Survey of insect growth regulator (IGR) resistance in house flies (Musca domestica L.) from southwestern Turkey

Insect growth regulators (IGRs) are currently the fastest‐growing class of insecticides, and in Turkey these products represent a new approach to pest control. In recent years, several IGRs were also registered for the control of the house fly, Musca domestica L. (Diptera: Muscidae), in Turkey. A field survey was conducted in the summers of 2006 and 2007 to evaluate resistance to some agriculturally and medically used IGRs on house flies from livestock farms and garbage dumps in the greenhouse production areas (Merkez, Kumluca, Manavgat, and Serik) of Antalya province (Southwestern Turkey). The results of larval feeding assay with technical diflubenzuron, methoprene, novaluron, pyripoxyfen, and triflumuron indicate that low levels (RF<10‐fold) of resistance to the IGRs exist in the house fly populations from Antalya province. Exceptions, however, were two populations, Guzoren and Toptas, from the Kumluca area which showed moderate resistance to diflubenzuron with 11.8‐fold in 2006 and 13.2‐fold in 2007, respectively. We found substantial variation in susceptibility of field‐collected house fly populations from year to year and from product to product. We generally observed an increase in resistance at many localities sampled from 2006 to 2007. The implications of these results to the future use of IGRs for house fly control are discussed. It will be critically important to continue monitoring efforts so that appropriate steps can be taken if resistance levels start to increase.     

Electrophoretic analysis of genetic variability in the house fly (Musca domestica L.)

Methods are described for the resolution of house fly, Musca domestica L., enzymes by vertical polyacrylamide gel electrophoresis. An electrophoretic survey in Ames, Iowa, of 51 loci distributed among 26 enzyme systems revealed that 40% of the loci are polymorphic. Observed and expected heterozygosities measured at 33 loci were 0.0981 and 0.1148, respectively. A significant deficiency of heterozygotes was noted at certain loci.Journal Paper No. J-11423 of the Iowa Agriculture and Home Economics Experiment Station, Ames. Project No. 2411.     

Ovarian suppression by DDT and resistance in the house fly (Musca domestica L.)

Suggested by immunological theory, this study was initiated to test an hypothesis on physiological induction of resistance to insecticides. The hypothesis was proved untenable in the test system, but from the experimentation emerged evidence for a chronically toxic action of DDT expressed in reduced fecundity in female house flies fed sub-lethal amounts of this insecticide. This action can be a strong selective force, promptly revealing tolerant genotypes in the population. The usual selection for resistance does not necessarily also select for ovarian tolerance; even DDT-resistant flies can show ovarian suppression when fed DDT-contaminated food.It is possible that the route of administration of the DDT is important as the means by which the physiologic events described can occur as a chronic intoxication without the usual acutely toxic effects.

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Zusammenfassung Der vorliegenden Arbeit liegt die Frage zugrunde, ob Stubenfliegen, die bereits im Embryonalstadium DDT ausgesetzt werden, diesem gegenüber Resistenz erwerben können. Fütterung erwachsener Stubenfliegen mit C¹⁴-markiertem DDT führt zu dessen Inkorporation schon in den Eiern der Ovarien; die Inkorporation konnte in den schlüpfenden Larven weite verfolgt werden.In Versuchen, in denen je Versuchsglied stets nur die Nachkommenschaft eines Elternpaares (ein Eigelege) verwendet wurde, spalteten sich zwei gleichgrossen Populationen heraus: Während die eine die gleiche Anfälligkeit gegenüber DDT (0,12 g/Fliege) aufwies wie die Nachkommenschaft DDT-ungefütterter Eltern, war die andere Population dieser Dosis gegenüber tolerant.Die Ergebnisse von weiteren Versuchen belegen eindeutig, dass die durch DDT-Behandlung im Embryonalstadium hervorgerufene DDT-Toleranz primär nicht physiologisch bedingt ist, sondern primär auf genetischen Ursachen beruhen muss: Wurden DDT-gefütterte Weibchen mit DDT-anfälligen bzw. DDT-resistenten Männchen, denen kein DDT zum Futter gemischt worden war, gekreuzt, so war die gesamte Nachkommenschaft DDT-anfällig bzw. DDT-resistent.Es ergibt sich die Frage, welches Prinzip diese genotypisch verankerte Toleranz phänotypisch in Erscheinung treten lässt. Die in den Versuchen verwendeten DDT-Dosen waren ohne wesentlichen Einfluss auf den Eischlupf und die Mortalität von Larven und Fliegen. Dagegen senkte die Fütterung deutlich die Anzahl der zur Eiablage befähigten Weibchen und die Anzahl der von den anderen Weibchen gelegten Eier.

