Number Of Adult Flies Research Articles

Are Dung Beetles Driving Dung-Fly Abundance in Traditional Agricultural Areas in the Amazon?

We evaluated the effects of different land-use systems on the ability of dung beetles to control the population of detritus-feeding flies. We tested the hypotheses that intensification of land use will reduce dung beetles richness, abundance and biomass and, consequently, their dung burial ability, affecting the interaction between dung beetles and flies and reducing its effectiveness as a natural biological control. In the Brazilian Amazon we sampled dung beetles, fly larvae and adults; and recorded the rate of dung removal by dung beetles across a gradient of land-use intensity from primary forest, secondary forest, agroforestry, agriculture to pasture. Our results provide evidence that land-use intensification results in a reduction of the richness, abundance and biomass of dung beetles, and this in turn results in lower rates of dung removal in the most simplified systems. We found no significant differences in the abundance of fly larvae between the different systems of land use. However, the number of adult flies differed significantly between land-use systems, presenting higher abundance in those sites with greater intensity of use (pasture and agriculture) and a lower abundance of adult flies in forested systems (primary and secondary forests, and agroforestry). Information-theoretic model selection based on AICc revealed strong support for the influence of land-use systems, dung removal rates and dung beetle abundance, biomass and richness on adult dung-fly abundance. Our results also reveal that dung beetles are not solely responsible for fly control and that other factors linked to land use are influencing the populations of these detritus-feeding insects.

Genome‐Wide P‐element Screen for Hypoxia Tolerance Genes in Drosophila melanogaster

Hypoxia occurs during normal conditions (high altitude) or during pathologic states (sickle cell anemia). Our research is focused on understanding the molecular mechanisms that lead to injury or adaptation to hypoxic stress using Drosophila as a model system. To identify the genes involved in hypoxia tolerance, we screened P‐element insertion lines generated by Gene Disruption Project. For hypoxia tolerance, we screened for a) eclosion rates after following the development of embryos placed in 5% O2 to eclosion and adulthood, b) number of adult flies surviving after eclosion. Out of 2367 lines screened, 44 P‐element lines had eclosion rates significantly higher (>70% eclosion) than the controls (eclosion rate ~7–8%) under hypoxia. The molecular function of these lines ranged from cell cycle regulation, DNA or protein binding, ATPase activity, and transcriptional co‐regulators. In this screen, we found certain interesting candidate genes such as sec8, cyclin E, osa, l(3)mbn, lqf which show tremendous hypoxia tolerance during all stages of the developmental cycle. Furthermore, we employed the UAS–Gal4 system to further dissect the role of these genes ubiquitously or in specific tissues in vivo. Interestingly, we found that regulation by single genes, such as osa can play an important role in survival and development during hypoxia.This work has been supported by NIH grant (RO1 NS037756) to Dr. Gabriel Haddad.

Maize more attractive than Napier grass as non-host plants for Bactrocera cucurbitae and Dacus demmerezi

Some species of fruit flies (Diptera: Tephritidae) shelter and roost in non-host plants surrounding crops. The aim of this study was to compare the attractiveness of two plants (Poaceae): maize, Zea mays (Linne) and Napier grass, Pennisetum purpureum (Schumacher) for two species of Dacini damaging cucurbits in Reunion Island: Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae) and Dacus demmerezi (Bezzi) (Diptera: Tephritidae). Plants of the two plant species were established in pots and presented to adult flies in field cages. In each cage, a cohort consisting of adults of a given species, of known sex and age, was released. For each species, the experiment was replicated four times. The number of adult flies on the different plants as well as their location on the plant was recorded. Maize was more attractive to adults of B. cucurbitae and D. demmerezi than Napier grass irrespective of sex and sexual maturity. Most adults of both species were found under the leaves of maize and Napier grass. The effects of the date, time of day, age, and sex of flies on their attraction to plants are discussed. A possible application of this study would be to use maize as a border plant to apply bait for the control of fruit flies.

