Ditylenchus Species Research Articles

Unveiling two novel Ditylenchus (Nematoda: Anguinidae) species inhabiting the growing medium of Rhododendron simsii imported from Japan

Summary The present study describes two new Ditylenchus species, isolated from the growing medium of Rhododendron simsii imported from Japan, at the Ningbo plant quarantine laboratory, Ningbo, P.R. China. Ditylenchus parvicauda n. sp. is an amphimictic species. Females have six incisures in the lateral fields, a medium length slim body, a short delicate stylet with asymmetrical stylet knobs, the secretory-excretory (S-E) pore located posterior to the isthmus and in the anterior region of the basal pharyngeal bulb, a posteriorly located vulva (V = 80.9-83.0), post-uterine sac (PUS) tube-like, and the tail cylindrical, tapering gradually towards finely rounded terminus. Males are similar to females in general morphology and have 10.1-14.9 μm long spicules. The second new species, D. gracicauda n. sp. is characterised by having a long and slender body, the presence of a vulval flap, four lines in the lateral field, a narrow and low lip region not offset, the S-E pore located posterior to the isthmus but not in the anterior region of the basal pharyngeal bulb, a posteriorly located vulva (V = 71.1-76.2), a short post-vulval uterine sac short (4.5-9.2 μm), and the tail slender, tapering gradually towards finely rounded to wedge-shaped terminus. The two new species were also characterised molecularly using 18S, ITS and the D2-D3 expansion segments of 28S rRNA genes. Our phylogenetic analyses showed their independent place among available Ditylenchus species. Several Ditylenchus species are regulated pests, and the introduction of these species into a new environment may result in diseases among native plants or vegetation in the area. Therefore, careful attention must be directed towards newly discovered species, particularly those under quarantine observation.

Soil and Roots Nematodes of Banana (Musa sapientum L.) in Otuoke Community, Bayelsa State, Nigeria

Banana (Musa sapientum L.) cultivation in rural communities creates job opportunities and generates income. Soil nematodes, a major pest, can lead to yield loss and financial loss. To ensure sustainable production and food security, it's crucial to survey potential threats and identify incumbent nematode species. Identifying these species can help develop effective pest management strategies. A survey was carried out to determine the potential nematode species of threat to banana production in Otuoke community, Bayelsa State. The random sampling technique was employed and soil and roots from two banana mono-cultured vegetations were tested. The modified sieve plate technique was used for nematode extraction and nematode pictorial key was employed for nematode identification to genera level. A total of 438 nematodes representing 8 genera were identified, among which 51.4% occurred in farm 1 and 48.6% were reported from farm 2. Nematodes of significant economic interest reported in this survey were Meloidogyne species (23.1%), Pratylenchus species (18.5%), Ditylenchus species (15.3%), Helicotylenchus species (10.0%), Hemicyclophora species (9.8%), Rotylenchus species (9.1%), Radopholus species (8.4%) and Paratylenchus species (5.7%). The occurrence of nematodes against farm types displayed disparities which was indicative that nematodes survival strategy depends on the prevailing field conditions. The study revealed that nematodes compose a prominent pest group infesting banana in Otuoke and should be checked to ameliorate food security.

Detection and description of Ditylenchus israelensis n. sp. (Nematoda: Anguinidae) from bulbs of the Persian buttercup (Ranunculus asiaticus L.)

Summary The present study describes a new Ditylenchus species, isolated from the bulbs of the Persian buttercup (Ranunculus asiaticus L.) imported from Israel at the Ningbo plant quarantine lab, Ningbo, P.R. China. Ditylenchus israelensis n. sp. is an amphimictic species; females have six incisures in the lateral field, a long and slim body, a delicate, short stylet (7-8 μm) with small and rounded knobs, excretory pore in the anterior region of the basal pharyngeal bulb, posteriorly located vulva (V = 78.6-83.1), a short PUS (15.0-24.0 μm), and a long conical tail with a pointed terminus. Males are similar to females in general morphology and have 14.0-18.0 μm long spicules. The new species was also characterised molecularly using 18S, ITS and D2-D3 expansion segments of 28S rDNA genes. Our phylogenetic analyses showed its independent position among available Ditylenchus species and a close phylogenetic affinity with D. valveus. Several Ditylenchus species are regulated pests; their detection in a given sample can implement quarantine measures. However, to our knowledge D. israelensis n. sp. did not cause any damage to the R. asiaticus bulbs. In addition, future studies regarding fecundity and host association may shed some light on the pathogenic potential of D. israelensis n. sp.

