Fly Infestation Research Articles

Dot-ELISA based on recombinant Hypodermin C of Przhevalskiana silenus for field diagnosis of goat warble fly infestation.

Goat warble fly infestation (GWFI) is an economically important myiasis caused by larvae of Przhevalskiana silenus (Diptera, Oestridae), prevalent in countries of the Mediterranean Basin and Indian subcontinent. GWFI is characterized by the presence of subcutaneous warbles at the lumbar and sacral region of dorsum in the infested animal. The early larval instars (L1 and L2) remain inaccessible to physical detection due to their small size and subcutaneous presence thus causing hindrance in the diagnosis. The objective of present study was to develop a field applicable early diagnostic intervention for GWFI monitoring and prophylactic management for effective control of the disease. Recombinant Hypodermin C (rHyC) antigen of P. silenus was expressed in Escherichia coli. The purified protein was used for optimizing dot-ELISA in a checkerboard titration using goat warble fly infested serum as known positive. The optimized assay was further tested for lower temperature (18°C) and incubation time (30 min). The optimized assay was assessed for inter-rater reliability and field samples. The optimized conditions require 188 ng of protein/dot, 1:800 dilution of serum sample, 1:4000 dilution of anti-goat IgG conjugate and 5% skim milk powder in phosphate buffer saline as blocking buffer. The assay was found to have a diagnostic sensitivity and specificity of 97.3% and 95.8%, respectively. The inter-rater reliability of dot ELISA with rHyC indirect ELISA was found to be almost perfect with a Cohen's kappa index of 0.973. Further testing at ambient temperature (18°C) and shorter incubation steps (30 min) supported suitability of the assay for field diagnosis of GWFI. The present study provides the first report of a sensitive and specific dot-ELISA for early diagnosis of GWFI which is rapid and cost effective. The test may provide an effective field applicable tool for sustainable control of GWFI.

Comparative study of green gram cultivation in natural farming vs recommended practices

A comparative study on green gram cultivation in natural farming vs recommended practices was carried out at Krishi Vigyan Kendra, Abusar Jhunjhunu in Kharif-2022 to assess future possibilities of Natural farming practices in the district. In natural farming plot no manure and fertilizer were applied, seeds were treated with beejamrit and after sowing Jeevamrit was applied in field as per recommendation while in other plots all recommended doses of fertilizers were applied, seeds were treated with imidacloprid and NPK consortia, for management of weeds herbicide pendamethalin was applied after sowing. Whiteflies were observed in both plots. Neemastra and imidacloprid were applied in natural farming and other plots to control white flies. All observations were recorded from both plots and analyzed. Results revealed that lower yield was observed in natural farming plots (4.54 q/ha) than recommended practices (5.82 q/ha.). Possible causes of low yield in natural farming plots were weeds and severe white fly infestation. In recommended practices, pendamethalin herbicide was applied as pre-emergence, which reduced weed population, while Imidacloprid was sprayed to control white flies, reducing pest infestation. Soil samples after harvesting of crops were taken from both plots and analyzed for available organic carbon and NPK level. In the natural farming plot organic carbon level was slightly higher than in another plot which is a positive sign that it may increase the yield of the next crop.

Seasonal incidence of major insect pests of bottle gourd (Lagenaria siceraria) in South-western Haryana

Bottle gourd is an important vegetable crop that fetches recurrent income from farmers. The present investigation was carried out during the kharif season of 2019 to study the incidence of prevailing four insect pests of bottle gourd in relation to weather. The seasonal incidence of major insect pests such as Aulacophora foveicollis Lucas, Bactrocera cucurbitae Coquillett, Aphis gossypii Glover and Bemicia tabaci Gennadius was studied. The fruit infestation by Bactrocera cucurbitae was initiated in the 34th SMW, and the maximum infestation was noticed in the 36th SMW. The fruit fly infestation was significant and positively correlated with evening relative humidity and rainfall. Aulacophora foveicollis incidence in bottle gourd was maximum in the 38th SMW. The beetle population was significantly and negatively correlated with minimum temperature and evening relative humidity. The maximum infestation of aphids and whitefly was noticed in the later stage of the crop during the 39th SMW, and the aphid population was significantly correlated with minimum temperature, evening relative humidity and rainfall, whereas the whitefly population was correlated significantly with evening relative humidity and rainfall.

