Belonolaimus gracilis
Steiner, 1949

Female: 2.15 mm; a = 52; b = 10; c = 19.2; V = 52
Male:  1.7 mm; a = 52; b = 9; c = 14.7
Characters of the genus.  Lip region set off by deep constriction, bearing about nine annules.  A face view shows the head to be four-lobed, with deep lateral grooves in which the amphid apertures are located.  These grooves are in alignment with the lateral body lines, which extend to the lip region.  Labial disc a prominent feature.  Spear 157 u long, with strong, rounded knobs.  Esophageal lumen convoluted in procorpus when spear is retracted.  Median bulb spherical, more than half as wide as neck.  Nerve ring almost adjacent to median bulb.  Hemizonid adjacent to excretory pore.  Basal portion of esophagus extended in a broad lobe.  Junction of esophagus and intestine an obscure muscular valve.  Intestine extending into tail cavity, with rectum attached ventrally.  Ovaries outstretched, with spermatheca.  Phasmids of both sexes slightly anterior to middle of tail.  Male tail enveloped by bursa, which rises anterior to spicula.

Belonolaimus gracilis is distinguished from B. longicaudatus by the shorter tail, longer spear, and greater relative width.

Hosts and distribution:  Slash pine, Pinus caribaea Morelet, Ocala, Florida, and longleaf pine seedlings in forest nurseries in other parts of the state.  According to Rau, Belonolaimus gracilis has a very limited distribution.
(Description- Thorne, 1961)