New Records of Ditylenchus Species from Southern Alberta, Canada.

The presence of plant-parasitic nematodes (PPNs) in cultivated areas is a limiting factor in achieving marketable crop yield. To control and alleviate the effects of these nematodes and determine appropriate management strategies, species-level identification is crucial. Therefore, we conducted a nematode diversity survey, which resulted in the detection of four Ditylenchus species in cultivated areas of southern Alberta, Canada. The recovered species had six lines in the lateral field, delicate stylets (>10 µm long), distinct postvulval uterine sacs, and pointed to rounded tail tips. The morphological and molecular characterization of these nematodes revealed their identity as D. anchilisposomus, D. clarus, D. tenuidens and D. valveus, all of which are members of the D. triformis group. All of the identified species were found to be new records in Canada except for D. valveus. Accurate Ditylenchus species identification is crucial because false-positive identification can result in the implementation of quarantine measures over the detected area. Our current study not only documented the presence of Ditylenchus species from southern Alberta, but also described their morpho-molecular characteristics and subsequent phylogenetic relationships with related species. The results of our study will aid in the decision on whether these species should become a part of nematode management programs since nontarget species can become pests due to changes in cropping patterns or climate.

Ditylenchus rafiqi n. sp. from pomegranate (Punica granatum L.) from India with a tabular key for the species known from India

Summary Ditylenchus rafiqi n. sp. was recovered from the rhizosphere of pomegranate in New Delhi (India), and it is characterised by morphological, morphometrical and molecular methods. The new species is characterised by having a body length of 553-901 μm, delicate stylet (7-10 μm long), longer conus length (5.0-5.5 μm in females and 4.5-5.5 μm in males) with small round knobs sloping backward, seven lateral lines at the mid-body, median bulb well developed with thickening of lumen walls, a post-uterine sac well developed (27-47 μm), tail long, elongate conoid with an almost round terminus (45-74 μm) and male spicule of 15-17.5 μm, gubernaculum simple, leptoderan type of bursa enveloping the tail almost >50% of its tail length. A detailed study based on morphological and morphometrical methods clearly demarcates that D. rafiqi n. sp. differs from other known species of Ditylenchus. The molecular characterisation was done using D2-D3 of 28S rRNA and ITS rRNA markers. Molecular characterisation shows that the new species is closely related to D. acutus, D. gilanicus (D2-D3 marker), and D. medicaginis (ITS rRNA markers). Based on phylogenetic analyses using D2-D3 of LSU and ITS rRNA markers, D. rafiqi n. sp. forms an intermediate clade between the D. triformis and D. dipsaci groups.

Characterisation of Ditylenchus paraoncogenus n. sp. (Nematoda: Anguinidae), a new stem nematode parasitising tumble thistle

Summary During a survey, three populations of a new stem nematode were isolated from galls on the shoots of tumble thistle (Gundelia tournefortii) plants in Fars province, Iran, and identified. Ditylenchus paraoncogenus n. sp. is described based on morphometric and morphological characters. It is characterised by having long-sized females, 1252 (943-1628) μm long, narrow lateral fields with six incisures, rather developed stylet 9.9 (9.0-11.3) μm long with round knobs, usually elongate and offset from intestine basal pharyngeal bulb, oocytes in two rows in distal part of ovary, V = 83.3 (80.3-86.2), post-vulval uterine sac 68.1 (46.9-86.1)% of vulva to anus distance long, bursa covering 63.2 (33.3-74.4)% of tail length, spicules 24.7 (21.0-27.9) μm long with minute processes at the base of its manubrium and anteriorly pointed cuticle parts within the lamina, and thick conical tail, usually with a pointed terminus. In addition, the ITS and 18S rDNA sequences of 17 populations of D. destructor, D. dipsaci, D. medicaginis, D. myceliophagus, D. paraoncogenus n. sp., Ditylenchus sp. and Nothotylenchus geraerti plus one population of Anguinidae sp. were analysed. The results showed a close relationship between D. paraoncogenus n. sp. and the stem nematodes D. oncogenus, D. gigas, D. weischeri and D. dipsaci. Ditylenchus species were divided into two clades, one clade comprising stem nematodes and gall-forming nematodes of the family Anguinidae, and the other clade containing fungivorous species. Observations showed that the second-stage juvenile is the dormant stage of D. paraoncogenus n. sp. and can survive in anhydrobiotic condition for at least 4 years.

