Fundam. appl. Nematol., 1995,18 (6), 513-522

Ecology and pathogenicity of the (Nemata) from the sahelian zone of West Mrica. 8. Senegalonema sorghi Germani, Luc & Baldwin, 1984 and comparison with Linford & Oliveira, 1940

Pierre BAuJARD* and Bernard rvtARTINY ORSTOM, Laboratoire de Nématologie, B.P. 1386, Dakar, Sénégal. Accepted for publication 29 August 1994.

Summary - The geographical distribution, host plants, population dynamics and vertical distribution were srudied for the Senegalonema sorghi in Senegal. The observations of sorghum roots parasitized by S. sorghi showed the absence of gelatinous matrix and the presence of a shell around the marure females. The development of the female inside the roots induced the bursting and tearing of the cortical tissues of the roots. The factors influencing the multiplication rate and the effects of anhydrobio­ sis were srudied in the laboratory for S. sorghi and ROlylenchulus ren~formis. The results showed that the highest multiplication rates of both species were recorded at relatively low soil temperarure and high soil moisrure. Both species were able to enter anhydrobiosis during the dry season, with survival rates of 20-40 %. S. sorghi parasitized only wild and cropped cereals. During the dry season, it was under hydrobiotic conditions at depth in cropped soils and under anhydrobiosis in the upper layers of the soils under fal1ow. The restricted distribution of R. reniformis in the vegetable crops under irrigation might be explained by its narrow host range; ail other ecological characteristics were the same as for S. sorghi.

Résum.é - Écologie et nocuité des Hoplolaimidae (Nemata) de la zone sahélienne de ['Afrique de l'Ouest. 8. Senegalo­ nema sorghï Gennani, Luc & Baldwin, 1984 et comparaison avec Rotylenchulus reniformis Linford & Oliveira, 1940 - La répartition géographique, les plantes hôtes, la dynamique et la répartition verticale des populations ont été érudiées au Sénégal pour Senegalonema sorghi. L'observation des racines de sorgho parasitées par S. sorghi montre l'absence de gangue gélatineuse et la présence d'une coque de narure inconnue chez les femelles marures dont le renflement provoque l'éclatement des tissus corticaux des racines. Les facteurs influençant le taux de multiplication et les effets de l'anhydrobiose ont été érudiés au laboratoire pour S. sorghi et ROlylenchulus reniformis. Ces deux espèces sont caractérisées par leur préférence pour des tempérarures du sol relative­ ment faibles et des humidités élevées; toutes deux sont capables d'entrer en anhydrobiose pendant la dessication des sols lors de la saison sèche avec des taux de survie de l'ordre de 20 à 40 %. S. sorghi semble strictement inféodé aux céréales sauvages et cultivées; cette espèce est, pendant la saison sèche, active et localisée en profondeur dans les sols cultivés et en anhydrobiose dans les horizons superficiels dans les sols en jachère. Seule la gamme d'hôtes relativement étroite de R. reniformis pourrait expliquer son absence des sols non irrigués dans la zone sahélienne ouest africaine, les autres caractéristiques écologiques étant identiques à celle de S. sorghi.

Key-words : Senegalonema sorghi, ROlylenchulus reniformis, nematode, West Africa, geographical distribution, population dynamics, vertical distribution, soil temperarure, soil moisrure, host plant, multiplication rate, anhydrobiosis, pathogenicity.

This eighth paper on the ecology and pathogenicity of species, Senegalonema sorghi, associated with sorghum the Hoplolaimidae (Baujard & Maniny, 1995 b, c, d, eJ, roots in the centre of the peanut cropping area of Sene­ g, h) presents the results of field and laboratory studies gal. This genus has been identified recently in Mozam­ on Senegalonema sorghi and Rotylenchulus renijormis. bique around roots of sugar cane CVan den Berg, 1993). Genera and species of the subfarnily Rotylenchulinae Examination of these specimens kindly sent to us by Dr. (Hoplolaimidae) are frequently recorded in soils ofWest Van den Berg showed that they differ from S. sorghi and Africa: Germani (1978) Iisted several populations of probably represent a new species of this rare genus. R. reniformis, R. parvus and R. borealis from this region. In the peanut cropping area of Senegal, the distribu­ Baujard and Maniny (1994) found R. borealis in Mali; tion of R. renij01mis is restricted to fields under irrigation Germani et al. (1984) described a new genus and a new where this species is frequent (Baujard & Martiny,

(*) Present address: Muséum National d'Histoire Naturelle, Laboratoire de Biologie Parasitaire, Protistologie, Helminlhologie, 61, rue Buffon, 75005 Paris, France.

