Evidence of Amblyseius largoensis and Euseius alatus as biological control agent of Aceria guerreronis

Abstract

Amblyseius largoensis (Muma) (Acari: Phytoseiidae) and Euseius alatus De Leon (Acari: Phytoseiidae) are predatory mites that are mostly found on leaves and on the exposed fruit surface of coconut plants. Their morphology hampers the access to the microhabitat occupied by Aceria guerreronis Keifer (Acari: Eriophyidae), the most important pest of coconut fruits throughout the world. However, it was suggested that they can prey on A. guerreronis under natural conditions when this pest leaves its refuge to disperse. Since the trophic interactions between A. largoensis or E. alatus and A. guerreronis are unknown, we compare the frequencies of occurrence of A. largoensis and E. alatus under the bracts of coconut fruits and on coconut leaflets. In addition, because phytoseiids feed by liquid ingestion, we used molecular analysis to confirm the potential role of A. largoensis or E. alatus as predators of A. guerreronis and to assess how fast the A. guerreronis DNA fragment is degradated in the A. largoensis digestive tract. Our study demonstrated that E. alatus was only present on coconut leaflets whereas A. largoensis was found mostly on leaflets and, to a much lesser extent, under the bracts of coconuts. Species-specific ITS primers designed for A. guerreronis were shown to have a high degree of specificity for A. guerreronis DNA and did not produce any PCR product from DNA templates of the other insects and mites associated with the coconut agroecosystem. Based on molecular analysis, we confirmed that the predatory mites, A. largoensis and E. alatus, had preyed on the coconut mite in the field. Overall the predatory mites collected in the field exhibited low levels of predation (26.7% of A. largoensis and 8.9% of E. alatus tested positive for A. guerreronis DNA). The fragment of A. guerreronis DNA remained intact for a very short time (no more than 6 h after feeding) in the digestive tract of A. largoensis.

The predatory mite Neoseiulus paspalivorus (Phytoseiidae) in Brazil: taxonomic status, reproductive compatibility and morphological and molecular variability

“…The lack of reproductive isolation between the most morphometrically distant N. paspalivorus populations (RN and PB) supports the hypothesis that the studied populations belong to a single species, according to the biological concept of species (Mayr 1977). Previous studies have reported reproductive incompatibility among three geographically distant, N. paspalivorus populations (Benin, Ghana and Brazil) because of their association with different endosymbionts.…”

Predator performance is impaired by the presence of a second prey species

“…Among these pests, there are many phytophagous mites (~10 species) that develop on the meristematic zone of the fruits, which is partly covered by the fruit perianth (Navia et al , 2005 a ; Lawson-Balagbo et al , 2008; Negloh et al , 2011). Under these perianths, the phytophagous mites are protected from pesticides and from many natural enemies, except for the smallest predatory mites (Lima et al , 2012; Monteiro et al , 2012; Melo et al , 2015; Da Silva et al , 2016). The feeding of the phytophagous mites on the meristematic zone of the fruits causes significant damage, with the fruit surface becoming necrotic, resulting in distorted coconuts and sometimes even in fruit abortion (Moore & Howard, 1996).…”

“…Over time, the distance between the perianth and the fruit surface becomes large enough to allow the entrance of some predator species (Lima et al , 2012). Several predatory mite species are frequently found associated with A. guerreronis on coconuts (Lawson-Balagbo et al , 2008; Reis et al , 2008; Negloh et al , 2011; Lima et al , 2012; Melo et al , 2015). Among them, Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae) is the most abundant predator, capable of developing and reproducing when feeding on coconut mites (Domingos et al , 2010; Melo et al , 2015).…”

“…Several predatory mite species are frequently found associated with A. guerreronis on coconuts (Lawson-Balagbo et al , 2008; Reis et al , 2008; Negloh et al , 2011; Lima et al , 2012; Melo et al , 2015). Among them, Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae) is the most abundant predator, capable of developing and reproducing when feeding on coconut mites (Domingos et al , 2010; Melo et al , 2015). The small size of N. baraki ensures relatively early access (fruits of around 2 months old) to the microhabitat occupied by A. guerreronis (Lima et al , 2012).…”

Gut-content analysis of predatory phytoseiid mites using fluorescent-labeled polymerase chain reaction: age of spider-mite eggs influences detection rates

“…The establishment of an effective analytical method that can identify egg remains from the phytoseiid gut will allow us to better evaluate predator-prey interactions between phytoseiid mites and spider mites, while also identifying the best predator. However, few such studies have examined the gut contents of phytoseiid mites (Melo et al, 2015;Rivera-Rivera et al, 2012;Wari et al, 2014). Therefore, in this study, I conducted laboratory feeding experiments in conjunction with fluorescent-labeled PCR to analyze the gut contents of phytoseiid mites.…”