Browsing by Author "Malan, Antoinette P."
Now showing 1 - 20 of 36
Results Per Page
Sort Options
- ItemAccelerated microbial degradation of nematicides in vineyard and orchard soils(South African Society for Enology and Viticulture, 2014-03) Hugo, H. J.; Mouton, C.; Malan, Antoinette P.Accelerated microbial degradation (AMD) of organophosphate and carbamate nematicides is a phenomenon whereby biodegradation in the soil is increased, leading to a dramatically shortened persistence of nematicides. More intensified agriculture practices in South Africa in response to the future demand for food may lead to increased pest and disease pressure, which in turn will lead to more frequent pesticide application. The same principle applies to plant-parasitic nematode control practices, and the overuse and misuse will have a pronounced effect on the enhancement of AMD. With limited management options available, the responsible use of nematicides becomes more pertinent. Producers should be aware of the problems associated with multiple soil applications of organophosphates and carbamates against plant-parasitic nematodes. This article reviews factors contributing to the AMD of carbamate and organophosphate nematicides in soil and makes practical recommendations to avoid the occurrence of AMD in vineyard and orchards.
- ItemAdjuvants to improve aerial control of the citrus mealybug Planococcus citri (Hemiptera: Pseudococcidae) using entomopathogenic nematodes(Cambridge University Press - CUP, 2013-11) Van Niekerk, S.; Malan, Antoinette P.The citrus mealybug, Planococcus citri, is a highly destructive pest of citrus, occurring only in the aerial parts of plants. Humidity will be one of the key factors to consider when using entomopathogenic nematodes (EPN) as biological control agents. Different adjuvants can be added to suspensions of EPNs, to improve control as a foliar application. An aqueous suspension containing Heterorhabditis zealandica and 0.3% Zeba® significantly increased P. citri mortality by 22% at 80% relative humidity (RH) with a temperature cycle starting at 22°C for 14 h and 11°C for 11 h. The same polymer formulation was tested for Steinernema yirgalemense and mortality of P. citri increased by 21% at 60% RH and by 27% at 80% RH. The addition of Nu-Film-Pw and Zebaw to H. zealandica suspensions did not significantly retard application run-off on citrus leaves. The combination of Nu-Film-P® and Zeba®, however, was able to significantly retard sedimentation, increasing the average number of nematodes deposited on 2-cm² leaf discs by 10 nematodes. In an aqueous suspension, nematodes settle rapidly to the bottom, resulting in an uneven distribution of nematodes. Xanthan gum, at a concentration of 0.2%, was highly effective at retarding sedimentation, with 72% of the initial nematode number still in suspension after 1 h. Zeba®, at a concentration of 0.3%, despite not being as effective as Xanthan gum, nevertheless still retarded sedimentation significantly. This is the first report of the potential of Nu-Film-P® and Zeba® to improve EPN performance against P. citri when used above ground in citrus orchards.
- ItemAngiostoma margaretae n. sp (Nematoda: Angiostomatidae), a parasite of the milacid slug Milax gagates Draparnaud collected near Caledon, South Africa(Springer Verlag, 2011) Ross, Jenna L.; Malan, Antoinette P.; Ivanova, Elena S.Angiostoma margaretae n. sp. (Angiostomatidae) is described from the oesophagus of the slug Milax gagates Draparnaud collected near Caledon in the Western Cape Province of South Africa. The new species closely resembles another parasite of a milacid slug, A. milacis Ivanova & Wilson, 2009, with a similar head, stoma and spicule shape, the presence of distally outstretched ovaries, coiled oviducts, the same number of caudal papillae and enlarged rectal glands. However, A. margaretae differs from the latter by having: a shorter, wider tail with a rounded vs pointed tip; the distal parts of both ovaries with a particular hook-like shape due to an expansion closely following the short initial zone; ovoviparous females; and a different arrangement of male papillae. A. margaretae is comparable with A. limacis Dujardin, 1845, A. asamati (Spiridonov, 1985), A. coloaense (Pham Van Luc, Spiridonov & Wilson, 2005) and A. stammeri (Mengert, 1953), which have a similar stoma shape and size, but can be readily differentiated by the presence of distally outstretched vs reflexed ovaries and the presence vs lack of enlarged rectal glands. The new species has a similar arrangement of the ovaries to A. kimmeriense Korol & Spiridonov, 1991 and A. zonitidis Ivanova & Wilson, 2009, but is clearly differentiated by the lack of an off-set lip region and presence of a large bowl-shaped vs tubular stoma and less numerous male caudal papillae (seven pairs vs nine in A. kimmeriense and 10 in A. zonitidis). © 2011 Springer Science+Business Media B.V.
