Chloropidae Research Articles

Observations sur les Mœurs Prédatrices de Quelques Asilides [Dipt. Brachycera] de la Basse-Provence

SummaryJ. J. Musso: Observations on the predation behavior of some species of Provence Robber flies (Diptera: Asilidae).The predation behavior of the Robber flies presents various appearances according to the families, the genera, and often the species. Some observations on the predation behavior of caracteristic species of Provence Robber flies are noted in this work.Four types of foraging behavior can be distinguished: foraging from the dead stems of trees, foraging from the ground, foraging from the lower stratum of vegetation and foraging from the tips of dead branches of trees or small shrubs.Nota: La sous-famille des Leptogastrinae est considérée par Martin C. H. (1968) comme une nouvelle famille (The new family Leptogastridae, the Grass flies, compared with the Asilidae(Robber flies). — Journ. Kansas, Ent. Soc., 41, p. 70-100). Oldroyd H. (1969) pense que l'ancienne classification doit être conservée (The family Leptogastridae. — Proc. R. ent. Soc. Land (B), 38, p. 27-31).

The susceptibility of the eye gnat Hippelates collusor to entomogenous bacteria and fungi

A number of entomogenous bacteria and fungi were tested for their pathogenicity to the eye gnat Hippelates collusor. None of the bacteria at the concentrations used caused high mortality when tried against larvae. Those that were relatively more pathogenic, producing mortalities in the range of 40 to 60%, included Bacillus thuringiensis var. alesti, B. thuringiensis var. entomocidus, B. thuringiensis var. thuringiensis, a Bacterium sp. originally isolated from the house fly, and several pigmented strains of Serratia marcescens. The only fungus that possessed pathogenicity against the eye gnat was Beauveria bassiana. It caused up to 100% mortality in both adults and larvae and, therefore, appeared to the much more effective than the best of the bacteria that were tested.

Hippelates Eye Gnat1 Attractants. 1. Isolation and Identification of Ether-Soluble Coattractants Produced by Fermentation of Whole-Egg Solids

Fermented aqueous suspension of whole-egg powder is attractive to Hippelates collusor (Townsend) (Diptera: Chloropidae) eye gnats and has been used for trapping eye gnats. Distillate of the fermented aqueous suspension was separated into water- and ether-soluble fractions by ether extraction. The 2 fractions were less attractive when tested individually. However, when these 2 fractions were combined and evaluated in an olfactometer against eye gnats in the field, the combination showed a significant increase in attractancy over the combined attractancies when evaluated separately. From the ethersoluble fraction, 10 carboxylic acids, n -butyric, iso -valeric, iso -caproic, myristic, palmitic, palmitoleic, stearic, oleic, linoleic, and linolenic, were isolated and identified as their esters with gas-liquid chromatography. Among these 10 acids, oleic and linoleic each enhanced the attractiveness of the water-soluble fraction; n -butyric, iso -valeric, and iso -caproic acids decreased the attractiveness of the water-soluble fraction; while myristic, palmitic, palmitoleic, stearic, and linolenic acids did not significantly influence the attractiveness of the water-soluble fraction.

Crop Rotation and Soil Pathogens — Trends in Germany

AbstractThe need to cut costs has led to a simplification of crop rotation in several fields of plant cultivation. The results of Thormann, who has grown wheat continuously on parts of his farmland for 10 years, are discussed. Also, the preliminary results of our own experiments with increasing proportions of wheat and barley suggest that more wheat and barley may be cultivated in crop rotation than is allowed according to the conventional limits determined by the increase of foot rot diseases and cereal root eelworm. Even in successive crops of maize the problem of soil‐borne pathogens can be tackled: the spread of blister smut is stopped by the control of the frit fly and by selection of tolerant varieties; root and stem rots of maize are overcome by the selection of appropriate varieties, too. On the contrary, the potato root eelworm is a serious pest in all sites of intensive potato production. Only an integrated control including the use of resistant varieties and the application of nematicides gives success. Much research work has to be done mainly to get more information on the biotical defence mechanisms of the soil.

Sterilization of Hippelates pusio with tepa and metepa.