     

Sterol utilization and ecdysteroid content in the house fly,Musca domestica (L.)

Larvae of the house fly, Musca domestica were reared aseptically on diets which contained either cholesterol, campesterol or sitosterol as the dietary sterol at a concentration of 0.1% dry wt. Analysis of puraria (24 h post-pupariation) reared on campesterol or sitosterol diets revealed they contained from 2.7 to 4.6% cholesterol, indicating an ability to accumulate this sterol even where it is present in only minute quantities. Purparia on all diets produced the 27-carbon molting hormones, ecdysone and 20-hydroxyecdysone. When the concentration of campesterol was increased to 0.2% dry wt, puparia also contained the 28-carbon ecdysteroid, makisterone A, although it accounted for only 20.7% of the total ecdysteroid produced.     

Visual targets for capture and management of house flies, Musca domestica L.

House flies and stable flies were collected on a Florida dairy farm using a commercial Alsynite sticky cylinder trap that was either used alone or covered with white, blue, or black outdoor awning fabric. Collections of both species of flies were highest on exposed Alsynite (house flies, 506.2 flies/day; stable flies, 19.1) followed by blue fabric (house flies, 308.1 flies/day; stable flies 12.5). Responses of both species to white and black fabric were 70% lower than to either of the former materials. When blue fabric was used to cover 50% of the surface area of Alsynite cylinders, house fly responses were significantly higher (290.2 flies/day) than to blue fabric alone (165.2); stable fly responses to the bi-colored target were significantly higher (152.6) than to Alsynite alone (93.8). Comparison of fly counts in the blue-covered versus uncovered Alsynite with traps of a single material indicated that house fly attraction to blue fabric was enhanced by the presence of clear Alsynite, whereas stable fly attraction to Alsynite was enhanced by the presence of blue fabric. The presence of blue+Alsynite visual targets increased collections of house flies in pans of dry fly bait but not in baited jug traps. Visual targets treated with 1.2% bifenthrin controlled >50% and 90% of house flies in large cages by days two and four after placement, respectively.     

Colored bait preferences of house Fly (Musca domestica L.) (Dipetera: Muscidae)

The housefly, Musca domestica L. (Dipetera: Muscidae) transmits disease, contaminates laboratories, hospitals, equipment and can be annoying to people and animals. They are considered a serious urban pest worldwide. An important tool used to control houseflies is baiting. This study was undertaken to review the preference of housefly for different colored baits. Various colored baits were prepared and evaluated under laboratory conditions. These were colored blue, white, yellow, red, purple and green. Among the different colored baits used, the blue bait was preferred the most by the houseflies, followed by the white and yellow baits, and the red, purple and green baits were least attractive to the houseflies. Similarly, the blue bait was detected faster by the houseflies and was consumed significantly more than the red, purple or green baits. Also, the blue bait attracted a significantly higher number of flies than the red, purple and green baits.     

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.     