Is phosphine an ideal candidate for fruit fly disinfestation in Java apple, Syzygium samarangense?

Java apple, Syzygium samarangense, a nutritionally rich fruit species cultivated in Southeast Asia is prone to fruit fly infestation. Since no commercial management protocols currently exist for disinfesting java apple against fruit flies, the present study investigated the suitability of phosphine fumigation for post-harvest disinfestation of java apple fruit. Fruit exposed to gravid female Bactrocera dorsalis overnight were subjected to phosphine fumigation at concentrations ranging from 0.14 to 2.78 mg/L for 24, 48 and 72 h at ambient conditions. Gas chromatographic analysis of the PH3 concentration revealed that approximately 65% of phosphine gas was lost in treatment chambers fumigated with highest concentration of 2.78 mg/L for 72 h. B. dorsalis eggs could be mitigated by exposing java apple fruit to a concentration × time product of 16.67 mg/L-h of PH3 or more. Fumigating fruit at PH3 concentrations below 0.69 mg/L for 24 h and 48 h did not significantly change the color of treated fruit. Furthermore, the texture of the fruit post PH3 fumigation remained unaffected. Phosphine treated java apple fruit showed no trace of phosphine residues at exposures shorter than 72 h. In conclusion, phosphine can be a viable treatment for the management of B. dorsalis eggs in S. samarangense fruit at lower concentrations and shorter durations without affecting the fruit quality.

DETERRENCE EFFECT OF COLORED DIVERSION SHEETS ON THE POPULATION DENSITY OF MELON FRUIT FLIES BACTROCERA CUCURBITAE (COQUILLETT) AND YIELD PARAMETERS OF BITTER GOURD (MOMORDICA CHARANTIA L.)

The bitter melon, or the bitter gourd (Momordica charantia L.), is a tropical and subtropical area vegetable. Bactrocera cucurbitae (Coquillett), causes 30 to 100% crop loss. This study used refractive color sheets to examine reduced-risk insecticide spinosad formulations of prevalence and infestation of fruit flies on bitter gourd plants. Three different angles (30°, 60°, and 90°) of reflective sheets were put in M. charantia beds. Results showed that fruit flies were substantially more prevalent (60%) in the control condition. Compared to other color sheets, treatments using yellow refractive sheets showed the highest occurrence of fruit flies. Spinosad, a low-risk insecticide, had the lowest fruit FI% (6%) and the highest commercial yield (860g/bed), followed by blue-colored refractive sheets. Installation angles had no appreciable impact on any of the examined characteristics. Additionally, treatments using yellow-colored refractive sheets and the spinosad formulation (1:1.8), (1:4.9) were found to have the highest and lowest CBR. Installing refractive sheets in colors other than yellow at angles of 30° or 60° has been determined to be a more successful and cost-efficient technique for reducing fruit fly incidence on several vegetable crops. This is especially true when combined with biorational insecticides like spinosad.

Genetic variability, heritability and character association among linseed genotypes for yield and yield attributing traits

The present investigation has been conducted to determine genetic variability, heritability, and character association among 38 linseed genotypes for yield and thirteen morphological traits at Bihar Agricultural College Sabour Farm of Bihar Agricultural University Sabour, Bhagalpur (Bihar) during the rabi 2020-21. Thirty-eight genotypes including four checks, namely, Sabour Tisi-1, Sabour Tisi-2, Shekhar and T-397 were evaluated inRBD design with three replications. Analysis of variance for fourteen characters indicated that there was a sufficient amount of variability among the genotypes for all the characters studied. The characters, namely, flowering period, plant height, bud fly infestation, bud blight infestation, number of primary branches per plant, number of capsules per plant, number of seeds per capsule, 1000-seed weight and seed yield per plant exhibited high GCV, PCV and high heritability alongwith high genetic advance. A correlation study showed a significant and positive correlation between seed yield per plant and flowering period, flower diameter, number of primary branches per plant, number of capsules per plant, number of seeds per capsule, seed length and 1000-seed weight, whereas, days to 50% flowering, days to 50% maturity, plant height and bud fly infestation were found to be a significant and negative correlation with seed yield per plant. However oil content had a non-significant correlation with seed yield per plant but in the positive direction. Path coefficient analysis indicated that the number of capsules per plant exhibited high and positive direct effect on seed yield per plant, while, bud fly infestation showed a moderate and negative direct effect on seed yield per plant.

