clove and Tick-Infestations

The present study aimed to evaluate the acaricidal action of the chemically modified essential oil of Cymbopogon spp. and Corymbia citriodora on Rhipicephalus (Boophilus) microplus. Citronellal was converted into N-butylcitronellylamine and in N-prop-2-inylcitronellylamine, analogs of juvenoids, by reductive amination using butylamine (N1 to N3) and propargylamine (N4 to N7). In vitro assays included the adult immersion, and larval packet tests. Engorged females were weighed in groups of 10 and tested in three replicates for six concentrations. They were immersed in the modified oils or control solution and incubated. In the larval packet test, the same substances and concentrations were evaluated in three replicates. In the in vivo test, six pastured heifers naturally infested with R. (B.) microplus were used per treatment: negative control, positive control (amitraz, Triatox(®)), original oil of C. citriodora at 1.5%, and modified oil containing 0.9% N-prop-2-inylcitronellylamine (N7). Ticks were counted in the right side of the body in 24 animals from day D-3 to D21. LC50 and LC90 were obtained by Probit analysis, while the in vivo results were log transformed and compared using the Tukey test. Among the nitrocellylamines tested in vitro, N6 was most effective on the engorged females (100% efficacy at 50mg/mL) and N7 on the larvae (100% efficacy at 6.25mg/mL). In the test with larvae, the original oil of C. citriodora was less effective than the counterpart modified oil (N7), proving that the chemical modification optimized its effect. In the in vivo test, no significant difference was observed between N7 and the negative control. The average numbers of ticks on the animals' right side were 32.8, 8.1, 37.9 and 35.4 for the negative control, positive control, original oil and N7, respectively. The chemical modification improved the efficacy in vitro, but it was not observed in vivo, perhaps due to the low stability of the amines under field conditions. The evaluation carried out here has not been previously studied, so this concept expands the horizon for research into chemically modified substances for parasite control and shed light on the challenges to find effective formulations and application methods.

Topics: Acaricides; Animals; Cattle; Cattle Diseases; Cymbopogon; Female; Larva; Myrtaceae; Oils, Volatile; Plant Oils; Rhipicephalus; Tick Infestations

Rhipicephalus microplus is the main ectoparasite of cattle and its parasitism can reduce weight gain of hosts, in addition to causing anemia, increasing the risk of myiasis, and resulting in the transmission of Babesia bovis and Anaplasma marginale, among other pathogens. The use of synthetic chemicals plays an important role in controlling these ticks. However, its frequent and indiscriminate use has contributed to the selection of resistant strains, resulting in greater interest in the search for natural-origin products. The shrub Callistemon viminalis (Myrtaceae), also known as weeping bottlebrush, is known for its antibacterial, acaricidal, repellent, and antifungal activities, but there are no reports in the literature about its effects on the internal morphology of ticks. This study aimed to extract and characterize the essential oil obtained from the leaves of C. viminalis. Additionally, its effects on the ovary morphology of engorged R. microplus were assessed through histological, histochemical, and morphometric techniques. Exposure to C. viminalis caused dose-dependent morphological changes, such as cellular alterations in the epithelial layer lining the ovary lumen and the pedicel, irregularity of the chorion and oocyte shape, changes in protein and carbohydrate content, decrease in oocyte size, reduction in the size of the nucleus as well as cytoplasmic and nucleolar vacuolation. Thus, C. viminalis essential oil exhibited a toxic effect on the reproductive system of R. microplus, which may result in the reproductive impairment of this tick species.

Topics: Acaricides; Animals; Cattle; Cattle Diseases; Female; Ixodidae; Myrtaceae; Oils, Volatile; Ovary; Rhipicephalus; Tick Infestations

The ticks Rhipicephalus microplus and Rhipicephalus sanguineus sensu lato (s.l) are of great importance to agriculture, veterinary medicine and public health. Due to a number of problems related to the use of synthetic acaricides, natural products emerge as promising substances for alternative tick control. In the present study, essential oils of Backhousia citriodora, Callistemon viminalis and Cinnamodendron dinisii were extracted by hydrodistillation, characterized by GC-MS and GC-FID and biologically evaluated for acaricidal activity against R. microplus and repellent activity against R. sanguineus s.l. Inhibition of acetylcholinesterase (AChe) by the essential oils was also evaluated. The major constituent of B. citriodora is citral (98.9 %), whereas the essential oil from C. viminalis is rich in 1.8-cineole (78.1 %), α-pinene (12.5 %) and limonene (3.36 %), and that from C. dinisii contains α-pinene (30.8 %), β-pinene (12.5 %) and sabinene (11.3 %) as the principal constituents. The median lethal concentrations (LC 50) estimated for the essential oils on engorged R. microplus females were 3.276 μL.mL