Description of Ditylenchus paraparvus n. sp. from Iran with an updated list of Ditylenchus Filipjev, 1936 (Nematoda: Anguinidae).

During a survey, 12 known and one new species of Ditylenchus Filipjev, 1936 were collected from southern provinces of Iran during 2013-2017. Ditylenchus paraparvus n. sp. is characterised by a short body length (441-543 µm), lateral field with four lines, delicate and short stylet (6-7.5 µm) with small rounded or posteriorly sloping knobs, pyriform and offset basal pharyngeal bulb, V = 67.7-76.4, short post-vulval uterine sac less than one vulval body width long, small spicules (12.5-15 µm) and almost cylindrical tail (71-90 µm) with rounded end. Morphometric data of studied species are presented and intraspecific variation of their morphometrics and morphological characters is discussed. The list of the world Ditylenchus species is updated, and a dichotomous identification key and an updated tabular compendium for 63 valid species is provided.

Ditylenchus sarvarae sp. n. (Tylenchina: Anguinidae) from Iran.

During a survey of soil nematodes in Iran, a new species of Ditylenchus Filipjev, 1936 was discovered. Ditylenchus sarvarae sp. n. is characterised by its body length (1.0-1.4 mm), lateral field with seven incisures and without areolation, long postuterine sac (1.8-2.8 times the corresponding body diameter) and conical female tail with pointed tip (68-89 μm long, c = 13.7-18.2, c' = 4.2-5.1). Male specimens have conical tails (64-70 μm long, c = 14.5-16.7, c' = 4.0-4.5), spicules (22-26 μm long) and gubernaculum (8-10 μm long). Measurements and illustrations are provided for this new species. A molecular study of the 28S rDNA region of D. sarvarae sp. n. demonstrates that the Iranian species belongs to a separate group compared with the other molecularly characterized species of genus Ditylenchus.

Molecular Characterization and Phylogeny of Ditylenchus weischeri from Cirsium arvense in the Prairie Provinces of Canada.

Ditylenchus weischeri that parasitizes the weed Cirsium arvense (L.) Scop., 1772, (creeping thistle) was described in 2011 from Russia based on their morphology, ITS-RFLP analysis, and Hsp 90 gene sequence of a few individuals and one field collection of the plant. More recently, we found C. arvense parasitized by D. weischeri in the Prairie Provinces of Canada. Plant host preference for D. weischeri was also distinct from D. dipsaci (Kühn) Filipjev, 1936. In the current study, a comprehensive molecular analysis of many D. weischeri specimens from Canada is presented. Individuals from 41 C. arvense or yellow pea grain samples with seeds of C. arvense from the Prairie Provinces were sequenced for the internal transcribed spacer (ITS rDNA), large subunit (LSU) D2D3 28S rDNA, partial segment of small subunit (SSU) 18S rDNA, and the heat shock protein Hsp 90 gene. The analysis also included D. weischeri individuals from C. arvense from Russia and garlic with D. dipsaci from the Provinces of Ontario and Quebec in Canada. Available sequence data of Ditylenchus species retrieved from GenBank were used to phylogenetically position this species within the genus Ditylenchus . In all studied genes, several single-nucleotide polymorphisms between the Canadian D. weischeri and both Russian haplotype and individuals of D. weischeri from C. arvense from Russia were found. The sequences of ITS rDNA, LSU D2D3 28S rDNA, and Hsp 90 were used to construct separate dendrograms. For each of the three genes examined, D. weischeri was grouped separately from the other Ditylenchus . Ditylenchus samples from C. arvense was positioned to a single clade such as D. weischeri and distinct from D. dipsaci . With past reports of plant host preference and morphology, the results of this study provide further evidence for the fact that D. weischeri is distinct to be separated from D. dipsaci . Furthermore, minor differences in molecular divergence and morphology to the Russian haplotype and limited symptoms of disease on C. arvense in Prairie Canada suggest the Canadian and Russian populations of D. weischeri may be diverging.

