The pecan tree beetle is the only pest that grows within the pecan kernel itself, causing instant damage to your home garden trees. The eponymous pecan tree beetle is commonly referred to as the pecan weevil. Though detection can be a bit tricky, familiarize yourself with a reliable method of recognition as well as control methods to keep your trees healthy and productive.
Pecan tree beetles (Curculio caryae Horn) display legless cream/white bodies with brown/red heads in their larval stage; larvae grow to a length of 3/5 inch. In their adult form, pecan beetles display brown bodies with snouts that make up half of their entire length of 3/8 inch, according to the Texas A&M University AgriLife Extension.
For pecan trees that are more likely to resist or fight a pecan tree beetle infestation, keep your trees as vigorous as possible. Healthy trees are more resilient than weakened trees. Grow pecan trees in locations that provide full sunlight, according to the University of Arkansas Cooperative Extension Service. Pecan trees prefer fertile soil and need at least 35 feet of space between each tree for successful growth and optimal health.
Symptoms and Damage
Adult pecan tree beetles chew a hole into the shell of pecan nuts and lay their eggs within. Once hatched, larvae feed on the tissue of the kernel inside of the shell from the end of the summer season until autumn. Within approximately six weeks, larvae chew out of the shell and fall from the tree where they dig into soil and remain until fully grown. Adults are "chewing" bugs that also feed on nuts. Damaged nuts fall from the tree and crop losses can be significant, according to the Texas A&M University AgriLife Extension.
Identifying a problem early on will allow you to diagnose and treat your pecan trees before extensive damage is done. The easiest, least expensive method of detection and identification is placing a light colored piece of fabric or paper beneath the tree and tapping the branches. Pecan tree beetles are knocked from the tree onto the material below. Additionally, damaged nuts may fall and may be inspected for typical larval damage, according to the Texas A&M University AgriLife Extension.
Once you have identified a pecan tree beetle problem, a management program is essential. For a natural method, consider the release of natural enemies into the garden. These enemies include lady beetles, predatory mites, lacewings and parasitic wasps that will hunt and kill beetles without causing damage to your pecan trees, according to the Texas A&M University AgriLife Extension. Find these enemies in garden supply catalogs or stores. As chemical control methods are effective but hazardous, contact a licensed professional for appropriate application with reduced potential for drift or harm of people, animals and desired plants.