Topics: Acaricides; Acetylcholinesterase; Animals; Female; Larva; Magnoliopsida; Myrtaceae; Oils, Volatile; Plant Oils; Rhipicephalus; Tick Infestations

Ectoparasitic infections are of particular interest for endangered wildlife, as ectoparasites are potential vectors for inter- and intraspecific pathogen transmission and may be indicators to assess the health status of endangered populations. Here, ectoparasite dynamics in sympatric populations of two Malagasy mouse lemur species, Microcebus murinus and M. ravelobensis, were investigated over an 11-month period. Furthermore, the animals' body mass was determined as an indicator of body condition, reflecting seasonal and environmental challenges. Living in sympatry, the two study species experience the same environmental conditions, but show distinct differences in socioecology: Microcebus murinus sleeps in tree holes, either solitarily (males) or sometimes in groups (females only), whereas M. ravelobensis sleeps in mixed-sex groups in more open vegetation.. Both mouse lemur species hosted ticks (Haemaphysalis sp.), lice (Lemurpediculus sp.) and mites (Trombiculidae gen. sp. and Laelaptidae gen. sp.). Host species, as well as temporal variations (month and year), were identified as the main factors influencing infestation. Tick infestation peaked in the late dry season and was significantly more often observed in M. murinus (P = 0.011), while lice infestation was more likely in M. ravelobensis (P < 0.001) and showed a continuous increase over the course of the dry season. Genetic analyses identified Lemurpediculus sp. infesting both mouse lemur species. Ticks morphologically conform to H. lemuris, but genetic analysis showed a clear differentiation of the specimens collected in this study, suggesting a potentially new tick species. Host body mass decreased from the early to the late dry season, indicating nutritional stress during this period, which may render individuals more susceptible to parasitic infections.. Seasonal differences and species-specific variations in sleeping site ecology in terms of sleeping site type and sociality were determined as key factors influencing ectoparasitism in M. murinus and M. ravelobensis. This needs to be taken into account when evaluating ectoparasite infestations at a given time point. The detection of the same parasite species on two closely related and sympatric host species furthermore indicates a potential pathway for disease transmission, not only within but also between lemur species.

Topics: Animal Distribution; Animals; Behavior, Animal; Cheirogaleidae; Female; Lice Infestations; Madagascar; Male; Mite Infestations; Seasons; Social Behavior; Species Specificity; Tick Infestations; Time Factors

Little is known about the role of endemic ticks as vectors for bacterial and protozoan pathogens for animals and humans in Madagascar and their interaction in anthropogenic habitats where humans, their livestock and native Malagasy species (vectors and hosts) come into more frequent contact than in natural forest ecosystems. The aims of the study were (1) to test whether habitat degradation is associated with increased infestation of tortoises by ticks and (2) to investigate whether ticks carried Babesia, Borrelia or Rickettsia species that might be pathogenic for humans and livestock. We studied hard ticks of two endemic Malagasy tortoises, Astrochelys radiata and Pyxis arachnoides in March and April 2013 in southwest Madagascar. Two tortoise habitats were compared, the National Park of Tsimanampetsotsa and the adjacent degraded pasture and agricultural land at the end of the wet season. Ticks were screened for protozoan and bacterial pathogens via PCR on DNA isolated from ticks using genus-specific primers. Only one out of 42 A. radiata collected from both habitats had ticks. The low prevalence did not allow further analyses of the effect of habitat degradation. Forty-two P. arachnoides were found in the anthropogenic habitat and 36 individuals in the national park. Tick infestation rates of P. arachnoides differed significantly between the two study sites. Tortoises inside the park had lower tick prevalence than outside (8 of 36 (22%) versus 32 of 42 individuals (76%)) and infected animals tended to have fewer ticks inside than outside the park. All ticks collected in both habitats were adults of the ixodid tick Amblyomma chabaudi, which is supposed to be a host-specific tick of P. arachnoides. Screening for Borrelia sp. and Babesia sp. was negative in all ticks. But all A. chabaudi ticks were infected with Rickettsia africae, known to cause spotted fever in humans. Thus, habitat degradation seems to be linked to higher infestation of tortoises with ticks with possible consequences for humans and their livestock.

