Morphology : Radopholus similis 
		   Classification

		Kingdom  : Animalia

		Phylum   : Nematoda 

		Class    : Secernentea 

		Subclass : Diplogasteria

		Order	 : Tylenchida

		Family   : Pratylenchidae

		Genus    : Radopholus

		Species  : similis
Morphometric characteristics in μm
Character Female Male
Body length 690 630
Body length/maximum body width (a) 27 35
Body length/oesophageal length (b) 6.5 6.4
Body length/tail length (c) 10.6 9
Distance from head end to vulva/ body length x 100 (V) 56 -
Body length/distance from head end to posterior end of oesophageal glands (b’) 4.5 4.8
Tail length/body width at anus(c’) 3.4 5.7
Occurence
Radopholus similis is found world-wide in tropical and sub-tropical regions, and occurs wherever bananas are grown. Originally described from the Fiji Islands but are also found in the following areas where the burrowing nematode is known to occur, primarily on banana: throughout Africa, parts of Asia, Florida, Central and South America, Cuba, Australia and several countries in southern Europe. An extremely serious and wide spread nematode, particularly in Karnataka, Kerala and Tamil Nadu also reported from Andhra Pradesh. In the United States, the nematode is found in most of the Southeastern US, Puerto Rico and Hawaii. In the 1960’s it was imported into several European countries (France, Belgium, the Netherlands, and Germany) with ornamental plants. The principal means of burrowing nematode transmission to new localities, including citrus groves, is by the movement of infected plants. The burrowing nematode is also spread with soil which may be carried from one area to another whether in bulk or on the roots of plants. Widespread in most banana-growing regions of the world and present in glasshouses in temperate areas (Orton Williams & Siddiqi, 1973; O'Bannon, 1977).
Morphology and anatomy
Female Male
Oesophagus and spear degenerate; median bulb and valvular apparatus indistinct, spear without distinct knobs. Lip region elevated, four-lobed, with lateral lip considerably reduced, not strongly sclerotized, with three to five annules posteriorly. Hemizonid just anterior to excretory pore which is usually two to three body widths behind median oesophageal bulb. Single testis, outstretched anteriorly; spermatocytes in three rows followed by five. Bursa coarsely crenate, enveloping about 2/3rd of tail. Spicules strongly cephalated, 18-22 long, with pointed distal ends. Gubernaculum rod-like, protrusible, with distinct sharp, claw-like titillae at distal end. (see: Fig. 4) Larva: Seven larvae were found to be 315-400 in length, with spears 13-14 long. Tail tapering to a bluntly rounded terminus; hyaline portion much shorter than in female. Genital primordium near mid-body. Body straight to slightly arcuate ventrally; cuticle distinctly annulated. Lateral field with four incisures, not aerolated except towards extremities, arising from near median oesophageal bulb and ending near tail terminus; inner incisures coalescing near middle of tail. Lip region hemispherical , sometimes offset, usually with three to four annules; sclerotization strong; dorsal and ventral arms of framework not wider than submedians; lips six, equal. Anterior cephalids just posterior to labial sclerotization. Spear about 18 long, with well developed round basal knobs which are usually indented anteriorly; dorsal knob sometimes appearing larger than subventrals. Median oesophageal bulb well developed, round to oval, valvular apparatus prominent. Oseophageal glands three, in separate lobes, overlapping intestine dorsally and dorso-laterally; dorsal gland anteriormost. Hemizonid three annules long, just anterior to excretory pore which is at or just behind the level of the oseophago-intestinal valve. Vulva prominent, just postequatorial. Reproductive organs paired, opposed, outstretched. Spermathecae spherical, usually packed with small rod-shaped sperm. Ovaries generally with a single row of oocytes. Intestines filled with spherical granules, indistinctly overlapping rectum. Tail somewhat elongate-conoid with a narrow rounded or indented terminus.