ISSN 1164-5571/95/06 S 4.00 / © Gauthier-Villars - ORSTOM 513 P. Bal/jard & B. Marliny

1995 a). S. sorghi is a rare species, mostly found in the soil temperature for 60 days in a greenhouse with natu­ central and southern parts of this area associated with raI Iighting. The four treatments were replicated ten rainfed crops and wild plants (Baujard & Martiny, times in a completely randomized design. 1995 a). R. renijorrnis : tubes were inoculated with 140 ± 6 ne­ matodes originating from roots extraction in the soil Material and methods temperature experiment, planted with tomato, and Studies on geographical distribution, field population maintained at 30 oC constant soil temperature as men­ dynamics, and vertical distribution have been conducted tioned above. as previously described (Baujard & Martiny, 1995 b). HOST PLANT AND TEST FOR Unless otherwise stated, nematode extractions, nema­ ANHYDROBIOTIC SURVIVAL tode cultures, technics, host plants and cultivars [peanut (Arachis hypogea L.) cv. 55437, millet (penniseturn ty­ S. sorghi: tubes were inoculated with 120 ± 10 nema­ phoides Rich.) cv. Souna III, sorghum (Sorghurn vulgare todes originating from a 60-day-old stock culture on L.) cv. 5169, cowpea (Vigna unguiculaw L.) (Walp.) sorghum, planted with one of the four host plants (cow­ cv. N58 57] used for laboratory studies are those de­ pea, millet, peanut or sorghum), and maintained at scribed by Baujard (1995). For the two species, inocula 32°C constant soil temperature and 10 % constant soil consisted of mixtures of vermiform stages (juveniles, moisture in a greenhouse. The four treatments were immature females and males). replicated twenty times in a completely randomized de­ sign. After 60 days, were extracted from ten ORJGIN OF NEMATODES, LABORATORY replications to obtain final population counts. At this STOCK CULTURE CONDITIONS, time, watering was stopped for the ten remaining repli­ AND ROOTS OBSERVATIONS cations of each treatment. These tubes were kept at S. sorghi : nematodes originated from soil samples tak­ 32 oC constant soil temperature and weighed daily to en at Nebe in an experimental field cropped with sor­ follow the progress of soil desiccation. Sixty days later, ghum in October 1985 at the end of the rainy season. nematodes were extracted by elutriation. The nematodes were extracted and reared on sorghum R. renijorrnis : tubes were inoculated with 93 ± 10 ne­ at constant soil temperature (32 oC and soil moisture matodes originating from soil of the previous experi­ (10 %) in the laboratory until May 1992. Observations ment on soil moisture, planted with one of the five host on sorghum roots infestation by S. sorghi were made on plants (cowpea, millet, peanut, sorghum or tomato), root systems of stock cultures stained by fuschin acid and maintained at 30 oC constant soil temperature and (Hooper, 1986). 10 % constant soil moisture in a greenhouse. The exper­ R. remforrnis : nematodes originated from soil samples iment was conducted as mentioned above. taken at Bambey in an irrigated field cropped with veg­ SCREENING OF HOST PLANTS OF S. SORGHI etables in April 1990. The nematodes were extraeted and reared on tomato (Lycopersicon esculenlurn L.) cv. Tubes were inoculated with 188 ± 27 nematodes Roma; this cultivar has been used for alllaboratory ex­ originating from 60-day-old stock cultures on sorghum periments) at constant soil temperature (30 OC) and soil and planted with one of sixteen different plants [Andro­ moisture (10%) in the laboratory until May 1992. pogon guayanus Hack., Cenchrus biflorus Roxb., Eragros­ lis pilosa (L.) Beauv., Digilanà exilis Stapf, Panicurn SOIL TEMPERATURE rnaxirnurn ]acq., Penniseturn violaceurn L., Zea rnays L., S. sorghi: tubes were inoculated with 118 ± 17 nema­ Gossypiurn hirsulUrn L. cv. Irma, Solanurn rnelongena L., todes originating from 60-day-old stock cultures, plant­ Abelrnoschus esculenlUS ((L.) Moench, Sesbania pachycar­ ed with sorghum, and maintained at four constant soil pa Oc., Cuiera senegalensis]. F. Gme!., Piliostigrna relic­ temperature levels (30, 32, 34 or 36 OC) with seven ulaturn (OC) Hochst., Prosopis juliflora Oc., Acacia albi­ replications for each temperature level, at 10 % constant da De!., Acacia tortilis ssp. raddiana Savi.] with eight soil moisture, for 60 days in a growth chamber with replications per plant, and maintained at 32 oC constant anificial lighting (16-h photoperiod). soil temperature and 10 % constant soil moisture for R. renijorrnis: Tubes were inoculated with 117 ± 8 60 days in a greenhouse. nematodes originating from stock cultures on tomato, PATHOGENICITY OF S. SORGHI TO PEANUT, MILLET, planted with tomato, and maintained as mentioned AND SORGHUM above. Separate experiments were conducted with each crop SOIL MOISTURE species at 32 oC soil temperature and 10% soil moisrure S. sorghi: tubes were inoculated with 76 ± 5 nema­ in a greenhouse. Nematodes originating from 60-day­ todes originating from the soil temperature experiment, old stock cultures on sorghum were inoculated onto planted with sorghum, and maintained at four constant peanut and millet at two inoculum levels (500 ± 30 or soil moisture levels (5, 7, 9 or Il %) at 32 oC constant 1000 ± 60), and onto sorghum at one inoculum level