Topics: Adult; Animals; Arachnid Vectors; Babesia; Borrelia; Ecosystem; Endemic Diseases; Female; Humans; Ixodidae; Livestock; Madagascar; Male; Rickettsia; Tick Infestations; Tick-Borne Diseases; Turtles

Although Amblyomma variegatum is now regularly recorded up to 1600 m in altitude in the Malagasy highlands, where it was previously reported not to persist without a constant supply of ticks introduced from lower infested regions, some parts of the highlands remain tick-free. Studies were carried out to verify whether the cold climate prevailing in these areas in June-September could prevent the survival and moulting of nymphs, the tick life stage present in the environment at this period. Cohorts of engorged A. variegatum nymphs were released from June to August in six different sites (three in 2010, altitudes 1200-1415 m; three in 2011, altitudes 1585-1960 m) which were reported to be either tick-infested (two in 2010, one in 2011) or tick-free. The ticks were placed in cages driven into the soil and open at the bottom so that they could hide in the soil or root network. Of the 1975 nymphs released in 2010 and the 1494 released in 2011, 86% and 85% were recovered, respectively. Twenty to 23% of the recovered ticks were dead, and some of them were obviously predated; predation also likely contributed to the disappearance of the non-recovered ticks. When the rainy season started in October, 59% of the newly moulted adults were still alive in the cages. The moulting period lasted up to 20 weeks, depending on the site and release period. As verified in 2011, unfed nymphs could also survive the cold season. Various A. variegatum life stages are thus able to survive the adverse cold and/or dry seasons: unfed nymphs, engorged nymphs in developmental diapause, moulted adults in behavioural diapause as observed previously. Strong variation in mortality and recovery rates was observed between cages, highlighting the importance of the micro-environment and micro-climate for tick survival. The minimum temperature recorded in the field sites varied from 1.1 °C to 6.8 °C, but the tick-free sites were not the coldest ones; they were, however, those for which the temperature remained below 10 °C for the longest time over the study period. Recovery and mortality rates in the tick-free sites were similar to those of the tick-infested sites: the temperatures recorded during the study periods did not prevent ticks from surviving and moulting although it did delay the metamorphosis. Low temperature alone can therefore not explain the persistence of tick-free areas in the highlands. To further monitor survival, cohorts of engorged nymphs were also maintained in an incubator

Topics: Adaptation, Biological; Animals; Cattle; Cold Temperature; Ixodidae; Madagascar; Molting; Nymph; Seasons; Tick Infestations

Abstract :  A new tick species belonging to the African subgenus Afrixodes Morel, 1966 of the genus Ixodes Latreille, 1795, namely, Ixodes (Afrixodes) microgalei n. sp., is described. Females of this species are most similar to those of Ixodes colasbelcouri Arthur, 1957 and Ixodes nesomys Uilenberg & Hoogstraal, 1969. The female of the new species can easily be differentiated from I. colasbelcouri by a short spur on coxae IV, and from I. nesomys by longer spurs on coxae I and large punctations on its scutum. Ixodes microgalei is known only from the eastern humid forest of Madagascar, specifically in the Province of Antananarivo, where its females have been collected from several species of shrew tenrecs (Afrosoricida, Tenrecidae), namely, Microgale dobsoni Thomas, Microgale parvula Grandidier, and Microgale soricoides Jenkins.

Topics: Animals; Eulipotyphla; Female; Ixodes; Madagascar; Tick Infestations

The ixodid ticks parasitizing small-bodied nocturnal mouse and dwarf lemurs (Primates, Cheirogaleidae) in Madagascar are poorly documented. At Tsinjoarivo, a high-altitude eastern rain forest, mouse and dwarf lemurs were parasitized by ixodid ticks. At Ranomafana, a montane southeastern rain forest, dwarf lemurs hosted a species of Ixodes, whereas mouse lemurs were parasitized by Haemaphysalis lemuris. Ixodes specimens represent all active stages, and females are morphologically consistent with previous descriptions of Ixodes lemuris females, the only described stage in the literature. Morphological comparisons and genetic analysis using fragments of COI gene confirm that all Ixodes ticks from Tsinjoarivo and Ranomafana forests belong to the same species, i.e., Ixodes lemuris. Thus, we are able to provide descriptions of the previously unknown larva, nymph, and male. Mouse lemurs at both locations were parasitized only by immature stages of I. lemuris (at Tsinjoarivo) or H. lemuris (at Ranomafana), whereas dwarf lemurs were parasitized by all stages of I. lemuris. We suggest that ecological and biogeographical conditions may affect the pattern of tick infestation at Tsinjoarivo and Ranomafana. Additional studies are necessary to understand the tick-host associations of small-bodied nocturnal lemurs.