- ItemBacteria of the genus xenorhabdus, a novel source of bioactive compounds(Frontiers Media, 2018-12-19) Dreyer, Jonike; Malan, Antoinette P.; Dicks, Leon Milner Theodore, 1961-The genus Xenorhabdus of the family Enterobacteriaceae, are mutualistically associated with entomopathogenic nematodes of the genus Steinernema. Although most of the associations are species-specific, a specific Xenorhabdus sp. may infect more than one Steinernema sp. During the Xenorhabdus–Steinernema life cycle, insect larvae are infected and killed, while both mutualists produce bioactive compounds. These compounds act synergistically to ensure reproduction and proliferation of the nematodes and bacteria. A single strain of Xenorhabdus may produce a variety of antibacterial and antifungal compounds, some of which are also active against insects, nematodes, protozoa, and cancer cells. Antimicrobial compounds produced by Xenorhabdus spp. have not been researched to the same extent as other soil bacteria and they may hold the answer to novel antibacterial and antifungal compounds. This review summarizes the bioactive secondary metabolites produced by Xenorhabdus spp. and their application in disease control. Gene regulation and increasing the production of a few of these antimicrobial compounds are discussed. Aspects limiting future development of these novel bioactive compounds are also pointed out.
- ItemCharacterisation of Metarhizium majus (Hypocreales : Clavicipitaceae) isolated from the Western Cape Province, South Africa(Public Library of Science, 2021-03-19) Mathulwe, Letodi L.; Jacobs, Karin; Malan, Antoinette P.; Birkhofer, Klaus; Addison, Matthew F.; Addison, PiaEntomopathogenic fungi (EPF) are important soil-dwelling entomopathogens, which can be used as biological control agents against pest insects. EPF are capable of causing lethal epizootics in pest insect populations in agroecosystems. During a survey of the orchard soil at an organic farm, different EPF species were collected and identified to species level, using both morphological and molecular techniques. The EPF were trapped from soil samples taken from an apricot orchard. The traps, which were baited in the laboratory, used susceptible host insects, including the last-instar larvae of Galleria mellonella (wax moth larvae) and Tenebrio molitor (mealworm larvae). The potential pathogenicity of the local Metarhizium majus isolate was tested and verified using susceptible laboratory-reared last-instar T. molitor larvae. The identification of the M. majus isolated from South African soil was verified using both morphological and molecular techniques. The occurrence of M. majus in the South African soil environment had not previously been reported.
- ItemControl potential of brassicaceae cover crops as green manure and their host status for meloidogyne javanica and criconemoides xenoplax(South African Society for Enology and Viticulture, 2015-12) Kruger, D. H. M.; Fourie, J. C.; Malan, Antoinette P.Laboratory bioassays were undertaken to determine the potential of Avena sativa cv. Pallinup (Pallinup oats), Sinapis alba cv. Braco (white mustard), Brassica napus cv. AV Jade (canola), Brassica juncea cv. Caliente 199 (Caliente) and Eruca sativa cv. Nemat (Nemat) to suppress Meloidogyne javanica (root-knot nematode) and Criconemoides xenoplax (ring nematode) when applied as green manure. The host status of the crops also was determined during glasshouse trials. Plant material of the different cover crops was macerated and mixed with nematode-inoculated soil. After a period of 14 and 28 days respectively, susceptible tomato plants were planted in the soil, where they were left to grow in a glasshouse, prior to the performance of a root gall index. The same procedure was followed for C. xenoplax, except that, in this case, the nematodes were extracted from the soil after 14 and 28 days to determine the impact of the plant biomass on nematode numbers. To determine the host status of the cover crops concerned, potted plants were inoculated with the two nematode species. Results from the bioassays showed significant suppression of M. javanica by white mustard, Caliente 199 and Nemat. However, no significant differences were found in the C. xenoplax bioassays. In the M. javanica glasshouse host trials, Nemat was classified as a poor host. In the C. xenoplax host trials, canola was found to have a suppressing effect on C. xenoplax. The results are the first to show the effect of biofumigation on C. xenoplax nematode.