Tepa and metepa sterilized the eye gnat Hippelates pusio Loew by: exposing adults to residues on nylonmesh screen, allowing newly eclosed adults to emerge through treated polystyrene foam strands, and allowing anesthetized adults to recover and crawl through treated polystyrene foam strands. The 3rd method however produced the greatest sterility with least mortality on both field and laboratory eye gnats.

Descriptions of some new Chloropidae (Diptera) from India

Abstract Four new species of Chloropidae belonging to the genera Siphunculina, Tricimba and Chlorops viz. S. ulceria, S. faciata, Tricimba sexialis and Chlorops nigripedalis are described here. The genus Tricimba Lioy is being recorded for the first time from India.

Susceptibility of Adult Hippelates pusio to Insecticidal Fogs12

The mortalities of caged, laboratory-reared Hippelates pusio Loew (eye gnats) exposed to thermal fogs of 9 insecticides were determined under field conditions. Naled and propoxur were most toxic. DDT was least toxic. The other insecticides of intermediate toxicity were: fenthion, dichlorvos, Dursban® ( O,O -diethyl O -3,5,6-tri-chloro-2-pyridyl phosphorothioate), Gardona® (2-chloro-1-(2,4,5-trichlorophenyl) vinyl dimethyl phosphate), CIBA C-9491 O -(2,5-dichloro-4-iodophenyl) O,O -dimethyl phosphorothioate), and a mixture of malathion and Lethane 384® (2-(2-butoxyethoxy) ethyl thiocyanate).

Susceptibilities of adult Hippelates eye gnats to insecticidal deposits.

Susceptibilities of eye gnats, Hippelates pusio Loew and H. pallipes (Loew), to deposits of 17 insecticides were determined under laboratory conditions. The two species exhibited similar susceptibilities. The most toxic chernicals were Dursban® ( O,O -diethyl O -3,5,6-trichloro-2-phosphorothioate), ronnel, fenthion, diazinon, malathion, dimethoate, naled, and dieldrin. Gardona® (2-chloro-1-(2,4,5-trichlorophenyl) vinyl dimethyl phosphate) was moderately toxic. Lower toxicity was exhibited by dimetilan, propoxur, crotoxyphos and trichlorofon. Very low toxicity was exhibited by lindane and DDT and extremely low toxicity by Abate® (O,O -dimethyl phosphorothioate O,O -diester with 4,4'-thiodiphenol) and methoxychlor.

A method of assessing losses in spring oats from frit fly (Oscinella frit (L.)) shoot attack

Grain losses per unit area in oats following shoot attack by frit fly (Oscinella frit (L.)) were assessed in plots at Rothamsted. Individual plants were marked, and two categories of attacked plants (tillers and both main shoot plus tillers attacked) were distinguished because losses in the former were low or negligible compared with those in the latter. There was no evidence of compensatory growth for lost or damaged plants, so that losses could be assessed by comparing actual yield with yield expected had no plants been attacked. The percentage loss, weighted according to incidence and effect of attack in the two categories, was calculated from hand-harvested samples. The loss per unit area was then estimated from the actual yield obtained by combineharvesting. Estimates of actual yield were affected by the method of harvesting, so that estimates of loss were not precise.

Further Results on the Effects of Phorate on Losses of Sweet Corn (Zea mays L.) Caused by Frit Fly (Oscinella frit L.)

Further Results on the Effects of Phorate on Losses of Sweet Corn (<i>Zea mays</i> L.) Caused by Frit Fly (<i>Oscinella frit</i> L.)

Culicidae and tabanidae as potential vectors of anaplasmosis in Mississippi.

The role of all hematophagous Diptera or all except Tabanidae as potential vectors of anaplasmosis was assessed for 3 years in Mississippi by exposing groups of anaplasmosis-negative splenectomized steers in the presence of anaplasmosis-carrier steers. However, during the 1st year of the study, another group of Diptera, the eye gnats, Hippelates spp. (Chloropidae), also appeared to be potential vectors; the role of this group was therefore assessed during the 2nd and 3rd years of the study. Populations of insects were surveyed with light traps, animalbaited traps, collections from a bait steer, and eye gnat traps. Of the animals exposed to all Diptera, 32% contracted anaplasmosis. Of those protected from tabanids, none contracted the disease. Also, the animals protected from tabanids were protected from eye gnats.