Effects of microwaves on the puffing pattern of D. melanogaster

Abstract The influence of electromagnetic field exposure on puffing pattern of salivary gland polythene chromosomes, viability and fertility of Drosophila melanogaster of the wild type Canton-S line was studied. Experimental conditions: Electromagnetic field characteristics: frequency — 36.64 GHz, power density — 0.4 W/m2, exposure time −10 seconds. Electromagnetic field exposure was conducted on the egg stage. Results: in larvae developed from the exposed eggs 3 of 8 chromosomal puffs tested (71CE, 82EF, and 83E) had significantly smaller dimensions than these in control at the prepupal stage. Viability of Drosophila estimated by the number of adult flies hatched from exposed eggs decreased, while the number of dominant lethal mutations increased. Conclusion: the exposure to a low-level microwave irradiation suppressed puffing activity at ecdysone-inducible loci of Drosophila polythene chromosomes, increased frequency of dominant lethal mutations and decreased Drosophila viability but did not influence Drosophila fertility.

The adoption of silvopastoral systems promotes the recovery of ecological processes regulated by dung beetles in the Colombian Andes

Abstract 1. Conventional cattle ranching with low plant diversity and a high dependence on chemical fertilisers and herbicides, simplifies ecosystems and negatively affects their functioning. In tropical regions, the cattle ranching systems that use fodder trees and shrubs along with grasses offer a useful landscape management tool that may contribute to the conservation of biodiversity and the stability of ecological processes. 2. Given the functional importance of dung beetles in natural and anthropogenic ecosystems, this study evaluates the recovery of some of the ecological services in which these insects play a role by comparing treeless improved pastures (IP) with those that have been converted into silvopastoral systems (SPS: two species of grass, Cynodon plectostachyus and Pannicum maximum, in association with Leucaena leucocephala trees) in a cattle ranching landscape of the Colombian Andes. 3. The results reveal an increment in the abundance of dung beetles in SPS and, as a consequence, an increase in dung, soil and seed removal, as well as a reduction in the number of adult flies and their larvae compared with IP. 4. This suggests that SPS offer suitable refuges for the dung beetle fauna that complement the role of protected forest remnants, riparian forests and live fences in conserving the integrity of key ecological processes in cattle ranching landscapes.

Investigation of the Factors Affecting Adult Fly Production in Biosolid Cake

The seasonal pattern of adult fly production in both fresh and aged biosolid cake was established by the exposure of biosolid cake to natural conditions in the central coastal region of Perth, Western Australia, over the course of a year. Relationships between fly emergence and six factors (weeks exposed, pH, NH(4), rainfall, temperature, and moisture) suspected of facilitating the attraction of adult flies to biosolid cake were measured. The aim was to study the production of adult flies with regard to weeks exposed in different seasons to establish a "best practice" storage procedure for aged biosolid cake. Four fly species were collected during the study; Musca domestica L. (house fly), Stomoxys calcitrans L. (stable fly), Fannia canicularis L. (lesser house fly), and Muscina stabulans (Fallén) (false stable fly). Of the 5,303 flies identified, >97% of these were either M. domestica or S. calcitrans. Adult flies emerged from biosolid cake all year round with a sharp decline in winter. The number of emerged flies peaked in summer (3,163 flies) and declined during autumn (1,545 flies) and spring (532 flies). Significant positive relationships were observed between the number of adult flies emerging from biosolid cake and ambient temperature, NH(4) content, and weeks exposed. Higher ambient temperatures and a higher NH(4) content of the biosolid cake were associated with increased number of adult flies emerging from the biosolid cake. Similarly, the majority of flies emerged from biosolid cake in the first 10 wk of exposure to fly activity.

House Fly (Musca domestica L.) (Diptera Muscidae) Development in Different Types of Manure

A B S T R A C T Animal production units with different management systems can be found along the Huasco Valley, Region of Atacama, Chile. These constitute sources of house flies (Musca domestica L.) and other vector fly species that cause damage to animals and nuisance problems in urban areas. In order to asses the importance of fly breeding sources, an experiment was carried out under laboratory conditions to evaluate different types of animal manure and composted swine manure. Time of larval development, larva mortality, pupa size, and weight and time of development to the adult stage were assessed. Results show that swine, poultry and calf manure produced a significantly higher number of adult flies, shorter life cycles and larger and heavier pupae. Cow, dog, goat and horse manure follow in effectiveness for fly production. Composted swine manure was totally ineffective for domestic fly development.

