Meloidogyne microcephala n. sp. (Meloidogynidae), a Root-knot Nematode from Thailand

Meloidogyne microcephala n. sp. is described and illustrated from specimens obtained from tobacco (Nicotiana tabacum L.) in Thailand. The female perineal pattern usually has a low dorsal arch, coarse striae, and a series of small cuticular flaps around the tail terminus. The stylet of the female is 14.4 μm long, with large, square to rectangular stylet knobs, The distinctive male head region is narrow, small, and truncate with a low, flattened head cap. The stylet length is 20.6 μm, and the knobs are small, angular, and set off from the shaft. Mean length of second-stage juveniles is 457.5 μm, and stylet length is 9.3 μm. The tail tip in the juveniles is set off from the rest of the tail as a small finger-like projection. M. microcephala reproduces by mitotic parthenogenesis, and has a chromosome number of 2n = 36.     

Meloidogyne platani n. sp. (Meloidogynidae), a Root-knot Nematode Parasitizing American Sycamore

Meloidogyne platani n. sp. is described and illustrated from specimens obtained from roots of American sycamore, Platanus occidentalis, in Virginia. This new species shows certain similarities with M. arenaria but differs from it by a number of distinctive characters. The perineal pattern of females is rounded with fine, wavy to zig-zag striae and raised, convoluted striae in the inner lateral line regions. The stylet of females is 16.5 μm long with large, rounded stylet knobs set off from the shaft. Males have a low head cap and smooth head region. The styler length is 22.0 μm, and the stylet knobs are rounded and set off from the shaft. Mean second-stage juvenile length is 443.0 μm, and stylet length is 12.2 μm. The head region of juveniles is not annulated, and the tail has a definite terminus. This nematode causes severe galling and reproduces well on sycamore. Other good hosts include white ash and tobacco cv. NC 95. M. platani n. sp. reproduces by mitotic parthenogenesis and has a somatic chromosome number of approximately 45 (2n).     

Meloidogyne mayaguensis n. sp. (Meloidogynidae), a Root-knot Nematode from Puerto Rico

Meloidogyne mayaguensis n. sp. is described and illustrated from specimens obtained from galled roots of eggplant, Solanum melongena L., from Puerto Rico. The perineal pattern of females is round to ovoid with fine, widely spaced striae. It has occasional breaks of striation laterally and a circular tail tip area lacking striae. The stylet, 15.8 μm long, has reniform knobs that merge gradually with the stylet shaft. Males have a high, rectangular, smooth head region, not set off from the body contour. The labial disc is continuous with the medial lips which do not slope posteriorly. The styler, 22.9 μm long, has large rounded backward sloping knobs; the shaft is of uneven diameter. Mean body length of second-stage juveniles is 453.6 μm. The truncate head region is not annulated, and the rounded, slightly raised labial disc and the crescentic medial lips form dumbbell-shaped lip structures. The stylet, 11.6 μm long, has rounded, posteriorly sloping knobs. The slender tail, 54.4 μm long, gradually tapers to a bluntly pointed tip. Tomato, tobacco, pepper, and watermelon are good hosts; cotton and peanut are not hosts. M. mayaguensis n. sp. reproduces by mitotic parthenogenesis and has a somatic chromosome number of 2n = 44-45. The enzyme patterns are unique among Meloidogyne species.     

Meloidogyne paranaensis n. sp. (Nemata: Meloidogynidae), a Root-Knot Nematode Parasitizing Coffee in Brazil

A root-knot nematode parasitizing coffee in Paran  State, Brazil, is described as Meloidogyne paranaensis n. sp. The suggested common name is Paraná coffee root-knot nematode. The perineal pattern is similar to that of M. incognita; the labial disc and medial lips of the female are fused and asymmetric and rectangular; the lateral lips are small, triangular, and fused laterally with the head region. The female stylet is 15.0-17.5 μm long, with broad, distinctly set-off knobs; the distance from the dorsal esophageal gland orifice (DGO) to the stylet base is 4.2-5.5 μm. Males have a high, round head cap continuous with the body contour. The labial disc is fused with the medial lips to form an elongate lip structure. The head region is frequently marked by an incomplete annulation. The stylet is robust, 20-27 μm long, usually with round to transversely elongate knobs, sometimes with one or two projections protruding from the shaft. The stylet length of second-stage juveniles is 13-14 μm, the distance of the DGO to the stylet base is 4.0-4.5 μm, and the tail length is 48-51 μm. Biochemically, the esterase (F₁) and malate dehydrogenase (N₁) phenotypes are the most useful characters to differentiate M. paranaensis from other species. However, the esterase phenotype appears similar to that of M. konaensis. Reproduction is by mitotic parthenogenesis, 3n = 50-52. In differential host tests, tobacco, watermelon, and tomato were good hosts, whereas cotton, pepper, and peanut were nonhosts.     