Effect of Cultivation on Emergence of Eye Gnats (Hippelates spp.) in South Carolina1

Two experiments using 10 field plots in Barnwell County, S. C., were conducted to determine the effect of cultivation on emergence of eye gnats. In Experiment 1, 2247 Hippelates were trapped on plowed and 17 Hippelates on unplowed plots. In Experiment 2, 1761 Hippelates were trapped on plowed and 74 on unplowed plots. The same 4 species were trapped in both experiments. They were H. pusio Loew, H. pusio variant, H. bishoppi Sabrosky, and H. dissidens (Tucker). The numbers of each species trapped of Hippelates , except H. dissidens in Experiment 2, increased significantly as a result of plowing.

The family Leptogastridae (Diptera)

SYNOPSISMartin (1968) proposes to segregate Leptogaster and allied genera into a new family, Leptogastridae (grass flies). Martin's evidence is examined in detail, and it is concluded that the customary limits of the falllily Asilidae should be maintained.

Chemosterilants for control of reproduction in the eye gnat (Hippelates collusor) and the mosquito (Culex quinquefasciatus)

A number of chemical sterilants as well as some antibiotic compounds were evaluated in the laboratory and field for reproduction control in the eye gnat Hippelates collusor (Townsend) and the mosquito Culex quinquefasciatus Say. Reproduction control here denotes the suppression of fecundity. It is achieved either through the reduction in the number of ova produced or a decrease in their viability, or both. The materials were made available to the adult eye gnat as sugar baits, water solutions, deposits on glass surfaces, and also as pupal dips. The chemosterilants were offered as sugar solutions on cotton pads, to the adult mosquitoes. Against larval and pupal stages the chemosterilants were tested as water solutions or suspensions. Metepa applied as a contact chemosterilant for 1 hour at 0.8 ?g/cm2 sterilized both male and female eye gnats. Apholate did not appreciably suppress reproduction when tested by the contact technique. Apholate and metepa also produced high levels of reproduction control when offered in water solutions to gnats of both sexes. Apholate was highly effective at 0.1 per cent in sugar bait, as was Upjohn 14743 (porfiromycin) at safe rates. Olin 53356 at 0.1 to 0.5 per cent in sugar bait yielded complete control of reproduction, while Olin 53264 at 0.01 and 0.05 per cent in sugar bait produced high levels of control. No appreciable control resulted from metepa used for pupal dips. In laboratory screening against adult eye gnats, U-15800 (pactamycin), U-14743 (porfiromycin) and U-4527 gave good control, but this was not true of U-7726 and U-10071 (tubercidin). Olin 53356, Olin 53061, and Olin 53139 produced good to complete suppression, while Olin 53362, and Olin 53247 produced low levels of reproduction control. Eastman Inhibitor HPT at 0.1 and 1.0 per cent resulted in good to complete suppression; Acti-dione Oxime, GC-6936, GC-8993, and Dowco 186 yielded low to moderate levels of control. In the field, female eye gnats (attractant available for females only) were readily sterilized with apholate offered in sugar bait or water solution. Merepa as a contact material also readily sterilized the natural populations of female gnats. Against mosquito larvae, apholate (0.002 per cent water solution) yielded complete control of reproduction in the resulting adults, while metepa at 0.01 per cent water solution gave a very high level of control. Both materials at 0.01 and 0.1 per cent, respectively, yielded good to complete control. Apholate used in this manner proved over 10 times as effective as metepa. Against larvae, none of the Olin series of compounds (with the exception of Olin 53356) showed any appreciable activity, and none was found effective against pupae. U-7726 against larvae suppressed reproduction markedly, U-10071 produced a moderate reduction, while U-14743 resulted in complete control. Results with V-15800 are inconclusive. Sugar baits of Olin 53139, Olin 53356, and Olin 53362, used against adult mosquitoes, completely suppressed reproduction. U-10071 and U-15800, offered as sugar bait to the adult mosquito, yielded a high level of control; with U-14743, control was almost complete. U-7726 was not effective at the concentrations used. In general, the margin of safety between sterilizing concentrations and those causing appreciable mortality was found to be narrow. This would possibly pose some problems in the sterilization of laboratory and field populations of insects. The full potential of chemoscerilants for the control or eradication of insects harmful to humans and animals is not well established as yet. Many more fundamental studies will have to be conducted before these potentially useful compounds can be recommended for the control or eradication of insects.

