Simulation Model Refinement: Ferris 201

5. FERRIS, H., and M. V. McKENRY. 1974. 11. NICHOLSON, A. J. 1933. The balance of Seasonal fluctuations in the spatial distribu- populations. J. Anita. "Ecol. 2:132-178. tion of populations in a California 12. OOSTENBRINK, M. 1966. Major characteristics vineyard. J. Nematol. 6:203-210. of the relation between and plants. 6. FERRIS, H., and R. H. SMALL. 1975. Computer Meded. LandbHogesch. Wageningen 66:46 p. simulation of Meloidogyne arenaria egg 13. SEINHORST, J. W. 1965. The relation between development and hatch at fluctuating tem- nematode density and damage to plants. perature. J. Netnatol. 7:322 (Abstr.). Nematologica 11 : 137-154. 7. FREEMAN, B. M., and R. E. SMART. 1976. 14. TYLER, J. 1933. Development of the root-knot Research note: a root ohservation laboratory nematode as affected by temperature. Hil- for studies with grapevines. Am. J. Enol. gardia 7:391-415. Viticult. 27:36-39. 15. VANDERPLANK, J. E. 1963. Plant Diseases: 8. GRIFFIN, G. D., and J. H. ELGIN, JR. 1977. Epidemics and Control. Academic Press, Penetration and development of Meloidogyne New York. 349 p. hapla in resistant and susceptible alfalfa 16. WALLACE, H. R. 1973. Nematode Ecology and under differing temperatures. J. Nematol. Plant Disease. Edward Arnold, New York. 9:51-56. 228 p. 9. McCLURE, M. A. 1977. Meloidogyne incognita: 17. WINKLER, A. J., J. A. COOK, W. M. a metabolic sink. J. Nematol. 9:88-90. KLIEWER, and L. A. LIDER. 1974. General 10. MILNE, D. L., and D. P. DUPLESSIS. 1964. De- Viticulture. University of California Press, velopment of Meloidogyne javanica (Treub) Berkeley. 710 p. Chit., on tobacco under fluctuating soil temperatures. S. Afr. J. Agr. Sci. 7:673-680.

Dolichodorus aestuarius n. sp. (Nematode: ) 1

F. H. CHOW and A. L. TAYLOW Abstract: aestuarius n. sp. from an estuarine habitat near Cedar Key, Florida is described. This nematode has a stylet range of 62-76 #m in females and 60-72 #m in males. The styler is shorter than those of all described species except D. brevistilus. The probable host plant is Juncus roemerianus. Key Words: nematode, .

During May 1976, a survey of nematode 11.7), c 58.9 (52.6-67.9), stylet 66.2 /zm fauna in estuarine habitats in the Cedar (60-72 tLm). Spicule 49.43 /~m (47-51 #m) Key, Florida area was conducted, and a new and gubernaculum 26.8 t~m (26-29 /~m) species of the awl nematode (Dolichodorus) (average of 7 specimens). was found in a habitat where Juncus Allotype (male): L 2.31 mm, a 51.3, b roemerianus Scheele was the only plant. It 9.7, c 60.8, styler 68 /zm, spicule 48 izm, is presumed that the nematode was feeding gubernaculum 29/~m. upon the roots of this plant. DESCRIPTION: Dolichodorus aestuarius n.sp. Females.--Body long and cylindrical, DIMENSIONS: somewhat ventrally curved; tapers gradually Paratypes (14 females): L 2.66 mm (2.50- anteriorly and abruptly posteriorly to con- cave, conoid terminus (Fig. 1-C,H). Cuticle 2.87 mm), a 42.6 (38.8-47.8), b 11.3 (10.1- very finely striated, 1.5 /zm/annule at mid- 12.1), c 34.7 (30.9-44.8), V 55% (51-59%), body; lateral field areolated with three stylet 68.1 /~m (62-76 t~m). Holotype (female): L 2.87 mm, a 44.2, incisures on most of the body; incisures start b 11.9, c 39.9, V 2s.2, 53 %, ~0.s, stylet 68 /~m. as one, about 15 annules posterior to head, and end as one, just anterior to phasmid Paratypes ( 11 males): L 2.32 mm (2.11- (Fig. 1-C,E,H). Head with six lips; laterals 2.59 mm), a 48.1 (39.1-60.0), b 10.1 (9.2- bear amphid (Fig. l-B). Stylet with com- Received for publication 30 March 1977. paratively broad shaft and rounded knobs; xFlorida Agricultural Experiment Station Journal Series No. stylet slopes gently at posterior; guiding 462. ~Department of Entomology and Nematology, University of ring not seen. Esophagus typical for genus; Florida, Gainesville, Florida 32611. dorsal gland orifice about 5 tzm behind 202 Journal o[ Nematology, Volume 10, No. 2, April 1978