Seasonal incidence of stem fly, Melanagromyza sojae (Zehntner) infesting black gram (Vigna mungo L.) in kharif

A field experiment on the seasonal incidence of stem fly, Melanagromyza sojae (Zehntner) infesting black gram was carried out in variety GU 1 (Gujarat Urd 1) during kharif 2017 and 2021 at Entomology farm, B. A. College of Agriculture, AAU, Anand. Infestation of M. sojaewas observed from 1st WAS i.e., 34th SMW. Later on, infestation increased gradually and its highest infestation was observed during the 39th SMW i.e., 68.33 and 73.33% of kharif, 2017 and 2021, respectively. Stem fly infestation exhibited a highly significant positive association (r = 0.519** and 0.655**, respectively) with bright sunshine hours (BSS) and maximum temperature (MaxT), respectively. Abiotic factors viz., rainfall (RF) exhibited a significant negative association (-0.458*), while evaporation (EP) showed a significant positive association (0.466*).

Comparative Analysis of Different ELISA Methods for the Serodiagnosis of Przhevalskiana silenus Infestation in Goats

Przhevalskiana silenus (warble fly) grubs cause myiasis in goats, in mountainous and semi-mountainous areas and different regions in Pakistan, and cause substantial losses to livestock. The palpation method for detecting warble flies generally neglects the infestation intensity; therefore, the development of a reliable and efficient diagnostic technique is extremely necessary. This study compared three indirect enzyme-linked immunosorbent assay (ELISA) methods for detecting anti-P. silenus antibodies using the hypodermin C (HyC) purified from Hypoderma spp. Larvae collected in cattle (local isolate, Microbiology Laboratory, PMAS-Arid Agriculture University, Rawalpindi), the crude antigen from the first instar stage of P. silenus, and a commercial Bovine Hypodermosis Antibody ELISA kit (IDEXX Laboratory), for accurately estimating the seroprevalence of goat warble fly infestation (GWFI) in the Pothwar plateau, Punjab, Pakistan. The ELISA with the crude antigen of P. silenus proved very sensitive and specific, 91% and 93%, respectively. The optical density exhibited a monthly variation, and the antibody titer began increasing from June, continually increased from July to December, and gradually decreased thereafter until March. The study confirmed the endemic status of GWFI in the Pothwar region and identified that ELISA based on the crude antigen of P. silenus was a more sensitive and specific immunodiagnostic method for determining seroprevalence, and could be employed for initiating nationwide eradication campaigns.

Species diversity and daily infestation patterns of Haematophagus flies in cattle farms at Tanah Bumbu District, South Kalimantan Province, Indonesia

Abstract. Hairani B, Hadi UK, Supriyono. 2023. Species diversity and daily infestation patterns of Haematophagus flies in cattle farms at Tanah Bumbu District, South Kalimantan Province, Indonesia. Biodiversitas 24: 2995-3003. Blood-sucking flies act as livestock pests and vectors of zoonotic diseases. This study aims to know the species diversity of blood-sucking flies, relative abundance, frequency, and dominance of species and their correlation to weather parameters on beef cattle farms with three different ecosystems in the Tanah Bumbu District, South Kalimantan, Indonesia. The research was conducted from August to October 2022 on 6 beef cattle farms in Tanah Bumbu District with different types of ecosystems, namely forest, non-forest, and coastal areas. The flies was collected by using sweep nets, NZI traps. and Vavoua traps. Blood meal activity was measured by counting flies infestation on the cow's body. The results showed that there were 11 species of blood-sucking flies, i.e., Stomoxys calcitrans Linnaeus 1758, S. sitiens Rondani 1873, S. indicus Picard 1908, S. bengalensis Picard 1908, Haematobia exigua Meijere 1903, Therioplectes sp., Chrysops fixissimus Walker 1856, Tabanus optatus Walker 1856, T. striatus Fabricius 1787, T. rubidus Wiedemann 1821, and Hippobosca sp. The S. calcitrans population appears to be dominat in each type of ecosystem. The peak of blood-sucking fly infestations on the body of beef cattle in each ecosystem occurred at 10AM-2PM. In addition, the environmental temperature and humidity were significantly correlated to fluctuations in blood-sucking fly infestations in each ecosystem, and the light intensity was significantly correlated to the population of H. exigua in coastal ecosystems, while the wind velocity was not significantly correlated to all species in all ecosystems.