Evaluation of the behavioural response of the flies Megaselia halterata and Lycoriella castanescens to different mushroom cultivation materials

AbstractA static‐air olfactometer was used to investigate the behavioural responses of adult female phorid [Megaselia halterata (Wood) (Diptera: Phoridae)] and sciarid [Lycoriella castanescens (Lengersdorf) (Diptera: Sciaridae)] flies to the commercial white mushroom, Agaricus bisporus (Lange) Imbach, grown on a standard pasteurised composted substrate. The attraction of the flies was measured in relation to four test materials: composted substrate spawned with A. bisporus mycelium for 4 days and 14 days, uncolonised composted substrate, and A. bisporus sporophores. The experiment was done according to a 4 × 4 × 4 Latin cube design, and the results were analysed using a generalised linear model. It was found that both the occasion on which a bioassay was run and the position of the olfactometer within a 4 × 4 array could affect the proportion of the fly population responding to a test material. Megalesia halterata preferred spawned compost to unspawned compost, and the level of response to compost spawned for 14 days was greater than to compost spawned for 4 days. In contrast, L. castanescens were attracted equally to all of the materials tested. Overall, L. castanescens showed a greater level of activity than M. halterata, and was more likely to enter the pitfall traps in the olfactometer. For both M. halterata and L. castanescens, the type of test material affected the numbers of adult flies of the F1 generation that emerged from it following oviposition. The highest numbers of emerging M. halterata were obtained from a composted substrate spawned for 4 days, and none emerged from the unspawned compost. Emergence of L. castanescens was highest from the uncolonised composted substrate, and there was a negative relationship between emergence and the amount of mycelium in the composted substrate. The results are consistent with the use of volatiles in the detection of oviposition sites by both species; however, further studies of the materials will be necessary to determine precisely which oviposition cues the insects use.

Temporal and spatial allozyme variation in the South American cactophilic Drosophila antonietae (Diptera; Drosophilidae).

Drosophila antonietae is an endemic South American cactophilic species that uses Cereus hildmaniannus rotting cladodes as breeding sites. We assessed temporal and spatial intrapopulational allozyme variation of two natural populations. Our results suggest that environmental variation (rain precipitation) is probably influencing allozyme temporal variation. Moreover, it seems that D. antonietae does not have intrapopulation structure and has N(ev) (variance effective size) approximately equal to 83 and N(ec) (number of adult flies that colonize each rotting cladode) = 21. The deficiency of heterozygotes found must be due to null alleles, a temporal Wahlund effect, or selection against heterozygotes. Assortative mating and inbreeding are discarded. This is the first report on allozyme variation in D. antonietae. It gives some insight on intrapopulational genetics through space and time for this species. This is important to understand its general genetic variability and will be essential to future works on the natural history and evolution of this species.

Influence of genotype on endoreduplication of giant chromosomes and expressivity of character eyeless in Drosophila melanogaster

In Drosophila melanogaster lines LA (low activity), HA (high activity), and Oregon-R (wild type), the effect of genetic background on endoreplication in giant chromosomes of salivary glands, fecundity, and expression of mutation ey was studied. The degree of chromosome polyteny and the number of adult flies in saturated lines eyHA, eyBA, and eyOr were significantly higher than in the original lines. The degree of chromosome polyteny was correlated with fecundity. The expressivity of the ey character was shown to be far lower in lines eyLA, eyHA, and eyOr than in the original eyeless line. In the saturated lines, the eye facets were reduced to a similar degree. All the lines studied displayed clear-cut sexual distinctions in this parameter. In the eyHA line, the coefficients of variation for the degree of chromosome polyteny, fecundity, and expressivity of the ey mutation were much lower than in lines eyeless, eyLA, and eyOr.