- ItemCover crops with biofumigation properties for the suppression of plant-parasitic nematodes : a review(South African Society for Enology and Viticulture, 2013-08) Kruger, D. H. M.; Fourie, J. C.; Malan, Antoinette P.Plant-parasitic nematodes are a problem in vineyards worldwide, with some species acting as vectors of grapevine soil-transmitted viruses. Global pressure on the use of soil-applied chemical nematicides has led to a search for new control options, or for alternative methods to suppress plant-parasitic nematodes as part of integrated pest management. This paper gives valuable background information on the use of cover crops with biofumigation properties for the suppression of plant-parasitic nematodes in vineyards.
- ItemDescription of Xenorhabdus khoisanae sp. nov., the symbiont of the entomopathogenic nematode Steinernema khoisanae(Society for General Microbiology, 2013-09) Ferreira, Tiarin; Van Reenen, Carol A.; Endo, Akihito; Sproer, Cathrin; Malan, Antoinette P.; Dicks, Leon Milner Theodore, 1961-Bacterial strain SF87T, and additional strains SF80, SF362 and 106-C, isolated from the nematode Steinernema khoisanae, are non-bioluminescent Gram-reaction-negative bacteria that share many of the carbohydrate fermentation reactions recorded for the type strains of recognized Xenorhabdus species. Based on 16S rRNA gene sequence data, strain SF87T is shown to be closely related (98 % similarity) to Xenorhabdus hominickii DSM 17903T. Nucleotide sequences of strain SF87 obtained from the recA, dnaN, gltX, gyrB and infB genes showed 96–97 % similarity with Xenorhabdus miraniensis DSM 17902T. However, strain SF87 shares only 52.7 % DNA–DNA relatedness with the type strain of X. miraniensis, confirming that it belongs to a different species. Strains SF87T, SF80, SF362 and 106-C are phenotypically similar to X. miraniensis and X. beddingii, except that they do not produce acid from aesculin. These strains are thus considered to represent a novel species of the genus Xenorhabdus, for which the name Xenorhabdus khoisanae sp. nov. is proposed. The type strain is SF87T ( = DSM 25463T = ATCC BAA-2406T).
- ItemDifferentiation of South African potato cyst nematodes (PCN) by analysis of the rDNA internal transcribed spacer region(SA ePublications, 2006) Knoetze, R.; Malan, Antoinette P.; Mouton, C.Cysts from nematode-infested plots on eight potato farms in the Sandveld and Ceres regions of South Africa were analysed by means of rDNA-RFLP. The size of the PCR amplification products for all populations was typical for the genus Globodera. Restriction digestion of the amplified products with MspI and HinfI confirmed Globodera rostochiensisto be present in both the Sandveld and Ceres regions and Globodera pallidato be absent from South African potato cyst nematode populations. However, several populations from the Sandveld region showed no recognition of the HinfI restriction site and no digestion took place, indicating them to be a distinct Globodera species. Sequencing of the ITS1 region confirmed the presence of G. rostochiensis and an unknown Globodera species, and the absence of G. pallida in South Africa. Species-specific primers for the identification of G. rostochiensis and G. pallida were optimised.
- ItemDistribution of longidoridae in the viticultural regions of the Cape Province(South African Society for Enology and Viticulture, 1994) Malan, Antoinette P.; Meyer, A. J.Soil samples from five viticultural regions in the Cape Province were analysed for the presence of longidorid nematodes. Sixteen species of Xiphinema were found, the most common species being X. elongatum, X. americanum and X. brevicolle. X. index was recorded from three of the five regions. A survey in the Theewaterskloof area was conducted and nine Xiphinema species were recorded but X. index was absent.
- ItemDivergent thermal specialisation of two South African entomopathogenic nematodes(PeerJ, 2015-07-02) Hill, Matthew P.; Malan, Antoinette P.; Terblanche, John S.Thermal physiology of entomopathogenic nematodes (EPN) is a critical aspect of field performance and fitness. Thermal limits for survival and activity, and the ability of these limits to adjust (i.e., show phenotypic flexibility) depending on recent thermal history, are generally poorly established, especially for non-model nematode species. Here we report the acute thermal limits for survival, and the thermal acclimation-related plasticity thereof for two key endemic South African EPN species, Steinernema yirgalemense and Heterorhabditis zealandica. Results including LT50 indicate S. yirgalemense (LT50 = 40.8 ± 0.3 ◦C) has greater high temperature tolerance than H. zealandica (LT50 = 36.7 ± 0.2 ◦C), but S. yirgalemense (LT50 = −2.4 ± 0 ◦C) has poorer low temperature tolerance in comparison to H. zealandica (LT50=−9.7±0.3 ◦C), suggesting these two EPN species occupy divergent thermal niches to one another. Acclimation had both negative and positive effects on temperature stress survival of both species, although the overall variation meant that many of these effects were non-significant. There was no indication of a consistent loss of plasticity with improved basal thermal tolerance for either species at upper lethal temperatures. At lower temperatures measured for H. zealandica, the 5 ◦C acclimation lowered survival until below−12.5 ◦C, where after it increased survival. Such results indicate that the thermal niche breadth of EPN species can differ significantly depending on recent thermal conditions, and should be characterized across a broad range of species to understand the evolution of thermal limits to performance and survival in this group.
