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Pablo Castillo and Gracia Liébanas

Abstract

Six crucifer species as potential cover crops, Ethiopian mustard (Brassica carinata line C-101), turnip (Brassica rapa cv. Norfolk), radish (Raphanus sativus), wild rocket (Eruca vesicaria), wild cabbage (Moricandia moricandioides) and white mustard (Sinapis alba), were tested for susceptibility to Meloidogyne arenaria race 2, M. incognita race 1 and M. javanica. Experiments were conducted under glasshouse conditions at 22-28°C for 2 months after inoculation of plants with eggs and second-stage juveniles. All crucifers were infected by Meloidogyne spp. The nematode and crucifer species significantly influenced the severity of root galling and nematode reproduction. Among the plants tested, turnip was the most suitable host for all three Meloidogyne spp. as indicated by severity of root galling and nematode reproduction. The least suitable hosts were wild rocket for M. arenaria, radish for M. incognita and white mustard for M. javanica. The reproduction fitness of M. javanica was greater than that of M. arenaria race 2 and M. incognita race 1 on all plants.

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Gracia Liébanas and Reyes Peña-Santiago

Abstract

Three Costa Rican species with a simple uterus, two new and one known, belonging to the genus Oriverutus are described. Descriptions, measurements and illustrations are provided. A detailed study of O. asaccatus, including SEM pictures, is presented and its diagnosis emended; O. sturhani is regarded as its junior synonym. Oriverutus costaricensis sp. n. is distinguished by its body 1.07-1.24 mm long, lip region offset by constriction and 14-15 μm broad, odontostyle 23.5-24 μm long, neck 277-353 μm long, pharyngeal-expansion 125-179 μm long or 45-51% of total neck length, cardia asymmetrical, a dorsal cell mass present at level of pharyngo-intestinal junction, female genital system amphidelphic, V = 45-48, tail conical and slightly bent dorsad at the end (42-43 μm long, c = 25-29, c′ = 1.7-1.8), and males unknown. Oriverutus hemihystera sp. n. is characterised by its body 0.92-1.17 mm long, lip region offset by shallow depression or almost continuous and 10-11.5 μm broad, odontostyle 22-24 μm long, neck 280-330 μm long, pharyngeal expansion 115-138 μm long or 41-43% of total neck length, female genital system amphidelphic but anterior genital branch reduced, V = 43-45, tail conical and slightly bent dorsad at the end (62-65 μm long, c = 15-18, c′ = 3.1-3.4), and males unknown.

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Reyes Peña-Santiago and Gracia Liébanas

Abstract

Abundant material of the nematode species Chitwoodiellus parafuscus (Peña-Santiago, 1991) Jiménez-Guirado & PeñaSantiago, 1992 collected from 17 localities in the south east of the Iberian Peninsula has been studied. Wide intraspecific variability in its measurements and ratios has been noted and analysed. Some of its morphological features are re-examined and revised, and a new concept of the species is proposed. SEM illustrations of this species, and also of the genus, are provided for the first time. Finally, a new diagnosis of the genus Chitwoodiellus and a compendium of its species are given.

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Reyes Peña-Santiago, Pablo Guerrero and Gracia Liébanas

Abstract

New observations on three similar species of the genus Enchodelus, namely E. groenlandicus, E. macrodorus and E. saxifragae, are provided on the basis of material collected in the southern Iberian Peninsula. Enchodelus groenlandicus is redescribed, this being the first record of the species after its original description 80 years ago. An emended diagnosis is given for E. macrodorus in addition to a compendium and analysis of its previous records. Enchodelus saxifragae, certainly the most widely distributed species in the studied area, is also redescribed. Measurements, illustrations, including LM and SEM, and remarks on the identity of the three species, are presented. Together with E. distinctus and E. microdoroides, the three species form a species group characterised by a long odontostyle (>35 μm), flanged odontophore, tripartite uterus and short, rounded tail. These five species are compared in detail and a key to their identification provided.

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Reyes Peña-Santiago, Pablo Guerrero and Gracia Liébanas

Abstract

Two new and one known species belonging to the genus Enchodelus from the southeast of the Iberian Peninsula are described and illustrated. Enchodelus ameliae sp. n. is a medium-sized nematode (1.37-1.55 mm) with lip region offset by constriction, odontostyle 30-32 μm long, female reproductive system amphidelphic with tripartite uterus, vulva almost equatorial (V = 47-50), spicules 49-60 μm long, 11-14 spaced ventromedian supplements and short rounded conoid tail. Enchodelus longispiculus sp. n. is characterised by its medium-sized body (1.32-1.87 mm), lip region offset by shallow depression, odontostyle 27-31 μm long, female reproductive system amphidelphic with tripartite uterus, vulva pre-equatorial (V = 41-48), spicules 63-72 μm long, 8-14 spaced ventromedian supplements and short rounded conoid tail. Enchodelus hopedoroides is redescribed on the basis of Andalusian material and observations on the Swiss holotype. These three species share some features, such as medium-sized odontostyle (ca 30 μm long), tripartite uterus and short, rounded, tail. They are compared in detail with other similar species, namely E. altherri, E. analatus, E. arcticus, E. georgiensis, E. hopedorus and E. ponorensis. A key to their identification is provided.