Description of a New Anguinid Nematode, Nothotylenchus phoenixae n. sp. (Nematoda: Anguinidae) Associated with Palm Date Trees and Its Phylogenetic Relations within the Family Anguinidae

Nothotylenchus phoenixae n. sp. is described and illustrated from soil samples of palm trees in Kermanshah Province, western Iran. The new species is characterized by a body length of 784 (663 to 925) μm in females and 677 to 715 μm in males; a delicate stylet 6 (5 to 7) μm long and six lines in the lateral field; median bulb of pharynx fusiform, nonmuscular, and nonvalvate; isthmus elongate, slender ending to a pyriform basal pharyngeal bulb not overlapping intestine; postvulval uterine sac well developed, 15 (14 to 17) μm long, female tail elongate-conoid with pointed terminus; and male with adanal bursa and spicules 21 to 22 μm long (n = 2). The new species comes close in morphology and morphometrics to five known species of the genus, namely N. affinis, N. hexaglyphus, N. persicus, N. taylori, and N. uniformis. Molecular analyses of the partial 18S, D2/D3 expansion segments of the partial 28S and internal transcribed spacer (ITS) revealed this as a new species. The sequences of the partial 18S and 28S D2/D3 regions confirmed the close phylogenetic relationship between N. phoenixae n. sp. and other anguinids, but Nothotylenchus is clearly separated from Ditylenchus species and should be considered as a valid genus.

New record of three species of Ditylenchus Filipjev, 1936 (Nematoda: Anguinidae), with a key to the species reported from Iran

Fifteen species of the genus Ditylenchus were recovered and identified from Kermanshah province, western Iran. Morphological and morphometric characters of three known species namely D. filimus, D. hexaglyphus and D. nanus, being new records for Iran's nematode fauna, are given and discussed. Ditylenchus filimus is characterized by having a short stylet (7-8 µm), four lines in lateral fields, well-developed and valvate median bulb, and the typical female tail ending to a filamentous process. D. hexaglyphus, is characterized by having a short stylet (6.5-8.0 µm), six lines in lateral fields, not developed and non-valvate median bulb, and conoid tail with rounded tip. D. nanus, is characterised by having a short stylet (6-7 µm), six lines in lateral fields, median bulb well-developed and valvate, and tail conoid with finely rounded tip. A dichotomous key for identification of the species occurring in Iran is also provided.

Paraphyletic genus Ditylenchus Filipjev (Nematoda, Tylenchida), corresponding to the D. triformis-group and the D. dipsaci-group scheme.

The genus Ditylenchus has been divided into 2 groups: the Ditylenchus triformis-group, and the Ditylenchus dipsaci-group based on morphological and biological characters. A total of 18 populations belong to 5 species of Ditylenchus was studied: Ditylenchus africanus, Ditylenchus destructor, Ditylenchus myceliophagus and dipsaci, Ditylenchus weischeri, the first 3 belong to the Ditylenchus triformis-group, the last 2 the Ditylenchus dipsaci-group. The species of Ditylenchus triformis-group were cultured on fungi, while the species from Ditylenchus dispaci-group cultured on excised roots of plant hosts in petri dish. DNA sequences of regions of the nuclear ribosomal first internal transcribed spacer (ITS1) and the small subunit 18S were PCR amplified, sequenced and the phylogenetic analyses also including the sequences of the closely related species from the GenBank. The randomly amplified polymorphisms of genomic DNA (RAPD) were also generated. Two clusters or clades corresponding to the 2 groups were consistently observed with significant statistical support from the 3 datasets. The phylogenetic analysis also revealed that the genus is paraphyletic, separating the 2 groups by species of Anguina and Subanguina.

Nothotylenchus persicus n. sp. (Nematoda: Anguinidae) from Kermanshah province, Iran

A new species of the genus Nothotylenchus, N. persicus n. sp. was collected around the roots of grapevine and is described and illustrated herein based on morphological and molecular studies. The new species is characterised by a body length of 776-900 μm, delicate stylet 5-6 μm long, six lines in the lateral field, post-vulval uterine sac short, 10-18 μm long, female tail elongate-conoid with pointed terminus, and bursa covering 40-45% of tail length. Morphologically, N. persicus n. sp. appears closer to four known species of the genus, namely: N. hexaglyphus, N. affinis, N. medians and N. taylori. The results of phylogenetic analyses based on sequences of D2-D3 expansion region of 28S rRNA gene confirmed the close molecular relationship between N. persicus n. sp. and other anguinids, but Nothotylenchus claded separately from Ditylenchus species.

