Musca Domestica Larvae Research Articles

Radiation-induced Biochemical Changes in the Larvae of Housefly, Musca domestica

Radiation-induced changes in the third instar larvae of Musca domestica were investigated. Pupariation delay was evident in the irradiated larvae. Both 5 and 10 kR exerted similar pupariation delays. At biochemical level, glycogen seems to show an enhancement in the irradiated larvae as compared to control. Free sugars register initial rise followed by decline in the irradiated larvae. Total ninhydrin positive compounds showed a similar trend as free sugars. The irradiated larvae exhibited a delayed increase in protein content as compared to control. There was no significant change in ribosidic compounds due to irradiation. These results are discussed in the light of the likely targets of radiation at the cellular level.

Latent toxicity of dieldrin in the housefly, Musca domestica L. (diptera, muscidae)

AbstractThe effects on the emerging adult of topical application of 14C-dieldrin to third-instar larvae of Musca domestica L., and the distribution of the insecticide in the fly, the puparial case, and the holding medium, were examined. The dose ranged from 0·04 to ca 13 μg/larva. All flies emerging after treatments of 1 μg and above showed symptoms of poisoning some time after emergence. With the larger doses an increasing number of flies, although they escaped the puparium, were unable to reach the surface of the holding medium. With the two top doses some were unable to escape fully from the puparial case. These flies contained amounts of dieldrin well in excess of the LD99 dose. However, even the highest dose allowed some flies to emerge normally. None of the treatments affected metamorphosis and all flies appeared morphologically normal. The data provided evidence that the transfer of dieldrin to the adult via the pupal stage accounts for the effects in the newly emerged fly.

Physiological action of Loxosceles reclusa (G&M) venom on insect larvae

Larvae of Musca domestica (L.) and Heliothis virescens (F.), normal and envenomized by Loxosceles reclusa (G&M) were incubated, sectioned in a cryostat, stained, and examined with a light microscope. Morphological changes of cells and tissues were studied, and enzyme activities tabulated. Morphological changes included lysis of gut epithelial cells, peritrophic membrane, basement membranes of gut epithelium and epidermis, circular gut muscle, sarcolemma of trunk muscles, epidermis, fat cell membrane, and fat cell proteins. A depletion of proteins in tissues occurred with a subsequent increase in the hemolymph proteins. Enzyme activities were studied by histochemical methods. Proteases, lipase, esterase, and alkaline phosphatase showed stronger reactions in envenomized larvae; monoamine oxidase activity was questionable. Hemolymph samples taken from envenomized larvae showed lysis, coagulation, and disc-sphere transformation of hemocytes.

Effect of dietary cholesterol deficiency upon its distribution in the larvae of the housefly, Musca domestica

The free sterol, total phospholipids and protein content of the various tissues and haemolymph lipoproteins obtained from the larvae of Musca domestica, reared on the diets containing 0.56 μmole cholesterol/g wet weight of diet (normal) and 0.05 μmole cholesterol/g wet weight of diet (deficient) have been determined. The cholesterol in the diet was found to be taken up by the larvae and distributed between all the tissues examined. About 60% of the free sterol in the larvae was recovered from the composite gut fraction and muscle. Cholesterol deficiency reduced both the growth of larvae and the free sterol content of the various tissues and haemolymph when compared to that of normal larvae. Cholesterol deficiency resulted in a slightly higher proportion of sterol and protein of the larval haemolymph being associated with the lipoproteins having slower electrophoretic mobility. Most of the different tissues from the cholesterol deficient larvae contained a much smaller proportion of their normal free sterol content than of their phospholipid or protein; the brain tissue however contained a higher percentage of free sterol and the haemolymph a much lower percentage than would be expected from the lowering of phospholipid and protein content as a result of the deficiency. When the sterol content was expressed relative to the protein, the ratio was higher in the brain tissue of both the normal and deficient larvae than the ratio present in the remaining tissues, apart from the composite gut fraction of the normal larvae. The results suggest that a disproportionate amount of available cholesterol was being concentrated into the nervous system of the cholesterol deficient insect. A rather higher proportion of the total sterol fraction recovered from the various tissues and haemolymph lipoproteins of cholesterol deficient larvae behaved as ‘polar metabolites’ of cholesterol when compared with that of normal larvae.

Neuroendocrine control of moulting cycle in mealworms: Bioassay of moulting hormone

The moulting hormone content of mealworm homogenates was determined by injection of partially purified fractions into abdomens of mature larvae of Musca domestica. In mealworms with a 12-day interval between ecdyses, moulting hormone was at a maximum at 8 days.

