Fly Resistance Research Articles

Testing fly resistance to thuringiensin produced by Bacillus thuringiensis, serotype H-1

A Bacillus thuringiensis preparation used for microbial control of flies was tested for development of resistance to thuringiensin in Drosophila melanogaster. A 10-fold resistance developed in 30 generations in fruitflies reared in medium containing 0.3 to 1.0% preparation but did not rise from generations F 30 to F 70. A 6-fold resistance was obtained at 0.2 to 0.5% preparation. Flies reared in 2 and 3% preparation were very weak and did not develop resistance during selection. On the contrary, they died out in generation F 58. Tests with fruitflies resistant to chemicals have shown that there is no cross-resistance between chemicals and thuringiensin. These data are discussed relative to the use of thuringiensin in controlling flies.

New approaches to the chemical control of arthropod pests of livestock

Chemicals are important tools in our effort to control livestock ectoparasites, and they are likely to remain so in the foreseeable future. Chemical control is the most widely used and in most cases the only method available to the producer. Therefore, it is imperative that we continue to seek new chemicals as well as new systems for delivery of those chemicals in an effective, efficient, and safe manner. New approaches to chemical control involve both new chemicals and new delivery systems in a complementary and often a synergistic relationship. Three relatively new classes of chemicals, pyrethroids, insect growth regulators, and avermectins, have provided special opportunities for development of new delivery systems. The development of the insecticidal ear tag has been perhaps the most significant new approach to chemical control of livestock ectoparasites in recent years. Although originally developed for control of ear ticks, the tag has had its greatest impact on control of the horn fly, a major pest of cattle in the U.S. The pyrethroid tags provided season-long control of horn flies in most climates and at the same time dramatically reduced the use of pesticide. Unfortunately, the problem of resistance to pyrethroids in the tags has been encountered. Unless effective techniques for resistance management can be developed, the producer may lose this valuable new tool. Sustained-release boluses provide a means of delivering IGR's, such as methoprene and diflubenzuron, for control of immature stages of the horn fly and face fly in manure of cattle. These devices are designed to lodge in the reticulum of cattle and release the chemical to the digestive tract over an extended period. Bolus formulations may in fact provide a tool for management of horn fly resistance to pyrethroids. Ivermectin, a potent new chemical from a new class of agricultural pesticides, provides an important opportunity for developing innovative delivery systems for control of livestock pests. Its systemic activity against ticks and blood-sucking flies at extremely low dosages provides potential for development of long-lasting subcutaneous implants. Its ability to control immature stages of dung-breeding flies, such as the horn fly and face fly, offers the potential for development of sustained-release boluses for larvicidal treatments. These three selected examples of new approaches to chemical control of livestock ectoparasites point to two obvious trends: 1) reduction in quantity of a chemical to be applied without sacrifice of efficacy and 2) use of controlled-release technology to prolong effectiveness of the chemical. Although the examples presented are focused on applications to cattle, similar approaches have application for other livestock. New approaches such as these have important implications in implementation of either area-wide or IPM control programs. Such programs will need convenient and effective chemical delivery systems to be successful if in fact chemicals are to be a part of the programs.

RESPONSE OF TRITICALE TO THE HESSIAN FLY (DIPTERA: CECIDOMYIIDAE)

Hessian fly infestation on triticale (X triticosecale Wittmack) has not been previously reported. Severe infestations on wheat in Georgia prompted the evaluation of triticale germplasm in the greenhouse to known biotypes of Hessian fly and in the field to natural populations. Susceptible triticale plants showed the same characteristics as susceptible wheat plants. ‘Beagle 82’, ‘Wytch’, and ‘Marta’, as well as several experimental lines, were highly resistant to biotype D Hessian fly. ‘M2A-Beagle’ and ‘Great Northern’ were the only entries highly resistant to biotype E, the predominant biotype population in the Southeast. The total number of flies per 30-cm row averaged 58 and 283 at Experiment and Plains, respectively. Morrison had the lowest percentage of infested tillers. ‘Jenkins’ and ‘Council’ were the most severely infested cultivars. Crosses have been made to determine the genetics of Hessian fly resistance identified in these studies.