Description of the Kona Coffee Root-knot Nematode,Meloidogyne konaensis n. sp.

Meloidogyne konaensis n. sp. is described from coffee from Kona on the island of Hawaii. The perineal pattern of the female is variable in morphology, the medial lips of the female are divided into distinct lip pairs, and the excretory pore is 2-3 stylet lengths from the base of the stylet. Mean stylet length is 16.0 μm, and the knobs gradually merge with the shaft. The knobs are indented anteriorly and rounded posteriorly and the dorsal esophageal gland orifice (DEGO) is long, 3.5-7 μm. The morphology of the stylet of the male is the most useful diagnostic character, with 6-12 large projections protruding from the shaft. One medial lip may be divided into distinct lip pairs. A large intestinal caecum often extends nearly to the level of the DEGO. Mean juvenile length is 502 μm, mean stylet length is 13.4 μm, and mean tail length is 58 μm. The tail may be distinctly curved ventrally and the phasmids are located in the ventral incisure about one anal body width posterior to the anus.     

Meloidogyne petuniae n. sp. (Nemata: Meloidogynidae), a Root-knot Nematode Parasitic on Petunia in Brazil

Meloidogyne petuniae n. sp. is described and illustrated from specimens parasitic on petunia (Petunia hybrida L.) in Brasilia, Brazil. The perineal pattern of the female is elongate to ovoid with a high, squarish arch and widely spaced, coarse striae. The stylet of the female is 12.9-16.5 µm long and has three small, rounded knobs that are distinctly set off from the shaft. Each knob is marked by a deep longitudinal indentation posteriorly and anteriorly. In SEM the base of the shaft appears to be divided into six distinct ridges. The excretory pore opens about 15.4-53.6 µm from the head end. Males are approximately 0.8-2.2 mm long. Most specimens have a high and narrow head cap, but in some the head cap is narrow and low. The stylet of the male is 21.1-26.0 µm long and has small, rounded knobs, set off from the shaft, but not indented as in the female. Second-stage juveniles are 353-464 µm long; the labial disc is fused with the medial lips to form a dumbbell-shaped head cap; the medial lips are indented posteriorly; and the head region is marked with one to two irregular annulations. The stylet is 9.2-10.8 µm long and has rounded, posteriorly sloping knobs. The tail is slender, approximately 46.4-57.2 µm long, and has a short hyaline terminus, 10.3-13.5 µm long. The somatic chromosome number is 2n = 41 and the esterase phenotype is VS1-S1, with S1 being a weak band. The malate dehydrogenase phenotype is N1, which is unique for this species. Petunia, tomato, tobacco, pea, and bean are good hosts; pepper, watermelon, and sweet corn are poor hosts; and peanut, cotton, and soybean are non-hosts. Galls produced by this species are smaller on petunia than on tomato.     

Meloidogyne hispanica n. sp. (Nematoda: Meloidogynidae), the 'Seville Root-Knot Nematode'

Meloidogyne hispanica n. sp. is described and illustrated from specimens obtained from peach rootstock, Prunus persica silvestris Batsch, from the Seville district of Spain. The perineal pattern of the female is oval shaped to rectangular with low dorsal arch and often widely spaced lateral lines with fringe-like striae. The stylet, 14.1 μm long, has broad, distinctly set off knobs. Males have a high, rounded head cap that slopes posteriorly. Labial disc and medial lips are fused to form elongate lip structures. The robust styler, 23.5 μm long, has large, rounded knobs that are slightly set off from the shaft. Mean second-stage juveniles length is 392.6 μm. The truncate head region is generally not annulated. The distinctly rounded and raised labial disc and the crescent-shaped medial lips form dumbbell-shaped lip structures. The stylet, 11.1 μm long, has rounded, posteriorly sloping knobs. The slender tail, 46.4 μm long, has large irregular-sized annules in the posterior region and ends in a bluntly rounded tip. Tomato was a good host; tobacco, pepper, and watermelon were poor hosts; cotton and peanut were nonhosts. Meloidogyne hispanica n. sp. reproduces by mitotic parthenogenesis and has a somatic chromosome number of 2n = 33-36. The esterase pattern is unique among Meloidogyne species.     