Influence of Some Dipterous Larvae on Nitrogen Loss from Cattle Dung

Nitrogen (N) loss from cattle dung was measured in dishes of fresh feces exposed outdoors in a screened cage. Musca domestica larvae were used to determine the contribution of coprophagous Diptera to this loss. Little N was lost from naturally dried pads when insects were absent. Nitrogen loss from artificial 960-g dung pads exposed to other insects in the field did not exceed 13.5% after 16 days. Ten days after infestation of a series of dung pads with different numbers of fly larvae, the total N content of the dung was found to have decreased with each increase in the degree of fly infestation. Heavy infestations of dipterous larvae caused the loss of more N than was incorporated into insect tissue.

Biosynthesis of α- and β-ecdysone in isolated abdomens of larvae of Musca domestica

Abdomens of housefly larvae which are isolated before pupariation and injected with labelled or unlabelled cholesterol are shown by bioassay, thin-layer and gas-liquid chromatography, and tracer experiments to synthesize α- and β-ecdysone. Autoradiography of cross-sections of abdomens injected with labelled cholesterol show that oenocytes are intensively labelled. The results are discussed with respect to the validity of the Calliphora or Musca assay for ecdysones.

Dietary cholesterol requirements of housefly, Musca domestica, larvae

Quantitative analyses have been made of the dietary cholesterol requirement for the growth of the larvae of Musca domestica. The larvae will not grow on diets to which no cholesterol is added, a few pupae and adults are obtained when the concentration of cholesterol is 0·05 μmol/g of diet, but the concentration has to be raised to 0·36 μmol/g of diet before the maximum numbers of pupae and adults are obtained. Further addition of cholesterol above 0·36 μmol/g diet did not have any significant effect on the weight and growth of the larvae. However, the ratios of the cholesterol to phospholipid fractions recovered from the larvae increased rapidly when the concentration of cholesterol in the diet was raised from 0·05 to 0·56 μmol/g of diet. Above this concentration only a slight increase in the ratios was observed. Larvae reared on diets containing 0·05 μmol cholesterol/g of diet contain only 25 per cent of the cholesterol content of the larvae reared on the diets containing more than 0·28 μmol of cholesterol/g of diet, the cholesterol content being expressed relative to the weight of the larvae, The absence of cholesterol synthesis has been demonstrated in the larvae by feeding [4- 14C] cholesterol. The specific activity of the cholesterol recovered from the larvae is the same as that of cholesterol added to the diet. Irrespective of the cholesterol concentration of the larval diet, approximately 97 per cent of the radioactivity recovered from the larvae behaved as free cholesterol, less than 1 per cent as cholesterol esters and the rest as unidentified ‘polar sterols’. The results are compared with those from similar studies on other insects.

Feeding TH 6040 to chickens: effect on larval house flies in manure and determination of residues in eggs.

Thompson-Hayward 6040 ( N -[4-chlorophenyl]- N ′[2,6-difluorobenzoyl]urea) was fed in rations to laying hens at decreasing amounts from 50 to 1.6 ppm. The level that gave complete inhibition of development of larvae of Musca domestica L. fell between 6.2 and 12.5 ppm. Residues of TH 6040 were found in the eggs of all treated chickens.

Eine Methode zur qualitativen und quantitativen Bestimmung von drei Juvenilhormonen von Insekten

Abstract A method is presented permitting the qualitative and quantitative determination of all three presently known hormones (JH1-3). The determination is based on the method of radioactive isotope dilution, whereby a very small known amount of tritium-labelled JH-1 is added to the ether extract of the particular species. The addition of radioactive JH-1 permits the isolation of all three hormones, because of their similar behaviour during the chosen work up. The quantitative determination was carried out by gas chromatography and the identification was confirmed with the help of retention-times and GC-MS combination. The method was checked by using an extract of Hyalophora cecropia. For the first time methyl 10,11-epoxy-3,7,11-trimethyl-2-trans-6-trans-dodecadienoate (JH-3) could also be identified as the juvenile hormone of Melo­lontha melolontha. In Vanessa io larvae, Tenebrio molitor larvae and adults and in Musca domestica larvae none of the three known hormones could be detected. The preparation of JH-1 labelled with tritium in the methyl group of the ester was accomplished with very high specific activity (4.34 Ci/mmol) of the tritiated acid with diazomethane.