Avermectin Trunk Injections: A Promising Approach for Managing the Walnut Husk Fly (Rhagoletis completa)

This study examined the larvicidal effect of trunk-injected abamectin and emamectin benzoate against the walnut husk fly (Rhagoletis completa Cresson, 1929). Walnut trees in two locations in two years were injected with the pesticides at different concentrations. For the toxicokinetic studies, the active ingredient content was measured in the leaves, flowers, husks, and kernels, using a UHPLC-MS/MS analytical method. The walnut husk fly infestation rates were between 3 and 70% and 10 and 34% for abamectin and emamectin benzoate, respectively, and were much lower compared to those measured for the control. The active ingredient content in the walnut husk showed a positive correlation with the larvicidal effect. The injections had a measurable but unsatisfactory insecticidal effect in the second year, when the economic threshold was exceeded. Trace amounts of the active ingredients were detected in the flowers. The residue analysis showed a declining concentration trend in the leaves over time. The largest quantities were detected in the leaves (≤439 ng/g of abamectin; ≤19,079 ng/g of emamectin benzoate), with concentrations in the husks of orders of magnitude lower (≤5.86 ng/g; ≤50.19 ng/g). The measurements showed no active ingredient residue above the MRLs in either fresh or dried kernels. The results indicate that trunk injections of abamectin, as well as trunk injections of emamectin benzoate, have the potential to suppress walnut husk fly populations.

Modulation of enzymes and metabolites in response to shoot fly infestation in resistant and susceptible sorghum genotypes

Modulation of enzymes and metabolites in response to shoot fly infestation in resistant and susceptible sorghum genotypes

Novel insecticides for the management of shoot fly, Atherigona approximata Malloch (Diptera: Muscidae): an emerging insect pest of wheat in India

Shoot flies (Atherigona spp.) are the members of muscidae family which have got economic importance as pest of several crops of Gramineae family mainly cereals and millets. One of the most effective management strategies for controlling shoot fly is the use of novel insecticides either as seed dressers, soil applicators or as foliar treatment. Under the field condition, seed treatment with thiamethoxam 30 FS @ 5 ml/kg seed followed by a spray of cypermethrin 10 EC @ 0.5 ml/l has recorded least shoot fly oviposition (0.84 and 0.94 eggs/plant), dead heart (8.90% and 9.96%), more per cent productive tillers (79.68% and 79.50%), grain yield (32.22 and 31.27 q/ha) and BC ratio (2.05 and 1.99) as compared to the rest of the combinations during the investigation in rabi, 2019–20 and 2020–21, respectively. Under the changing climate where, the minor insect pests attaining major pest status, the present investigation would help the policy makers to reduce the losses caused by shoot fly infestation significantly by using an effective above-mentioned chemical treatment combination that can be integrated in future IPM modules.

Study of Uzi Fly, <i>Exorista bombycis</i> (Louis) Infestation during Rearing of Mulberry Silkworm in Different Seasons in Karnataka

Present investigation was carried out during summer and rainy seasons under laboratory conditions at the Department of Sericulture, Chintamani UAS (B) during 2012-13. Rearing of bivoltine silkworm hybrid CSR2 X CSR4 in different seasons reveals that rainy season open rearing is found to be susceptible for Uzi infestation as compared to summer season under protected and open rearing. Uzi fly incidence on top position tray was observed significantly maximum in rainy season open rearing as compared to summer season open batch and least observed in summer season protected rearing. Longevity of the uzi fly is reported to be negatively correlated with weather parameters such as temperature; higher the temperature lower the adult longevity. Experimental observation revealed that rearing of silkworm in summer with all the precautionary measures under protection is suitable for more yield of cocoon with least uzi fly infestation in Karnataka.

