Response of Tortricid Moths and Non-Target Insects to PheromoneTrap Color in Commercial Apple Orchards

Pheromone traps are a widely-used tool for monitoring pest activity in commercial apple orchards. Studies were conducted to evaluate delta-style traps painted with different colors (orange, red, yellow, green, blue, and white) for capture of obliquebanded leafroller, Choristoneura rosaceana (Harris), and oriental fruit moth, Grapholita molesta (Busck), as well as nontarget muscoid flies (Diptera: Muscidae) and honeybees, Apis mellifera L. An additional study evaluated plastic, four-sided LepTrap® traps of various colors in comparison with a standard delta trap for capture of obliquebanded leafroller, oriental fruit moth, tufted apple bud moth (Platynota idaeusalis (Walker)), and codling moth (Cydia pomonella L.). Capture of obliquebanded leafroller and oriental fruit moth was not significantly affected by trap color. Capture of nontarget flies and honeybees tended to be higher in blue and white (both painted and unpainted) delta-style traps in New York apple orchards, although there was some variability in this response by orchard site. There were no differences in capture of 4 pest species in Pennsylvania between colored, plastic LepTrap® traps and standard unpainted white delta-style traps. Given the observed differences in nontarget capture and the improved efficiencies of finding traps placed within tree canopies, we recommend using yellow, red, or orange delta traps for monitoring of obliquebanded leafroller, oriental fruit moth, and tufted apple bud moth in apple production areas in the eastern United States.

Relative Susceptibility of New Apple Cultivars to Arthropod Pests

As part of a regional NE-183 project (Multidisciplinary Evaluation of New Apple Cultivars), 23 apple (Malus ×domestica Borkh.) cultivars were evaluated for arthropod pest susceptibility. Incidence or injury data were collected from six foliage and eight fruit pests under field conditions over a four year period (2000–03). Cultivars were ranked based on susceptibility (least to most) to each pest, and rankings were summed for members of the foliage and fruit pest group to develop a susceptibility rating for foliage, fruit and all pests combined. Cultivars with lowest susceptibility to foliage pests included `GoldRush' and `Pioneer Mac', whereas `Yataka' and `Cameo' were most susceptible. For fruit pests, susceptibility was lowest for `Pristine' and `Sunrise', and highest for `Cameo', `Fuji Red Sport #2', and `Gala Supreme'. When both foliage and fruit pests were combined, susceptibility was lowest for `Sunrise' and `Pioneer Mac', and highest for `Cameo'. Some increasingly popular cultivars had high levels of injury from a few pests, including plum curculio and apple maggot on `Ginger Gold', codling moth and oriental fruit moth on `Cameo', and japanese beetle, plum curculio and apple maggot on `Honeycrisp'. A positive and significant correlation was found between day of harvest and percent fruit injury from codling moth/oriental fruit moth and tufted apple bud moth/redbanded leafroller, with later maturing cultivars experiencing higher injury levels presumably due to more exposure to later generations of these pests. Differences among cultivars in pest incidence and injury can be used by growers to improve pest management through cultivar selection, or by making modifications in control programs based on cultivar susceptibility.

Insect Growth Regulator Impact on Fecundity and Fertility of Adult Tufted Apple Bud Moth, Platynota idaeusalis Walker

The tufted apple bud moth, Platynota idaeusalis Walker, is a major pest of apples in the eastern United States. Resistance to conventional insecticide chemistries has made this pest difficult to control. The insect growth regulators (IGRs) tebufenozide and methoxyfenozide, which are target-specific to lepidopteran pests, have been shown to have high efficacy against P. idaeusalis larvae. These compounds are known to affect adult moths in related tortricid species, but the effects of exposure on adult P. idaeusalis are unknown. This study investigated the effects of adult exposure on the fecundity and fertility of P. idaeusalis. Both tebufenozide and methoxyfenozide significantly reduced the fecundity and fertility of female P. idaeusalis adults that were exposed to dry films of formulated IGR residue. Female fecundity and fertility also were reduced when untreated or treated females mated with treated males. Contrary to other related studies, there was no difference in fecundity/fertility reduction efficacy between tebufenozide and methoxyfenozide. Thus, because tebufenozide and methoxyfenozide have reproductive activity against adults, such compounds may bring significant benefits to integrated pest management (IPM) of tree fruits.