Bacillus thuringiensis and microbial control of flies

Some strains ofBacillus thuringiensis (B.t.) primarily the H serotype 1, produce in the surrounding medium a nucleotide, called thuringiensin, which is structurally related to ATP. Thuringiensin is a larvicide, affecting the moulting and pupation of certain species of the orders Lepidoptera, Diptera, Hymenoptera, Coleoptera and Orthoptera. The highest susceptibility is found in Diptera. Muscabac (Farmos Group Ltd.) is aB.t. preparation, registered in Finland for fly control in livestock buildings and compost toilets. It hasB.t. spores and thuringiensin as active components. Contrary to theB.t. products, based on the proteinaceous endotoxin and used for control of lepidopterous pests, Muscabac has a long-lasting effect due to the growth of the bacterium, and thus continued production of thuringiensin in the treated larval growth sites. Use of chemical insecticides has created a control problem because of the development of resistance. The possibility of fly resistance toB.t. has been tested, rearing 70 generations of the fruit flyDrosophila melanogaster in increasing concentrations of thuringiensin. No true resistance developed, neither was there cross resistance between chemicals and exotoxin. The efficacy of Muscabac for fly control has also been tested in compost and pit latrines in Dar es Salaam, Tanzania, with very promising results.

Effect of insecticide impregnated ear tags on horn fly populations and suckling calf performance (1984)

Three trials were conducted to determine the effect of insecticide impregnated ear tags on horn fly counts and weight gain of suckling calves. In trials 1 and 2, cow calf pairs on two Kansas ranches were assigned to these treatments: 1) Control - no tag, 2) Cows Only - 1 tag per cow, 3) Calf Only - 1 tag per calf, and 4) Cow and Calf - 1 tag each. Each tag treatment was in a separate pasture. All insecticide tag treatments reduced (P<.05) horn flies on cows and calves in July and August; however, by September the tags were only reducing (P<.05) flies on cows. While the weight gain response to tags was variable, when trials were combined, all tag treatments increased (P<.05) calf gains over controls. Using a single tag per cow was better (P<.05) than a single tag per calf, while tagging both the cow and calf was no better than either single tag treatment. Average fly counts for each pasture were negatively correlated with calf weight gains indicating a strong relationship between fly populations and calf performance. In trial 3, apparent horn fly resistance to the insecticide in the tags resulted in terminating the trial mid-summer. Research in Kansas and other states indicates that horn fly resistance to pyrethroid insecticides is becoming a common problem which means that producers may need to revert to previously used methods of horn fly control.

Evaluation of personal protection methods against phlebotomine sand flies including vectors of leishmaniasis in Panama.

Three personal protection methods were evaluated against phlebotomine sand flies in Panama. Skin applications of five selected repellents including deet (N,N-diethyl-m-toluamide) provided a mean coefficient of protection (CP) of 99.2% against the attack of at least three sand fly species. Deet-treated net jackets also provided good protection, but it was concluded that an additional application of repellent to the unprotected face was necessary for maximum protection. Permethrin-treated clothing did not provide the protection expected. Apparently sand fly behavior and resistance to quick knock-down were responsible for the numbers of bites recorded, and therefore maximum protection from bites would require application of deet or another suitable repellent to the exposed skin when wearing permethrin-treated clothing.

Resistance

Abstract Sir. — Much has been said and written about anthelmintic resistance, but although careful watch is kept, little has emerged on fly resistance to organic phosphorus compounds. Between Christmas 1981 and New Year 1982 I was in communication with a situation in the Wairau Valley in Marlborough (from whence dieldrin resistance was first recorded) that initially looked disturbing.

Expression and Inheritance of Resistance to Hessian Fly in Synthetic Hexaploid Wheats Derived from Triticum tauschii (Coss) Schmal.1

Seventeen synthetic hexaploid (SH) wheats, derived from crosses between six tetraploid Triticum species and a diverse group of diploid T. tauschii (Coss.) Schmal., were evaluated for resistance to biotype D of Hessian fly, Mayetiola destructor (Say). Resistance was identified in four of the SH wheats. Based on rections of the tetraploid × diploid crosses and the parental Triticum species to larval feeding, resistance was derived from specific lines of T. tauschii. Other lines of T. tauschii and the tetraploid Triticum species were homozygous susceptible. Resistance of the SH wheats and T. tauschii was expressed as antibiosis in that larvae died in the first instar of development.Two resistant SH wheats were crossed with susceptible common wheat (T. aestivum L. em Thell.) cultivars ‘Amigo’ and ‘Eagle’ to study the inheritance of Hessian fly resistance derived from T. tauschii. F2 populations segregated in a 3:1 ratio of resistant to susceptible plants, an indication that resistance was conditioned by a single dominant gene. Segregation ratios of F3 lines and F3 plants within segregating lines supported the single‐factor resistance hypothesis. F4 lines derived from homozygous resistant F3 lines bred true for resistance, On the basis of present knowledge of genetic relationships among wheat genes for resistance to Hessian fly, T. tauschii appears to be a new source of resistance that can be readily transferred to hexaploid wheat.

