In vitro efficacy of Metarhizium anisopliae sensu lato against unfed Amblyomma parvum (Acari: Ixodidae)

Abstract

Amblyomma parvum Aragão (Acari: Ixodidae) is a tick species found with wide distribution in the Neotropical region. Even though it is a wildlife-related tick, it is also a frequent parasite of domestic animals, is aggressive to human beings and may harbor pathogenic microorganisms. Therefore, it is a target species for control on domestic animals, particularly those at the rural-wildlife interface. Herein, the efficacy of two isolates (E9 and IBCB 425) of an entomopathogenic fungus, Metarhizium anisopliae sensu lato, already evaluated for ticks that parasitize domestic animals, was tested against unfed A. parvum adults. Both isolates displayed high acaricidal efficacy after immersion in fungal conidial suspensions for 5 min. Isolate E9 killed all ticks by the 7th day post-treatment, and isolate IBCB 425 did so by the 11th day. Tick mortality of 80 and 90% was achieved as early as the 3rd and 4th days, respectively, with both treatments. Thus, if a commercial M. anisopliae s.l. acaricide against domestic animal ticks is developed, it would also be effective against A. parvum.

Fungi and Oomycetes–Allies in Eliminating Environmental Pathogens

“…Currently, many fungi are known with a high potential to eliminate various evolutionary forms of ticks. Among them are: Beauveria bassiana, Beauveria brognardi, Metarhizium anisopliae, Metarhizium robertsii, Metarhizium brunneum, Fusarium sp., Aspergillus fumigatus, Aspergillus ochraceus, Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, Isaria fumosorosea, Scopulariopsis brevicaulis, Paecilomyces lilacinus, Paecilomyces farinosus, Paecilomyces fumosoroseus, Penicillium insectivorum, Conidiobolus coronatus, Trichothecium roseum, Verticillium aranearum, Verticillium lecanii, Isaria fumosorosea, Isaria farinose, Curvularia lunata, Rhizopus thailandensis, and Rhizopus arrhizus [96][97][98][99][100][101][102][103][104][105][106][107][108][109][110][111][112][113][114].…”

La garrapata Amblyomma parvum como vector potencial de patógenos en animales y seres humanos

“…Sin embargo, Lifschitz et al (2008) evaluaron el tratamiento de ivermectina y eprinomectina para el control de A. parvum en cabras y encontraron que éstas sustancias no tuvieron eficacia para su control. Por otro lado, García et al (2018) evaluaron la eficacia in vitro de dos aislados del hongo Metarhizium anisopliae contra adultos no alimentados de A. parvum y encontraron que los dos aislados ocasionaron mortalidad de las garrapatas a los días 3 (80 %) y 4 (90 %) post-tratamiento (PT). El 100 % de mortalidad de las garrapatas se logró del día 7 al 11 PT.…”

Entomopathogenic Fungi and Bacteria in a Veterinary Perspective

“…anisopliae appeared active against Rhipicephalus variegatus, R. sanguineus and Ixodes scapularis, but led to a limited mortality in Dermacentor variabilis, which was sensitive to B. bassiana [116]. It was proven to be effective against Amblyomma parvum [136] and Haemaphysalis qinghaiensis, such as B. bassiana [137]. In a trial on Dermacentor albipictus larvae, a spray application of M. anisopliae was more effective and active in a shorter time, such as M. brunneum, when compared to B. bassiana [138].…”

“…I. fumosorosea was able to reduce the hatching percentage of treated eggs but was scarcely effective on larvae [162]. I. fumosorosea induced a low mortality of larvae in R. sanguineus [114], in D. reticulatus and I. ricinus [136]. For these reasons, its use as mycoacaricide against ticks is not recommended [139].…”

“…Amblyomma americanum Beauveria bassiana [149] Amblyomma parvum Metarhizium anisopliae [136] Amblyomma variegatum Beauveria bassiana [152] Amblyomma variegatum Metarhizium anisopliae [152] Amblyomma variegatum M. anisopliae + B. bassiana [153] Boophilus microplus Beauveria bassiana [186] Boophilus microplus Metarhizium anisopliae [130,131,[186][187][188][189] Boophilus sp. Fusarium sp.…”