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Gracia María Liébanas and Reyes Peña-Santiago

Abstract

Two new species of the genus Carcharodiscus are described from southeastern Spain. Carcharodiscus procerus sp. n. is characterised by: a very slender (a = 52 - 62) body 1.67 - 2.17 mm long, lip region offset by constriction and 17 - 18 μm diam., anterior portion of the cheilostome 12 - 13× 7.0- 7.5 μm with abundant denticles on its walls, odontostyle 10 - 12 μm long or ca 66% of the lip region diam., presence of a dorsal cell chord behind the cardia, female genital system amphidelphic, vulva longitudinal and somewhat posterior (V = 52 - 58), presence of cuticular irregularities near the vulva area, tail rounded conoid (22 - 28 μm; c = 70 - 83; c′ = 1.0 - 1.2), and male unknown. Carcharodiscus olearum sp. n. is distinguished by its very slender (a = 51 - 55) and long (L = 2.36 2.79 mm) body, lip region offset by deep constriction and 22 - 27 μm in diam., anterior portion of the cheilostome 16.5- 18.0 × 8.0- 9.5 μm with abundant denticles on its walls, odontostyle 16.0- 17.5 μm long or 0.7 to 0.8 times the lip region in diam., presence of a dorsal cell chord behind the cardia, female genital system amphidelphic, vulva longitudinal and somewhat posterior (V = 50 - 58), tail rounded conoid (25 - 28 μm; c = 89 - 99; c′ = 0.8- 0.9), and male unknown. Carcharolaimus eximius is transferred to Carcharodiscus. A list of the species of the genus and key to their identification are also provided.

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Pablo Guerrero, Gracia Liébanas and Reyes Peña-Santiago

Abstract

Two new and two known species belonging to the genus Enchodelus from the southeast of the Iberian Peninsula are described and illustrated. Enchodelus porosus sp. n. is characterised by its medium-sized body (1.39-1.70 mm), lateral chord bearing conspicuous pores surrounded by a refractive ring, odontostyle 16.5-18.0 μ m long, female reproductive system amphidelphic with uterus bipartite including irregular refractive bodies, pars refringens vaginae absent, spicules 39-45 μ m long, 4-6 separated ventromedian supplements and ventrally curved conical tail. Enchodelus veletensis sp. n. is a medium-to large-sized nematode (1.78-2.06 mm), with odontostyle 29-31 μ m long, female genital system amphidelphic with uterus bipartite, vagina bearing two sclerotisations surrounded by a spherical pars distalis and ventrally curved conical tail. In addition, E. morgensis is redescribed and new observations on E. brevidentatus are provided and discussed.

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Gracia Liébanas, Pablo Castillo and Nicola Vovlas

Abstract

SEM studies on a Meloidogyne baetica population provided additional details of the external morphology for female, male and second-stage juveniles. The labial disc in female and male specimens is fused with the medial lips forming a single structure. In second-stage juveniles the lateral lips are triangular with rounded margins. The amphidial opening for all life stages appears oval to rectangular in shape and is located between the labial disc and lateral lips. Lateral fields of male and second-stage juveniles have four incisures irregularly areolated along the entire body. The results of a host-range study for additional natural hosts of M. baetica conducted in wild olive communities growing at Vejer de la Frontera (Cádiz province) in southern Spain are also reported. Apart from the type host, M. baetica was found to infect two natural woody host plants, lentisc (Pistacia lentiscus) and Aristolochia baetica. Hostparasite relationships in these new hosts confirmed the typical susceptible reaction observed in wild and cultivated olives. Similarly, the reproductive fitness, evaluated as the number of eggs per egg mass, was not significantly different in all plant hosts. No infections or galled roots were observed in herbaceous plant species studied and M. baetica must therefore be considered as a parasite of woody plants.

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Baltasar Torres, Joaquín Abolafia, Reyes Peña-Santiago and Gracia Liébanas

Abstract

Two new species of the genus Discolaimus Cobb, 1913 are described from southeastern Spain. D. mariae sp. n. is distinguished by its large size (L = 2.4-3.3 mm), lip region diameter 29-35 μm, odontostyle 23-25 μm, pharyngeal expansion occupying two-thirds of the total neck length, presence of dorsal cell bodies close to cardia, V = 46-53, female genital system didelphicamphidelphic, tail conical with rounded terminus (33-39 μm, c = 72-88, c′ = 0.9-1.0) and with a terminal gap in the inner cuticle, and males absent. D. labiatus sp. n. is characterised by being medium sized (L = 0.99-1.20 mm), lip region diameter 14-17 μm wide, labial disc with no radial but six longitudinal grooves, inner (perioral) labial portion forming well developed liplets, odontostyle 10.0-12.5 μm, vulva relatively anterior (V = 39-43), female tail conical with rounded terminus (26-27 μm, c = 37-46, c′ = 1.5-1.7), and male unknown. Scanning electron microscope observations of the species are also presented.