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FIG. I-(A-I-I). Dolichodorus aestuarius n. sp..4) Entire female and reproductive system, lateral view. B) Female, en face view. (7) Female, anterior end, lateral view. D) Female, vulval region, lateral view. E) Female tail, lateral view. F) Male tail, ventral view. G) Male tail, lateral view. H) Female, head region, lateral view. Dolichodorus aestuarius n. sp.: Chow, Taylor 203 stylet knob; nerve ring encircles posterior found 1.4 km from state road 24, on the part of isthmus (Fig. l-C). Excretory pore unpaved road southwest of Cedar Key city located slightly anterior to basal bulb. dump area, Cedar Key, Florida, U.S.A. Hemizonid not observed. Intestine without peculiar characteristic. Vulva slit-like and DIAGNOSIS: deep with four peg-like cuticularized struc- DoIichodorus aestuarius n. sp. has three tures around opening; muscles of vagina incisures in the lateral field, which distin- uterina well developed (Fig. l-D). Ovaries guishes it from D. obtusus Allen, 1957; D. outstretched (Fig. l-A). Concave conoid arenarius Clark, 1963; D. adelaidensis point of tail with more abrupt reduction in Fisher, 1964; D. brevistilus Heyns and Har- diameter ventrally than dorsally. There are ris, 1973; and D. cassati Luc and Dalmasso, about 60 annules on the tail; anal body 1971, all of which have four incisures (1, 2, diameter is about 37/~m; the last 15 annules 4, 7, 11). D. aestuarius may be separated on the tip are at an angle of 30-45 ° to from other species having three incisures as preceding annules (Fig. l-E). Phasmids follows: from D. silvestris Gillespie and located about 25-30 /~m posterior to anus Adams, 1962; D. puIvinus Khan and (Fig. l-E). Seshadri, 1971; D. profundus Luc, 1960; and Males.--About 10-12% shorter but about D. nigeriensis Luc and Caveness, 1963 in as wide as females; similar to females as that tile excretory pore is a little anterior regards anterior part, nerve ring, excretory to tile basal bulb in D. aestuarius and op- pore, intestine, annulation, and lateral posite tile medium bulb in tire others (5, 8, field. Bursa tri-lobed with striations to tips 9, 10). In D. similis Golden, 1958, the ex- (Fig. 1-F,G); spicules massive, heavily cretory pore is opposite the middle of cuticularized; gubernaculum mostly straight tile basal bulb (6). The stylet of D. with curved and pointed distal end (Fig. heterocephalus is more than I00 /~m long l-G). (3) in comparison with 68 /~m in D. DISTRIBUTION: aestuarius. Holotype (female).--Collected on May LITERATURE CITED 12, 1976 by F. H. Chow and D. E. Stokes. Type collection, Nematology Laboratory, 1. ALLEN, M. W. 1957. A new species of the U.S.D.A., Beltsville, Maryland, U.S.A. genus Dolichodorus from California. (Nema- tode: ). Proc. Helminthol. Soc. Allotype (male).--Same as holotype. Wash. 24:95-98. Paratypes.--Same data as holotype, and 2. CLARK, W. C. 1963. A new species of distributed as follows: Dolichodorus (Nematoda: Tylenchida) from Four females, four males: Department of coast dune sand. New Zealand J. Sci. 6:531- Entomology and Nematology, University of 534. 3. COBB, N. A. 1914. The North American free- Florida, Gainesville, Florida, U.S.A. living freshwater nematodes. Contributions Four females, four males: Department of to a science of nematology. Tr. Am. Micr. Entomology and Nematology, University of Soc. 33:69-134. Florida, Gainesville, Florida, U.S.A. 4. FISHER, J. M. 1964. Dolichodorus adelaidensis Two females, one male: Same as holo- n. sp. and Paralongidorus eucalypti n. sp. from S. Australia. Nematologica. 10:464-470. type. 5. GILLESPIE, W. H., and R. E. ADAMS. 1962. Two females, one male: Department of An awl nematode, Dolichodorus silvestris Nematology, University of California, n. sp. from West Virginia. Nematologica. 8: Riverside, California, U.S.A. 93 -98. Two females, one male: Laboratorium 6. GOLDEN, A. M. 1958. Dolichodorus similis, (Dolichodorinae), a new species of plant voor Nematologie, Binnenhaven 15, Wagen- nematode. Proc. Hehninthol. Soc. Wash. 25: ingen, The Netherlands. 17-20. One female, one male. Nematology 7. HEYNS, J., and R. H. G. HARRIS. 1973. Department, Rothamsted Experimental Dolichodorus brevistilus n.sp. (Tylenchida) a plant parasitic nematode found in surgar- Station, Harpenden, Herts., England. cane fields in Natal. I'hytophylactica. 5:123- TYPE LOCALITY: 126. 8. KHAN, E., A. R. SESHADRI, B. WEISCHER, Around roots of ]uncus roernerianus and K. MATHEN. 1971. Five new nematode Scheele, a common brackish marsh plant, species associated with in Kerala, 204 Journal o[ Nematology, Volume 10~ No. 2, April 1978

