Insecticidal, Repellent and Antifeedant Activity of Essential Oils from Blepharocalyx cruckshanksii (Hook. & Arn.) Nied. Leaves and Pilgerodendron uviferum (D. Don) Florin Heartwood against Horn Flies, Haematobia irritans (Diptera: Muscidae)

Haematobia irritans is a cosmopolitan obligate blood-feeding ectoparasite of cattle and is the major global pest of livestock production. Currently, H. irritans management is largely dependent on broad-spectrum pesticides, which has led to the development of insecticide resistance. Thus, alternative control methods are needed. Essential oils have been studied as an alternative due to their wide spectrum of biological activities against insects. Thus, the main aim of this study was to evaluate the insecticidal, repellent and antifeedant activity of the essential oils from Blepharocalyx cruckshanksii leaves and Pilgerodendron uviferum heartwood against horn flies in laboratory conditions. The composition of the essential oils was analyzed using gas chromatography coupled to mass spectrometry. Accordingly, α-pinene (36.50%) and limonene (20.50%) were the principal components of the B. cruckchanksii essential oil, and δ-cadinol (24.16%), cubenol (22.64%), 15-copaenol (15.46%) and δ-cadinene (10.81%) were the most abundant compounds in the P. uviferum essential oil. Mortality of flies and feeding behavior were evaluated by non-choice tests, and olfactory response was evaluated using a Y-tube olfactometer. Both essential oils were toxic to horn flies, with LC50 values for B. cruckchanksii essential oil of 3.58 µL L−1 air at 4 h, and for P. uviferum essential oil of 9.41 µL L−1 air and 1.02 µL L−1 air at 1 and 4 h, respectively. Moreover, the essential oils exhibited spatial repellency in the olfactometer using only 10 µg of each oil, and these significantly reduced the horn fly feeding at all doses evaluated. Although further laboratory and field studies related to the insectistatic and insecticide properties of these essential oils against H. irritans are necessary, B. cruckshanksii leaves and P. uviferum heartwood essential oils are promising candidates for horn fly management.

Ectoparasite Infestation on Beef Cattle (Bos Indicus) in Kendit Sub-District, Situbondo District

The purpose of this study was to determine the type and percentage of ectoparasites attacking the cattle cow in the Kendit Sub-District, Situbondo District. The research was conducted from July to September 2020 with 100 samples of cow taken. The identification of ectoparasites was carried out at The Laboratory of the Animal Health Center of Situbondo Regency. This study was survey with a cross-sectional design. This study found several ectoparasites of the type of flies that infested the cattle cow: Musca domestica 29.20%, Haematobia irritans 58.96%, Stomoxys calcitrans 2.82%, Tabanus rubidus 0.42%, Tabanus megalops 0.56%, Hippobosca maculata 0.14%. In addition, this study also found ectoparasites of fleas that attacked the cattle cow, among others Bovicola bovis 2.12%, and Haematopinus eurysternus 5.78%. In this study, the dominant type of fly ectoparasite was Haematobia irritans 58.96% and the dominant ectoparasite from flea was Haematopinus eurysternus 5.78%. The suggestions for this research were this research should be continued with a longer time, the fishing method must be more varied because the more fishing methods used, the higher diversity results and it is advisable to maintain cage sanitation, improve maintenance management, and the cleanliness of cattle sheds surroundings to maintain cattle condition.

Evaluación de la eficacia de productos mosquicidas para el control de la mosca del cuerno (Haematobia irritans) en condiciones de infestación natural en dos regiones de México / Evaluation of fly control efficacy of new drug prototypes for the control of horn- fly (Haematobia irritans) under natural infestation conditions in two regions of Mexico

Las parasitosis por la moscas de los cuernos (Haematobia irritans) en el trópico de México generan importantes pérdidas económicas. El objetivo de esta investigación fue evaluar bajo condiciones de infestación natural, la eficacia de tres prototipos farmacéuticos indicados para el control de la mosca de los cuernos. Se utilizaron 80 vacas asignadas aleatoriamente a cuatro grupos de 20 animales en dos regiones México. Grupo 1: 593.10, Grupo 2: 593.11, Grupo 3: 593.12 y Grupo 4: control-sin tratamiento. El tratamiento fue por derrame dorsal a una dosis de 1 mL/10 kg de peso vivo. Se determinó la eficacia contando el número moscas en los días 1, 3, 7, 14, 21 y 28 post-tratamiento, las moscas fueron contadas in situ y comparado mediante fotografías de alta resolución que fueron tomadas sobre condiciones normales de pastoreo. El porcentaje de eficacia de los prototipos de prueba fue de aproximadamente 70-80 % al día 21 y ≥ 50 % entre los días 25 y 28 post-tratamiento. Los prototipos de prueba (mezcla de activos) resultaron altamente eficaces contra la mosca de los cuernos y podrían ser una alternativa para el control del parasito, contemplando las condiciones ambientales de las diferentes zonas geográficas donde son evaluados, la época de mayor incidencia de la mosca y estableciendo el umbral de carga parasitaria que provoca estrés en los bovinos. No se registró diferencia estadística significativa en eficacia entre los tres ectoparasiticidas, el uso de fármacos alternativos podrían ser una estrategia en la rotación de productos que disminuya la resistencia a las diferentes moléculas que contienen los productos comerciales.