Yield protection afforded by imidacloprid during Hessian fly infestation in six genotypes

AbstractThe Hessian fly (Mayetiola destructor Say) is a gall midge that infests and feeds upon wheat (Triticum aestivum L.). Recently, a new form of tolerance (QHft.nc‐7D) was identified in the breeding line LA03136E71 (PI 700336). Partial resistance allows immature Hessian fly to thrive in small numbers and does not function like antibiosis. Little is known about the potential yield drag of using partial resistance. In this study, we evaluated six genotypes: one containing QHft.nc‐7D (LA03136E71), one containing H13, and four potentially susceptible genotypes. All genotypes were evaluated with two different seed treatment regiments of imidacloprid: no treatment and a two times rate of imidacloprid. All tested genotypes were planted in six‐to‐eight replications of a full factorial design in four environments. Subsamples of yield trial plots were taken to measure percent infested tillers and a number of larvae/pupae per tiller. Plots were harvested and grain yield was recorded. There was a significant (p[>F] < 0.05) reduction of percent infested tillers and a number of larvae/pupae per tiller related to the imidacloprid treatment. Imidacloprid treatment significantly (p[>T] < 0.05) reduced the number of larvae/pupae per tiller for LA03136E71. There was no significant (p[>T] > 0.05) grain yield increase associated with treatment for LA03136E71. This indicates that a two times application of imidacloprid on LA03136E71 (QHft.nc‐7D) did not improve yield yet reduced infestation. Therefore, QHft.nc‐7D, while allowing Hessian fly to thrive on the plant, does not significantly compromise yield.

Quality parameters of olive oils at different ripening periods as affected by olive fruit fly infestation and olive anthracnose

Olive pests and diseases influence olive oil quality. Ayvalik olive cultivar is important between local cultivars grown in Turkey. This study aimed to monitor the effects of olive pests and diseases (olive fruit fly attack and olive anthracnose) on Ayvalik olive oil quality parameters such as free fatty acids (FFA), peroxide value (PV), specific extinction coefficients (K232, K270, and ΔK). Besides, Ayvalik olive fruits were collected at six harvest times, and the level of ripening with olive pests was also evaluated. Results showed that the FFA level influenced negatively by olive pests, mainly olive anthracnose. At the end of harvesting, FFA of oils from damaged olive anthracnose reached up to 5.42 (% oleic acid). Except for the first harvest period, the other quality parameters remained between limit values, and slight differences were observed between healthy and damaged olives. At the first harvest period, PV and K232 (7.02 mEq O2/kg, 2.22) of olive oil from fly-infected olive had higher values than the other samples. The stage of ripening, healthy, and damaged olives affected slightly certain fatty acids of the oils. Total phenolics, o-diphenol, and α-tocopherol content of oils from healthy fruits had higher values than oils from damaged olives. Besides, the antioxidant activity of oils obtained from healthy olives showed higher values compared to the oils from infected olive fruits.

Combining Ability of Quantitative Traits in Snake Gourd (Trichosanthes Cucumerina Var. Anguina)

