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The navel orangeworm, Amyelois transitella (Walker), is the most significant pest of California almonds. Direct feeding on the kernel by the larvae causes reductions in salable crop, crop quality, and exportability. Pheromone mating disruption (MD) targeting navel orangeworm is a relatively new technique with the potential to improve management. In 2017, we used replicated ~16-ha plots to compare the efficacy of four commercial MD systems (CheckMate, Cidetrak, Isomate, and Semios) for their relative impacts on the number of navel orangeworm in monitoring traps and crop quality. From 2017 to 2018, we conducted nine direct comparison studies in 16 to 40 ha almond orchards to compare conventional pest management programs to programs incorporating pheromone MD systems. Across all studies, MD reduced male moth captures in pheromone traps by >94%. In the efficacy study, use of mating disruption led to 35% and 53% reductions in kernel damage in Nonpareil and pollinizer cultivars, respectively, and an average increase in crop value of $370 ha−1. In the direct comparison, kernel damage to Nonpareil and pollinizer cultivars was reduced by 65% and 78%, respectively, resulting in an average increase in crop value of $357 ha−1. Economic analyses showed that increases in crop returns exceeded the costs of implementing MD systems with the break-even point ranging from 0.86 to 1.06% of kernel damage. These results suggest that adding MD to an existing navel orangeworm management program is a cost-effective way to reduce damage while promoting sustainable pest management practices. [ABSTRACT FROM AUTHOR]

Experiments were conducted to test a mating disruption program for the mealybug Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae) in California vineyards. The sprayable, microencapsulated formulation of the racemic sex pheromone lavandulyl senecioate was applied with an air-blast sprayer, using three and four applications in 2003 and 2004, respectively. Mating disruption was combined with an application of buprofezin (2004) in June. Compared with a no-pheromone control, there were significantly lower season-long trap catches of adult males, season-long mealybug densities (2003 only), and crop damage in mating disruption plots. The amount of mealybug reduction and mechanisms that resulted in lower crop damage in mating disruption plots is discussed. In samples taken during the growing season (April to September), mealybug density was only 12.0 ± 15.6 and 31.1 ± 11.6% lower in the mating disruption plots than in control plots in 2003 and 2004, respectively. In the mating disruption treatment, mealybug egg production was significantly lower (2003 only), as were the proportion of ovisacs and crawlers produced. There was no treatment impact on percentage of parasitism. Mealybug density influenced treatment impact. In 2004, vines were categorized as having low, medium, or high mealybug densities during a preapplication survey. After treatment application, mealybug density was reduced by 86.3 ± 6.3% on vines in the low mealybug density category, but it was unchanged on vines in the high density category. Another factor that reduced treatment impact was the relatively short effective lifetime of the sprayable formulation. [ABSTRACT FROM AUTHOR]

The sex pheromone component muscalure [(Z)-9-tricosene] on the cuticles of female house flies (Musca domestica L.) was quantified using gas chromatography. Laboratory and wild-strain house fly colonies were derived from poultry and dairy farms and a horse-riding stable. Muscalure levels from strain MB females were highest after 13 and 23 generations in culture, but 30-70% of females from early generations (F8-F12) had no detectable levels of muscalure. Flies <2 d old from the MB laboratory colony (F23) had less muscalure than did older flies, and levels tended to increase as flies aged from 3 to 8 d. Of 10 wild house fly populations sampled at 3 d of age (72-96 h old) between F1 and F7 in culture, 1 had no detectable muscalure, and 8 of 10 averaged ≤218 ng of muscalure per female, comprising ≤1.6% of total cuticular hydrocarbons. In 6 of 10 field populations, ≥67% of females had no detectable muscalure. In contrast, two field strains had average levels of 559 and 1,113 ng muscalure/female (comprising 3.2 and 5.0% of total hydrocarbons), which was comparable to long- established laboratory strains such as the UCR strain (751 ng muscalure/female, comprising 3.0% of total hydrocarbons). More than 70% of females from those two field strains had muscalure. Flies from the Cooper laboratory strain also lacked detectable muscalure. Muscalure amounts were highly variable; it was rare or lacking in many field populations and thus does not seem to be essential for house fly reproduction. [ABSTRACT FROM AUTHOR]

The mealybug, Planococcus ficus (Signoret), is one of the more damaging vineyard pests and an important vector of Grapevine leafroll-associated viruses. Pheromone-mediated mating disruption is a commercially available and environmentally sustainable control tool for P. ficus. Here we report on a three-year areawide study of P. ficus mating disruption in Napa County, California, where pheromone dispensers were deployed across large (53–66 ha) multi-owner sites that were paired with sites that did not receive pheromone. Male P. ficus captures in pheromone traps were correlated with mealybug numbers and crop damage, and were useful in identifying 'hotspots' to be targeted with insecticide applications for areawide control. Trap catches at mating disruption sites were far lower than untreated sites, although mealybugs were still present at mating disruption sites. Evidence indicated that mating disruption reduced P. ficus density and spread, particularly in areas with low initial mealybug densities. In the third year, areawide mating disruption was discontinued at the former mating disruption sites and, as evidence of its impact, P. ficus trap captures increased. These results suggest that mating disruption and well-timed, effective insecticide applications play complementary roles, and that monitoring the areawide distribution of pests is a critical component of programs for controlling P. ficus. • Pheromone traps were useful in identifying 'hotspots' of the mealybug Planococcus ficus. • Mating disruption appeared to limit Pl. ficus density and spread over large vineyard areas. • Effects of mating disruption were most pronounced in areas with low mealybug densities. • Pl. ficus trap captures increased at most sites after mating disruption was discontinued. • Mating disruption and insecticides likely play complementary roles in Pl. ficus control. [ABSTRACT FROM AUTHOR]