Optimal application strategies for entomopathogenic nematodes: integrating theoretical and empirical approaches

Summary The nematode Steinernema feltiae has been developed commercially as a biocontrol agent and is successful in controlling sciarid flies in mushroom houses. We used a simple model developed in parallel with a series of field trials, to optimize the application strategy of the nematode. The first field trial provided life‐history parameter estimates for both the sciarid flies and the nematodes and showed there to be substantial levels of nematode recycling, leading to high levels of control. Crucially, the field trial showed that by splitting the application into two, and applying half the nematodes at day 0 and half at day 7, the overall number of nematodes (dose) could be substantially reduced from currently recommended levels without sacrificing control success. The model confirmed that there should be a benefit in splitting the dose, if the second application is timed to coincide with the peak in numbers of highly susceptible sciarid larvae. Importantly, the model provided insight into the dynamics of the sciarid larvae, even though the original data set only recorded adult fly numbers. Using a split dose, optimally timed, the model suggested that total doses could be reduced by up to 75% and still achieve control comparable to that found with currently recommended dosages. The timing of the second application of nematodes was crucial in determining the level of control. The model predictions were validated against a second independent field trial with considerably lower fly densities. Even under these different conditions, the predictions were accurate, indicating the robustness of the modelling approach. To date models have rarely provided genuine practical advice to applied agriculturists and biocontrol practitioners. This study shows how a simple model developed in parallel with replicated field trials leads to a better understanding of the biological processes underlying successful control, resulting in improvements in recommended application strategies.

Biological Control: An Important Component in Integrated Management ofMusca domestica(Diptera: Muscidae) in Caged-Layer Poultry Houses in Buenos Aires, Argentina

An Integrated Management program to controlMusca domesticaL. was developed by evaluating cultural + chemical control, cultural + biological control + granular bait (IMP 1), and cultural + chemical + biological control + granular bait (IMP 2) in poultry houses in Argentina. Adult fly density was estimated by a modified Scudder-grid method. Percentage of house fly parasitism was estimated by direct and indirect methods.Spalangia endiusWalker andMuscidifurax raptorGirault & Sanders were released at a rate of 10 parasitoids/hen/week. Complete absence of control practices allowed a sustained growth of the fly population. When larvicides and adulticides were used, the number of adult flies decreased but parasitism was adversely affected. When insecticide use was decreased, the number of flies increased. Cultural + biological control + granular bait (IMP 1) produced a reduction of adults from 14 to 3 flies/grid. Where cultural + chemical + biological control + granular bait (IMP 2) was employed, the adult number was reduced from 40 flies/grid to 1 fly/grid. IMP 2 was efficient for reducing the number of larval development sites in the manure. Percentage parasitism exceeded 90% in both IMP 1 and IMP 2 treatments. IMP 1 and IMP 2 treatments both allowed for maximum control of house flies with minimal use of pesticides. With IMP 2, the potential effectiveness of the biological control agents was maximized by reducing adult fly populations with pesticide sprays, then terminating spray applications before parasitoids were released. Thus, IMP 2 would be most suitable for farms which have large adult house fly populations at the initiation of the treatment. The only pesticide used in IMP 1 was a granular bait. Thus, IMP 1 would be most efficient in situations with low initial adult house fly populations and small amounts of manure to ensure the success of the cultural strategy.

The response of an insect parasitoid, Ormia ochracea (Tachinidae), to the uncertainty of larval success during infestation

Ormia ochracea is a parasitoid fly which lays its larvae on its hosts, the field crickets Gryllus integer and Gryllus rubens, in two distinct modes: (1) directly on the host and (2) around the host. In the field, 12.7% of male crickets were parasitized and 3.2% were super-parasitized. Despite the disadvantages of parasitizing infested hosts, there was no evidence that O. ochracea avoided superparasitism. This and other experiments suggest that the host assessment ability of O. ochracea is less than that reported for many hymenopteran parasitoids. by manipulating the number of larvae in each cricket, we determined that four to five larvae per host resulted in the largest number of adult flies. However, as larval number per host increased from one to six, pupal size, and hence adult size, declined. In the field, hosts were found with a mean of 1.7 ± 1.0 (SD) larvae per cricket, suggesting that there may be some selection pressure against larger clutch sizes. Nevertheless clutch sizes larger than the host can support were sometimes found in the field. During the first mode of larviposition, gravid flies deposited no more than three larvae directly onto the host. Larvae deposited directly on the host had a high probability of infesting it. During the second mode of larviposition, gravid flies laid a larger number of larvae around the host (6.1 ± 5.2). Larvae that were laid around the host were less likely to infest a cricket than were larvae that were deposited directly onto it. O. ochracea is unique in that its two different modes of larviposition have different probabilities of larval success. Even though the success rate for larvae laid during the second mode of larviposition was low, the possibility of parasitizing more hosts appears to have selected for flies laying more larvae (e.g. increasing clutch size) than is optimal if all the larvae successfully entered a single host.

