Influence of fruit traits on oviposition preference of the olive fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae), on three Portuguese olive varieties (Cobrançosa, Madural and Verdeal Transmontana)

Identification of leaf volatiles from olive (Olea europaea) and their possible role in the ovipositional preferences of olive fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae)

“…Our hypothesis is that volatiles emitted by olive leaves may interfere in olive fly females' host selection in conjunction with olives (Malheiro et al, 2015b) and with other factors, such as physical (fruit and leaf color, shape, volume) (Rizzo et al, 2012) and biochemical aspects (olives maturation) (Gonçalves et al, 2012). In fact, when host volatiles from olive leaves and fruits were tested in electroantenographic studies in olive fly males and females (mated and unmated), higher EAG signals were obtained with olive leaf volatiles, especially in mated males (Liscia et al, 2013).…”

“…These olive cultivars were selected due to their different susceptibilities to the olive fly in Portugal, where the Verdeal Transmontana and Madural cultivars are highly susceptible, while cv. Cobrançosa is less attacked (Gonçalves et al, 2012). The possible relationships between volatile types and amounts and cultivar susceptibility to B. oleae attack are discussed as well.…”

“…Bactrocera oleae (Rossi) (Diptera: Tephritidae), the olive fly, is considered the key pest in several regions in the world, particularly in the Mediterranean area (Daane and Jonhson, 2010), causing important economic and quality losses (Malheiro et al, 2015a). The female of this dipteran shows cultivar preference by attacking specific olive cultivars (Burrack and Zalom, 2008;Iannotta et al, 2007;Navrozidis et al, 2007;Gonçalves et al, 2012). Host selection for oviposition is believed to be based on chemical (Imperato et al, 2012;Kombargi et al, 1998;Spadafora et al, 2008), physical (Neuenschwander et al, 1985;Rizzo et al, 2012), and molecular aspects .…”

Adaptive decision making or differential mortality: what causes offspring emergence in a gregarious parasitoid?

“…Low‐quality hosts have repeatedly been shown to yield lower offspring numbers for parasitoid insects (Zaviezo & Mills, ; West et al., ; Bezemer & Mills, ; Peters, ; Goncalves et al., ) and two mechanisms may lead to this pattern: the clutch size decision made by the mother and developmental mortality among the offspring.…”

“…Depending on host quality, this may lead to competition between larvae within the same host, resulting in increased mortality (Withers et al., ; Hoffmeister & Rohlfs, ; Pexton et al., ) and/or decreased offspring fitness (Hardy et al., ; Withers et al., ; Desouhant et al., ; Zaviezo & Mills, ). In gregarious species, low‐quality hosts have been reported to yield fewer offspring (Zaviezo & Mills, ; West et al., ; Bezemer & Mills, ; Peters, ; Goncalves et al., ) and two mechanisms are likely to create this pattern in final offspring eclosion, namely, the mother's initial clutch size decision or increased developmental mortality of the offspring.…”