514 Fl/ndam. appl. NemalOl. Ecology of Hoplolaimidae. 8

16·

peanut cropping area 13" • woodlands s. sorghl distribution

1 1 17" 16" , 5· 14"

Fig. 1. Known distribution of Senegalonema sorghi in the peanut cropping area ofSenegal.

(300 ±40). Nematode effects were compared to control Willd. or Euphorbia balsamzfera Ait. plants without nematodes. The treatrnents were repli­ FIELD STUDLES ON S. SORGHI cated ten times in a completely randomized design. M­ ter 40 days, nematodes were extracted from soil and Population dynamics roots to determine the multiplication rate, and the fresh No population development was recorded in plots weight ofroots and fresh and dry weights ofshoots were under peanut and cowpea monoculrures and in plots measured. under peanut-millet rotation. Smail and erratic increases occurred under sorghum probably in relation with the Results poor growth of the crop. Significant population increas­ es appeared only in plots under millet monoculrure and GEOGRAPHICAL DISTRIBUTION AND FIELD HOST permanent fallow (Fig. 2). The soil population in­ PLANTS OF S. SORGHI IN SENEGAL creased from the beginning to the end of the rainy sea­ S. sorghi is a rare species occurring only in 7 % of 266 son. Nematodes invaded the plant root system with a samples collected in the peanut cropping area of Sene­ maximum of 500 nematodes per root system. During gal. Its distribution is restricted to the centre and the the rainy season, population densities increased regu­ south ofthis area (Fig. 1). This species has been found i) larly over the last three years of the srudy (Fig. 2). At the in field cropped with peanut or millet, il) in the roots of end, or just after the end of the rainy season, population wild herbaceous (A. guayanus) and arborescent (Icacina densities decreased rapidly and remained undetectable senegalensis A. Juss., Combretum glutinosum Perr., P. re­ throughout the dry season (Fig. 2). Although millet ap­ ticulatum) plants, iii) associated with the roots of trees at peared to be a good host for the nematode, no multipli­ depth [A. albida (50 cm deep), Acaczà nilotica (L.) cation occurred with this crop in 1985 or in 1987 in the Willd. (from 20 to 100 cm deep), A. tortilis ssp. raddiana plots under peanut-millet rotation (Figs 2, 3). Multipli­ (from 50 to 200 cm deep), P. julijlora (from 20 to 60 cm cation rates during the rainy season varied from 0 to 300 deep)). It has not been found associated with sorghum, and survival rates during the dry season from 0 to 50 % cowpea or vegetable crops nor with Acacia Senegal (L.) according to the crop and to the year (Fig. 3).