Meloidogyne lusitanica n. sp. (Nematoda: Meloidogynidae), a Root-knot Nematode Parasitizing Olive Tree (Olea europaea L.)

A root-knot nematode from Portugal, Meloidogyne lusitanica n. sp., is described and illustrated from specimens obtained from olive trees (Olea europaea L.). Females of the new species have a characteristic perineal pattern with medium to high trapezoidal dorsal arch with distinct punctuations in the tail terminus area. The excretory pore is located posterior to the stylet, about 1.5-2.5 stylet lengths from the anterior end. The stylet is 17.1 μm long with pear-shaped knobs. Males have a rounded, posteriorly sloping head cap and head region not annulated. The robust stylet, 24.5 μ long, has large, elongate knobs. Mean length of the second-stage juveniles is 449.5 μm, stylet length 14.2 μm, and tail length 44.1 μm. Scanning electron microscope observations provide further details of perineal patterns and head and stylet morphology of females, males, and second-stage juveniles. Meloidogyne lusitanica n. sp. did not reproduce on any of the differential hosts used to separate the four most common Meloidogyne species. The common name "olive root-knot nematode" is proposed for M. lusitanica n. sp.     

Meloidogyne morocciensis n. sp. (Meloidogyninae), a Root-knot Nematode from Morocco

Meloidogyne morocciensis n. sp. is described from specimens parasitic on peach rootstock from Morocco. This species exhibits a combination of morphological characters similar to M. arenaria, M. incognita, and M. javanica. The perineal pattern of females is oval to squarish with a moderately high to high dorsal arch, and widely spaced, smooth striae; lateral lines are absent. The stylet, 16.5 μm long, has transversely ovoid, set-off knobs. Males have a set-off, annulated head region. The large, rounded labial disc is distinctly demarcated from the crescent-shaped medial lips; lateral lips are absent. The robust stylet, 24.6 μm long, has large, rounded knobs that taper slightly posteriorly. Mean second-stage juvenile (J2) length is 401 μm. The set-offhead region has incomplete annulations; the lip structures are dumbbell shaped. The stylet, 12.3 μm long, has rounded knobs that slope posteriorly. The J2 tail, 52.6 μm long, has irregularly sized annules in the posterior region and ends in a bluntly rounded tip. Tomato, tobacco, pepper, and watermelon are good hosts; cotton and peanut are not hosts. Meloidogyne morocciensis n. sp. reproduces by mitotic parthenogenesis and has a somatic chromosome number of 47-49. Its esterase phenotype is identical with the three-banded phenotype (A3) of M. arenaria.     

Morphological,Molecular, and Differential-Host Characterization of Meloidogyne floridensis n. sp. (Nematoda: Meloidogynidae), a Root-Knot Nematode Parasitizing Peach in Florida

A root-knot nematode, Meloidogyne floridensis n. sp., is described and illustrated from peach originally collected from Gainesville, Florida. This new species resembles M. incognita, M. christiei, M. graminicola, and M. hispanica, but with LM and SEM observations it differs from these species either by the body length, shape of head, tail and tail terminus of second-stage juveniles, body length and shape of spicules in males, and its distinctive female perineal pattern. This pattern has a high to narrowly rounded arch with coarsely broken and network-like striae in and around anal area, faint lateral lines interrupting transverse striae, a sunken vulva and anus, and large distinct phasmids. Molecular data from ribosomal IGS illustrate that M. floridensis n. sp. is different from the mitotic species M. arenaria, M. incognita, and M. javanica. Data from RAPDs confirm it and suggest that this new species lies in an intermediate phylogenetic position between the previous species and the meiotic species M. hapla, M. fallax, and M. chitwoodi. Differential host tests based on annual crops and on Prunus accessions are reported.     

