Host Odor Mediated Response of Female Navel Orangeworm Moths (Lepidoptera: Pyralidae) to Black and White Sticky Traps

Abstract

In laboratory and field experiments, we used fatty acids found in crude almond oil and a crude almond oil/fatty acid blend (1:l) as attractants and found highly significant differences in numbers of navel or angewor m, Amyelois transitella (Walker), female moths that were attracted to and caught in black versus white sticky traps. In a mark-release-recapture experiment, 98 2% of the recaptured females were recovered in black traps after 7 d Black traps also caught more than 85% of the wild A transitella females compared with white traps Wind tunnel bioassays on the upwind flight behavior of A transitella females showed that females were more likely to appioach, land, and become caught in black traps than in identically baited white traps KEY WORDS Insecta, Amyelois transitella, female attraction, almonds PROMISING ALTERNATIVES to conventional insecticide applications for contr oiling navel orange-worm, Amyelois transitella (Walker), populations in almonds, Prunus amygdalus Batsch, were shown by Phelan & Baker (1987) and Van Steenwyk & Bar nett (1987) These control strategies involve the use of almond by-products in an attracticide bait (Phelan & Baker 1987) and oviposition disruption (Van Steenwyk & Barnett 1987) The objective of the first strategy is to reduce A tiansitella population densities by attracting gravid females to bait laced with insecticide The objective of the second is to reduce almond infestation by promoting egg laying on or near attractants that were applied before hull-split of new-crop nuts 01 away from new-cr op nuts after hull-split Additional research has shown that fatty acids in crude almond oil are responsible for eliciting the complete behavioral sequence of upwind flight and host source location in mated A transitella female moths (P L Phelan & T C.B , unpublished data) Thus, another major use for these highly attractive fatty acids may lie in the direct monitoring of the oviposition flights of adult females à ‡ Rice (1976) was the first to selectively monitor A transitella in almonds by counting eggs laid on a specialized trap baited with standard A transi-tella rearing media The Pherocon IV egg trap (Trece, Salinas, Calif) is the commercial version of this trap that consists of a 92 4-ml clear plastic vial with two large openings covered with organdy Although Pherocon IV traps are useful for indi-'