Vol. 18, n° 6 - 1995 515 P. Baujard & B. Marliny

a 200

0 000 o~ogoo~0œ+o0 00 ..J 0 ,----,.--- ~ (/) LL D 0 1000 M ::E: c 800 a: UJ c. 600 a: UJ 400 ID ::E: :::> z 200 UJ C 0 0 1-« 200 ::E: UJ rr=~~+oo DD~oo D~l_ ~oe eU~D8 z 0 =l 200 ~~DDDDo~ID5P DDDD~~_~oDooU~=+=-DDo-o 0 IF 1 -, ~ ~ ~ ~ 1000 G HF/f------'f------I

800

600

400

200

0 1984 1985 1986 1987 1988

Fig. 2. Populalion dynamics of Senegalonema sorghi according 10 lhe cultural praaices. A : Peanul monoculture; B: Peamu-millel rOlalWn withoul nemalicallrealmenl; C: Peanut-millel rotalion with nemalicallreatment; D: Millet monoculture; E: Sorghum monocul­ lure; F: Cowpea monoculture; G: Permanent fallow (Hatched areas =rainy seasons; squares = soil population; diarnonds = root population).

516 Fundam. appl. Nemawl. Ecology ofHoplolaimidae. 8

_. SAISON OES PLUIES SAISON SECHE • 111&-4 rJ 18815 Dl 1886 El 1887 1 • 188~-1ll86 o 1886-1888 1!l1886-1887 El 1987-1988 300 100 1 -1

::- 250 c. ~ 80 [ .= w 200 ii: 1-« cr [ 60 z w 1- 0 150 F i= ~ « u «...J 40 :::::i 100 > c. :; i= cr ...J :) :) III 20 :E 50 ~ ~ ~ a H 91 a v:L A BC 0 ~E .F G A B C 0• E F G CULTURAL PRACTICES CULTURAL PRACTICES

Fig. 3. Multiplication and surviva1 rares of Senega10nema sorghi aaording ID the cU/lUTaI practices andyear ofobservations (see Fig. 1 for me legend).

Vertical distribution in the soil Factors affecting the multiplication rate During the dry season, the distribution pattern of the nematode varied according to the crop. Under peanut, Soil temperature and soil moisture affected signif­ millet and sorghum, the nematode was located at depth, icantJy the multiplication rate of both the species in the 30-35 cm below the soil surface where soil moisture same way. Higher muJtiplication occurred at 30-32 oC never falls below 1.5 % preventing anhydrobiosis. Un­ and at the highest soil moisture levels (Figs 6, 7). Root der falJow, the nematodes are located at a 20-25 cm popuJation densities were not affected by soil tempera­ depth in anhydrobiotic conditons. During the rainy sea­ ture or moisture, 31-54 % for S. sorghi and 16.3-30.7 % son, the nematode was recovered onJy in the plots under for R. renijormis (Table 1). Host plants had a significant millet or fallow, evenJy distributed from the top to a effect on the multiplication rate of both the species depth of 80 cm (Fig. 4). (Figs 6, 7). OnJy millet and sorghum allowed the repro­ duction of S. sorghl~ whereas millet, sorghum, cowpea and tomato allowed it for R. renijormis. Multiplication LABORATORY STUDIES rates of R. remformis were low and variable with millet Observations on laboratory stock cultures ofs. sorghi (x 1.25±2.13) and sorghum (3.50± 1.70). Sorghum appeared to be the best host for S. sorghi. Root pop­ Ail stages (juveniles, immature and mature females uJation levels remained stable. There was no relation and maJes) were found in the roots of sorghum. Juve­ between muJtiplication rates and root population densi­ niles and immature femaJes (Fig. 5 A) are located in the ties with R. renijormis (Table 1). cortical cells, the head being direcred to the stele. The posrerior two thirds of the female body widens progress­ ively (Fig. 5 B-D). Following this body width increase, the root tissues burst and tear so that the posterior part Ability to enter anhydrobiosis ofthe female body protrudes from the root (Fig. 5 D-F). At this stage, an ovoid shell appears around the female Cessation of watering induced a decrease of soil body (Fig. 5, F) and its volume increases following the moisture down to 0.2 % in 15 days. Nematodes survived development of the female body (Fig. 5 H-J). Eggs were soil desiccation for 60 days, survivaJ being related to the laid in the cavity formed by this shell (Fig. 5 J, K). No population densities before watering was stopped for gelatinous matrix was observed. Copulation and ferti­ S. sorghi and R. renijormis (Figs 6, 7). SurvivaJ rates of lization of females by maJes were not observed. 20-40 % were recorded for the two species (Fig. 8).

