rewarding patch and locate more resources within it. The intensity of their response correlates with the quality of the resource. In the absence of visual cues, patch shape affects foraging success; flies find more resources in circular than in linear resource distributions. The effects of visual cues, however, render patch shape unimportant. Various substrate contrasts are effective as resource information for flies: dark (e.g., green) figures on bright (e.g., white) backgrounds or bright figures on dark backgrounds. Responses to substrate contrasts measured in this study indicate that, over the short term, house flies can learn a visual cue associated with a food source.     

Cryopreservation of Musca domestica (Diptera: Muscidae) embryos

Prior studies on cryopreserving embryos of several non-drosophilid flies established that two Drosophila melanogaster embryo cryopreservation protocols were not directly suitable for use with these species. This paper describes our work on developing a protocol for cryopreservation of embryos of the housefly, Musca domestica. Significant progress was made when permeabilization of the vitelline membrane was optimized, a vitrification solution containing ethylene glycol, polyethylene glycol, and trehalose was formulated, and when cooling and recovery of the cryopreservation protocol included a step which passed the embryos through liquid nitrogen vapor. More than 70% of housefly embryos withstand treatments of dechorionation, permeabilization, loading with cryoprotectant, and dehydration in vitrification solution, but the cooling, warming, and poststorage rearing steps still cause a considerable reduction in survival. About 53% of the vitrified M. domestica embryos hatched into larvae. Relative to the percentage of the control adult emergence, about 13% of the embryos stored in liquid nitrogen developed into fertile adults. Hatching of the F(1) progeny of adults having been cryopreserved as embryos was similar to control levels.     

Mortality and knockdown effects of imidacloprid and methomyl in house fly (Musca domestica L., Diptera: Muscidae) populations

In this study, the knockdown and mortality effects of imidacloprid and methomyl were investigated. The residual surface applications were carried out to determine the knockdown effects (KDt₅₀ and KDt₉₅) and mortality (LD₅₀ and LD₉₅) induced by each insecticide. For mortality comparisons, the susceptible house fly (Musca domestica L., Diptera: Muscidae) of a WHO population and three natural field‐collected M. domestica populations from Turkey were used. In conclusion, it was found that the resistance to imidacloprid and methomyl was significantly higher in the field populations when compared to the susceptible population from WHO. The results showed that applicators and pest management decision‐makers should control and conduct an integrated pest management strategy by including biological agents to prevent the development of high levels of resistance in the field populations.     

Host age and pathogen exposure level as factors in the susceptibility of the house fly,Musca domestica (Diptera: Muscidae) to Beauveria bassiana

Adult house flies, Musca domestica L., of four ages, <1, 3, 7, and 14 day post-eclosion, were exposed to three strains of Beauveria bassiana (P89, L90 and 447). Flies were exposed to moistened filter paper treated with either a low (1.57×10⁴ conidia/cm²) or high (1.57×10⁵ conidia/cm²) concentration of each fungal strain for 6 h. Strain 447 was superior to the two house fly-derived B. bassiana strains in inducing host infection and mortality. Significant spikes in infection and mortality occurred as early as 5 days post-exposure with higher concentration exposures acting more quickly. Few differences were observed in either infection or mortality among the four fly age classes. On Day 10 post-exposure, 77% of the high-concentration, 447-exposed flies were infected, compared with only 24% of the flies from the P89 low-concentration exposure. Potential applications of these results in integrated house fly management programs are discussed.     

Methods for monitoring outdoor populations of house flies, Musca domestica L. (Diptera: Muscidae).

Relative collections of house flies were compared on two Florida dairy farms using several monitoring methods: sticky cylinders, baited jug traps (Farnam Terminator and Victor Fly Magnet), and bait strips (Wellmark QuikStrike). Bait strips were placed over collecting pans and under 61 cm square plywood roofs to protect the toxicant from sunlight ("sheltered QuikStrike traps"). Sticky cylinders collected the fewest flies (515-679 flies/trap/day) and sheltered QuikStrike traps the most (5,659-8,814 flies/trap/day). The sheltered QuikStrike traps are promising tools for disease surveillance programs. The two baited jugs collected a similar and intermediate number of flies, with collections highest during the first 2 days after placement (2,920-5,462 flies/trap/day). Jug trap collections were low after 4 days of use in the field, apparently due to deterioration in the attractiveness of the bait over time. Jug traps collected mostly females, whereas sticky cylinders and sheltered QuikStrike traps collected mostly males. Exposure of jug trap bait (Farnam) to fly cadavers for 3 days did not increase attractiveness of the bait. Combinations of the Farnam and Victor attractants were more attractive than either attractant alone and 25-43% more attractive than expected based on the sum of collections in the single-attractant jug traps. A 25% solution of farm-grade blackstrap molasses was as effective as either of the two proprietary baits tested, offering a low-cost alternative for fly population monitoring.     