Topics: Animals; Base Sequence; Cheirogaleidae; DNA; Female; Genetic Variation; Ixodes; Ixodidae; Larva; Madagascar; Male; Nymph; Polymerase Chain Reaction; Primate Diseases; Sequence Alignment; Tick Infestations

Sucking lice and ticks were collected from live-trapped eastern rufous mouse lemurs, Microcebus rufus Geoffroy, in and around the periphery of Ranomafana National Park, southeastern Madagascar, from 2007 to 2009. Samples of 53 sucking lice (Insecta: Phthiraptera: Anoplura) and 28 hard ticks (Acari: Ixodidae) were collected from 36 lemur captures representing 26 different host individuals. All of the lice were Lemurpediculus verruculosus (Ward) (6 males, 46 females, 1 third instar nymph). Only the holotype female was known previously for this louse and the host was stated to be a "mouse lemur." Therefore, we describe the male and third instar nymph of L. verruculosus and confirm M. rufus as a host (possibly the only host) of this louse. All of the ticks were nymphs and consisted of 16 Haemaphysalis lemuris Hoogstraal, 11 Haemaphysalis sp., and 1 Ixodes sp. The last 2 ticks listed did not morphologically match any of the Madagascar Haemaphysalis or Ixodes ticks for which nymphal stages have been described.

Topics: Animals; Anoplura; Cheirogaleidae; Ear Auricle; Female; Ixodidae; Lice Infestations; Madagascar; Male; Nymph; Primate Diseases; Tick Infestations

In 1999, we measured the body mass of 101 wild ring-tailed lemurs (Lemur catta) inhabiting the Berenty Reserve, Madagascar. In addition, we counted the number of ticks [Haemaphysalis (Rhipistoma) lemuris Hoogstraal, 1953] infesting their facial skin and external auditory meatuses. For both males and females, the body mass appeared to increase until the age of 3 years. With the apparent exception of infants, there were no sexual differences in body mass. Within a group, higher-ranked adult males tended to be heavier than lower-ranked males. In contrast, there was no consistent correlation between the body mass of females and their ranks. Among the study groups, there was a small difference in body mass and significant difference in the number of ticks infesting the facial skin and external auditory meatuses. In particular, lemurs of a group who inhabited an area of gallery forest in the study area exhibited the smallest values of body mass and were severely infested with ticks. Such group variations were not consistently correlated with the reproductive parameters of the study groups. In three groups moderately infested with ticks, ticks infested adult males and subadults more heavily than adult females, juveniles, and infants.

Topics: Age Factors; Animals; Body Weight; Female; Hierarchy, Social; Lemur; Madagascar; Male; Monkey Diseases; Sex Factors; Tick Infestations

Renitelo breed is a cattle breed created at Kianjasoa station (Madagascar) by a triple crossing Malagasy Zebu x Limousine x Afrikander. This breed besides many valuable advantages, such as rapid growth and drought power, presents a huge disadvantage which is sensitivity to skin disease, dermatophilosis, previously known as streptotrichosis. This disease caused by Dermatophilus congolensis is one of the major threats for the population of Renitelo cattle. An allele of MHC gene has been shown to be dramatically associated to hypersensitivity to the disease in other cattle breed. To bring further information to tick borne disease clinical survey, mainly dermatophilosis, we wanted to verify if such allele could be found in this breed. Renitelo cattle included in this study were chosen for the presence of dermatophilosis lesions in more or less severe form (N = 17). These animals were blood sampled and a genetic analysis on the MHC gene BoLA-DRB3 was performed, by PCR amplification using BOD 31 & BOD 32 primers. Amplified products were analyzed by RFLP using enzymes. Restriction band profiles were characterized according to previously defined patterns. Three cows out of the 17 cattle analyzed for MHC gene presented the hypersensitive allele FDA. Two out of the three hypersensitive cows were pure breed while one was half breed. All the cows presented dermatophilosis lesions at least during rainy season but one of them particularly suffered from severe lesions covering all its body and died of the illness. This study shows that hypersensitivity allele found in other bovine breeds can be found in Renitelo breed. This result seemed to suggest that this characterization could be utilized in breeding program for this breed.

Topics: Actinomycetales Infections; Alleles; Animals; Breeding; Cattle; Cattle Diseases; Crosses, Genetic; Disease Susceptibility; Gene Amplification; Immunity, Innate; Madagascar; Major Histocompatibility Complex; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Skin Diseases, Bacterial; Tick Infestations