Acknowledgments classification of Tylenchulus semipenelrans biotypes. J. NemalOl., 12 : 283-287. The author thanks Dr. Pinochet for suggesting this study and Dr. Inserra for useful procedure suggestions. Thanks are LAMBERT!, F., VOVLAS, N. & TIRRO, A (1976). An Italian also given to Mrs. Casanovas for typing this manuscript. biotype of the citrus . Nemalol. medit., 4 : 117-120. MARTINEZ BERINGOLA, M. L., CARCELES, A & GUTIERREZ, M. P. (1987). Ensayos de nematicidas contra el nematodo de References los agrios, Tylenchulus semipenelrans. Boln Sanid. Vegel. BAINES, R. c., CAMERON, ]. W. & SOOST, R. K. (1974). Four Plagas, 13 : 261-271. biotypes of Tylenchulus semipenelrans in Califomia ident­ MCSORLEY, R., PARRADO,]. L. & DANKERs, W. H. (1984). A ified, and their importance in the development of resistant quantitative comparison of sorne methods for the extraction citrus root-stocks. J. NemalOl, 6 : 63-66. of from roots. Nemalropica, 14 : 72-84. BELLO, A, NAvAs, A., BELART, C. & ALV1RA, P. (1986). Los ORTUNO MARTINEZ, A, GOMEZ GOMEZ, ]. & CANOVAS CAN­ nemalodos de los cilncas. Monografia. Excelentisimo Ayun­ DEL, F. (1969). Poblaciones nematol6gicas fitoparasitas en tamiento de Castellon de la Plana, 222 p. los suelos de la huerta de Murcia. An. Edafol. Agrobiol., 28 : GOTTLIEB, Y., COHN, E. & SPIEGEL-Roy, P. (1986). Biotypes of 389-398. the citrus nematode (Tylenchulus semipenelrans Cobb) in T ARJAN, A C. (1972). Observations on extracting citrus nema­ Israel. PhylOparasitica, 14 : 193-198. todes, Tylenchulus semipenelrans, from citrus roots. PI. Dis. INsERRA, R. N., VOVLAS, N. & O'BANNON, ]. H. (1980). A Replr, 56 : 186-188.

A NEMATODE FEEDING , PUTRESCENTIAE (SARCOPTIFORMIS : )

Anwar L. BILGRAMI * and Qudsia TAHSEEN *

• Section of NemalOlogy, Department ofZoology, Aligarh Muslim University, Aligarh-202002, India.

Accepted for publication 14 october 1991.

Key-words : Tyrophagus, Acaridae, nematodes.

There are few reports confirming nematodes as the plastic ring (1 cm high; 2 cm diam.) glued to a coverslip diet of soil . Linford and Oliviera (1938) observed at one end, was fixed in the middle of a metallic slide. mites feeding on root knot nematodes. Murphy and The chamber, thus formed, was filled with 1 % water Doncaster (1957) reported injury of Helerodera cysts by agar. The mites and prey nematodes were then inocu­ a mite. The most definite association came from the lated and the ring was sealed with another coverslip to work of Rodriguez el al. (1962) who observed that when prevent air drying and escape of mites. Predation was given equal choice, the adult mite Macrocheles muscae­ observed on Rhabditis sp., Cephalobus sp., Hirschman­ domesticae preferred house fly eggs over nematodes niella oryzae and mashhoodi. The rate while proto- and deutonymph under same conditions of predation by T putrescentiae was determined by using preferred nematodes. An oribatid mite Pergalumna sp., five adult mites against 50 individuals ofprey. The effect fed upon Pelodera lambdiense and Tylenchorhynchus of prey density on the rate of predation by T putrescen­ martini in large numbers (Rocken & Woodring, 1965). tiae was observed by placing 25,50,75, 100, 125, 150, Muraoka and Ishibishi (1976) described feeding by 175 and 200 individuals of H. oryzae separately with five many species of mites which were identified as nema­ predators. The number of individuals killed or con­ tode predators. Recently, Imbriani and Mankau (1983) sumed by the mites was recorded after 24 h. Ali exper­ observed feeding of a neostigmatid mite, Lasioseius iments were carried out at 28 ± 2 "c and replicated five scapulatus on avenae and Cephalobus sp. times. In the present work observations were made on the predatory behaviour of (Sar­ Predatory behaviour coptiformis : Acridae) using nematodes as prey. T putrescentiae feed on nematodes and other micro­ Materials and methods organisms in culture dishes. During routine observ­ ations the cultures of saprophagous species of nema­ Prey catching and feeding mechanisms were studied todes viz., Acrobeloides, Cephalobus, Rhabditis, Pana­ in culture dishes and special observation chambers. A grellus and predaceous nematodes viz., Mononchus