The influence of the sowing time on the intensity of attack by the panicle generation of frit fly

Early sowing of winter and spring barley and oats are in general more effective in relation to the attack of frit fly panicle generation than the later sowing, with the exception of late varieties.

Ovarian development, pheromone production, and mating in the eye gnat, Hippelates collusor

Mating in female eye gnats is correlated with the degree of ovarian development which is utilized as a physiological age indicator. Mating occurred in females having egg development of stages 6 to 9. Females at stage 7 mated more frequently than females at the other stages of ovarian development when the males were given a choice of different aged females. Live females with ovaries in stages 6 to 9 produced a sex attractant and females at stage 10 produced a repellent. Females with stages 2 to 4 ovaries did not attract males. Ether extracts from females with stages 6 to 9 ovaries attracted males, extracts from females with mature eggs repelled males, and extracts from females with stage 2 ovaries did not attract males. Attractancy was only detectable in laboratory olfactometer tests. Field tests on female extracts did not attract males in the field. The sex attractant produced by female eye gnats probably acts as a sex recognition scent.

Studies on Resistance in Oats to the Frit Fly

SUMMARYOat cultivars reported resistant to frit fly attack in the tiller and panicle stages were investigated. Doefleurs Weihenstephan, Hohenheimer V, von Lochow's Yellow, Hede Havre and Summer proved to be the least susceptible. The resistance possessed by these cultivars was found to be only relative and appeared to be associated with swift initial development and erectness. Since it appeared doubtful that these cultivars would maintain superiority in pure stands, it is considered that their inclusion in a breeding programme is not merited.

A Soil-Wash Puparia Extractor for Brachycerous Diptera1

Advantages of this puparia extractor are: (1) it avoids surface film adhesion of puparia to trash, (2) it automatically concentrates washed puparia onto small screens convenient for placing beneath a dissecting microscope, and (3) it is 30-60% more efficient than conventional soil-wash separation techniques. It was designed to recover Hippelates eye gnat puparia. Puparia recovery from uncultivated debris-laden desert soil was 70-85%; and 86-100% from relatively debris-free soil. Extractor efficiency was not influenced by operator inexperience.

Yield Reductions in Reed Canarygrass Caused by Frit Fly Infestation1

Yields of reed canarygrass were reduced 0.52 metric ton per hectare in second harvest due to frit fly infestation. Plant height and weight of individual tillers were reduced by as much as one‐half by infestation. Insect control resulted in aftermath yield increases of 32% in low nitrogen plots and 17% in high nitrogen plots. Infestation interrupted normal morphological and physiological development. It is proposed that residue left by the feeding larvae may influence forage acceptability of grazing animals.

Control of the Midge Glyptotendipes paripes with Low-Volume Aerial Sprays of Malathion

Aerial applications of low-volume concentrate sprays of malathion when applied at the rate of 2 and 4 ounces per acre, gave excellent control of Glyptotendipes paripes Edwards adults. At the 4-ounce dosage rate, control was achieved within 3 hours and the residual effect of the spray gave control for 4 days. At the 2-ounce dosage rate, it took almost 6 hours to achieve a satisfactory kill, and the residual effect usually lasted 3 days. It appears that there is no difference in the initial kill when 1, 2, or 3 swaths are laid down. However, there are indications that the residual action is slightly less with 1 swath. At malathion concentration of 0.5 and 1.6 ppm, there was complete mortality of mosquito larvae and good control of midge larvae, but no mortality of the mosquito pupae. In the field, after spraying there was mortality of Hippelates eye gnats, muscid flies, small beetles, and wasps.