What's eating my pecan 'desirable'?

Pecan 'Desirable' is a high-quality but scab-susceptible southern cultivar attacked by pecan weevil, pecan nut casebearer, and aphids. Pecan weevil is the most economically damaging nut pest in the Southeast. Crows and squirrels also raid the crop. Deer browse young growth in establishing orchards.

Adults puncture developing shells and lay eggs inside; larvae consume the kernel entirely, leaving a hollow, darkened nut that drops prematurely. Apply carbaryl or permethrin at the water-stage (gel kernel) and again at shell-hardening; monitor with emergence cages from the soil; remove shuck worms promptly.

First-generation larvae destroy nutlets at pollination; later generations bore into developing nuts, destroying kernels and causing premature drop. Time insecticide applications (carbaryl, spinosad) to egg-hatch, monitored by pheromone traps; the second generation targeting post-pollination is the most critical spray window.

Black pecan aphids inject toxins producing angular yellow blotches on leaflets; yellow aphids coat foliage with honeydew and sooty mold, reducing photosynthesis late-season. Preserve natural enemies (lacewings, lady beetles, parasitic wasps); apply imidacloprid soil drench or foliar insecticide only when populations are high and defoliation is occurring.

Squirrels harvest and bury nuts from shuck-split through October; losses can reach 30–50% in home orchards near wooded edges. Metal trunk banding; live trapping; netting individual limbs during final ripening; harvest immediately at shuck split.