Vol. 15, nO 5 - 1992 477 aqualicus, Mononchoides jorlidens, M. longicaudalus, Table 1. Rate of predation by Tyrophagus putrescentiae upon Dorylaimus stagnalis, Aqualides lhornei were ail found to different prey nematodes. be contaminated and consumed by T. pUlrescenliae. It restricted multiplication and reproduction of nematodes Prey species No. of prey killed in culture dishes and as a result of predation brought down their population at a low level. Rhabdilis sp. 29-33 T. pUlrescemiae could hold its prey using its palp (34 ± 1.6) (used to identify prey organisms and other objects) and Cephalobus sp. 21-27 legs as soon as the prey came in contact. The legs are (24 ± 2.4) generally used for holding and wounding the prey. 28-34 Chelicerae are the main killing and feeding organ, also (30 ± 2.6) used for grasping and crushing the prey. The ingestion Tylenchorhynchus mashhoodi 24-31 of prey contents was intermittent (two or three feeding (27 ± 2.5) bouts) with short periods of resting activity at regular intervals. Mites also consumed its own faecal matter while moving randomly generally in absence of prey Table 2. Effect of prey density (Hirschmanniella oryzae)on the nematodes. No cannibalistic tendency was observed in rate of predation by Tyrophagus purrescentiae. T. pUlrescemiae. The nymphal stages of T. pUlrescemiae fed mostly on dead nematodes, their remains or upon Preynumber No. of prey killed % the agar containing bacterial and fungal growth. T. pUlrescemiae killed Rhabditis sp. and H. oryzae most 25 6-14 40 while Cephalobus sp. the least (Table 1). Maximum (10 ± 3.0) predation occurred in the population of 200 prey in­ 50 23-29 52 dividuals which was double the number of prey killed (26 ± 2.0) when 25 individuals of H. oryzae were used as prey 75 39-43 55 (Table 2). (41 ± 1.9) 100 58-62 61 (61 ± 3.0) Conclusions 125 82-88 68 (85 ± 2.8) Observations on T. pUlrescemiae suggest its pre­ 150 108-113 73 daceous nature. These predatory mites appeared to (109 ± 2.3) possess greater predatory potentials mainly because of 175 131-136 76 their ability to kill variety of nematodes in large num­ (133 ± 2.6) bers. T. pUlrescemiae fed most upon Rhabditis sp. and H. 200 158-164 81 oryzae. Besides, mites also consumed bacterial and (161 ± 2.3) fungal populations grown over the agar. Increased predation by T. pUlrescemiae with increasing number of Ali figures are nearesl 10 whole numbers. H. oryzae suggests density dependant predation as is the case with many predaceous nematodes (Bilgrami el al., 1984; 1985; Bilgrami & Jairajpuri, 1990). The copro­ scapulalUs, a neostigmatid mite predaceous on nematodes. J. phagous behaviour of T. pUlrescemiae may be an added NemalOl., 15 : 523-528. advantage as it could avoid intraspecific interactions L1NFORD, M. B. & OUVlERA, ]. M. (1938). Potential agent of (cannibalism). biological control of plant parasitic nematodes. PhylOpatho­ logy, 28 : 14. MURAOKA, M. & ISHIBISHI, N. (1976). Nematode feeding mites References and their feeding behaviour. Appl. Ent. Zool., 11 : 1-7. BILGRAl\1I, A. L. & JAlRAjPURI, M. S. (1990). Predation by MURPHY, P. W. & DONCASTER, C. C. (1957). A culture method lvfononchoides forlidens and M. 10ngicaudalUs (Nematoda : for soil microfauna and its application to the study of Diplogasterida). NemalOlogica, 35 : 475-488. nematode predation. NemalOlogica, 2 : 202-214. BILGRAMI, A. L., AHMAD, 1. & JAlRAjPURI, M. S. (1984). ROCKETT, C. L. & WOODRING, ]. P. (1966). Biological inves­ Observations on the predatory behaviour of Mononchus tigation on a new species of ceratozetes and of Pergalumna. aqualicus. NemalOl. medil., 12 : 41-45. Acarologia, 8 : 14-18. BILGRAMI, A. L., AHMAD, 1. & JAIRAjPURI, M. S. (1985). RODRIGUEZ, T. G., WADE, C. F. & WELLS, C. N. (1962). Predatory behaviour of Aquarides lhornei Nygolaimina : Nematodes as natural food for Macrocheles muscaedomeSli­ Nematoda). NemalOlogica, 30 (1984) : 457-462. cae (Acarina : Macrochelidae) a predator of the house fly IMBRIANI, ]. 1. & MANKAU, R. (1983). Studies on Lasioseius egg. Ann. Ent. Soc. Am., 55 : 507-511.

478 Fundam. appl. NemalOl.