Effect of formulated Metarhizium anisopliae on eggs and eclosing nymphs of Triatoma infestans

Abstract

Little is known about the ovicidal effects of fungi that attack nymphs and adults of triatomine vectors. A combined formulation of Metarhizium anisopliae IP 46 conidia prepared with diatomaceous earth (DE) and vegetable oil was tested against eggs of Triatoma infestans. Eggs were highly susceptible to fungal infection at relative humidity close to saturation [>98% relative humidity (RH)] but not at 75% RH regardless of the formulation applied. Susceptibility of eggs decreased with longer post‐ovipositional embryonation periods before treatments. The eventual eclosion of nymphs was best suppressed by application of conidia prepared with DE + oil and at a >98% RH incubation. Moreover, nymphs were less affected by the fungus when exposed for only a 24‐h period after eclosion to a treated surface than individuals that were in constant contact with the conidia. These findings contribute to a better understanding of the potential of M. anisopliae as an agent against all developmental stages of T. infestans.

Significant mortality of eggs and young larvae of two pine processionary moth species due to the entomopathogenic fungus Metarhizium brunneum

“…Our study shows that young eggs are more susceptible to entomopathogenic fungi ovicidal activity than older egg masses. These observations are in accord with those reported for Chilo partellus Swinhoe, T. infestans and Nilaparvata lugens (Stål) where susceptibility of the eggs to entomopathogenic fungi decreased with egg age (Maniania, 1991;Rodrigues et al, 2015;Li et al, 2013). Welldeveloped embryos inside the eggs presumably do not provide the right cues to encourage fungal infection.…”

“…Beauveria) fungi at the egg mass surface triggered spore germination and saprophytic fungi growth with egg death caused by the activity of hydrolytic enzymes, toxic metabolites and mechanical damage; as reported for other arthropods (Fernandes et al, 2003;Zhang et al, 2014;Santos et al, 2009). Rodrigues et al, (2015) reported that high humidity was essential for development of M. anisopliae on eggs of Triatoma infestans (Klug), and under drier conditions the eggs completely resisted infection.…”

Survival and immune response of the Chagas vector Meccus pallidipennis (Hemiptera: Reduviidae) against two entomopathogenic fungi, Metarhizium anisopliae and Isaria fumosorosea

“…Use of these fungi has been highly successful for controlling different insect pests and vectors such as Asian tiger mosquitoes Aedes albopictus [ 16 ], cattle ticks Rhipicephalus microplus [ 17 ], Asian citrus psyllids Diaphorina citri [ 18 ] and diamondback moth Plutella xylostella [ 19 ]. As a matter of fact, several strains of M. anisopliae and I. fumosorosea , that are highly efficient to kill triatomines, have been identified [ 20 – 23 ]. Thus, entomopathogenic fungi seem a viable route for triatomine biological control [ 12 , 23 – 25 ].…”

New insights into the infection of the American cockroachPeriplaneta americananymphs withMetarhizium anisopliaes.l. (Ascomycota: Hypocreales)

“…Compounds in the epicuticle affect both conidial germination and hyphal growth, and are related to specific susceptibility patterns of the host (Boucias and Latg e 1988;Sosa-Gomez et al 1997;Wang and St. Leger 2005;Pedrini et al 2007;Gołe z biowski et al 2011). IP 46, active against this cockroach (Hubner-Campos et al 2013) but also against other insects such as triatomines (Rocha and Luz 2011;Luz et al 2012;Rodrigues et al 2015) and mosquitoes (Mnyone et al 2009;Santos et al 2009;Sousa et al 2013;Lobo et al 2016), in this cockroach and some factors that affect the infection process. We investigated the cuticular lipids of P. americana and present new findings on the activity of M. anisopliae s.l.…”

“…We investigated the cuticular lipids of P. americana and present new findings on the activity of M. anisopliae s.l. IP 46, active against this cockroach (Hubner-Campos et al 2013) but also against other insects such as triatomines (Rocha and Luz 2011;Luz et al 2012;Rodrigues et al 2015) and mosquitoes (Mnyone et al 2009;Santos et al 2009;Sousa et al 2013;Lobo et al 2016), in this cockroach and some factors that affect the infection process.…”