Field and laboratory evaluation of a sex pheromone trap for the autodissemination of the fungal entomopathogen Zoophthora radicans (Entomophthorales) by the diamondback moth, Plutella xylostella (Lepidoptera: Yponomeutidae)

Abstract

The effectiveness of a sex pheromone trap designed specifically to deliver conidia (infective fungal propagules) of the entomopathogenic fungus Zoophthora radicans Brefeld (Zygomycetes: Entomophthorales) to male Plutella xylostella (Linnaeus) was investigated. In field experiments in the Cameron Highlands of Malaysia, synthetic pheromone lures attracted adult males P. xylostella at all times of the day whereas lures of virgin female moths attracted males only between the hours of dusk and dawn, when females are known to produce their pheromone. Adult male moths attracted to traps baited with synthetic pheromone spent a geometric mean time of 88 seconds within the inoculation chamber, a time compatible with the period adults must spend within a shower of Z. radicans conidia produced by uniform mycelial mats in order to become infected. The field longevity of male and female P. xylostella adults was found to be similar, with individuals living for a mean time of 4.9 days. This was sufficient time for male moths to respond to the pheromone, enter the trap, become infected with Z. radicans and succumb to that infection in the field (3-3.5 days) thereby releasing infective conidia into the cabbage crop.

The effect of the coccinellid Harmonia axyridis (Coleoptera: Coccinellidae) on transmission of the fungal pathogen Pandora neoaphidis (Entomophthorales: Entomophthoraceae)

“…However, Roy et al (2003) found that C. septempunctata inoculated with P. neoaphidis were only able to vector the pathogen within 4 h of inoculation and conidia vectored onto plants by foraging C. septempunctata were only infective up to 24 h post conidia dispersal (Roy et al, 2003). Nonetheless, vectoring is seen as an important form of dispersal and methods of manipulating this in augmentative and conservation biocontrol strategies are being investigated (Furlong et al, 1995;Bird et al, 2004;Ekesi et al, 2005;Down et al, 2009;Baverstock et al, 2010).…”

Entomopathogenic fungi and insect behaviour: from unsuspecting hosts to targeted vectors

“…It was suggested that the females became contaminated through mating with contaminated males. The potential of using either artificial sex pheromones or those released from females to lure adult male diamond back moths, P. xylostella, into devices where they were contaminated with Z. radicans has been assessed (Furlong et al 1995;Pell et al 1993). Whereas males only entered devices containing virgin female moths between dusk and dawn (when sex pheromone is naturally released), males entered devices containing synthetic pheromone throughout the day.…”

Responses of Russian Wheat Aphid (Homoptera: Aphididae) to Aphid Alarm Pheromone

“…We did not test for altered feeding behaviors among apparently undisturbed aphids in the presence of injured aphids. Studies also are needed to explore the possible synergy between pheromone applications and other control agents (Smart et al 1994, Furlong et al 1995. …”