Efficacy of Muscovy Ducks as an Adjunct for House Fly (Diptera: Muscidae) Control in Swine and Dairy Operations

Field studies were conducted using Muscovy ducks, Cairina moschata L., to control house flies, Musca domestica L., in swine and dairy facilities. In fly-proof calf pens, one Muscovy duck per pen reduced the adult fly numbers by 96.8% when compared with pens without a duck. The maggot population was reduced by 98.7% when compared with pens without a duck. In an enclosed calf room, fly populations on animals were reduced by 84 and 93% when compared with the times when ducks were not present. However, in open areas of the dairy facility which allowed for immigration and emigration of house flies, statistically significant reductions were not observed. Ducks reduced fly populations on animals by 91% in an enclosed swine farrowing room. In an open dry sow facility, ducks reduced the house fly population by up to 86%. Female ducks consumed house flies up to three times faster than the males. During most experiments, duck health was maintained without any supplementary feedings. Ducks had access to flies, water, and spilled (wasted) feed. On conclusion of the studies, the least valuable ducks were sold for twice the invested cost ($2 cost versus $4 sale), yielding a 100% return on investment. Farmer acceptability was good.

Why do guava fruit flies,Anastrepha striata(Tephritidae), avoid the upper canopy of host trees?

Abstract The within‐tree distribution of the guava fruit fly, Anastrepha striata in sour guava, Psidium friedrichsthalianum and common guava, P. guajava in the seasonal highlands and non‐seasonal lowlands of Costa Rica, was examined in relation to host fruit distribution, temperature, and ambient light levels. Larvae and adult flies were significantly more abundant in the middle and lower parts of trees than in the upper canopy layer where temperatures inside sun‐exposed, potential host fruits reached lethal levels for eggs and larvae of A. striata. The number of adult flies was also significantly greater in relatively compact foliage than in fairly open foliage of host trees. The results suggest that the foliage structure of host trees, through its influences on the temperature inside host fruits, is determining the within‐tree distribution of Anastrepha fruit flies.

Sequential latent effects of a sub‐lethal dose of ivermectin in Calliphora vomitoria L.

AbstractA single sub‐lethal dose of 0‐3 μg ivermectin applied topically to third (last) instar larvae of Calliphora vomitoria prevents a significant number of adult flies from escaping from their puparia after metamorphosis, although the flies show no signs of physical abnormality. Of the insects that manage to emerge, a significant number of females do not develop mature oocytes. Ivermectin in sub‐lethal doses seriously impairs post‐embryonic development in Calliphora at four independent levels: interference with pupariation, suppression of adult head development, inhibition of emergence from the puparium, and disruption of ovarian development in the adult female. These findings are discussed in relation to ivermectin's efficacy as a pesticide and particularly to non‐specific effects upon dung‐inhabiting insects.

Field and glasshouse studies on components of resistance to root fly attack in swedes

SUMMARYField trials in two years indicated that egg‐laying antixenosis was the major component of resistance in swede cvs Angus and Melfort against root flies (Delia floralis and D. radicum). Between four and eight times as many D. floralis eggs were laid on the susceptible cv. Doon Major as on the resistant cv. Angus. The degree of antixenosis effective against D. radicum was more variable in 1985, due to low numbers of adult flies, but in 1986, when adult fly numbers were higher, D. radicum laid 34 times as many eggs on susceptible cv. Sator Øtofte as on Angus.Root antibiosis against larval feeding is a second but less important component of resistance against D. floralis. In egg inoculation tests, 1.3‐2.0 times more D. floralis pupae developed on Doon Major than on Angus or Melfort. Larval feeding on resistant cultivars was restricted to surface root tissue only, compared with deeper tunnelling on susceptible cultivars. Tolerance to root damage may also occur under certain conditions. Although increased dry matter content was significantly correlated with root antibiosis, its effect on larval feeding was apparently not due to increased tissue hardness. It seems likely that chemical differences in the outer root tissues influence larval feeding and development.

