Two new species of Prismatolaimus are described from Orange Bay, Hoste Island, Chile. Prismatolaimus novoporus sp. n. is distinguished by its females being 1.08-1.28 mm long and monovarial with a long postvulvar sac, and having a long tail (c' = 21.5-32.2); males have 11-20 supplements confined to the posterior part of the body. Prismatolaimus chilensis sp. n. is distinguished by its amphidelphic reproductive system, short tail (c' = 9.5), V = 63.4; males have 23 supplements reaching up to the neck region. A well-developed dorsal body pore behind the cardia connected with an apparently glandular organ is reported in P. novoporus sp. n. Function of the organ is unknown, and it is not a general feature in the genus. The generic diagnosis of Prismatolaimus is emended and keys to species, both females and males, are presented. The systematic position of Prismatolaimus is discussed, and it is judged to be the only genus of Prismatolaimidae. Also, it is concluded that Prismatolaimidae and Bastianidae represent two sister taxa in Araeolaimida or Leptolaimina.
taxonomy; morphology; new species; Prismatolaimus; Nemata
Three new species of Etamphidelus are described from Orange Bay, Hoste Island, Chile. All three are distinguished from previously described species by their numerous longitudinal cuticular ridges. E. acucephalus n. sp. is further distinguished by its extremely narrowed anterior body region and posteriorly situated amphids. E. fueguensis n. sp. is distinguished from E. acucephalus by its anteriorly located amphideal fovea, fewer cuticular ridges, smaller V-an/tail ratio and presence of males. E. yamani n. sp. is more similar to E. fueguensis n. sp. differing from it by a wider head end, more posteriorly located excretory pore, longer V-an/tail ratio, more numerous cuticular ridges and smaller spermatozoa. E. puccinelliae (Lorenzen, 1966) Andrássy, 1977 is transferred to Paramphidelus puccinelliae (Lorenzen, 1966) n. comb. The generic diagnosis of Etamphidelus is amended, and a key to species is presented.
taxonomy; morphology; new species; Etamphidelus
Two new species of nematodes from southern Chile are described and illustrated. Pratylenchus australis n. sp. is distinguished by its heavy cephalic sclerotization, smooth tail terminus, lack of spermatheca, and absence of males. Eutylenchus fueguensis n. sp. differs from other Eutylenchus spp. by the long female stylet (31 [28-32] μm), strongly sclerotized excretory duct opening posterior to nerve ring, and broadly rounded caudal alae of males.
Five grape rootstocks were inoculated with 0, 100, 1,000, and 10,000 Pratylenchus vulnus. Dogridge and Saltcreek supported low average total numbers of P. vulnus, 136-705/pot, at 12 months after inoculation. Growth of both rootstocks was not affected. Harmony, Couderc 1613, and Ganzin 1 supported high average total numbers, 6-856 times the inoculum levels. Numbers in Harmony continued to increase at all levels but reduced root weight only at the 10,000 level after 12 months. Numbers in Couderc 1613 decreased by 15-30% after 12 months, and root weight was reduced at the 10,000 level. In Ganzin 1, total nematode numbers diminished after 12 months but were still at high levels; growth reduction was proportional to numbers of nematodes added. Meloidogyne incognita, M. javanica, and M. arenaria produced galls and egg masses in Harmony and Couderc 1613 only at 36 C. Galling in Ganzin 1 increased with increasing temperature. Galls in Ganzin 1 at 18 C supported mature females after 90 days. Harmony was resistant to M. incognita in single and concomitant inoculations of P. vulnus and M. incognita. At 250 days after inoculation, total numbers of P. vulnus increased above the inoculum level and the 150-day values; increase was greatest in P. vulnus added singly. Neither nematode species affected growth of Harmony.
inoculum levels; temperature; Harmony; Couderc 1613; Ganzin 1; Saltcreek; Dogridge; M. incognita; M. javanica; M. arenaria
Brachydorus swarupi sp. n. is described from soil about roots of arecanut palm in Kerala State, India. It is the second species to be described in Brachydorus De Guiran and Germani 1968 and differs from B. tenuis, the type species, by its greater length (1.52-2.34 mm for B. swarupi vs. 1.03-1.32 mm for B. tenuis); longer and more delicate stylet (26-35 μm for B. swarupi vs. 20-23 μm for B. tenuis); head shape with concave protrusion at oral aperture (simple rounded in B. tenuis); shorter isthmus and larger posterior bulb in B. swarupi; shorter tail (in B. tenuis c = 9.7 [8.6-11.5] in female, c = 42.3 [33-48] in male); larger spicules and gubernaculum (22-39 μm and 9 -1 2 μm, respectively, for B. tenuis); and phasmids near posterior connection of caudalalae and tail (almost central on caudalalae of B. tenuis). The relationship of Brachydorus to Dolichodorus is discussed.