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 µm long and has broad, distinctly set-off knobs. The excretory pore opens 40-118 µm from the head, approximately halfway between the anterior end and the metacorpus. Males are 1.2-2.4 µm 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 µm long and has wide knobs that are rounded and distinctly set off from the shaft. Mean second-stage juvenile length is 419 µm. 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 µm long and has rounded, posteriorly sloping knobs. The slender tail, 58-74 µm long, has a distinct, inflated rectum and a slightly rounded tip. The hyaline tail terminus is 11-16 µm 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.     

Description of the Blueberry Root-knot Nematode,Meloidogyne carolinensis n. sp.

Meloidogyne carolinensis n. sp. is described from cultivated highbush blueberry (cultivars derived from hybrids of Vaccinium corymbosum L. and V. lamarckii Camp) in North Carolina. The perineal pattern of the female has a large cuticular ridge that surrounds the perivulval area, and the excretory pore is near the level of the base of the stylet. The stylet is 15.9 μm long and the knobs gradually merge with the shaft. The head shape and stylet morphology of the male are quite variable. The typical head and four variants, as well as the typical stylet and two variants, are described. The labial disc, medial lips, and lateral lips of second-stage juveniles are fused and in the same contour. The head region is not annulated. Mean juvenile length is 463.7 μm, stylet length is 11.9 μm, and tail length is 42.5 μm.     

Description and SEM Observations of Meloidogyne sasseri n. sp. (Nematoda: Meloidogynidae), Parasitizing Beachgrasses

Meloidogyne sasseri n. sp. is described and illustrated from American beachgrass (Ammophila breviliffulata) originally collected from Henlopen State Park and Fenwick Island near the Maryland state line in Delaware, United States (6). Its relationship to M. graminis, M. spartinae, and M. californiensis is discussed. Primary distinctive characters of the female perineal pattern were a high to rounded arch with shoulders, widely spaced lateral lines interrupting transverse striations, a sunken vulva and anus, and coarse broken striae around the anal area. Second-stage juvenile body length was 554 μm (470-550), stylet length 14 μm (13-14.5), tail length 93 μm (83-115), tapering to a finely rounded terminus. Male stylet length 20 μm (19-21.5), spicule length 33 μm (30-36). Scanning electron microscope observations provided additional details of perineal patterns and face views of the female, male, and J2 head. Wheat, rice, oat, Ammophila sp., Panicum sp., bermudagrass, zoysiagrass and St. Augustinegrass were tested as hosts. Distribution of the species was the coasts of Delaware and Maryland. The common name "beachgrass root-knot" is proposed for M. sasseri n. sp.     

Meloidogyne grahami n. sp. (Meloidogynidae), A Root-knot Nematode on Resistant Tobacco in South Carolina

Meloidogyne grahami n. sp. is described and illustrated from specimens on tobacco (Nicotiana tabacum) originally from Florence, South Carolina. Considered for several years to be only a race of M. ineognita, this new species readily attacks NC-95 tobacco, a variety with resistance to the M. incognita group that is common in the major U.S. tobacco-producing areas. M. grahami n. sp. is related most closely to the three subspecies of the M. incognita group but differs from all of them, especially in its distinctive perineal pattern and larger larvae (av. 421 μm, vs. 385 μm or less). Also, the dorsal esophageal gland orifice of females of M. grahami n. sp. is further from the base of the styler (5 μm) than in M. i. incognita and M. i. acrita. Comments are given on the distribution of this new species.     

Meloidogyne polycephannulata n. sp. (Nematoda: Meloidogynidae), a root-knot nematode parasitizing carrot in Brazil

