Entomopathogenic nematodes in pharmaceutical formulations for Rhipicephalus microplus (Acari: Ixodidae) control: In vitro evaluation of compatibility, thermotolerance, and efficiency

Publication date: Available online 18 March 2019Source: Ticks and Tick-borne DiseasesAuthor(s): Alessandra Ésther de Mendonça, Raiana Gonçalves Moreira, Maria da Penha Henriques do Amaral, Caio Márcio de Oliveira Monteiro, Valéria de Mello, Fernanda Maria Pinto Vilela, Fernanda Cristina Mendonça Homem, John Furlong, Cláudia Dolinski, Márcia Cristina de Azevedo Prata, Evelize Folly das ChagasAbstractThis work aimed to investigate candidate biological control agents against the cattle tick Rhipicephalus microplus by studying three entomopathogenic nematodes (EPN) isolates from two species, Heterorhabditis bacteriophora (isolates LPP30 and HP88) and Heterorhabditis baujardi (isolate LPP7). The study comprised the pharmacotechnical development of four test formulations, and their biological evaluation, in three stages: 1) selection of the fittest EPN isolate at 16 ± 1 °C after 120 h of incorporation in the formulations; 2) determination of the effects of temperature and incubation time on the survival of the selected isolate in formulations; 3) evaluation of the in vitro efficacy (infectivity) of the selected EPN formulations and their components against R. microplus females after 72 h exposure. H. baujardi LPP7 presented the highest survival rates in 0.1 % carboxymethyl cellulose sodium (CMC) formulations (100 % at 25 °C, up to 10 days after incorporation). At the highest tested temperature (34.2 °C), 54 % of LPP7 survived for up to 72 h in CMC formul...
Source: Ticks and Tick borne Diseases - Category: Zoology Source Type: research