VoL 18, n° 6 - 1995 517 P. Baujard & B. Marliny

5 A,D 5 D 10 10

15 15

20 20 Ê Ê ~ 25 ~ 30 :I: :I: 1- 1- Q. 30 Q. W a aW 35 50

40 60

45 70

50 60

o 10 20 30 40 50 60 70 BO 90 100 o 10 20 30 40 50 60 70 BO 90 100 PERCENTAGE OF THE TOTAL POPULATION PERCENTAGE OF THE TOTAL POPULATION

5 G 5 G 10 10

15 15

20 20 Ê ~ Ê 25 ~ 30 :I: :I: 1- 1- Q. 30 Q. 40 W a aW 35 50

40 60

45 70

50 BO j'-- o 10 20 30 40 50 60 70 BO 90 100 o 10 20 30 40 50 60 70 BO 90 100 PERCENTAGE OF THE TOTAL POPULATION PERCENTAGE OF THE TOTAL POPULATION

5 E 10

15

20 Ê ~ 25 :I: ~ 30 w a 35

40

45

o 10 20 30 40 50 60 70 BO 90 100 PERCENTAGE OF THE TOTAL POPULATION

Fig. 4. Vertical distribution ofSenegalonema sorghi cu:cording 10 the cultural prcu:tices and the season ofobservation (See Fig. 1 for me legend; left column : dry season; right column : rainy season).

518 Flmdam. appl. NemalOl. Ecology of Hoplolaimidae. 8

Fig. 5. Development ofSenegalonema sorghi in lhe raOls ofsorghum. A : lmmalltrefemale in lhe parenchyma; B-E: Swelling (aTTOWS) of lhe poslerior pan oflhe body; F-G : Formation ofthe shell (arrows) around the body and progress ofbody swelling; H-J: End oflhe swelling process; J-I : Egg laying Witholll gelalinous malnx.

Vol. 18, n° 6 - 1995 519 P. Baujard & B. Marliny

50 A Screening of host plants ofs. sorghi 40 / Ali the graminaceous plants tested were hosts for the ~ nematode with multiplication rates varying from 3 to < cr: z 30 32 : P. violaceum (x 2.8), Z. mays (x 8.5), A. guayanus o >= (x 8.8), P. maximum (x 16.4), C. bijloms (x 20.9), E. pt­ < u losa (x 27.7), D. exilis (31.9). The other plants tested ~ 20 ~ did not allow the multiplication of the nematode and no ::> :l' nematodes were recovered from the root systems. .0 Pathogenicity S. sorghi did not have any significant effect on growth 30 32 34 36 SûlL TEMPERATURE re) of peanut at the inoculum levels tested. The nematode

50 significantiy reduced the root development of millet, and reduced dry weights ofroots and shoots ofsorghum

40 (Table 2). Root population levels varied as in the previ­ ~ ous experiments (Table 1). < cr: z 30 o >= Discussion < u ~ 20 ~ Field observations showed that S. sorghi is character­ ::> :i ized by i) its limited geographical distribution, it) its host .0 range being restricted to wild and cropped cereals, iit) its capaciry to survive in active stage at deeper soillevels, or under anhydrobiosis in the upper layers of the soil dur­ 7 • 11 SOIL MOISTURE (el.) ing the dry season. Laboratory experiments confirmed

50 these observations, showing that this nematode is not c well adapted to the ecological characteristics of the semi­ arid areas of West Africa. Relatively low soil temper­ 40 atures and high soil moisture levels are required for opti­ w ~ < mal development of this species. But the nematode is cr: z 30 o able to enter anhydrobiosis and it feeds only on gramina­ >= < u ceous plants including cereals. These characteristics and ~ 20 the distribution of the nematode in deeper soil areas in ~ ::> croped soil might explain its low frequency of detection :l' la during nematological surveys. R. reniformis exhibited the same ecological character­ istics as S. sorghi for optimal soil temperature and moist­ ure. Previous studies have shown that cereals are non­

5000 hosts or poor hosts for this species (Luc & de Guiran, o 1960; Caveness, 1967; Stoyanov, 1967) and these char­ acteristics might explain the limited distribution of this ~ . 4000 species to vegetable crops under irrigation in the semi­ .~ o arid tropics of West Aftica. ~ 3000 .s The shell embedding the mature female ofS. sorghi in Ô the roots of sorghum constitutes a new biological char­ i= 2000 :3 acteristic of swollen mature females in the Tylenchina. ~ Recent ultrastructural observations showed that this 1000 shell is probably of polysaccharidic composition (Mounport, pers. comm.); it appears similar to that de­