- ItemThe effect of cover crops and their management on plant-parasitic nematodes in vineyards(South African Society for Enology and Viticulture, 2015) Kruger, D. H. M.; Fourie, J. C.; Malan, Antoinette P.In South Africa the use of annual cover crops is an established soil cultivation practice in vineyards that is environmentally friendly and financially sustainable in the long term. Species from the Brassicaceae family are well known for their biofumigation potential. In this study, Sinapis alba (white mustard), Brassica napus cv. AV Jade (canola), Brassica juncea cv. Caliente 199 (Caliente), Eruca sativa cv. Nemat and Avena sativa cv. Pallinup were established as cover crops in a vineyard for three growing seasons and evaluated for their biofumigation impact, as well as crop host impact on the suppression of economically important plant-parasitic nematodes. Mechanical and chemical cover crop management practices on Criconemoides xenoplax (ring nematode) and Meloidogyne javanica (root-knot nematode) numbers were determined. Canola and Caliente showed a consistent reduction of C. xenoplax present in the vine row 60 days after the management practices applied at the end of the third growing season. This trend was found during the three-year trial period for all different sampling periods (0, 15, 30 and 60 days). Lowered numbers for the total plant-parasitic nematodes were also found for the three-year trial period measured at 60 days after the management practice sampling period. The results can be attributed mainly to the crop host status of the two cover crop species towards C. xenoplax. White mustard showed a constant increase in C. xenoplax numbers in the vine row over the three-year period compared to the treatments in which no cover crop was sown.
- ItemEffect of humidity and a superabsorbent polymer formulation on the efficacy of Heterorhabditis zealandica (Rhabditida: Heterorhabditidae) to control codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae)(Taylor & Francis, 2013-12) De Waal, Jeanne Y.; Malan, Antoinette P.; Addison, Matthew F.Adequate moisture levels are required for nematode survival and subsequent efficacy as entomopathogens. Formulation of nematodes aimed at aboveground applications may assist in maintaining such moisture levels. In this study, we report the effects of a superabsorbent polymer formulation, Zeba® on the performance of an entomopathogenic nematode, Heterorhabditis zealandica Poinar, for controlling diapausing codling moth, Cydia pomonella (L.) larvae in cryptic habitats on trees. Water activity (aw-value) on bark was considered to be an indication of moisture levels on trees in cryptic habitats where codling moth larvae are known to occur, thereby influencing nematode efficacy. H. zealandica was only able to infect codling moth larvae at aw≥0.92, with aw50=0.94 and aw90=0.96.
- ItemEffect of management practices applied to cover crops with biofumigation properties on cover crop performance and weed control in a vineyard(South African Society for Enology and Viticulture, 2015) Fourie, J. C.; Kruger, D. H. M.; Malan, Antoinette P.This five-year trial (2009 to 2013) was carried out in a full-bearing seven-year-old Shiraz/101-14 vineyard established on a sandy to sandy clay loam soil at Blaauwklippen farm (33°58’S, 18°50’E) near Stellenbosch, South Africa. Fourteen treatments were applied, consisting of two management practices applied to five cover crop species, winter-growing weeds (no cover crop), and winter-growing weeds (no cover crop) combined with a nematicide application in the vine row. The dry matter production (DMP) increased between 0.55 and 2.62 t/ha from 2009 to 2010 for the small-seeded Sinapis alba cv. Braco (white mustard), Brassica napus cv. AVJade (canola), Brassica juncea cv. Caliente 199 (Caliente) and Eruca sativa cv. Nemat (Nemat). This was attributed to the finer seedbed that could be created. All cover crops suppressed the winter-growing weeds throughout the study. Although the stand of summer-growing weeds differed significantly between treatments in 2010, 2011 and 2012, the cover crop treatments did not suppress these weeds significantly. However, for the duration of the study, the weed stand in the canola controlled chemically full surface (CC) during grapevine bud break tended to be lower than that of the canola controlled mechanically (MC) during grapevine bud break. The same trend occurred between CC and MC for Avena sativa cv. Pallinup (Pallinup oats) and the treatments in which no cover crops were sown, with the exception of in 2009 and 2010 respectively.
