Monitoring Amyelois transitella males and females with phenyl propionate traps in almonds and pistachios

Abstract

We examined phenyl propionate as an attractant for trapping navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae) adults, with the objective of developing a method of trapping both sexes more effectively than with almond meal. Two initial experiments maximized the total number of adults captured using phenyl propionate released from glass vials with cotton wicks. A third experiment compared the numbers of males and females captured using these glass dispensers in either bucket or sticky traps. The glass vial dispensers captured more adults than 0.1% phenyl propionate in water (as both attractant and killing agent), and far more adults were captured with glass vial phenyl propionate dispensers than with almond meal. On rare occasion, the glass vial dispensers captured as many adults as traps baited with virgin females, but usually phenyl propionate in glass vials captured fewer adults than virgin‐baited traps. Glass vial phenyl propionate dispensers were equally effective in sticky traps or bucket traps. The majority of females captured were mated, and the proportion of males captured increased over time within flights (generations). We conclude that phenyl propionate released from glass vials captured A. transitella adults more effectively than currently available options, and will be useful in research projects where capturing intact adults and comparing mating status are important. Developing a cost‐effective phenyl propionate‐based alternative to the egg traps currently used for commercial monitoring will be more difficult.

Diel Periodicity in Males of the Navel Orangeworm (Lepidoptera: Pyralidae) as Revealed by Automated Camera Traps

“…In the absence other information, the sex of the NOW adults captured and their reason for entering the camera trap might be open to interpretation. Previous studies, however, indicate that passive captures in unbaited traps occur very rarely, e.g., around 0.1 adults per trap every two weeks, or around 0.1% the rate of a pheromone trap ( Burks et al 2009 , 2016 ), and the rate of female captures in traps baited with pheromone is vanishingly small ( Higbee et al 2014 ). Taking these previous studies into account, the simplest explanation for capture of a few males in the pheromone baited camera traps at seemingly random hours is that they responded to the pheromone lure at that time.…”

Effect of Abundance of the Navel Orangeworm on Sampling Range and Interference Between Pheromone Traps

“…Insecticide treatments in almonds target either the Þrst ßight (overwintering generation) in spring or the second ßight around hull split (Zalom et al 2009), whereas insecticide treatment in pistachios typically targets the third ßight (Bentley et al 2010). In almonds the second ßight is typically a time of low abundance, whereas abundance in pistachios is often higher in the third ßight (Burks et al , 2009). Pistachios often have higher overall abundance compared with almonds , and a signiÞcant relationship has been detected between navel orangeworm damage to almonds and proximity to pistachios (which often have higher navel orangeworm abundance) at distances up to 5 km (Higbee and Siegel 2009).…”

Hull Split and Damaged Almond Volatiles Attract Male and Female Navel Orangeworm Moths

“…Although attractive to NOW moths, the authors concluded phenyl propionate was unlikely to be practical for economic and perceived safety reasons (personal communication, C. Burks). 11 On the basis of field observations (B.S.H.) that female NOW are attracted to the odor of damaged almonds, 12 attention was focused on mechanically damaged almonds 13 and almonds undergoing hull split.…”

“…The identification and use of semiochemicals to attract and monitor NOW moths in almond orchards remains elusive. In 2009, Burks et al investigated use of the single nonhost compound phenyl propionate in almond and pistachio orchards to capture adult NOW. Although attractive to NOW moths, the authors concluded phenyl propionate was unlikely to be practical for economic and perceived safety reasons (personal communication, C. Burks) …”