TY - JOUR
T1 - Long aculeus and behavior of Anastrepha ludens render gibberellic acid ineffective as an agent to reduce 'ruby red' grapefruit susceptibility to the attack of this pestiferous fruit fly in commercial groves
AU - Birke, Andrea
AU - Aluja, Martin
AU - Greany, Patrick
AU - Bigurra, Everardo
AU - Pérez-Staples, Diana
AU - McDonald, Roy
PY - 2006/8
Y1 - 2006/8
N2 - Treating Mexican grapefruit with gibberellic acid (GA3) before color break, significantly delayed peel color change and increased peel puncture resistance, but it did not reduce grapefruit susceptibility to Mexican fruit fly, Anastrepha ludens (Loew) attack under natural conditions. Despite GA 3 treatments, larval infestation levels increased with higher fruit fly populations, which also increased as the season progressed. Late in the season, infestation levels were even higher in GA3-treated fruit compared with untreated fruit, possibly because treated fruit were in better condition at that stage. Egg clutch size was significantly greater in very unripe, hard, GA3-treated fruit at the beginning of the harvest season and in December, compared with control fruit. Under laboratory conditions, egg injection into different regions of the fruit suggested that A. ludens eggs are intoxicated by peel oil content in the flavedo region. However, A. ludens' long aculeus allows females to oviposit eggs deeper into the peel (i.e., albedo), avoiding toxic essential oils in the flavedo. This makes A. ludens a particularly difficult species to control compared with other citrus-infesting species such as Anastrepha suspensa (Loew), Anastrepha fraterculus (Wiedemann), and Ceratitis capitata (Wiedemann) (fly species with significantly shorter aculei), which can be effectively managed with GA 3 sprays. We discuss our findings in light of their practical implications and with respect to the oviposition behavior of various fruit flies attacking citrus.
AB - Treating Mexican grapefruit with gibberellic acid (GA3) before color break, significantly delayed peel color change and increased peel puncture resistance, but it did not reduce grapefruit susceptibility to Mexican fruit fly, Anastrepha ludens (Loew) attack under natural conditions. Despite GA 3 treatments, larval infestation levels increased with higher fruit fly populations, which also increased as the season progressed. Late in the season, infestation levels were even higher in GA3-treated fruit compared with untreated fruit, possibly because treated fruit were in better condition at that stage. Egg clutch size was significantly greater in very unripe, hard, GA3-treated fruit at the beginning of the harvest season and in December, compared with control fruit. Under laboratory conditions, egg injection into different regions of the fruit suggested that A. ludens eggs are intoxicated by peel oil content in the flavedo region. However, A. ludens' long aculeus allows females to oviposit eggs deeper into the peel (i.e., albedo), avoiding toxic essential oils in the flavedo. This makes A. ludens a particularly difficult species to control compared with other citrus-infesting species such as Anastrepha suspensa (Loew), Anastrepha fraterculus (Wiedemann), and Ceratitis capitata (Wiedemann) (fly species with significantly shorter aculei), which can be effectively managed with GA 3 sprays. We discuss our findings in light of their practical implications and with respect to the oviposition behavior of various fruit flies attacking citrus.
KW - Anastrepha ludens
KW - Citrus paradisi
KW - Gibberellic acid
KW - Pest management
KW - Trap crops
UR - http://www.scopus.com/inward/record.url?scp=33750456154&partnerID=8YFLogxK
M3 - Article
C2 - 16937671
AN - SCOPUS:33750456154
SN - 0022-0493
VL - 99
SP - 1184
EP - 1193
JO - Journal of Economic Entomology
JF - Journal of Economic Entomology
IS - 4
ER -