Cytogenetics of Introgression from Saccharum into Sorghum1

Grain sorghum [Sorghum bicolor (L.) Moench] crosses with sugarcane (Saccharum officinarum L.) when the latter species is the female parent. These hybrids are male sterile but produce offspring when pollinated with either parent. Four backcrosses, the first and second with diploid (2n=20) and then with tetraploid sorghum (2n=40), produced plants that are male and female fertile even though they combine 40 Sorghum + 4–10 Saccharum chromosomes. Selfing or further backcrossing with sorghum for one or more generations, results in complete elimination of Saccharum chromosomes, and essentially pure or morphologically modified sorghums are recovered. Modified sorghums have various combinations of Saccharum characteristics superimposed on a basic Sorghum morphology. The study was initiated in an attempt to transfer shoot fly resistance from sugarcane to grain sorghum. Whether this aim was achieved is now being investigated.

House fly resistance in the Savannah, Georgia, area and its influence on chemical-control measures.

Resistance levels of Musca domestica L. from dairies and chicken ranches near Savannah, Georgia, were determined for 9 compounds by use of the immersion technique. The quantity of toxicant required to kill 95% of the field strains of flies was from 2 to 69 times the amount required to give the same level of kill of a susceptible NAIDM strain. Five compounds―dimethoate, OMS-1211(O-(2,5-dichloro-4-iodophenyl) O,O-dimethyl phosphorothioate), resmethrin (OMS-1206), crotoxyphos, and Mobam® (benzo[b]thien-4-yl methylcarbamate)―applied as residuals to dairies failed to give effective control (grill index of 20 or less) for more than 2 weeks. However, space sprays of naled and resmethrin and liquid baits of dichlorvos were still effective in killing these resistant field strains of house flies.

House fly control and insecticidal resistance in New Jersey.

In Somerset and Hunterdon Counties, N.J., residual applications in dairy barns of diazinon, dimethoate, ronnel, bromophos, Rabon® (2-chloro-1-(2,4,5-trichloro-phenyl) vinyl dimethyl phosphate), Ravap® (a formulation with 1% Rabon and 0.1% dichlorvos in the finished spray) and Ciba C-9491 ( O -(2,5-dichloro-4-iodophenyl) O,O -dimethyl phosphorothioate) applied at 1% failed to give satisfactory control of the house fly, Musca domestica L. The 1st application gave better control than retreatments. The F1 generation of flies, collected from barns before treatment in June and again in August, was exposed to topical applications of all of the insecticides as well as lindane. It was demonstrated that during the season where these materials were used house fly resistance increased at all locations and with all insecticides. SBP1382 (5-benzyl-3-furyl) methyl 2,2-dimethyl-3-(2-methylpropenyl) cyclopropanecarboxylate (ca. 70% trans, 30% cis isomers) at 0.25 and 0.5% gave inadequate control and showed slight increase in resistance during the season.

Enzymatic and physical factors in house fly resistance to naphthalene.

The nature of the resistance mechanisms in a strain of, Musca domestica L., resistant to naphthalene was investigated after isolating the factors by genetic methods. This study was done by (Tossing the naphthalene-resistant strain with a susceptible strain caning morphological markers for chromosomes II, III, and V and backcrossing the resulting hybrids with the susceptible parent. The progeny were separated according to phenotype, and their resistance characteristics were studied in vitro and in vivo by measuring mortality response to discriminating doses of naphthalene vapors, knock-down rate after treatment wth naphthalene, tributyltin chloride, and dieldrin, and activity of microsomal enzymes. The results indicated that 3 factors are involved in resistance to naphthalene. A factor on chromosome II is related to microsomal cnzymes and endows the strain carrying it with as much as 10 times the normal oxidase activity. The 2nd resistance factor, situated on chromosome III, results in a reduced rate of penetration of the cuticle, knockdown rates of strains carrying this factor being about ½ those of other strains. A factor on chromosome V, less important than the others, could not be so completely characterized, However, its effect in combination with the 2nd and 3rd chromosomal factors was significant. Each of the factors alone, in the respective backcross phenotypes, provided about 2-fold resistance to naphthalene vapors but when combined in the resistant parent gave a protection of 6- to 10-fold, depending upon the age of the insects.

