Ngate folks, here is a copy of a text (which some may have seen in their latest newsletters) with information about cankerworm control. If possible, will try to post this article to the NPNA Web page +/or Yahoo site for later review, sharing etc. It covers a lot of FAQs but if you have any other questions it doesnt answer, people will be available to ask them to at the upcoming two workshops remaining in September as noted in the other recent list post. (in case you missed it: September 17, 6:30-7:30pm at 721 Foster St (Cooperative Extension) and September 22, 6:30-7:30pm at Duke Gardens, register at durhamnc.gov/ich/cmo/sustainability/Pages/Cankerworm.aspx). Duke University and our NG Garden Club may have further activities relating to cankerworm tree banding - watch this space and our list serv (sign up at northgateparknc.org) for updates. Thanks and heres to a less inch-wormy spring in 2015 for all! -------------------------- Cankerworm Control: New season, new programs, free supplies! Last year’s fight against the cankerworm scourge met with substantial success, from reports ‘round the hood. The rematch is on this fall, with new resources & requests for folks to get involved. Our Urban Forester and Ag Extension team will again host workshop(s) in Sept/Oct, with free banding kits / tanglefoot tubes for attendees. Additionally, Duke’s Natural Resource Manager, Katie Rose Levin, hopes to save East Campus’ mature oaks; she’s sending out the call to nearby n’hood residents to help, and get supplies & guidance, at a series of workshops this Sept through April 2015. Please stay tuned to the n’hood list (northgateparknc.org to join) & Facebook (https://facebook/pages/Northgate-Park-Neighborhood-Association/678286752214997) + Durham City General Services/Duke websites for details on times/dates, and our own talk/workshop in NGP. A. Cankerworm insect/tree facts: Cankerworms: larvae of two native moth species whose numbers are recently in plague proportions. Reasons aren’t fully understood but may relate to weather, climate change impacts on life cycle, reduced predation, etc. Destruction cycle begins when flightless female moths crawl up trunks of trees, after/during mating with (winged) male moths. Females lay eggs in crowns of trees (Nov-March) from which worms hatch (March-April) and feed on leaves. Females will climb ANY trunk (large to tiny!) to attempt to get to canopy, even those without edible leaves, including some evergreens known to be heavily targeted as ‘ladders’. Hatched worms can travel surprising distances using wind and silk strands, and move through trees that touch canopies or are in the under canopy - as well as hitching rides on people, pets, cars etc. Willow Oaks are a preferred food source; but leaves of MANY other trees and plants are preyed on. Worms can defoliate all the spring growth on a large tree in as little as 48 hours. Loss of leaves (how the tree makes its food) weakens/stresses trees, making them susceptible to deadlier pathogens & diseases. Trees can use backup reserves to produce new leaves, but over several seasons may be unable to recover and can die. Older trees (like ours) are particularly susceptible. --------------------------- B. Cankerworm control info/how-tos: Two methods of reducing the numbers of worms are use of the insecticide Bt & manual tree banding. Bt is less preferred, having known impacts on all Lepidoptera (butterflies/moths) including key pollinators. Use in Charlotte has had considerable negative impacts with limited gain in combating cankerworm populations. Tree banding – seasonal barriers placed on tree trunks – are a chemical-free, effective alternative when done accurately. 1 or 2 layers of form-fitting material are attached around tree trunks, and plastered with a sticky natural/nontoxic substance (tanglefoot) in which female moths get stuck – preventing egg laying. No other known species climb to propagate, so impact to other insect populations is limited to what few get in the stickum (reportedly rare). Other animals have not been reported getting stuck on trees and should be big enough to avoid this. Banding is not an eradication but a control method, keeping moth/worm numbers in normal ranges & part of the food web controlled by predators (birds, frogs, other insects). It’s not advisable to apply tanglefoot directly to the tree; it drips/stains and is hard to apply consistently. A flat firm band is best to smear it on & keep it in place. Best practice: put up bands in fall when convenient, (about chest/head height); add tanglefoot when 90% of leaves have fallen from canopies – post Thanksgiving/early December (otherwise they get stuck and make a bridge for moths to cross over bands). Tanglefoot is harder to spread in the cold; loosen by placing a bucket/tube of it in warm water bath if needed. Bands should be checked & new tanglefoot applied if old fills up with moths; bands should come off by late April/early May when no more moth/worm activity (worms crawl up too) is evident. Bands left longer harm the underlying tree and can lead to weakening or infection/death.
Posted on: Tue, 16 Sep 2014 02:48:41 +0000