Southern Pine Beetle (SPB) - Dendroctonus frontalis

The SPB is a destructive pest of coniferous trees whose natural range is from Pennsylvania to Florida. The figure to the right indicates that the SPB naturally occurs in New Jersey. Research has indicated that there was a record of the SPB occurring in southern NJ in 1939. The extent and duration of the 1939 population is not known. There has not been another known record of it occurring in the Garden State until fall of 2001. (See Figure 1.) The adult beetle is approximately 1/8 inch long, brownish black with the posterior end rounded (Photo 1). Photo 1. Photo courtesy of bugwood.org and Texas A&M	Figure 1. Range map courtesy of bugwood.org
NJ Forest Service foresters have been investigating sites in Atlantic, Burlington, Cape May, Cumberland, and Salem Counties where outbreaks have killed pine trees. The affected areas are approximately 0.10 - 305 acres in size and scattered. The SPB attacks all species of pines, but prefers pitch, shortleaf, pond, and loblolly, which all occur in southern NJ. Initial SPB damage appears as yellow progressing to red and eventually brown (Photo 2). This can happen within 1 to 2 months. Throughout the Pinelands region approximately 2,508 acres have been infested according to our 2003 survey. Aerial reconnaissance for the 2004 survey is about to commence.	Photo 2.
Small yellowish-white pitch tubes found on the lower portion (approx. 15 feet from ground) of a tree is an indication of an infestation. The pitch tubes to the right range from a nickel to a quarter in size (Photo 3). In areas of southern NJ live active beetles were actually present in the tubes. If you gently squeeze the tubes and they are 'mushy' it can be an indication that the SPB has recently infested the area. If you gently squeeze the tubes and they are hard the SPB infestation may have occurred within the past year and the insects may or may not be present. Some pitch tubes may actually contain the insect that created them.	Photo 3.
Another indication that the SPB has attacked a tree is the exit holes on the bark. These are approximately half the size of BB pellets and are usually clustered together (Photo 4). The presence of these exit holes indicates that the SPBs have matured and left the tree.	Photo 4.
Other sign of an attack is reddish dust created during the boring of the tree. This dust can be found within the bark scales and on leaves at the base of infected trees. If bark is removed from an infected tree, signature S-shaped egg galleries can be seen on the wood (trunk) surface and in the inner bark. S-shaped galleries distinguish SPB damage from other bark beetles (Photo 5). The round object is a dime. This will give you a reference for gallery size.	Photo 5.
Larval mines are generally perpendicular to the egg gallery (red arrow) located in the cambium-phloem or cambium-phloem-middle bark and are packed with fine boring dust (Photo 6). Various galleries will contain adults (blue arrow) as well.	Photo 6.
The mortality of pine trees occurs within 3-4 months of initial attack. Needles falling off the branches land on understory vegetation creating a fuel ladder effect, which facilitates wildfires reaching the tree crowns. Trees that may still have dry dead needles on the branches could quickly erupt and wildfire could grow to conflagration proportions (Photo 7).	Photo 7. Photos by the New Jersey Forest Service

Theory on why and how the SPB has turned up in New Jersey

It is theorized that the late 1990's drought, interstate commerce and above average temperatures occurring in the Mid-Atlantic region have contributed to the SPB migrating northward to New Jersey. The forest environment has been under stress thereby increasing the tree's susceptibility to SPB attack. After establishing a presence in the Garden State, the beetles are capable of spreading through flight while being attracted to other beetles through pheromones and to other trees because of various stresses placed upon the forest. The SPB also senses damaged trees from lightning strikes from which fresh pitch acts as an attractant.

Current Actions to Assess the Existing Population and Potential Spread

• The NJFS deployed 18 traps in strategic locations in the south Jersey area to detect the SPB. This is an increase from 6 trap locations the previous year.
• Digital-Aerial Sketchmapping (D-ASM) has been initiated in conjunction with traditional aerial photographic interpretation to map the existing damage and help to predict the potential spread or decline.
• Based on the aerial survey the NJ Forest Service is ground truthing detected areas in our southern state parks and forests while gathering information provided by NJ Approved Consulting Foresters and the public. The NJ Forest Fire Service provided aerial support.
• Pilot suppression projects have been implemented and are being evaluated for effectiveness.
• Forest restoration proposals have been prepared.

If you think you may have the SPB call your consultant forester or NJ Forest Service regional office. While we may not be able to visit each site, we will record your information for survey purposes.