In greenhouse tests using potted grape plants three nematicides, aldicarb 10 G at 4.5 ai/ha, phenamiphos 15 G at 22 kg ai/ha, and oxamyl liquid at 4.5 kg ai/ha, were tested against Xiphinema index on 'Thompson Seedless' grape. Different timings for chemical treatments and X. index inoculations were used to determine some of the aspects of the mode of action. When nematodes and nematicides were applied simultaneously, nematodes were reduced from the initial 500 to the averages 5, 1, and 4, respectively, for aldicarb, phenamiphos, and oxamyl. Similar counts (respectively, 3, 1, and 2) were obtained when the nematicides were added first and the nematodes 14 d later. Nematode counts were 83, 112, and 1,346 when nematicides were applied first, and 14 days later plants were washed free of soil, repotted in untreated soil, and then inoculated. In untreated controls the population increased to an average of 2,703. Plant growth was inversely related to the level of nematode population resulting from the treatment.
Dagger nematodes; organophosphates; carbamates
Residue dynamics in giapevine of the nematicide aldicarb (2-methyl-(metbylthio) propionaldehyde-O-(Methylcarbamoyl) oxime) and its biologically similar active metabolites, aldicarb sulfoxide and aldicarb sulfone, were determined by gas chromatographic techniques. Residues were found in the roots, trunks, stems, and leaves of grapevine 120 d after application. Residues in leaves as high as 1.40 and 8.89 ppm resulted from 4.5 and 9 kg ai/ha respectively. In roots, trunks, and stems the residues had also declined after 180 d. No residues were detected in the newly forming immature fruit. Residues in roots, trunks, young branches, and leaves declined further after 270 d, but residues in mature fruit at harvest time were 0.03 and 0.05 ppm from application of 4.5 and 9 kg ai/ha, respectively. In other trials the amount of aldicarb toxic residues found in mature fruit at harvest time varied with grape varieties, time and rate of application, total amount of rainfall, irrigation water, and soil type.
Five new records of Paratylenchus, including P. pandus n.sp., are reported from Korea. An amended key to the genus is included on the basis of these findings. Macroposthonia tulagonovi is also reported with additional descriptions and illustrations.
taxonomy; Macroposthonia tulagonovi
In a taxonomic review of the species of the Heterodera "cacti group," H. thornei n. sp. is described and illustrated from Miner's lettuce in California. This new species is distinguishable especially by havpunctate egg shells and a larval stylet (27 μm) and tail (56 μm) longer than other related species. Heterodera weissi is redescribed, type specimens are designated, and new data added on the basis of original and topotype specimens. New morphometric data, along with illustrations, are given for H. cacti, H. amaranthi, and H. estonica, and certain details in the original descriptions are clarified on the latter two species. Diagnoses and a key for identification of these species are given. A common name for each species is proposed when one is lacking. Previously unrecognized tooth-like structures occurring in the vulval cone top of these species and in H. schachtii are characterized and named "vulval denticles." Because of its markedly different morphology, especially in cysts, H. betulae is removed from the H. cacti group and placed alone, since it is incompatible with any of the present Heterodera "groups." Know distribution of these species is given, with the result that many new areas and countries of occurrence for some of the species are listed.
Taxonomy; morphology; distribution; Heterodera species; cyst nematodes; new species; hosts
Discocriconemella repleta n.sp. from Brazil is described. The male of Criconemoides inusitatus Hoffmann, 1974, is described here for the first time.
Inoculation of 'Thompson Seedless' grapevines with 500 Xiphinerna index or 1,000 Pratylenchus vulnus alone or in combination suppressed vine shoot and root growth under greenhouse conditions. Pratytenchus vulnus caused greater stunting of roots than X. index. Each nematode species inhibited top growth about equally. Concomitant inoculations caused greater stunting of tops and roots than did inoculations of either nematode species alone. Differences in growth between inoculated and control plants increased with exposure time. Pratylenchus vulnus competed with and gradually superseded in numbers an established population of X. index. Both species reproduced on 'Thompson Seedless' roots, but P. vulnus increased to a much higher level than did X. index. The increase of P. vulnus, together with extensive damage, proves its pathogenicity to grapevines.
