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Effects of Metarhizium anisopliae on Meccus pallidipennis (Hemiptera: Reduviidae) over different types of wall surfaces

Author:
Murillo-Alonso, Karla Tatiana, Hernández-Velázquez, Victor Manuel, Salazar-Schettino, Paz María, Cabrera-Bravo, Margarita, Toriello, Conchita
Source:
Biocontrol science and technology 2019 v.29 no.5 pp. 466-477
ISSN:
1360-0478
Subject:
Chagas disease, Metarhizium anisopliae, Triatominae, bioassays, bricks, conidia, disease control, emulsifiers, entomopathogenic fungi, insect diseases, insects, instars, laboratory experimentation, mortality, mountain soils, nymphs, vegetable oil, virulence
Abstract:
The entomopathogenic fungus Metarhizium anisopliae is virulent for the insect triatomine Meccus pallidipennis. To evaluate the functionality of a fungal formulation (vegetable oil and emulsifiers) of this fungus, virulence was assayed by insect mortality on the pronotum of third instar nymphs (N3) M. pallidipennis in laboratory conditions and ST₅₀ was calculated. Mortality was evaluated directly: 100%, 97.33% and 98.66% mortalities were caused by formulation, emulsified formulation and fungal conidia, respectively, at day 8 of insect infection. Another bioassay was carried out in simulated external conditions (peridomicility) using red and gray brick walls, a stone fence and mountain soil (experimental units). These simulated conditions were infected with 10 ml of a 1 × 10⁹ conidia/ml emulsified formulation by means of a manual sprinkler prior to the placement of the nymphs. Ten N3 M. pallidipennis were deposited in each experimental unit and insect mortality was monitored every 12 h for 22 days. Each treatment was replicated four times. With the red brick wall, a mortality of 90% at day 22 and a ST₅₀ of 15 days were obtained on N3 M. pallidipennis; with the gray brick wall, 100% mortality and a ST₅₀ of 13 days; and with the stone fence, 88.33% mortality and a ST₅₀ of 21 days. The results obtained in this research work indicate that the formulation with conidia of the M. anisopliae strain EH-473/4 may be auxiliary in the development of strategies for the control of Chagas disease insect transmitters such as M. pallidipennis.
Agid:
6344946