Estímulos Olfativos Envolvidos na Localização de Presas pelo Ácaro Predador Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) em Macieiras e Plantas Hospedeiras Alternativas

Abstract

The phytophagous mites Panonychus ulmi (Koch) and Tetranychus urticae Koch (Tetranychidae) cause severe losses in apples in southern Brazil. An alternate means of managing both species, currently under way in orchards in Fraiburgo, SC, is the use of the predatory mite Neoseiulus californicus (McGregor). To understand how this predator interacts at the olfactive level with both prey on their host plants, we studied the responses of N. californicus on apple, Malus domestica (Borkham), as well as on three of the predator´s alternate winter hosts (Sida rhombifolia L., Plantago tomentosa Lamarck and Taraxacum officinale Weber), in a Y-tube olfactometer. On apple, the tests demonstrated that N. californicus responded significantly to allelochemicals associated with previouslyinfested leaves with or without P. ulmi or T. urticae or their associated byproducts (feces, eggs, exuviae, and webs), as well as to those associated with previously-uninfested leaves + prey and its byproducts. The predator also responded to a mixture of volatile odors from previously-uninfested apple leaves with T. urticae byproducts. In relation to the location of T. urticae by N. californicus on its alternate winter host plants, we observed that the prey byproducts are more attractive to the predator on S. rhombifolia and P. tomentosa, whereas infested leaves of T. officinale with or without prey and its byproducts did not elicit any response. These results indicate that the volatiles from the host plant, as well as those from the prey and its byproducts, serve as cues in the prey location by N. californicus. Additionally, volatiles from the flowers of the three alternate host plants were highly attractive to the predator, which suggests that this stimuli could be involved in locating pollen, another of its food sources.

Araruta: Planta alimentícia não convencional em sistema agroecológico

“…A presença de muitas moléculas estimulantes pode ocasionar confusão de resposta. Além disso, a presença de muitos voláteis pode inibir ou mascarar o efeito do outro, ocasionando respostas inesperadas (COLLIER et al, 2001).…”

Sélection d'ennemis naturarels pour la lutte biologique contre Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae), en Afrique

“…Ainsi, plusieurs odeurs libérées par les plantes sont utilisées par les ennemis naturels comme des stimulus qui indiquent l'habitat du ravageur (MORAES et al, 1998). Une particularité intéressante est la capacité des ennemis naturels de répondre aux substances chimiques produites par les plantes quand elles sont attaquées par le ravageur (COLLIER et al, 2001).…”

“…Les acariens prédateurs rencontrent les acariens phytophages à travers des substances semiochimiques appelées chairomones (ce sont des substances volatiles qui agissent entre les individus d'espèces différentes, en favorisant seulement le receveur de l'information) provenantes de la toile, des fèces, des oeufs et des exuvies des acariens phytophages en association avec les volatiles de la plante attaquée et qui fontionnent comme indicateurs de la présence des phytophages (MORAES & McMURTRY, 1985;COLLIER et al, 2001).…”

Responses of Tetranychus urticae (Koch, 1836) and Neoseiulus californicus (McGregor, 1954) to the application of salicylic acid on bean cultivars.

“…The two-spotted spider mite Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae) is one of the main species of phytophagous and polyphagous mites in the world (Jeppson et al 1975; Moraes and Flechtmann, 2008;Grbić et al 2011) and has been reported as resistant to several acaricides in different cultures. In order to minimize the negative impacts of pesticides, new technologies have been proposed as alternative control methods (Sato et Neoseiulus californicus (McGregor, 1954) (Acari: Phytoseiidae), cosmopolitan predatory mite, present in a wide variety of cultivated plants (Collier et al 2001;Ferla et al 2007; Demite et al 2021). This phytoseiid has been associated with the phytophagous mite T. urticae in several crops, such as blackberry (Robus spp.)…”