FIELD RECOVERY OF Eucelatoria brvani ON Heliothis armigera (Hubner)

Studies made on the field recovery of Eucalatorja bryani Sabroky from Heliothis armigera Hubner indicated that there was effective parasitism from December, to April to an extent of 20 per cent and emergence of adult flies was 9 from each parasitised larvan The pencentage of parasitism and emergence of adult flies were significantly high from the larvae of Heliothis armigera collected from tomato followed by redgram and Lab-lab. A positive correlation was found to exist between the number of larvae parasitised vs. percentage of parasitism as well as with the number of adult flies emerged. Regression: equation fitted with the above variables showed that for every parasitised host larvas in the field, there would be an increase of 5.63 per cent parasitism and 3.73 adult flies emergence. These studies significantly revealed the practical utility of this parasitoid for effective parasitism on Heliothis armegera by mass multiplication and release in the field.

Efficacy of Insect Suppression Treatments, Avian Influenza (Ai) Eradication Task Force, Lancaster County, Pennsylvania, 1983-84

Abstract Observations were conducted during Nov and Dec 1983 at 20 Al-infected poultry premises; 10 premises were high-rise houses (layer hens or pullets), 5 were broiler-breeder houses and 5 were shallow-pit houses (layer hens). Each house was treated with a regimen of 4 insecticidal applications to control insects in conjunction with the disinfection and cleanup of Al-quarantined poultry operations. The first treatment, a pyrethrin space spray, was applied within 24 h after depopulation of the flock. The second and third treatments were applied on the same day as the space spray or as soon as possible thereafter, and consisted of a 0.5% stirofos or 0.1% permethrin water-base spray to exterior building and ground surfaces around air vent fans, and a 0.5% stirofos water-base spray applied to manure under bird cages at 2 gal per 100 ft2. The fourth treatment, a 0.1% permethrin water-base spray to interior surfaces, was applied after approval for cleanup and disinfection, but before flock repopulation 30 days later. Treatments were applied by a commercial certified applicator consistent with label instructions. Insect populations were sampled on 2 occasions: 1) before application of space spray treatment and 2) after space spray and manure treatment but within 7 days following the pretreatment sample. Sampling procedures were as follows: In each high-rise house, the numbers of adult house flies and black garbage flies were counted on one side of 10 posts. Insects on and in manure down to a depth of 10-15 cm were talleyed by species and life stage (larvae or adult) at 10 sites on both sides of a central pathway; each sample site consisted of an area extending from the crest or middle of the manure bed to the center of the walkway and ca. 12 inches wide (ca. 3 ft2). Broiler-breeder houses were sampled by counting adult flies on 10 ceiling-support posts in the lower floor and by examining ca. 1 ft2 of litter at 10 sites around the base of posts, under feeders and at the base of walls. Shallow-pit houses were sampled by counting numbers of adult flies in an area of ca. 5-ft wide extending from the middle of the walkway to the top tier of cages. Insects on and in manure were sampled by the same procedure used in high-rise housing.

Effect of dietary purines and pyrimidines on growth and development of Drosophila

1. 1. Addition of purines (adenine and guanine) and pyrimidines (cytosine and thymine) to the nutrient medium affected the growth and development of Drosophila melanogaster. 2. 2. Adenine was detrimental to the metamorphosis of the flies and caused weight reduction in newly hatched flies. 3. 3. Addition of 0.23% of adenine per 100 g of the nutrient medium was sufficient to reduce by one-half the number of adult flies hatched (LD 50 = 0.23%). 4. 4. Adenine also changed purine-pyrimidine profiles in the larval and pupal stages, but had no effect on these profiles in adult flies.