India. India J. Nematol. 1:116-127. Dolichodoridae). Proc. Helminthol. Soc. Wash. 9.-LUC, M. 1960. Dolichodorus profundus n. sp. 30:297-299. (Nematoda Tylenchida). Nematologica. 5:1-6. 11. LUC, M., and A. DALMASSO. 1971. Dolicho- 10. LUC, M., and F. E. CAVENESS. 1963. dorus cassati n. sp. Ann. Zool. Ecol. Anita. 3: Dolichodorus nigeriensis n. sp. (Nematoda: 97-101.

Phytoparasitic Nematodes Adjacent to Established Strawberry Plantations 1 R. V. CROW and D. H. MACDONALD ~ Abstract: Plant-nematode populations associated with uncultivated vegetation, adjacent straw- berry plants, and alternate crop sites were studied at three locations in Minnesota. At one site (Forest Lake), Paratylenchus projectus, Meloidogyne hapla, and Pratylenchus tenuis were fre- quently associated with the roots of native vegetation. These nematode species were also present in adjacent strawberry beds. Among alternate crops observed, oats and muskmelon usually supported the fewest nematodes although moderate densities of Xiphinema americanum and P. tenuis were found at one location in plots planted to oats. Pratylenchus tenuis was also found on rye at one location. Key Words: Population dynamics, control, nonhost plants, Meloidogyne hapla, Paratylenchus sp.

Plant-parasitic nematodes in cultivated wooded areas in Maryland contained soil may be affected by the planting of cover Helicotylenchus dihystera, P. penetrans, crops, the use of alternate crop sequences, Xiphinema sp., Meloidogyne hapla, Ty- and fallow (I, 2, 3, 5). Cover crops can in- lenchorhynchus sp., Hoplolairnus sp., and fluence plant-nematode densities in newly Paratylenchus sp. These genera are also cleared and old agricultural land (1, 2). frequently found in commercial strawberry Investigations with alternate cropping and plantings. Such findings suggest the possi- short-term (6 weeks) fallow indicate that bility that nematodes found in strawberry nematodes may be controlled better by a plantings could be indigenous to the soil combination of the two practices than by (4). either alone (3, 5). Because of tile obligate of Morgan and Collins (8) observed that plant-parasitic nematodes, the use of host densities of Pratylenchus penetrans were and nonhost plants often results in striking low in strawberry plantings if favorable changes in nematode populations. Such weed hosts were removed. In a host range changes were studied in, and adjacent to, study, 55 species of weeds and 7 cultivated established strawberry plantings at three plant species growing near strawberry were locations in Minnesota. infected by P, penetrans (9). Weeds with soft-textured roots contained more nema- MATERIALS AND METHODS ,todes than those with hard-textured roots, and perennials supported higher nematode Soil samples, each consisting of 5-8 cores populations than did annuals. Townshend (2.5 x 25 cm) composited in a plastic bag, and Davidson (9) suggested that P. pene- were collected from strawberry beds and trans probably overwintered in weeds with contiguous areas. The number of samples soft-textured roots. taken from a strawberry bed depended upon Soil and root samples from wild straw- the bed length. Three samples were col- berry plants (Fragaria virginiana) in lected from beds 15 to 46 m long while five samples were taken from beds up to 153 m long. Fields or groves were sampled accord- Received for publication 5 October 1976. a Paper No. 9661, Scientific Journal Series, Minnesota Agri- ing to total area. Twelve samples were • cultural Experiment Station. University of Minnesota, St. collected from a 0.2- to 0.5-ha area, whereas Patti, MN 55108. ~Respectively, former Graduate Assistant, now Manager- 20 samples were taken from a 1-ha field. Agronomic Services, N-Ren Corporation, Cincinnati, Ohio The sampling techniques employed utilized 45226; and Associate Professor, Department of Plant Patl~qlogy, University of Minnesota, St, Paul, MN 55108. the recommendations of Langdon (7). An