Autosomal interactions and mechanisms of pyrethroid resistance in house flies, Musca domestica

Five BC? lines and 16 house fly mass-cross homozygous lines were generated from crosses of the pyrethroid resistant ALHF (wild-type) and susceptible aabys (bearing recessive morphological markers on each of five autosomes) strains. Each of the resulting homozygous lines had different combinations of autosomes from the resistant ALHF strain. Levels of resistance to permethrin were measured for each line to determine the autosomal linkage, interaction and, possibly, regulation in pyrethroid resistance of house flies. Results indicated that factors on autosome 4 are not involved in the development of resistance in house flies, while factors on autosomes 1, 2, 3 and 5 play important roles in pyrethroid resistance. The sodium channel gene has been mapped on autosome 3 and multiple cytochrome P450 genes overexpressed in resistant ALHF house flies have been genetically mapped on autosome 5, suggesting that P450 mediated detoxification and sodium channel-mediated target site insensitivity located on autosomes 3 and 5, respectively, are major factors related to resistance development in house flies. However, neither the factors on autosome 3 or 5 alone, nor the factors from both autosomes 3 and 5 combined could confer high levels of resistance to pyrethroid. In addition, strong synergistic effects on resistance was obtained when autosomes 1 and 2 interact with autosome 3 and/or 5, suggesting that the trans factors on autosomes 1 and 2 may interact with factors on autosomes 3 and 5, therefore, playing regulatory roles in the development of sodium channel insensitivity- and P450 detoxification-mediated resistance.     

Superoxide dismutase in the housefly,Musca domestica (L.)

Four superoxide dismutase (SOD) (E.C. 1.15.1.1) isozymes were present in whole tissue homogenates of Musca domestica when examined by polyacrylamide gel electrophoresis. One of the isozymes contained manganese, and the other three contained copper and zinc. All were observed in each of the body tagma (head, abdomen, and thorax) and at each developmental stage (egg to adult). The copper- and zinc-containing isozymes purified from newly emerged, adult M. domestica had a relative molecular weight of 34,800 as determined by gel filtration chromatography but consisted of two equal-size subunits of 16,000 as measured by sodium dodecylsulfate polyacrylamide gel electrophoresis. An isoelectric point between 4.8 and 5.1 was measured. Approximately 2 mol each of copper and zinc were present per dimer. The three copper, zinc isozymes were identified as charge variants. The amino acid composition of the enzyme was similar to that of copper, zinc-containing superoxide dismutases from other sources. Purified housefly copper, zinc superoxide dismutase was neither deactivated nor able to protect lactic dehydrogenase against deactivation in the presence of light and rose bengal, a known generator of singlet oxygen. The role of SOD in the phototoxic reaction involving rose bengal is discussed.     

拟除虫菊酯对家蝇Ca—ATPase和Ca—Mg—ATPase的抑制作用

通过对家蝇神经系统的Ca-ATPase、Ca-Mg-ATPase性质的研究,表明Ca-ATPase、Ca-Mg-AT-Pase反应的适宜pH值分别为7.0-8.5和6.5。适温皆为35-40℃;底物（ATP）最适浓度均为0.5mmol/L。比较测定了家蝇三个品系中两种ATPase的活性及拟除虫菊酯对该酶的抑制作用,实验证明,敏感与Del-R、2Cl-R品系间Ca-ATPase、Ca-Mg-ATPase活力无明显的差异。溴氰菊酯、氯菊酯可部分地抑制敏感品系家蝇Ca-ATPase活性,而对拟除虫菊酯抗性品系Ca-ATPase无抑制作用,从而证明,Del-R、2Cl-B品系Ca-ATPase对拟除虫菊酯的敏感性已明显降低,这可能能是击倒抗性机制之一。实验还表明,拟除虫菊酯对Ca-Mg-ATPase基本上无抑制作用,这说明在家蝇中,Ca-Mg-ATPase并不是拟除虫菊酯的一个靶标位点。     

Potential for biocontrol of house flies,Musca domestica,using fungal biopesticides

Chemical control of house flies in poultry production facilities is becoming increasingly difficult due to insecticide resistance and regulatory constraints. Biopesticides based on entomopathogenic fungi could provide an alternative approach. Here we evaluated population control potential of two fungal pathogens, Beauveria bassiana and Metarhizium anisopliae. Cohorts of adult flies were established in large plastic boxes in the laboratory and were exposed to residues of oil-formulated fungal conidia sprayed on strips of plastic sheeting attached to the box walls. Exposure to the biopesticide barrier treatments caused 100% mortality in adult populations within 8–16 days, depending on the fungal species. In contrast, control flies survived until 96–110 days. Additionally, fungal infections caused 13–20% reduction in egg viability and >70% reduction in fecundity of flies prior to death. The combined lethal and pre-lethal impacts resulted in 21- to 26-fold reduction in basic reproductive rate in the fungus-exposed populations relative to controls. Based on these promising proof-of-principle results, further research is currently under way to determine the feasibility of developing a biopesticide product for operational use.     