Part III covers species with female stylet length >41 μm which are considered by this author to comprise the genus Gracilacus Raski, 1962. Seven new species of Gracilacus are described and further observations given on 14 other species. Paratylenchus strenzkei (Volz, 1951) Oostenbrink, 1960 is transferred to species inquirendae. A key to the species of Gracilacus is included.
Four new species of the genus Hemicriconemoides (H. californianus n.sp., H. taiwanensis n.sp., H. annulatus n. sp., and H. nitida n.sp.) are described. The range of total length of H. mangiferae is increased on the basis of specimens collected in Israel, Observations on H. mangiferae and H. litchi support the validity of H. litchi as distinct from H. mangiferae.
Tylenchocriconema alleni n.g.n.sp, is described from soil about roots of a bromeliad from Guatemala City, Guatemala. It has characteristics of both the Tylenchoidea and Criconematoidea. Tylenchocriconematidae, n. fam., and Tylenchocriconematoidea, n. superfam., are proposed to express the relationship of this species to other taxa. Tylenchulidae and Paratylenchidae are considered closely related, and Tylenchulidoidea, n. rank, is proposed to indicate their relationship.
Part II covers species with average female stylet length of 22-38 μm. Seven new species are described and further observations are given on 12 other species. A key to the species covered in Parts I and II is included. Paratylenchus curvitatus van der Linde, 1938, is transferred to species inquirendae.
A revision of part of the genus Paratylenchus is reported covering those species with stylets averaging < 22 μm. Thirteen new species are described and further observations are given on the morphology and relationships of nine other species. Paratylenchus gahriciis transferred to the genus Hemicriconemoides. This article is the first of three parts: the second will treat Paratylenchus spp. with stylets averaging 24-40 μm (and include a key to the species described in parts 1 and2), the third will include species with stylets >40μm, respectively.
Particles of fanleaf and yellow mosaic viruses are reported in the lumen of the esophagus of Xiphinerna index. Differences in cuticular morphology suggest differences in charged receptor sites which may offer an explanation for virus location and orderly arrangement.
NEPO virus; morphology; esophagus; odontophore
The effect of infection by Meloidogyne javanica and Heterodera trifolii on number, size, structure and efficiency of nodules formed by Rhizobiurn trifolii on white clover roots was investigated. Introduction of nematodes one week before, simultaneously, or one week following inoculation with Rhizobium bacteria did not hinder nodule formation. Nodule size did not differ between nematode-infected and nematode-free plants. Formation of nodules on M. javanica galls and gall formation on the nodules have been reported. The structure of nodular tissues was not disturbed by nematode infection, even though giant cells were formed inside the vascular bundles. The nitrogen-fixation efficiency of nematode-infected nodules was not impaired; however, earlier disintegration of nodules as a result of M. javanica infection ultimately deprived the plants of nitrogenous materials. The drastic reduction of the total-N in H. trifolii-infected plants reflected stunting of the entire plant due to nematode infection. Both nematodes invaded the entire root system, uniformly showing preference for nodules.
Studies on the virus-vector interaction between the grapevine fanleaf virus (GFV) and its nematode vector, Xiphinema index, indicate the virus had no measurable effect on the rate of reproduction of its vector, but significantly influenced survNal of the nematodes.
In the present study, evaluations of the nominal species and descriptions (H. parvus, H. intermedius, H. insignis, H. microdoratus and H. brevicaudatus) are made of five new species. H. squamosus is proposed as a species inquirenda; H. mangiferae is judged a valid species. H. litchi and H. birchfieldi are synonymized with H. mangiferae and H. ureshinoensis with H. kanayaensis. H. strictathecatus is considered a valid species. A key to the species of the genus is given. The limitation of use of male diagnostic characters in a mixture of populations of Hemicriconemoides with some other criconematids is discussed. The life cycle of H. chitwoodi has four complete molts; one in the egg, three in soil, two of which have spines. The adult female has a sheath cuticle from an incomplete fifth molt.