- ItemEfficacy of entomopathogenic nematodes (Rhabditida : Heterorhabditidae and Steinernematidae) against codling moth, Cydia pomonella (Lepidoptera: Tortricidae) in temperate regions(Taylor & Francis, 2011-09) De Waal, Jeanne Y.; Malan, Antoinette P.; Addison, Matthew F.The biocontrol potential of South African isolates of Heterorhabditis zealandica, Steinernema citrae, S. khoisanae, S. yirgalemense, and Steinernema sp., was evaluated against codling moth, Cydia pomonella. Codling moth was susceptible to all six nematode isolates at a concentration of 50 infective juveniles/insect (78-100% mortality). Low temperatures (10 h at 17ºC; 14 h at 12ºC) negatively affected larvicidal activity (≤3%) for all isolates. All tested isolates were most effective at higher levels of water activity (aw=1). The average aw50-values for all isolates tested was 0.94 (0.93-0.95), except S. khoisanae 0.97 (0.97-0.98). Regarding host-seeking ability, no positive attraction to host cues could be detected amongst isolates, except for H. zealandica. Three of the isolates, H. zealandica, S. khoisanae, and the undescribed Steinernema sp., were selected for field-testing and proven to be effective (mortality >50%). Insect containment methods used during field experimentation was shown to influence larvacidal activity, as different levels of mortality were obtained using various containment methods (wooden planks vs. pear tree logs vs. mesh cages). Pear tree logs were impractical. Predictive equations were subsequently developed, enabling future trials to be conducted using either planks or cages, enabling the prediction of the expected level of control on tree logs. All tested isolates therefore showed a certain degree of biological control potential, however, none of the experiments showed clear efficacy-differences amongst isolates. The study highlighted the importance of environmental factors to ensure the successful application of these nematodes for the control of diapausing codling moth larvae in temperate regions.
- ItemEntomopathogenic nematodes (Steinernematidae and Heterorhabditidae) from the southwestern parts of South Africa(SA ePublications, 2006) Malan, Antoinette P.; Nguyen, Khuong B.; Addison, Matthew F.Soil samples were collected in the southwestern parts of South Africa to obtain entomopathogenic nematodes of the families Steinernematidae and Heterorhabditidae. In total, 498 samples were randomly taken from cultivated and uncultivated habitats, including deciduous fruit orchards, vineyards and natural vegetation. Entomopathogenic nematodes were isolated from 36 samples (7 %) by baiting with larvae of Galleria mellonella (greater wax moth). Heterorhabditis was the dominant genus isolated, while Steinernema was rare. The most common species was Heterorhabditis bacteriophora Other species identified were Heterorhabditis zealandica and Steinernema khoisanae. The isolation of H. zealandica represents a new record for South Africa, whereasS. khoisanae has thus far been recorded only from South Africa.
- ItemFirst report and molecular characterization of the dagger nematode, Xiphinema oxycaudatum (Nematoda, Dorylaimidae) from South Africa(Pensoft, 2019-12-03) Daramola, Fisayo Y.; Knoetze, Rinus; Swart, Antoinette; Malan, Antoinette P.Plant-parasitic nematodes of the genus Xiphinema Cobb, 1913 comprise a complex group of nematode species, some of which are important vectors of plant viruses. During a field survey to determine the soil health of an abandoned honeybush (Cyclopia genistoides) monoculture, a high density of the dagger nematode, Xiphinema oxycaudatum Lamberti & Bleve-Zacheo, 1979 (Nematoda, Dorylaimidae), was observed in soil around the roots of honeybush plants in an abandoned farmland at Bereaville, an old mission station in the Western Cape province of South Africa. Soil samples were taken from the rhizosphere of plants and nematodes were extracted from the soil using a modified extraction tray method. Specimen of the dagger nematodes were processed for scanning electron microscopy, morphological and molecular analysis. Molecular profiling of the nematode species was done in order to give an accurate diagnosis and to effectively discriminate the nematode from other species within the Xiphinema americanum group. Phylogenetic analysis based on the D2D3 expansion segment of the 28S gene supported a close relationship of species within the americanum group, however, the protein-coding cytochrome oxidase (coxI) of the mitochondrial gene provided a useful tool for distinguishing the nematode from other species within the group. This study represents the first report of X. oxycaudatum from South Africa.