Incorporation of the methyl group of methionine into lipids and RNA by Musca domestica larvae

Studies on the incorporation of the methyl group of 14C-labelled dietary methionine into various cellular constituents of axenically reared housefly larvae ( Musca domestica) are reported. The methyl group of methionine is incorporated into serine, ethanolamine, a non-polar lipid fraction, and into the 2′-O- methylnucleosides of ribonucleic acids, but not into choline. Smaller quantities are incorporated into glycerol and fatty acids. The data indicate that housefly larvae perform many of the reactions of one-carbon metabolism that occur in other animals.

Hemocytic changes associated with the encapsulation and melanization of some insect parasites

The hemocytic changes that attend parasite encapsulation and melanization in larvae of Drosophila, Musca domestica, and Orthellia caesarion are very similar to those changes occurring in noninfected individuals at metamporhosis. Some of the changes include the precocious differentiation and migration of hemocytes. Comparative and quantitative hemocytological data suggest that some stimulus in infected larvae, acting directly on the hemocytes or on the mechanism(s) controlling their activity, causes the cells to leave areas of the body where they are normally found and to encapsulate parasites. Questions concerning the origin and mode of action of the initial stimulus are raised, and as a basis for future experimentation it is proposed that the cellular immune reactions of these insects against internal metazoan parasites result from a hormonal imbalance.

The effect of dietary changes on the phospholipid composition of the haemolymph lipoproteins of larvae of the housefly, Musca domestica

Qualitative and quantitative analyses have been made of the phospholipid composition of haemolymph from larvae of Musca domestica and of the two lipoprotein fractions separated from it by agarose-gel electrophoresis. The effect of rearing the larvae on defined diets containing adequate choline, no added choline, and choline plus 2-aminobutan-1-ol on this composition has been studied. The haemolymph lipoproteins have a phospholipid pattern similar to that of the unfractionated haemolymph. The chief component is phosphatidylethanolamine. Diglycerides and free sterols are the major neutral lipids present in the haemolymph and the separated lipoproteins. The different diets cause changes in the various phospholipids present in the two lipoproteins which are similar to those that occur in other tissues of the larvae. Choline deficiency increased the proportion of the haemolymph phospholipid that is associated with the lipoprotein having the slower electrophoretic mobility. The results are compared with those obtained from other insects and vertebrates and the rôle of the lipoprotein in choline deficiency in the housefly is discussed.

Fly Control and Chronic Toxicity from Feeding Dursban® (0,0-Diethyl 0–3, 5, 6-Trichloro-2-Pyridyl Phosphorothioate) to Laying Hens ,

The effects of administering technical Dursban at concentrations of 25, 50, and 200 p.p.m. in the feed of laying hens were studied over a 52 week period. The estimated mean daily intake of Dursban was 2.48, 5.12, and 20.44 mg. per hen for those receiving 25, 50, and 200 p.p.m., respectively. Dursban at 50 p.p.m. resulted in excellent control of larvae of Musca domestica L., Fannia pusio (Wiedemann), Chrysomya megacephala (F.), and Boettcherisca peregrina (Robineau-Desvoidy) but only moderate control of Parasarcophaga argyrostoma (Robineau-Desvoidy). No hen mortality occurred that could be attributed to the insecticidal treatment. There was a direct relationship between Dursban concentration and blood plasma cholinesterase inhibition. However, overall feed consumption, body weight, egg production, feed efficiency, egg weight, interior egg quality, and shell thickness were normal. Eggs from treated hens had no detectable off-flavors or off-odors.

Temperature-dependent changes in sphingosine composition and composition of fatty acids of glycerophosphatides from Musca domestica larvae

The results show that the rearing temperature for Musca domestica larvae affects the sphingosine composition of ceramide phosphorylethanolamine and the fatty acid composition of phosphatidylserine, phosphatidylcholine, and phosphatidylethanolamine. When the rearing temperature was increased from 24 to 29°C. and to 37°C., the amount of hexadecasphinganine and hexadecasphing-4-enine increased and the amount of tetradecasphing-4-enine decreased. Similarly, as the rearing temperature was increased, the ratio of unsaturated to saturated fatty acids isolated from phosphatidylserine, phosphatidylcholine, and phosphatidylethanolamine decreased. The temperature-dependent changes in fatty acid composition were greatest for phosphatidylcholine, and were different for each of the above-mentioned phospholipids. The greatest changes were in C 16:1. Rearing the larvae in an atmosphere of pure oxygen did not affect the fatty acid composition.

