The adult is a reddish-brown elongate beetle approximately one-fourth inch in length. The male of the species has a pair of blunt tooth-like structures on the third abdominal segment. Several males are usually found in the presence of a single female. This species requires moist wood which is favorable to the growth of fungi upon which they feed. The adults bore into sapwood or heartwood of logs and lumber, making pin-sized holes which are stained by the ambrosia fungus. The female lays eggs in small clusters in the tunnel and the developing larvae excavate tiny cells extending from the tunnel parallel to the grain of wood. There may be several generations a year.
Ambrosia beetle damage to green sawlogs and lumber may result in considerable degrade and strength reduction. The best control is rapid utilization of dead or dying trees. Lumber should be seasoned as soon as possible to reduce or eliminate losses.
SOUTHERN PINE SAWYERS, Monochamus spp.
In the South, dying pines and fresh logs are quickly attacked by the pine sawyers. In sufficient numbers they may cause a significant loss of wood fiber and degrade sawlogs. These species are commonly found in the South infesting southern pine, fir, and spruce wherever the hosts grow.
Adult southern pine sawyer beetle.
The adults emerge in the spring or summer and begin to feed on the bark of twigs. After mating, the female gnaws pits through the bark of freshly felled or dying pine. The female beetle lays one to several eggs in each pit. After eggs hatch the larvae bore beneath the bark for 40-60 days, converting the inner bark into coarse, shredded frass. The larvae then enter the wood and make deep U-shaped cells through the heartwood and sapwood. The entrance is plugged with frass and the far end is excavated into a pupal chamber. The larvae pupate the following spring or early summer, transform into adults, and emerge that same season. The insect has two or three generations per year in the South.
Pine sawyers render storm- or fire-damaged pines unfit for salvage and are also a problem in wood-holding yards. Rapid salvage and utilization of dead or dying trees or green logs will reduce losses significantly.
NANTUCKET PINE TIP MOTH, Rhyacionia frustrana (Comstock)
The impact of the Nantucket pine tip moth on pine plantations varies widely with tree species, host vigor, and environmental factors. Heavily infested trees may be severely stunted or deformed but mortality is rare. Generally, the tree grows out of the susceptible stage within a few years. In seed orchards, the tip moth is receiving increasing attention because of its impact on height growth and, more importantly, because of its effect on flower and cone production. All species of pine within the range of the tip moth except white pine and longleaf pine, are attacked. It has been reported from all states in the eastern hard-pine region extending across east Texas, Oklahoma, Illinois, Indiana, Ohio, and southern New York State.