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Inspect landscapes for beetle damageBy Ray Ridlen There may be a lot of twigs littering the yard at this time. This is possibly a result of a long-horned beetle often referred to as the twig girdler. Close inspection of the twigs strewn around the landscape will reveal a distinct cut made by this particular beetle. The cut is a uniform V-shaped cut with a small central area with a jagged surface caused by the break. The small beetle, which is about half an inch long, is active from late August through early October, feeding on tender bark near branch ends where they lay eggs after they girdle the twig. The girdling extends through the bark and well into the wood in a complete circle around the stem and leaves only a thin column of the center wood attached. The twig will then die beyond the chewed portion and will remain hanging in the tree or fall to the ground when the wind blows and dislodges it. The eggs laid in the twigs will hatch in about three weeks. The small larvae over-winter in the dead twig, either in the tree or on the ground. Larvae grow rapidly in the spring and tunnel toward the severed end of the twig. The mature larva pupates in the twig and then emerges as an adult beetle in August and September. Twig girdlers are commonly found on pecan, hickory, persimmon and elm. They also attack oaks, honeylocust, hackberry, poplar, dogwood, sourwood and various fruit trees. It is not uncommon to see the ground under infested trees almost covered with twigs that have been cut off. This affects the beauty and aesthetic quality of ornamental plantings. The fruiting area of heavily infested pecan trees is often greatly reduced, resulting in low nut yields the following year and sometimes longer. This type of injury causes the development of many offshoots that adversely affect the symmetry of the tree. Control this time of year is best achieved by gathering and destroying the twigs this fall, winter and spring, when the eggs and larvae are in the twigs. Insecticides may be necessary next August and September to prevent damage from heavy infestations. Date: 10/15/2012
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