PEANUT MILLET SOAGHUM COWPEA scribed in the genus Achlysiella (Hunt et al., 1989). The HOST PL.ANT biology ofS. sorghi differs from that of R. reniformis by i) Fig. 6. Effeets ofsail temperalUre v:l), senl moislUre (B), and oost the presence of a shell around the mature female, ii) the plants (C), on the multiplication rate and effect ofsail desiccation on absence ofa gelatinous matrix, Iii) the presence of ail the survival (D) ofSenegalonema sorghi (In each experiment, data nematode stages (vs only females) in the roots (Linford followed by the same letter are Dot significanùy clifferent at & Oliveira, 1940; Sivakumar & Seshadri, 1971), IV) Jow P < 0.05). (x 20-50) vs high (1000-2000) multiplication rates.

520 Fundam. appl. NemalOl. Ecology of Hoplolaimidae. 8

2500 A Table 1. Percenlages of lhe populalion of Senegalonema sorghi

2000 and Rorylenchulus reniformis in lhe raols al lhe end oflhe dijfer­ enl experiments on multiplicalion Tale (ND : nol delermined).

1500

Experimem Treatrnem Root population 1000 as a % tube population of total 500 S. sorghi R. renijormis

32 3.. 36 SaiL TEMPERATURE (·e)

2600 Soil temperature 30 oC 31.6 26.9 8 32°C 47.2 27.9 34 oC 48.3 30.7 2000 36 oC 35.2 25.1 w... « Ir Soil moisture 5% 33.8 20.1 z 1500 0 7% 54.2 16.9 ;: « 9% 54.3 16.9 "~ '000 Il % 48.3 16.3 ~ :J :> Host plants peanut 0 0 '00 millet 33.1 37.5 sorghum 40.5 45.9 cowpea 0 36.0 7 9 11 tomato 30.0 SOIL MQISTURE (%) ND

2600 Pathogenicity c Peanut * 500 nematodes 0 ND 2000 1000 nematodes 0 ND w * «... Ir Millet z 1500 o ;: * 500 nematodes 60.5 ND ~ *1000 nematodes 59.3 ND ~ 1000 ~ Sorghum :> * 300 nematodes 62.1 ND 600 " inoculum per rube. c c PEANUT MILLET SOAGHUM COWPEA TOMATO HOST PLANT Table 2. Multiplicalion Tale and effecr.s of Senegalonema 260000 sorghi on peanut, millel, and sorghum (numbers followed by lhe same lmer are nol signijicanrly dijferenr al P < 0.05). .~ 200000 ~ Ë 150000 Plant Inoculum Multi- Fresh weight Dry weight ! ptication (g) (g) z l1lte 8 100000 ~ ~ Roots Shoots Shoots o .. soooo Peanut 0 1.72 a 6.63 a 1.15 a 500 0.03 1.88 a 6.55 a 1.11 a 1000 0.03 1.71 a 6.56 a 1.12 a PEANUT MILLET SOROHUM COWPEA TOMATO HOST PLANT Millet 0 2.16 a 4.62 a 0.74 a Fig. 7. Effecr.s of soil lemperawre (A), 5011 moiswre (B) and hosl 500 3.91 1.76 ab 4.46 a 0.63 a planLS (C) on lhe multiplicalion Tale and effeets of soil desiccalion 1000 2.72 1.31 a 3.57 Q 0.50 a on survival of Rorylenchulus reniforrnis (ln each experimem, Sorghwn 0 2.22 a 433a 0.66 a data followed by the same lener are noe significantly differem 300 3.29 1.58 b 3.74 a 0.53 b at P< 0.05).

Vol. 18, n° 6 - 1995 521 P, Baujard & B, Marliny

100 A BAUJARD, P. &MARTINY, B. (1995 e). Ecologyand pathogen­ icity of the Hoplolairnidae (Nemata) from the sahelian zone of West Africa. 4. The genus Aphasmatylenchus Sher, 1965. '0 Fundam. appl. Nematol" 18: 355-360. t uJ r 60 BAUJARD, P. & MARTINY, B. (19951). Ecology and pathogen­ < r! iciry of the Hoplolairnidae (Nemata) from the sahelian zone ~ < :> of West Africa. 5. AOl'olaimus macbelhi (Sher, 1964) Fortun­ ~ 40 r! er, 1987. Fundam. appl. Nematol., 18: 427-433.