Biochemical genetics of house fly resistance to carbamate insecticide chemicals.

One resistant strain (RHokota) and 2 susceptible multi-chromosomal marker strains (S2356and S2450) of house flies, Musca domestica L., were used for genetic analyses with the F1 male backcross experimental design for determining linkage groups. Genetic analyses were made as follows: (1) resistance to Baygon® ( O -isopropoxyphenyl methylcarbamate) in the presence and in the absence of the synergist piperonyl butoxide; (2) Baygon metabolism in living flies; (3) Baygon metabolism by the fly abdomen enzyme-reduced nicotinamide-adenine dinucleotide phosphate (NADPH2) system; (4) resistance to Matacil® [4-(dimethylamino)- m -tolyl methylcarbamate]; (5) Matacil metabolism by the fly abdomen enzyme-NADPH2 system. Each of these comparisons showed the importance of the 5th chromosomal effect in conferring both high carbamate resistance and high activity for microsomal oxidizes involved in metabolism by ring hydroxylation and attack on N -methyl and O -alkyl groups. The 3rd chromosome is secondary in importance to the 5th chromosome in each of the above comparisons, while the 2nd chromosome is also involved in the resistance but not in the enzyme activity. Piperonyl butoxide minimizes the importance of the 5th chromosome in conferring Baygon resistance. Differences in penetration rates do not contribute materially either to the resistance or synergistic effects. Detoxification reactions involving the microsome-NADPH 2 system, which are controlled by the 5th chromosomal gene (s), are important in the mechanism of resistance to carbamate insecticide chemicals; they may also be important with other types of insecticide chemicals which are metabolized by this system and to which resistance is conferred by 5th chromosomal factors.

Resistance of F1 Wheat Plants to Greenbugs and Hessian Fly1

Response of F1 hybrid wheat plants carrying genes for resistance to both Hessian fly, Mayietola destructor (Say), and greenbug, Schizaphis graminum (Rondani), was studied in greenhouse and in insectary at Manhattan, Kansas, 1962 and 1963. Greenbug resistance (gbgb) came from the Dickinson cultivar and Hessian fly resistance (H3H3) from Ottawa and CI 13548. Resistance of an F1 plant could be identified on the basis of insect reproduction (antibiosis) or damage (tolerance) to either insect in the seedling stage and later by damage to mature plants. F1 plants carrying the H3 gene for resistance to Hessian fty were intermediate to parents in damage; larvae of flaxseed were generally smaller and plants supported fewer larvae. F1 plants response to greenbug damage also was intermediate to parents but numbers of nymphs produced were nearly the same on the F1 plants and their parents. Identification of insect resistance in F1 plants from parents will be useful in conducting backcross breeding programs.

An analysis of house fly resistance to insecticides in California.

The pattern of insecticide resistance in house flies, Musca domestica L., from 6 areas of California was found to reflect the differing chemical-control practices in each area. DDT resistance continues to be high in all areas despite more than 10 years of nonuse of this compound for fly control. It shows positive correlation with diazinon resistance but not with malathion resistance, and thus its prolonged stability was likely enhanced by diazinon pressure. Dieldrin resistance also remains high, but shows no correlation with organophosphorus resistance. The non-identity of diazinon and malathion resistances was clearly discernible. High resistance to diazinon (20.7×) in the Anaheim strain was accompanied by only moderate resistance to malathion, and high resistance to malathion in the Moorpark strain was accompanied by only moderate resistance to diazinon (7.1×). The highest degree of resislance observed (at the LD90 level) by topical application of organophosphates and carbamates was: malathion >60×, diazinon 25×, ronnel 14×, fenthion 10.1×, dimethoate 4.2×, dimetilan 3.7× and Hercules 8717-E [ m -(2-propynyloxy) phenyl methylcarbamate] 3.5×.

