Meloidogyne haplanaria n. sp. (Nematoda: Meloidogynidae), a Root-knot Nematode Parasitizing Peanut in Texas.

Meloidogyne haplanaria n. sp. is described and illustrated from specimens parasitizing peanut in Texas. The perineal pattern of the female is rounded to oval with a dorsal arch that is high and rounded except for striae near the vulva, which are low with rounded shoulders. The striae are distinctly forked in the lateral field, and punctations often occur as a small group near the tail tip and singly within the whole perineal pattern. The female stylet is 13-16 microm long and has broad, distinctly set-off knobs. The excretory pore opens 40-118 microm from the head, approximately halfway between the anterior end and the metacorpus. Males are 1.2-2.4 microm in length and have a high, wide head cap that slopes posteriorly. The labial disc and medial lips are partially fused to form an elongated lip structure. In some specimens the labial disk is distinctly separated from the lips by a groove. The stylet is 17-22 microm long and has wide knobs that are rounded and distinctly set off from the shaft. Mean second-stage juvenile length is 419 microm. The head region is not annulated, and the large labial disc and crescent-shaped medial lips are fused to form a dumbbell-shaped head cap. The stylet is 9-12 microm long and has rounded, posteriorly sloping knobs. The slender tail, 58-74 microm long, has a distinct, inflated rectum and a slightly rounded tip. The hyaline tail terminus is 11-16 microm long. The isozyme phenotypes for esterase and malic dehydrogenase do not correspond to any other recognized Meloidogyne species. Tomato and peanut are good hosts; corn and wheat are very poor hosts; and cotton, tobacco, pepper, and watermelon are nonhosts.