The present study was carried out on snake gourd having seven diverse genotypes (TC 01, TC 05, TC 24, TC 33, TC 02, TC 46 and TC 53) used as parental lines and their 21 crosses generated from 7 × 7 half-diallel fashion at Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU) during March to June 2019 following RCBD with three replications. The aim of the study was to determine general combining ability (GCA) and specific combining ability (SCA) for fruit yield and its related traits including fruit quality traits. General prediction ratio (GPR) of these 14 traits was greater than 0.5 (50%), indicating predominance of additive gene effects over non-additive gene effects. The estimates of GCA for 19 quantitative traits revealed that the genotypes P2 and P6 were good general combiners for promoting earliness as well as most other important characters viz., number of fruits/ plant, individual fruit weight and fruit yield/ plant/ hectare; P2 and P6 were also good for fruit length and fruit diameter, respectively whereas, P4 was good for main vine length and number of nodes on main vine while, P3 was superior for long fruit and 100-seed weight whereas, P5 was good for number of seeds/ fruit and P1 good for less fruit fly infestation including individual fruit weight and fruit length. The most promising specific combiners for fruit yield, quality and yield components were from the 13 crosses viz., P1 × P2, P1 × P3, P1 × P4, P1 × P7, P2 × P3, P2 × P5, P2 × P6, P2 × P7, P3 × P7, P4 × P5, P4 × P6, P4 × P7 and P5 × P7. Out of 13 crosses only two crosses namely, P1 × P2 and P2 × P6 had both the good general combiner parents (high × high). These two crosses were therefore, amenable for improvement of the respective traits through pedigree selection. Remaining 11 crosses displaying high SCA effects for different traits were observed to be derived from parents having various types of GCA effects (high × medium, high × low, medium × low and low × low). The results of 13 crosses therefore, indicate the operation of additive × additive, additive × dominant and/ or dominant × dominant gene interactions for the genetic control of expression of the relative traits.
 Bangladesh J. Agril. Res. 46(4): 491-510, December 2021

Review Article Olive Fruit Fly Bacterocera Oleae Infestation of Olives: Effect on Quality and Detection in Olive Oil

Bacterocera oleae ‎ is the most common olive fruit pest in Jordan. The high incidence of olive fruit infestation with fruit fly in its stages of larvae and pupa is a common problem in olive oil production. Although not detected by simple means, it is believed to impart a “Grubby” taste that is detected only by experts and results in lowering the value of the oil from infested fruits. The effect of damage caused by B. oleae ‎ depends on the degree of infestation which is manifested in the presence of exit holes (EH) produced by the full-grown larvae which destroy the fruit skin and expose it to oxygen and other destructive factors like fungi. This results in the acceleration of hydrolytic and oxidative types of rancidity which can be estimated by measuring oil acidity (FFA) and peroxide value (PV). This review covers the literature related to the effect of olive fruit fly infestation on the quality of olive fruits and oil and the methods used in its control and detection.

Eco-friendly Management of Fruit Fly (Bactrocera cucurbitae) Infesting Bitter Gourd

Aims: This study aimed to evaluate some Bio insecticide and management against fruit fly in bitter gourd.
 Study Design: The experiment was laid out at a randomized complete block design with three replications.
 Place and Duration of Study: Experimental farm of Sher-e-Bangla Agricultural University, Bangladesh during the period from February,2022 to july,2022.
 Methodology: The experiment consisted of seven treatments viz. T1(Lycomax 2g/lit of water+ Cutrac+ Yellow Sticky trap+ Sanitation), T2(Lycomax 2g/lit of water+ Ceranock+ Yellow Sticky trap+ Cultural control), T3 (Biomax M 1.2 EC+ Cuelure+ Yellow Sticky trap), T4 (Lycomax 2g/ lit of water+ Yellow Sticky trap), T5 (Biomax M 1.2 EC + Ceronock+ Cutrac), T6 Sanitation+ Cultural control+ Cuelure), T7 (Untreated Control) were used at 7 days interval.
 Results: The degree of the fruit fly (Bactrocera cucurbitae) infestation at various phases of bitter gourd ripening was investigated in the field and in the lab, as well as the effectiveness of some bio-pesticides and other control methods used in combination. Among all treatments the highest number of fruit fly was captured in Lycomax 2g/lit of water+ Ceranock+ Yellow Sticky trap+ Cultural control treated plot.Healthy fruit per plant (9.50 fruit/plot) also found from T2 treated plot. whereas the maximum amount of infested fruit number (12.21 fruit/plot), number of punctures per fruit (6.74 puncture/fruit) and infested fruit weight (77.13gm) was found from the control plot. The highest percentage reduction of puncture number over control resulted in treatment T2 treated plot which was 92.58% which is near to treatment T4 (85.16%) and also highest amount of healthy fruit weight (232.75 gm) came from T2. In terms of maximum yield (2.54 kg/ plot) gained from Lycomax 2g/lit of water+ Ceranock+ Yellow Sticky trap+ Cultural control treated plot (T2). From the study it was found that all the treatments except control (T7) work effectively against fruit fly infestation.
 Conclusion: It is concluded that T2 treatment (Lycomax 2g/lit of water+ Ceranock+ Yellow Sticky trap+ Cultural control) was the best one among the all trerments.