Meloidogyne polycephannulata n. sp. is described from specimens collected from an area cultivated with carrot cv. Brasilia, in the city of Rio Paranaíba, in the region of Alto Paranaíba, Minas Gerais State, Brazil. The perineal pattern of the female is circular to ovoid with a high dorsal arch that has widely spaced, coarse annulations. The lateral field may have a deep furrow separating the dorsal and ventral arches. The medial lips are short and wide, whereas the lateral lips are large and triangular. The female stylet is 15-16 μm long with wide knobs, distinctly divided by an indentation in the center. Its tip is slightly curved dorsally. The excretory pore opens 34-65 μm from the anterior end. Females retain eggs and second-stage juveniles in their body cavity, similar to that of the cyst-forming nematodes. Males are 1.3-1.7 mm long and have a high head cap that is rounded and slopes posteriorly. The labial disc is fused to the medial lips. The head region has several irregular annulations that are similar in appearance to the first or second body annules that are likewise irregular, making the head region appear to be extremely large. The stylet of the male is 21-24 μm long; it is slender, and has small, rounded knobs, that are distinctly indented medially and appear heart-shaped. The shaft has several tiny projections throughout its length. Mean second-stage juvenile length is 411.7 μm. The juvenile head cap is elevated, the medial lips are small, and the lateral lips are elongate to triangular-shaped. The head region has several short, incomplete and irregular transverse annulations. The juvenile stylet is 14-23 μm long with small, rounded, and sloping knobs. The thin tail ends with a short hyaline portion that is variable in size (16-26 μm) and with a small, rounded tip. Isozyme profiles of esterases from Meloidogyne javanica show 3 strong bands (SB) at Rm 46, 59, and 66; profiles of M. polycephannulata n. sp. show a SB at Rm 47 and a weak band (WB) at Rm 52; M. petuniae has two SB at Rm 44 and 53; M. phaseoli has a SB at 53, 58, and 64 Rm; M. brasilensis has three SB at Rm 40, 58, and 66 and a WB at Rm 71; M. pisi has a SB at Rm 40, 60, and 64 and two WB at 46 and 50 Rm. Data from sequencing the 18S rDNA region of M. polycephannulata n. sp. confirms that it is different from M. arabicida, M. arenaria, M. ethiopica, M. incognita, M. javanica, M. paranaensis, and M. thailandica. Sequence identity among these eight species ranged between 85 to 93.4%. Meloidogyne polycephannulata n. sp. reproduces very well on carrot and tomato; poorly on pepper; and not at all on cotton, peanut, tobacco, watermelon, and sweet corn.     

Meloidogyne trifoliophila n. sp. (Nemata: Meloidogynidae), a Parasite of Clover from Tennessee

Meloidogyne trifoliophila n. sp. is described from white clover collected at Ames Plantation, Fayette County, Tennessee. The perineal pattern is rounded, with long, smooth striae and rounded arch, and without distinct lateral lines or perivulval striae. The female stylet is 12.6-15.5 μm long, the excretory pore is level with or up to one stylet length posterior to the stylet knobs, and the vulva is subterminal. The posterior terminus is weakly protuberant. The male lateral field is composed of approximately eight repeatedly broken or forked incisures. The male stylet is 17.0-18.9 μm long, the stylet knobs are rounded and sloping, gradually merging with the shaft, and the head region consists of one large annule. Second-stage juveniles are 357-400 μm long, with a stylet length of 11.9-13.6 μm and one head annule. The tail tapers to a slender tip. This new species is similar to M. graminicola and M. triticoryzae but differs from them in perineal pattern and lateral field morphology, and numerous morphometric characters.     

Description and SEM Observations of Meloidogyne chitwoodi n. sp. (Meloidogynidae), a Root-knot Nematode on Potato in the Pacific Northwest

Meloidogyne chitwoodi n. sp. is described and illustrated from potato (Solanum tuberosum) originally collected from Quincy, Washington, USA. This new species resembles M. hapla, but its perineal pattern is basically round to oval with distinctive and broken, curled, or twisted striae around and above the anal area. The vulva is in a sunken area devoid of striae. Vesicles or vesicle-like structures are present in the median bulb of females. The larva tail, being short and blunt with a hyaline tail terminal having little or no taper to its rounded terminus, is distinctively different from M. hapla. SEM observations revealed the nature of the perineal pattern and details of the head of larvae and males, and showed the spicules to have dentate tips ventrally. Hosts for M. chitwoodi n. sp. include potato, tomato, corn, and wheat but not strawberry, pepper, or peanut. The latter three crops are excellent hosts for M. hapla. The known distribntion of this new root-knot species presently involves certain areas of Idaho, Washington, and Oregon. The common name "Columbia root-knot nematode" is proposed for M. chitwoodi n. sp.     