Characterization of glycerophosphorylcholine, -ethanolamine, -serine, -inositol, and -glycerol hydrolytic activity in housefly larvae

Homogenates of Musca domestica (housefly) larvae contain glycerophosphodiesterase activity, which is found in the supernatant fluid after centrifugation at 88,000 g. The phosphodiesterase is inhibited by EDTA and is stimulated by Mg(2+), Ni(2+), Co(2+), and Mn(2+). The pH optimum is 7.2. The enzyme is stable to heating at 50 degrees C for 15 min and is insensitive to sulfhydryl inhibitors. Glycerophosphoryl diesters of choline, ethanolamine, inositol, serine, glycerol, and beta-methylcholine are hydrolyzed to the common product, l-alpha-glycerophosphate, and the appropriate free alcohol. The rate of glycerophosphorylcholine hydrolysis is 70% greater than the rate of hydrolysis of the other glycerophosphodiesters. Apparent K(m) values for glycerophosphorylcholine, glycerophosphorylethanolamine, and glycerophosphoryl-beta-methylcholine are 2-4 x 10(-4) m, and for glycerophosphorylinositol, 2 x 10(-3) m. Competitive studies using various pairs of substrates, as well as the exchange of free choline into both glycerophosphorylcholine and glycerophosphorylinositol, suggest that a single enzyme cleaves all substrates. Product inhibition and reversal of the reaction were not detected. Choline, but not l-alpha-glycerophosphate, exchanges into glycerophosphorylcholine and glycerophosphorylinositol.

Distribution of haemocytes in larvae of Musca domestica and Musca autumnalis and possible chemotaxis during parasitization

In each of the three larval instars of Musca domestica and M. autumnalis most of the haemocytes were accumulated in the haemocoele in the last two segments of the body. Very few circulating haemocytes were found, and only in second- and third-stage larvae. During development the posterior haemocytic masses increased in size. At the time of pupation the haemocytes were completely dispersed throughout the haemocoele. Experiments with ligated larvae and larvae fixed in liquid nitrogen indicated that the posterior haemocytic masses were not artifacts of fixation. It remains to be determined whether these posterior masses represent haemocytopoietic tissue. The possibility that the haemocytes exhibit chemotaxis during pupation and in response to parasitization is discussed.

γ-Glutamyl transpeptidase catalyses the synthesis of γ-glutamylphenylalanine in the larva of the housefly Musca domestica

γ-Glutamyl transpeptidase has been purified about one-hundredfold from acetone powder of housefly ( Musca domestica) larvae. The enzyme catalyses the synthesis of γ-glutamylphenylalanine (γ-glu-phe), a dipeptide found in large amounts in the larva of this species. Synthesis is via a classic γ-glutamyl transpeptidation in which the γ-glutamyl residue of γ-glutamylcysteinylglycine (glutathione) is transferred to phenylalanine. Many of the common α- l-amino-acids are also acceptors of the γ-glutamyl residue in vitro, resulting in γ-glutamyl-amino-acid formation. In vivo, however, only γ-glu-phe has been observed to date. Remarkable changes occurred in the amount of γ-glutamyl transpeptidase activity (units per insect or units per mg. protein) at the end of the larval period. Activity doubled at the formation of the puparium, increased a further 50 per cent within the next 1.5–2 hours to its peak level, and then fell abruptly to an almost undetectable level within the subsequent 24 hours. Peak activity coincided with the rapid disappearance of γ-glu-phe during the early stages of sclerotization of the puparium. It is suggested that γ-glu-phe and γ-glutamyl transpeptidase form part of a system of enzymes and their reaction products which constitute a ‘γ-glutamyl cycle’ for the transport of phenylalanine across certain cell membranes in this insect. The cycle appears to operate incompletely during larval growth, resulting in the formation of a pool of γ-glu-phe, while operating completely at puparium formation, resulting in utilization of the pool for sclerotization.

Somatic crossing-over in the housefly.

X-rays were found to produce genetically marked cells and cell clones in heterozygous larvae of Musca domestica. The results favor the conclusion that these marked clones originated by somatic crossing-over. The technique should prove useful in developmental analyses of the housefly.

Residues of Encapsulated Rabon in Poultry Manure and Its Larvicidal Activity to House Flies1

Three formulations of encapsulated Rabon® (2-chloro-1-2,4,5-trichlorophenyl) vinyl dimethyl phosphate were fed mixed with poultry mash to laying hens for a treatment period of 14 days. The dosages administered were 50, 100, 400, and 800 ppm of actual Rabon. Samples of manure collected on the 14th day were analyzed by gas chromatography using an electron capture detector, and amounts of actual Rabon were determined. On seeding the manure from the Rabon-fed hens with larvae of Musca domestica L., excellent control of susceptible and organophosphate-resistant flies was obtained.