Antifeedant Effects and Repellent Activity of Loline Alkaloids from Endophyte-Infected Tall Fescue against Horn Flies, Haematobia irritans (Diptera: Muscidae)

Haematobia irritans is an obligate bloodsucking ectoparasite of cattle and is the global major pest of livestock production. Currently, H. irritans management is largely dependent upon broad-spectrum pesticides, which lately has led to the development of insecticide resistance. Thus, alternative control methods are necessary. Endophyte-infected grasses have been studied as an alternative due to their capability to biosynthesize alkaloids associated with anti-insect activities. Thus, the main aim of this study was to evaluate the antifeedant and repellent activity of lolines obtained from endophyte-infected tall fescue against H. irritans adults in laboratory conditions. The alkaloid extract (ALKE) was obtained by acid–base extraction. N-formyl loline (NFL) and N-acetyl loline (NAL) were isolated by preparative thin layer chromatography (pTLC) and column chromatography (CC), and the loline was prepared by acid hydrolysis of a NFL/NAL mixture. Loline identification was performed by gas chromatography coupled to mass spectrometry (GC/MS). Feeding behavior was evaluated by a non-choice test, and olfactory response was evaluated using a Y-tube olfactometer. Accordingly, all samples showed antifeedant activities. NFL was the most antifeedant compound at 0.5 µg/µL and 1.0 µg/µL, and it was statistically equal to NAL but different to loline; however, NAL was not statistically different to loline. NFL and NAL at 0.25 µg/µL were more active than loline. All samples except loline exhibited spatial repellency in the olfactometer. Thus, the little or non-adverse effects for cattle and beneficial activities of those lolines make them suitable candidates for horn fly management.

Tristeza parasitária bovina: Revisão

A Tristeza Parasitária Bovina (TPB) é um complexo de doenças causadas por infecções parasitárias não contagiosas, sendo no Brasil, os principais agentes etiológicos dessa enfermidade Anaplasma marginale, a Babesia bovis e B. bigemia, comum em regiões tropicais e subtropicais, gerando perdas econômicas no desenvolvimento da pecuária no país, no Brasil ocorre em caráter endêmico. A transmissão biologicamente é realizada pelo carrapato Rhipicephalus (Boophilus) microplus e mecanicamente, na anaplasmose, por insetos hematófagos (Stomoxys calcitrans, tabanídeos e Haematobia irritans), fômites contaminados e de forma transplacentária. As perdas econômicas se relacionam à redução na produção, seja de leite ou carne, infertilidade temporária de machos e fêmeas, custo de tratamento, gastos com medidas preventivas, cuidados na introdução de animais de áreas livres em áreas endêmicas, qualidade do couro e principalmente, devido a morbidade e mortalidade. Os agentes de ambas as doenças são parasitas intra-eritrocitário obrigatórios, apresentando sinais clínicos semelhantes, sendo possível mais de um agente acometer o mesmo animal simultaneamente, tornando difícil o diagnóstico de diferenciação em campo. A prevenção é necessária, deste modo o fortalecimento do sistema imunológico pelas inoculações dos agentes infecciosos promove uma defesa natural à doença. A morbidade e mortalidade pela TPB em países de clima tropical e subtropical é alta, por isso o interesse em estudá-la.

Susceptibility of field populations of Haematobia irritans to fipronil in Uruguay

ABSTRACT: Fipronil was registered in Uruguay in 1997, and, since then, it has been used for the control of Haematobia irritans irritans and Rhipicephalus microplus. The susceptibility of H. irritants to this drug has not been evaluated. Therefore, the goal of the present study was to evaluate the resistance of H. irritans to fipronil. Additionally, a survey was carried out with the farmers to evaluate the use of fipronil for H. irritans control in the ranches where the flies came from. For the bioassays, 31 field populations of H. irritans were exposed to 10 concentrations of fipronil (3.2-16.0μg.cm2), and their LC50 values were calculated using probit analysis. A bioassay was performed with horn flies from the susceptible colony maintained at the USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory for comparison and calculation of resistance ratios (RRs). All 31 field populations surveyed in the study were susceptible to fipronil, with resistance ratios ranging from <0.5 to 2.2. Four populations with RRs >1 did not differ significantly from the susceptible strain. A single population showed an RR >2.2. Overall, the survey shows that fipronil was mostly used for R. microplus control, and in only three ranches, which were free of R. microplus, was fipronil used for horn fly control. Seventeen farmers did not use fipronil at all in the last three years. It is concluded that, in Uruguay, field populations of horn flies remain susceptible to fipronil.

