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BACKGROUND Root-feeding beetles, particularly Hylastes spp., Hylobius pales Herbst and Pachylobius picivorus Germar, increase in abundance in stressed forest stands and vector Grosmannia and Leptographium spp. fungi, which contribute to southern pine decline (SPD) in the southeastern United States. This study examined changes in the relative abundance of root-feeding beetles in response to mechanical thinning and clear-cut of even-age loblolly pine (Pinus taeda L.) stands in central Alabama and Georgia every 2 weeks during a 30 month study in 2009–2012. RESULTS The most abundant bark beetles were Hylastes salebrosus Eichhoff, H. porculus Erichson and H. tenuis Eichhoff. The relative abundance of the Hylastes spp. significantly increased after thinning treatments at all five sites. An initial decrease in Hylastes spp. occurred in response to clear-cut in some plots, but they typically recovered 2 months later and were stable for the remainder of the study. CONCLUSION This study reports on the relative abundance responses of pathogen-vectoring root-feeding beetles to a thinning and clear-cut treatment in P. taeda stands. Thinning treatments conducted during the summer and winter may increase the relative abundance of Hylastes spp., vectors of Leptographium and Grosmannia spp., which are known to contribute to SPD by triggering plants to release defensive volatile compounds. © 2013 Society of Chemical Industry

Summary. Helophorus rugosus Ol. and Helophorus porculus Bedel, have caused serious damage to late sown white turnips in several cases in the east of England during the last few years. A case in which the growing points of white turnips (planted out for seed growing) were eaten out by the larvae is recorded. Swedes and rape are damaged by these pests but not to the same extent as white turnips. Kale and cabbages are only slightly damaged. Lettuces were seriously damaged in Surrey in 1924. One case of an attack on beans by H. rugosus was also noticed. Most of the damage is caused by the larvae which gnaw or tunnel into the “bulb” of the turnip as well as feeding on the developing leaves. The adults also feed on the leaves. Eggs are probably laid in August and the larvae live from August until April or May. Pupation takes place in April or May and pupae live about three weeks. Adults were found from May until the following March. Descriptions of the larval, pupal and adult stages are given. Late sowing and frequent cruciferous crops appear to predispose plants to attacks.