Ecdysteroidostatin from the house fly,Musca domestica

Ovaries from house flies maintained on sucrose secrete large amounts of ecdysteroid when they are cultured with ovarian ecdysteroidogenic hormone, OEH. However, ovarian ecdysteroid secretion is reduced by incubation with both OEH and the ovarian ecdysteroidostatin (OES). A partially purified OES fraction from a semi-preparative reverse phase HPLC C₁₈ column caused a 98% inhibition of ovarian ecdysteroid secretion in vitro at a concentration of 0.8 equivalents per μl. Ovaries can be activated to produce ecdysteroid in vivo by feeding diet containing protein to flies maintained on sucrose. Ecdysteroid secretion was inhibited when the in vivo stimulated ovaries were cultured with OES. This suggests that OES does not interfere with the OEH activation mechanism, but blocks ovarian ecdysteroid synthesis or release. Furthermore, OES inhibition is reversible and ecdysteroid secretion resumes when OES is removed. Musca OES could explain the decrease in ecdysteroid levels found in flies after mid-vitellogenesis. Both adult male and female abdomens contain OES, but OES was not transferred to females during mating. Evidence is presented that OES is not a trypsin modulating oostatic factor. Arch. Insect Biochem. Physiol. 38:166–176, 1998. © 1998 Wiley-Liss, Inc.     

Circadian rhythms of sensitivity to insecticides in Musca domestica (Diptera, Muscidae)

Circadian rhythms of LD₅₀ values to DDT, dieldrin and malathion, topically applied, were determined for houseflies reared under LD 14:10 with dawn at 06.00 hr. There was a marked increase in susceptibility at 05.00 hr in each case. With dawn at 18.00 hr., DDT LD₅₀ values were lowest at 17.00 hr indicating independence of the flies' biological clocks from clock time of day. Flies reared under LD 18:6 and 10:14 also had circadian rhythms of sensitivity to DDT. Mean daily LD₅₀ values were inversely related to photophase length. The ratios of mean daily LD₅₀ to pre-dawn values were greatest for the longer photophases. Flies reared under LD 14:10 until the pupal stage, then DD until testing showed a normal circadian rhythm. Flies reared in total darkness (DD) showed no diel variations in susceptibility. W.H.O. standard strain flies were used for all the experiments. A fully susceptible (Cooper) and a DDT resistant (DEH-DOV) strain also showed significant circadian rhythms of sensitivity to DDT.

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Zusammenfassung Circadianrhythmen der LD 50-Werte gegenüber DDT, Dieldrin und Malathion-topical angewandt wurden bei Stubenfliegen ermittelt, die bei 14:10 h-Tag mit Tagesanbruch um 6.00 Uhr gezüchtet wurden. In allen Fällen war die Empfindlichkeit um 5.00 Uhr wesentlich erhöht. Bei Tagesanbruch um 18.00 Uhr waren die niedrigsten LD 50-Werte um 17.00 Uhr. Dies weist auf die Unabhängigkeit der biologischen Uhr der Fliegen von der Tageszeit hin. Fliegen, die bei 18:6 oder bei 10:14 LD gezüchtet wurden, zeigten ebenfalls einen Circadianrhythmus hinsichtlich der Empfindlichkeit gegenüber DDT. Die mittleren LD 50-Werte waren umgekehrt proportional zur Länge der Photophase. Das Verhältnis der mittleren täglichen LD 50-Werte zu den Vortagesanbruchwerten war am grössten bei längerer Photophase. Fliegen, die bei 14:10 LD bis zum Puppenstadium und anschliessend bei DD bis zur Testung gehalten wurden, zeigten einen normalen circadianen Rhythmus. Bei Züchtung in völliger Dunkelheit zeigten sie keine Tagesschwankungen in der Empfindlichkeit. Für alle Versuche wurde ein WHO-Standardstamm benutzt. Zwei andere Stämme, einer voll empfindlich (Cooper), der andere resistent (DEH-DOV) zeigten ebenfalls signifikante Circadianrhythmen in der DDT-Empfindlichkeir.

     

In vitro release of house fly,Musca domestica l. (Diptera : Muscidae), acrosomal material after treatments with secretion of female accessory gland and micropyle cap substance

Mature house fly, Musca domestica L. (Diptera : Muscidae), sperm were treated with female accessory gland secretion and micropyle cap substance to determine their effectiveness in eliciting an acrosome response. Scanning and transmission electron microscopy revealed that release of acrosomal material was achieved by treatment of the sperm with a combination of accessory gland secretion and micropyle cap substance but not by gland secretion alone. The gland secretion was utilized to dissolve the cap substance from mature ovarian eggs, and this combined solution was applied to sperm removed from the spermathecae of mated females. The acrosomes of several of the sperm were completely lacking, while others showed a partial effect of the treatment, i.e. extensive acrosomal membrane fragmentation and vesiculation. Most sperm that reacted to the treatment lacked a plasma membrane around the acrosome, suggesting that this membrane, along with the acrosomal membrane, is involved in formation of the vesicles alongside the acrosomal cavity.