Morphological and Molecular Characterization of a New Root-Knot Nematode,Meloidogyne thailandica n. sp. (Nematoda: Meloidogynidae), Parasitizing Ginger (Zingiber sp.)

A root-knot nematode Meloidogyne thailandica n. sp. was discovered on roots of ginger (Zingiber spp.) intercepted from Thailand in October 2002 by the U.S. Department of Agriculture Animal and Plant Health Inspection Service at the port of San Francisco. Comparison by light microscopy (LM) and scanning electron microscopy (SEM) to five other morphologically related species (M. incognita, M. arenaria, M. microcephala, M. megatyla, and M. enterolobii) revealed that the new species differs from these by one or more of the following: body, tail and hyaline tail length, shape of head, tail and tail terminus of second-stage juveniles; stylet length and shape of spicules in males; perineal pattern, stylet length and shape of knobs in females. The distinctive perineal pattern is oval to rectangular, with smooth to moderately wavy and coarse striae, and with characteristic radial structures present underneath the pattern area; the dorsal arch is high, sometimes round to rectangular, and striae in and around the anal area form a thick network-like pattern interrupted by lateral lines and large phasmids. Second-stage juveniles have a long, slender tail and long, gradually tapering hyaline tail region ending in a rounded terminus. Male spicules commonly have an acutely angled shaft with a bidentate terminus. Molecular data from the ribosomal large subunit D3 expansion segment revealed four haplotypes, two of which were unique and distinguish M. thailandica n. sp. from M. arenaria, M. incognita, and M. javanica.     

A New Root-Knot Nematode Parasitizing Sea Rocket from Spanish Mediterranean Coastal Dunes: Meloidogyne dunensis n. sp. (Nematoda: Meloidogynidae)

High infection rates of European sea rocket feeder roots by an unknown root-knot nematode were found in a coastal dune soil at Cullera (Valencia) in central eastern Spain. Morphometry, esterase and malate dehydrogenase electrophoretic phenotypes and phylogenetic trees demonstrated that this nematode species differs clearly from other previously described root-knot nematodes. Studies of host-parasite relationships showed a typical susceptible reaction in naturally infected European sea rocket plants and in artificially inoculated tomato (cv. Roma) and chickpea (cv. UC 27) plants. The species is herein described and illustrated and named as Meloidogyne dunensis n. sp. The new root-knot nematode can be distinguished from other Meloidogyne spp. by: (i) perineal pattern rounded-oval, formed of numerous fine dorsal and ventral cuticle striae and ridges, lateral fields clearly visible; (ii) female excretory pore at the level of stylet knobs, EP/ST ratio 1.6; (iii) second-stage juveniles with hemizonid located 1 to 2 annuli anteriorly to excretory pore and long, narrow, tapering tail; and (iv) males with lateral fields composed of four incisures anteriorly and posteriorly, while six distinct incisures are observed for large part at mid-body. Phylogenetic trees derived from distance and maximum parsimony analyses based on 18S, ITS1–5.8S-ITS2 and D2-D3 of 28S rDNA showed that M. dunensis n. sp. can be differentiated from all described root-knot nematode species, and it is clearly separated from other species with resemblance in morphology, such as M. duytsi, M. maritima, M. mayaguensis and M. minor.     

Meloidogyne incognita wartellei n. subsp. (Meloidogynidae), a Root-knot Nematode on Resistant Soybeans in Louisiana

Meloidogyne incognita wartellei n. subsp, is described and illustrated from roots of soybean (Glycine max L.) near Washington, Louisiana. It is rather limited in distribution in that state, being known at five locations comprising about 60,000 acres. It not only attacks commonly susceptihle soybeans but is a destructive pest on other commercial soybean varieties that are resistant to other forms of the M. incognita group in the area. This new subspecies is related most closely to M. i. incognita and M. i. acrita, but differs especially in the females having a delicate stylet with small, rounded knobs sloping posteriorly; dorsal esophageal gland orific further back (5 μm) from base of stylet; and excretory pore often two to three stylet lengths (sometimes more) from the anterior end. Also, males are often without detectable head annules and with an average stylet length of 22.4 μm. Comments and morphometric data are given on M. i. incognita and M. i. acrita.