60 BAUJARD, P. & l\1ARTINY, B. (1995 h). Ecology and patho­ ~ geniciry of the Hoplolaimidae (Nemata) from the sahelian w 60 zone of West Africa. 7. Helicolylenehus dihystem (Cobb, ~ a: 1893) Sher, 1961 and a comparison with Helieolylenchus multicinetus (Cobb, 1893) Golden, 1956. Fundam. appl. Ne­ matol., 18 : 503-511,

CAVENESS, F. E. (1967). Shadehouse host ranges of sorne 20 nigerian nematodes, Pl. Dis. Reptl', 51 : 33-37.

GERMAN!, G. (1978). Caractères morpho-biométriques de trois expèces ouest-africaines de Rotylenehulus Linford & Oliveira, 1940 (Nematoda: ), Revue Nématol., Fig. 8. Effects of host plants and soil desiccation on survival rate 1: 241-250. Senegalonema sorghi (A) and Rorylenchulus reniformis (B). GERMAN!, G. Luc, M. & BALDWIN, J. G. (1984), A new Rorylenchulinae : Senegalonema sOTghi n. gen., n. sp, (Nema­ Acknowledgtnents toda : Tylenchida). Revue Némalol., 7 : 49-56. The authors thank. Dr. E. van den Berg for sending speci­ mens of Senegalonema sp. from Mozambique. HOOPER, D. J. (1986). Preserving and staining nematodes in plant tissues. In : Southey J. F. (Ed.) Labomtory methods for References wOl'k with plant and soil nemalodes. London, Ministry of BAUJARD, P. (1995). Laboratory methods used for the study Agriculture, Fisheries & Foods : 81-85. of the ecology and pathogeniciry of Tylenchida, Longidori­ dae and Trichodoridae from rainy and semi-arid tropics of HUNT, D. J., BRIDGE, J, & MACHON, J. E. (1992). On Aehly­ West Africa, Fundam. appl. Nemalol" 18: 63-66. siella, a new genus of obese Prarylenchidae (Nematoda: ). Revue Nématol., 12: 401-407. BAUJARD, P, & MARTINY, B. (1994). Études nématologiques au Mali, Afrique de l'Ouest. 1. Prospection de deux zones LINFORD, M. B. & OLIVEIRA, J. M. (1940). Rotylenehulus arachidières. J. afT. Zool;, 108: 217-226. Tenif01mis nov. gen., n. sp., a nematode parasite of roots. BAUJARD, P. & MARTINY, B. (1995 a). Characteristics of the Pme. helminth. Soc. Wash., 7 : 35-42. soil nematode populations from the peanut cropping area of Senegal West Africa. J. afT. Zool., 109 (in press). Luc, M. & DE GUIRAN, G, (1960). Les nématodes associés aux plantes de l'Ouest Africain. Agmn. trop., Nogent, 15: BAUJARD, P.l\1ARTINY, B. (1995 b), Ecolog)' and pathogenic­ 434-449. ity of the Hoplolaimidae (Nemata) from the sahelian zone of West Africa. 1. Field studies on Scutellonema cavenessi Sher, SIVAKUl'vI.AR, C. V. & SESHADRJ, A. R. (1971). Life history of 1964. Fundam. appl. Nemalol., 18: 261-269. the reniform nematode, ROlylenehulus renijormis Lindford & BAUJARD, P, & MARTINY, B. (1995 c). Ecology and pathogen­ Oliveira, 1940. lndian J. Nematol., 1 : 7-20. iciry of the Hoplolaimidae (Nemata) from the sahelian zone STOYANOV, D. (1967). Additions to host records of Meloido­ of West Africa. 2. Laboratory studies on Scuœllonema cave­ gyne sp., Helicotylenehus multieinctus and Rotylenchulus reni­ nessi Sher, 1964. Fundam. appl. Nematol., 18: 335-345. formis. Nematologica, 13: 173. BAUJARD, P. & MARTINY, B. (1995 d). Ecology and patho­ geniciry of the Hoplolaimidae (Nemata) from the sahelian VAN DEN BERG, E. (1993). Nematology Section, Biosyste­ zone of West Africa. 3. Scutellonema clathrieaudalum White­ matics division, PPRl, Pretoria. Nemalol. Soc. southem Ajr, head, 1959. Fundam. appl. Nematol., 18: 347-353. Newsl., 28: 27-30.

522 Fundam, appl. Nematol.