Diagnostics of stem and bulb nematodes, Ditylenchus weischeri and D. dipsaci (Nematoda: Anguinidae), using PCR with species-specific primers

The stem and bulb nematodes of the Ditylenchus dipsaci (Kühn) Filipjev species complex are obligate endoparasites of various agricultural plants, causing stunting and swelling and resulting in significant economic losses. Recently, a new closely related Ditylenchus species, D. weischeri Chizhov, Borisov and Subbotin, a parasite of the cosmopolitan herbaceous perennial weed, Cirsium arvense (L.) Scop., was described. Many countries impose quarantine restrictions for the presence of D. dipsaci in imported plant and soil materials. In the current study, we developed PCR with species-specific primers for the rapid and reliable separation of D. weischeri and D. dipsaci using gel electrophoresis and melting curve analysis. Species-specific primer sets were designed based on the nucleotide sequence of the heat shock protein (hsp90) gene for both nematode species. The PCR protocol was verified using samples of D. weischeri, D. dipsaci and the closely related species, D. gigas, which parasitizes broadbean (Vicia faba L.). The species-specific primer sets were able to detect D. weischeri and D. dipsaci from samples containing mixtures of Ditylenchus species. The PCR species-specific protocol should allow for more rapid identification of Ditylenchus species recovered from plant materials than previously possible.

Intra-racial genetic variation of Ditylenchus dipsaci isolated from garlic in Ontario as revealed by random amplified polymorphic DNA analysis

The stem and bulb nematode (Ditylenchus dipsaci) was found in garlic from across Ontario in a survey conducted in 2011. Nematodes from the survey were extracted from garlic samples and the identification of Ditylenchus species was established using morphological and molecular methods. The genetic variation of 90 populations collected from different regions in the province was studied using the random amplified polymorphic DNA (RAPD) method. One population from onion and one population of D. destructor were included for comparison. Simple matching coefficiency and hierarchical cluster analysis were performed on the polymorphisms to demonstrate the intra-racial, intra-species and interspecies relationships. Genetic variation was detected in the D. dipsaci populations isolated from garlic in Ontario. All the D. dipsaci populations were separated into two distinct clusters: a small cluster consisting of 19 populations from counties in the southern part of the province, and a large cluster of 71 populations mostly from the eastern region but which also included a few populations from the southern western and northern regions of the province. The average similarity coefficiency among populations of D. dipsaci isolated from garlic was 82%. The grouping of the two distinct clusters seems to suggest that there were two separate introductions of D. dipsaci in Ontario. This is the first report of intra-racial genetic variations of D. dipsaci.

Insights into the structure and phylogeny of the 28S rRNA expansion segments D2 and D3 of the plant-infecting nematodes from the genus Ditylenchus (Nematoda: Anguinidae).

Recently, it has been shown that the stem nematode, Ditylenchus dipsaci (Nematoda: Anguinidae), is genetically more related to the gall-forming nematodes from genera Anguina , Heteroanguina , and Mesoanguina than to other members of the genus Ditylenchus . This finding was provided by molecular data written in the evolutionary variable, non-coding internal transcribed spacers (ITS1 and ITS2) of the ribosomal DNA (rDNA). In the current paper, we analyze the nucleotide sequences and predict the secondary structures of two expansion segments (D2, D3) of the 28S ribosomal RNA (rRNA)-coding gene for the plant-parasitic nematodes from the genus Ditylenchus and their related anguinids. In general, the expansion segment D2 appeared to be more variable than the segment D3 illustrating their different evolutionary constraints. Comparative analysis of the aligned sequences and predicted secondary structures revealed similar trend showing the tight relationships between the stem nematodes ( D. dipsaci , D. gigas , D. weischeri ) and gall-forming nematodes from the subfamily Anguininae. Phylogeny reconstructions disjoined the family Anguinidae into two monophyletic clusters (Clade 1 and 2). Clade 1 constitutes the stem nematodes ( D. dipsaci , D. gigas , etc) and gall-forming nematodes from the genera Anguina , Heteroanguina , Subanguina and Mesoanguina , while clade 2 includes other Ditylenchus species like D. destructor and D. halictus . Collectively, deciphering the exact phylogenetic relationships within the family Anguinidae (Nematoda: Tylenchida) with respect to our results should provide a framework for a taxonomic revision in order to reflect biological history of these nematodes. In addition, we provide novel molecular data, which may be exploited in diagnostic tools for phytosanitary control of these economically important plant parasites.