- ItemFirst screening of entomopathogenic nematodes and fungus as biocontrol agents against an emerging pest of sugarcane, Cacosceles newmannii (Coleoptera: Cerambycidae)(MDPI, 2019-04-25) Javal, Marion; Terblanche, John S.; Conlong, Desmond E.; Malan, Antoinette P.Cacosceles newmannii (Coleoptera: Cerambycidae) is an emerging pest of sugarcane in South Africa. The larvae of this cerambycid beetle live within the sugarcane stalk and drill galleries that considerably reduce sugar production. To provide an alternative to chemical control, entomopathogenic nematodes and fungus were investigated as potential biological control agents to be used in an integrated pest management system. The nematodes Steinernema yirgalemense, S. jeffreyense, Heterorhabditis indica, and different concentrations of the fungus Metarhizium pinghaense were screened for e cacy (i.e., mortality rate) against larvae of C. newmannii. The different biocontrol agents used, revealed a low level of pathogenicity to C. newmannii larvae, when compared to control treatments.
- ItemFoliar application of steinernema yirgalemense to control planococcus ficus : assessing adjuvants to improve efficacy(South African Society for Enology and Viticulture, 2018) Platt, T.; Stokwe, N. F.; Malan, Antoinette P.The vine mealybug (Planococcus ficus) is regarded as a key mealybug pest of grapevines in South Africa, with entomopathogenic nematodes (EPNs) being touted as a potential alternative to chemical control, although their vulnerability to above-ground environmental conditions has limited their use. In this study, tests were conducted to assess the ability of adjuvants to increase the deposition of S. yirgalemense on grapevine leaves. The combination of Nu-Film-P® and Zeba® resulted in significantly more infective juveniles (30) being deposited per 4 cm2 leaf disc than with either the control (14.8), or with Nu-Film-P® (23.3), although not significantly more than with Zeba® alone (29.2). The ability of S. yirgalemense, in conjunction with the two adjuvants, to control P. ficus on grapevine foliage was then assessed under controlled conditions. The application of S. yirgalemense with both Zeba® and Nu-Film-P® to P. ficus on leaf discs in a growth chamber resulted in 84% mortality, significantly greater than that attained by the application of S. yirgalemense with either Zeba® (47%), or water alone (26%). Similar results were observed in a glasshouse trial, in which the combination of S. yirgalemense, Zeba® and Nu-Film-P® offered 88% control of P. ficus on leaf discs hung on potted vines, compared with the control that was achieved with S. yirgalemense with either Zeba® (56%) or water alone (30%). This study demonstrates the potential of a combination of S. yirgalemense with adjuvants to give significant control of P. ficus on grapevine foliage, compared with using EPNs alone.
- ItemHeterorhabditis noenieputensis n. sp. (Rhabditida: Heterorhabditidae), a new entomopathogenic nematode from South Africa(Cambridge University Press - CUP, 2012-12) Malan, Antoinette P.; Knoetze, R.; Tiedt, L.A new entomopathogenic nematode in the genus Heterorhabditis is described from South Africa, from two singular isolates found 1000km from each other, from beneath a fig tree and in a citrus orchard, respectively. Morphological and molecular studies indicate both isolates to be the same and a new undescribed Heterorhabditis species. Comparison of sequences of the internal transcribed spacer (ITS) rDNA and the D2D3 region of the 28S rDNA gene with available sequences of other described species within the genus, indicate the two isolates as a new species. Phylogenetic analysis of the sequence data concerned placed the new species, H. noenieputensis n. sp., closest to H. indica and H. gerrardi in the indica-group. The new species, H. noenieputensis n. sp., is distinguished from other species in the genus by a combination of several morphological traits of the males and the infective juveniles (IJs). The new species differs from all other species previously described, as regards the body length of the IJs, except for H. indica and H. taysearae, in which the IJ is smaller. The IJ also differs from that of H. indica in the length of the oesophagus, the body diameter, the length of the tail and the E%. In addition, males of H. noenieputensis n. sp. differ from their closest relative, H. indica, in the position of the excretory pore, SW% and D%; and from H. gerrardi in the length of the oesophagus and SW%. The seventh pair of genital papillae of H. noenieputensis n. sp. are normally developed, while for H. indica they are often branched or swollen at the base, while 8 and 9 are usually absent in both species.