EFICÁCIA MOSQUICIDA DE UMA ASSOCIAÇÃO “POUR-ON” CONTENDO CLORPIRIFÓS 50% e CIPERMETRINA 20%, NO CONTROLE DA MOSCA DOS CHIFRES (Haematobia irritans) EM BOVINOS NATURALMENTE INFESTADOS

A mosca-dos-chifres (Haematobia irritans) é um pequeno ectoparasita díptero hematófago que parasita o bovino, causando prejuízos econômicos estimados em 3,24 bilhões de dólares, determinados principalmente pela espoliação e o incomodo ao animal que acarretam perda de peso e diminuição da produção leiteira dentre outros aspectos da produção. O estudo, aprovado pela Comissão de Ética no uso de Animais do Instituto de Veterinária da UFRRJ (CEUA Nº 4515061217), objetivou avaliar a eficácia da associação a base de clorpirifós e cipermetrina, contra H. irritans em bovinos naturalmente infestados. Foram utilizados 30 bovinos mestiços e o ranqueamento foi feito com base nas médias das contagens do número total de moscas, em ambos os lados do animal, realizadas nos dias D-3 e D-1. Os animais selecionados foram divididos em dois grupos, Grupo Controle (GC) e Grupo Tratado (GT), contendo em cada um, 15 animais. No dia D0, a associação do medicamento foi administrada por via tópica nos animais do GT em dose única de 5 litros por pulverização com auxílio de uma bomba costal. Os animais foram contidos em brete e tratados individualmente. O efeito contra H. irritans foi avaliado por meio de contagens do número de moscas vivas contidos em ambos os lados dos animais nos dias experimentais D+1, D+3, D+7, D+14, D+21, D+28, D+35 e D+42. Diferenças estatísticas significativas (p≤0,05) foram verificadas nas médias das contagens de moscas em todos os dias após tratamento dos animais. Os resultados das médias aritméticas de contagens de moscas foram os seguintes para o grupo controle (GC): 95,20 (D+1), 74,07 (D+3), 100,80 (D+7), 79,07 (D+14), 65,53 (D+21), 75,47 (D+28), 92,87 (D+35), 76,93 (D+42); e para o grupo tratado (GT): 0,53 (D+1), 0,40 (D+3), 1,27 (D+7), 4,27 (D+14), 11,80 (D+21), 16,67 (D+28), 29,47 (D+35), 40,07 (D+42). A eficácia observada por dia experimental foi de: 99,4% (D+1), 99,46% (D+3), 98,74% (D+7), 94,60% (D+14), 81,99% (D+21), 77,92% (D+28), 68,27% (D+35) e 47,92% (D+42). Através dos resultados da contagem de H. irritans pôde-se observar antes do tratamento variações de 34 a 114 moscas nos animais. Os resultados demostraram que a associação à base de clorpirifós 50% e cipermetrina 20%, empregada por pulverização, foi efetiva para o tratamento de bovinos naturalmente infestados por H. irritans, apresentando níveis de eficácia acima de 80% por até 21 dias após tratamento.

Indicadores de bienestar animal en vacas lecheras en un sistema silvopastoril del trópico alto colombiano

En el municipio de Saboyá, Boyacá, Colombia, se evaluó el número de moscas Haematobia irritans, temperatura de capa, frecuencia respiratoria, actividad motora, distancia de fuga, suciedad y presencia de mastitis subclínica, como indicadores de bienestar animal en vacas Holstein presentes en un sistema silvopastoril (asociación de Cenchrus clandestinus y Alnus acuminata) y en un sistema tradicional basado en el pastoreo de C. clandestinus en monocultivo. Se realizaron 10 muestreos mensuales entre agosto de 2015 y mayo de 2016 en 20-30 vacas en lactancia, seleccionadas al azar, por finca. Los datos se analizaron usando modelos de regresión lineal generalizado. El número de moscas por animal fue mayor (p<0.05) en el sistema tradicional en comparación con el sistema silvopastoril (56 ± 47.5 y 44 ± 40.0 moscas/animal, respectivamente); la temperatura promedio de capa en los animales del sistema tradicional fue de 37.4 ºC, mientras que en el sistema silvopastoril fue de 33.8 ºC (p<0.05). No hubo diferencias en la frecuencia respiratoria. Las vacas tuvieron mayor consumo de alimento durante las primeras horas del día en ambos sistemas. La distancia de fuga y nivel de suciedad fueron menores en el sistema silvopastoril (p<0.05), mientras que los porcentajes de mastitis subclínica fueron similares entre los dos sistemas. Los sistemas silvopastoriles favorecen la expresión de los indicadores de bienestar animal debido a la presencia de árboles en los potreros, los cuales ofrecen la diversificación del ecosistema y generan mejores condiciones para la permanencia de las vacas en pastoreo.