In vitro efficacy of essential oils against Haematobia irritans

The horn fly (Haematobia irritans) infestation in the cattle in Brazil leads to significant economic damage for livestock. The efficacy of many essential oils has been demonstrated in the control of veterinary ectoparasites. This study aimed to evaluate the in vitro efficacy of four essential oils to adult horn fly control. The essential oil from Mesosphaerum suaveolens (L.) Kuntze (Lamiaceae) was extracted by hydro-distillation, while that the water steam distillation method was used to extract the essential oils from Varronia curassavica (Jacq.) Roem. & Schult. (Boraginaceae), Alpinia zerumbet (Pers.) B.L. Burtt & R.M. Sm. (Zingiberaceae) and Psidium guajava L. (Myrtaceae). Afterwards, all the essential oils were analyzed by Gas Chromatography Mass Spectrometry (GC?MS) and Flame Ionization Detector (GC-FID) for determination of their chemical composition. The bioassays in vitro were performed according to the impregnated filter paper methodology. All the essential oils evaluated in this study exhibited efficacy in vitro against H. irritans. The highest mortality of H. irritans was determined by essential oils from A. zerumbet (100%) and M. suaveolens (96.2%) at 50 mg mL-1. In concentration of 100 mg mL-1 V. curassavica and P. guajava essential oils caused the mortality of 99.2% and 82.8%, respectively. The A. zerumbet, M. suaveolens, V. curassavica and P. guajava essential oils showed in vitro efficacy against H. irritans. Further studies with associations and nanoemultions are necessary to increase the efficacy and stability of these essential oils on field conditions.

Pathology and pathogenesis of cutaneous lesions in beef cattle associated with buffalo fly infestation.

Haematobia irritans exigua, commonly known as buffalo fly, is the major hematophagous ectoparasite of north Australian cattle herds. Lesions associated with buffalo fly infestation are generally alopecic, hyperkeratotic, or scab encrusted wounds with variable hemorrhagic ulceration. Buffalo flies can transmit a filarial nematode, Stephanofilaria sp., which has been implicated in the pathogenesis of buffalo fly lesions, but Stephanofilaria infection has not been detected in all lesions suggesting that other causal factors may be involved. This study characterized the pathology of buffalo fly lesions to identify the role of Stephanofilaria in lesion development, as well as to identify other potential agents. Lesion biopsies were collected from north and south Queensland and tested for the presence of Stephanofilaria by qPCR. Each lesion was scored grossly (0-4) for hemorrhage, ulceration, exudation, and alopecia. Lesions were also scored microscopically (0-4) for epidermal and dermal damage and inflammatory characters. Stephanofilaria infection was detected in 31% of lesion biopsies. Grossly, Stephanofilaria-infected lesions had significantly larger lesion area and higher scores for alopecia and hyperkeratosis than lesions where no nematodes were found (P < 0.05). Histologically, epidermal, dermal, and adnexal damage was significantly higher in Stephanofilaria infected lesions than lesions without nematodes. Eosinophils, macrophages, and lymphocytes were significantly more abundant in Stephanofilaria positive lesions as compared to negative lesions. This study also noted bacterial infection with colonies of coccoid bacteria, observed in skin sections from 19 lesions. Grossly, lesions with bacterial infection had significantly higher ulceration scores compared to Stephanofilaria positive lesions, and histologically epidermal disruption was significantly greater in bacteria-infected lesions. We found no evidence of bacteria or Stephanofilaria infection in 49% of the lesions assessed and tissue damage patterns and eosinophilic inflammation suggested hypersensitivity to buffalo fly feeding as a possible cause of these lesions. These findings suggest that although the presence of Stephanofilaria infection may increase the severity of lesion pathology, it is not essential for lesion development. These outcomes also suggest a potential role of bacteria and hypersensitivity in pathogenesis of some lesion. A better understanding of buffalo fly lesion etiology will contribute to the optimal treatment and control programmes.