Characterization of prostaglandin synthesis in the housefly,Musca domestica (L.)

The in vitro formation of prostaglandins (PG) was examined in the housefly Musca domestica. PG synthetase activity was detected in homogenates of whole insects and in head and thorax, abdomen, ovary and male reproductive tissues. Studies to determine the sub-cellular localization of PG synthetase indicated that the microsomal fraction contained the highest activity. Products obtained from radiolabeled arachidonic acid (20:4) and 8,11,14-eicosatrienoic acid (20:3, n-6) were PGE₂ and PGE₁, respectively, with lower amounts of the PGF series also present. In microsomal preparations from whole insects and reproductive tissues from both males and females, 20:3(n-6) was 2–2.5 times more efficiently converted to PG than was 20:4. Non-steroidal anti-inflammatory drugs (NSAID) fed to houseflies did not inhibit PG production from 20:4, whereas when they were included in microsomal preparations at high levels, they inhibited PG synthesis.     

Morphometric variations in the housefly,Musca domestica (L.) with latitude

Morphologic analysis of geographic strains of Musca domestica carried out on natural and laboratory experiments starting with 400 and 800 eggs showed phenotypic variations related with latitude. Females of the natural populations showed clines for several morphological traits of the wing, whereas male flies showed a reduction in the dispersion measures (s ² and CV) of wing width and length. The same reduction was obtained for males, females and total number of flies of the natural populations in dispersion of the number of bristles on the fourth abdominal sternite. A significant negative correlation was observed for the head width of females and for the total number of flies emerged in the laboratory experiments started with 400 eggs. All flies produced by the experiments starting with 800 eggs showed a reduction in variability of dispersion of the bristles on the fourth abdominal sternite in the strains obtained from locations south of the area analyzed. Evolutionary aspects of these correlation coefficients between morphometric traits and latitude are discussed.     

House Fly (Musca domestica L.) Attraction to Insect Honeydew

House flies are of major concern as vectors of food-borne pathogens to food crops. House flies are common pests on cattle feedlots and dairies, where they develop in and feed on animal waste. By contacting animal waste, house flies can acquire human pathogenic bacteria such as Escherichia coli and Salmonella spp., in addition to other bacteria, viruses, or parasites that may infect humans and animals. The subsequent dispersal of house flies from animal facilities to nearby agricultural fields containing food crops may lead to pre-harvest food contamination with these pathogens. We hypothesized that odors from honeydew, the sugary excreta produced by sucking insects feeding on crops, or molds and fungi growing on honeydew, may attract house flies, thereby increasing the risk of food crop contamination. House fly attraction to honeydew-contaminated plant material was evaluated using a laboratory bioassay. House flies were attracted to the following plant-pest-honeydew combinations: citrus mealybug on squash fruit, pea aphid on faba bean plants, whitefly on navel orange and grapefruit leaves, and combined citrus mealybug and cottony cushion scale on mandarin orange leaves. House flies were not attracted to field-collected samples of lerp psyllids on eucalyptus plants or aphids on crepe myrtle leaves. Fungi associated with field-collected honeydews were isolated and identified for further study as possible emitters of volatiles attractive to house flies. Two fungal species, Aureobasidium pullulans and Cladosporium cladosporioides, were repeatedly isolated from field-collected honeydew samples. Both fungal species were grown in potato dextrose enrichment broth and house fly attraction to volatiles from these fungal cultures was evaluated. House flies were attracted to odors from A. pullulans cultures but not to those of C. cladosporioides. Identification of specific honeydew odors that are attractive to house flies could be valuable for the development of improved house fly baits for management of this pest species.