Bursaphelenchus xylophilus

Pine Wilt Nematode
Aug. 20, 2003
Aug. 25, 2003
Sept. 2, 2003
Pine wilt disease progression- UNL East campus Scotch pine
Photo Gallery- Specimens from Dead pines

(Description- Nickle, 1981)
Description of maleSpicules large, uniquely arcuate, paired, with sharply pointed prominent rostrum; distal ends of spicules with typical disc-like expansions.  Tail arcuate, terminus pointed, appearing talon-like on lateral view, surrounded by short, oval caudal alae.  Seven caudal papillae, one adanal pair just pre-anal, single papilla just pre-anal centered; two post-anal pairs just before caudal alae origin.
Description of female:  Lip region high, offset with six lips.  Stylet with small basal swellings.  Esophageal glands slender, 3-4 body-widths long, overlapping dorsally.  Excretory pore opposite junction of esophagus and intestine, sometimes at level of nerve ring.  Hemizonid conspicuous, about two-thirds body width behind medium bulb.  Ovary outstretched, oocytes usually in single file.  Post uterine sac long, extending three-fourths distance to anus. Tail subcylindrical, usually with broadly rounded terminus.
DiagnosisB. xylophilus can be distinguished from other species in the genus by the shape of the spicules, the distinct vulvar flap and the lack of a digitate tail tip which is present in B. mucronatus which we recognize as a valid species.  One of us (YM) tried unsuccessfully to mate B. mucronatus with B. lignicolus, thus indicating their separate species status.  B. fraudulentus is similar to B. xylophilus, but the female has a digitate tail tip similar to B. mucronatus.

DNA Sequences Obtained
Specimen Collected:
FCP-31 Falls City, NE
FCP-32 Falls City, NE

Rapid wilting and death results from infestations of susceptible pine trees by the pinewood nematode.
Pictures of trees killed by pine wilt caused by B. xylophilus
The pine wilt disease was identified for the first time in the United States in Columbia, Missouri in 1979. Since that first report, Bursaphelenchus xylophilus has been found in 36 states, including all the Great Plains states except for North Dakota. The widespread distribution of the pinewood nematode suggests that it is native to the United States.

In North America, investigators have confirmed the disease on 27 species of pinus (pine), one each of abies (balsam) and pseudotsuya (fir), and two each of cedrus (cedar), larix (larch), and picea (spruce). It is considered to be a potentially serious problem in landscape settings, windbreaks, Christmas tree farms, and recreational plantings.
More information on Bursaphelenchus xylophilus and Pine wilt disease