| 摘要 |
<p>A low-traction barrier method and a apparatus are provided for preventing the traverse of gypsy moth caterpillars or similar destructive crawlers across the barrier. A strip of slippery, compliant material has low-traction characteristics with respect to gypsy moth caterpillars and thus initially arriving caterpillars do not become stuck on the harrier and do not form "bridges" across the barrier over which later arrivals can crawl. Self-adhering adhesive material extends longitudinally on one surface of the strip along at least one of its longitudinal margins. The strip is wrapped around and is adhered to the trunk of a tree to provide a barrier for preventing gypsy moth caterpillars from traversing either up or down the tree trunk by causing them to slip off of the barrier and fall to the ground whenever they attempt to traverse it. The compliant characteristics of this low-traction strip enable the adhesive coated margin of the strip to be inserted into indentations in the rough bark of a tree trunk as the strip is being wrapped around the tree for preventing the occurrence of vertical tunnels underneath the barrier through which smaller caterpillars could crawl. By positioning the low-traction strip around the trunk below the foliage of the tree, ascending caterpillars fall before they roach the foliage. Descending caterpillars also fall while attempting to traverse the strip and thereafter are prevented from ascending back up the tree by the low-traction strip. In one aspect of the invention, adhesive backing extends along the upper longitudinal margin of one side of the slippery compliant strip. This upper margin of strip is folded by crimping between the thumbs into approximately equidistantly spaced pleats as it is being wrapped around the trunk to form an outwardly flared, downwardly extending skirt from the main body of the strip. In this advantageous manner, the barrier formed by the flared skirt approxmately doubles the slippery surface area over which a caterpillar must traverse in order to climb up or down the tree, thus greatly enhancing the probability that the caterpillar will fall. Moreover, the skirt requires ascending caterpillars to negotiate a complete 180.degree. inversion around the lower edge of the strip with gravitational forces acting against them, further impeding their traverse.</p> |