Ditylenchus gallaeformans sp. n. (Tylenchida: Anguinidae) – a neotropical nematode with biocontrol potential against weedy Melastomataceae

Ditylenchus gallaeformans sp. n. was found on several hosts at numerous locations in Brazil and Costa Rica. In its native habitats it attacks several genera in the Melastomataceae, including two species ranked as among the worst invasive weeds of Pacific island forests, namely Miconia calvescens and Clidemia hirta. The new species causes a severe disease on infected plants involving the formation of gall-like structures on infected leaves, inflorescences and stems, and may cause significant impact on its hosts. Morphological study using light and scanning electron microscopy and analysis of the partial 18S rRNA, the D2-D3 expansion fragments of 28S rRNA and the ITS rRNA gene sequences showed little variations between populations from different hosts or geographical origins. The molecular study revealed that the new species is related to D. drepanocercus, which was recently found in association with M. calvescens but causing angular leaf spots on this host. Ditylenchus gallaeformans sp. n. is distinguished from D. drepanocercus by having a bursa reaching the tail tip (vs covering around 50% of tail in D. drepanocercus) and a conical tail, regularly tapering towards a variable tip (vs tail with a distinctive apical falciform appendage in both sexes in D. drepanocercus). PCR with species-specific primers was developed for diagnostics of both Ditylenchus species. Ditylenchus gallaeformans sp. n. deserves further investigation as a potential biocontrol agent against M. calvescens and C. hirta.

Nematode‐induced galls in Miconia albicans: effect of host plant density and correlations with performance

AbstractThe study of nematodes parasitizing native plants plays a crucial role in understanding plant–pathogen interactions. In the present study we describe the patterns of attack by an undescribed species of Ditylenchus occurring in Miconia albicans (Melastomataceae), a widespread, native shrub from the Brazilian cerrado. We also tested the hypothesis that nematode‐induced leaf galls negatively correlate to host plant performance and that gall density is a function of host plant density. We collected paired healthy and attacked shoots from 28 individuals of M. albicans and estimated the leaf area lost to nematode‐induced galls in up to 10 leaves per shoot. We analyzed the relationships between leaf area lost to nematode galls and reproductive traits. Nematode attack levels were also compared to the spatial distribution of the host plant. Inflorescence length and fruit production were significantly reduced in attacked shoots compared with healthy shoots. Seeds from attacked shoots showed no significant reduction in germinability or germination time when compared with seeds collected from healthy shoots. Gall density was positively correlated with host density. Despite being seldom studied in tropical ecosystems, nematodes may play an important role in plant fitness and in structuring tropical communities.

Ditylenchus halictus n. sp. (Nematoda: Anguinidae), an associate of the sweat bee, Halictus sexcinctus (Halictidae), from Germany

Abstract Ditylenchus halictus n. sp. was collected as dauer juveniles from the genital region of adult males and females of the soil-dwelling sweat bee, Halictus sexcinctus (Halictidae), in Brandenburg, Germany, and cultured on the fungus, Monilinia fructicola. It is the first species of Ditylenchus to be reported in an active phoretic association with insects and is described and illustrated herein. Dissections revealed that 25% of female bees carried the dauer juveniles of D. halictus n. sp. internally in the Dufour's gland and/or seminal receptacle and/or genital region (range 1-193 dauer juveniles per bee), and 38% of males were infested in the genital capsule, copulation apparatus, and/or distal testes with 1-64 dauer juveniles. Morphologically, D. halictus n. sp. has six lines in the lateral field and appears closest to D. myceliophagus but can be differentiated based upon a combination of morphological characters, the mode of reproduction and molecular sequence data. Molecular analysis of the near full length SSU rDNA, D2/D3 expansion segments of the large subunit (LSU) rDNA, and internal transcribed spacers (ITS-1 and 2) and 5.8S rDNA support that this nematode species is unique.

Ditylenchus destructor and Ditylenchus dipsaci

<i>Ditylenchus destructor</i> and <i>Ditylenchus dipsaci</i>