Controlling Hessian Fly with Phorate and Disulfoton

Resistant varieties are being widely adopted for preventing Hessian fly, Mayetiola destructor Say, losses. However, wheat hybrids may soon be in the hands of farmers and these may or may not be resistant to Hessian fly. Until fly resistance is known to be incorporated into the hybrids the farmer needs all available means of preventing the damage. Tests with granular formulations of phorate and disulfoton at 0.5 and 1.0 pounds per acre show that these materials applied with a grain drill prevent fly infestation and increase yields in infested fields. Application of the materials by broadcast was not successful.

Use of WHO tsetse fly kit for determining resistance in the stable fly.

Johnston and Blakeslee (1961) indicated that the World Health Organization test procedures for determining the susceptibility or resistance of adult mosquitoes to insecticides was highly satisfactory for testing adult stable flies, Stomoxys calcitrans (L.). A WHO tsetse fly resistance kit, which provided the same materials as those in the adult mosquito kit was used in this study.

Field Studies of House Fly Resistance to Diazinon, Ronnel, and Other Insecticides1

House fly (Musca domestica L.) populations and their resistance to insecticides were studied in 1960 and 1961 in 30 barns in Monmouth County, New Jersey. Barns were located within a 5-mile radius of key barns sprayed with Diazinon® ( O,O -diethyl O -(2-isopropyl-4-methyl-6-pyrimidinyl) phosphorothioate) or ronnel for 5 years or more. Resistance to Diazinon, ronnel, malathion, lindane, and DDT was present in varying degrees at all locations. Resistance to Diazinon was highest at barns treated with that insecticide and decreased as distance increased. Resistance to ronnel was highest at barns treated with organophosphorus compounds. Resistance to malathion did not show a clear pattern in relation to locations where it was used. Resistance to lindane and DDT were at a high level throughout the area. In general, resistance to all compounds was higher in 1961 than in 1960. Within a season, resistance to Diazinon and ronnel was high at the beginning of the season, but first decreased rapidly after which it gradually increased in intensity for the rest of the season. Fly populations were somewhat larger in 1961 than in 1960 though the patterns of increase were the same each year. A high breeding potential in barns resulted in increased resistance where residual sprays were used. Increase in resistance within a season is dependent upon sanitation, weather conditions, and migration of flies.

Evidence of Carrot Rust Fly Resistance to Aldrin and Heptachlor in Canada1

Evidence of Carrot Rust Fly Resistance to Aldrin and Heptachlor in Canada1

Preliminary Study of the Genetics of House Fly (Musca domestica) Resistance to Malathion1

The genetics of malathion resistance in a strain of house flies ( Musca domestica L.) was studied by selecting two strains, one susceptible and one resistant to malathion, from a slightly resistant field strain. The method of selection was by collecting eggs from individual females and increasing the population to sufficient numbers to determine their response. After three generations of selection a uniform malathion-resistant strain was obtained. A susceptible strain was obtained in one generation although selection was continued another generation. The parent strain was 1.7 times as resistant as the susceptible strain, while the resistant strain was 62 times as resistant. All insects used to determine response to malathion were laboratory-reared females which were tested 4 days after peak emergence with solutions made by diluting 95% technical malathion in glass-distilled acetone. Flies were held in recovery jars containing food, at a constant temperature until 24-hour mortality counts were taken. Strain differences other than malathion resistance were present. The resistant strain required a longer period from egg to adult than the susceptible strain. The males in the susceptible strain emerged significantly earlier than the females. The resistant strain was observed to have a lower fecundity than the parent and susceptible strains. The sex ratio in the selected strains did not differ from a 1:1 ratio. The F1 hybrids of reciprocal crosses between the susceptible and resistant strain segregated into 50% susceptible and 50% resistant individuals. The least tenuous explanation for this segregation is that malathion resistance is inherited by two allelic groups exhibiting incomplete duplicate dominance epistasis. The segregation of the F1 hybrids cannot be explained on the basis of a single gene or independent assortment of multiple genes, as the resistant strain is homogeneous malathion-resistant. The F2 hybrids did not differ significantly from the F1 hybrids. Maternal effects were present in the F1 hybrids but had disappeared in the F2 generation. That the F2 progeny of reciprocal crosses did not differ indicates that no sex-linkage is involved in the inheritance of malathion resistance.