8 Parasitic Nematodes of some Insects from Manipur , India

Manipur is situated in the north east of India. The state covers an area of 22,356 sq.kms of which the hilly region is about 91.75%, while the remaining 8.25% of the geographical area constitutes the central valley region. It lies between 23051`N and 25041`N latitudes and 9302`E to 94047`E longitudes. Generally, two types of climatic conditions are found in this state according to latitude, topography and direction of the prevailing wind system. Tropical monsoon type of climate prevails in the valley area whereas the cool temperate climate prevails in the hilly areas. The average maximum temperature of this state is 310C, the minimum temperature is 50C and the rainfall is about 2077mm per annum. Manipur being part of The North East India represents an important part of the Indo-Myanmar biodiversity hot spot recognized recently in the year 2005 among 34 Biodiversity hotspot of the world.


Introduction
Manipur is situated in the north east of India. The state covers an area of 22,356 sq.kms of which the hilly region is about 91.75%, while the remaining 8.25% of the geographical area constitutes the central valley region. It lies between 23 0 51`N and 25 0 41`N latitudes and 93 0 2`E to 94 0 47`E longitudes. Generally, two types of climatic conditions are found in this state according to latitude, topography and direction of the prevailing wind system. Tropical monsoon type of climate prevails in the valley area whereas the cool temperate climate prevails in the hilly areas. The average maximum temperature of this state is 31 0 C, the minimum temperature is 5 0 C and the rainfall is about 2077mm per annum. Manipur being part of The North East India represents an important part of the Indo-Myanmar biodiversity hot spot recognized recently in the year 2005 among 34 Biodiversity hotspot of the world.
The present work mainly concerns with the nematodes of insects of Manipur. Nematodes are regarded as the most numerous multicellular animals on earth. There are over 20,000 described species classified in the phylum Nematoda. Most of the free-living nematodes are microscopic; many of the parasitic species invade the body fluids such as blood or lymph channels of their hosts. They exhibit a wide range of feeding habits. Many feed entirely on the microorganisms present in decaying vegetable matter (saprophytic), others live on plants and wander destructively through the tissues and suck their sap. In vertebrates they may parasitize every organ often causing destructive and painful diseases and producing immeasurable hardships. Their life cycle ranges from very simple to extremely complicated. The majority of the nematodes are oviparous, but some are ovoviviparous. All nematode juveniles whether they hatch in water or soil or within the animal host must undergo a series of 4 moults before reaching maturity. Entomophilic or insect nematodes are distributed in 27 families among nine major groups of nematodes viz., Rhabditoid, Tylenchoid, Aphelenchoid, Strongyloid, Oxyuroid, Ascaridoid, Spiruroid, Filaroid and Mermithoid. The first eight groups belong to the Rhabditea (plant and animal parasitic form) and the 9th belong to the Enoplea (mostly free living, microbotrophic aquatic nematodes). The Order Oxyurida contains parasites that parasitize both invertebrate and vertebrate hosts. The nematodes parasitizing the vertebrate hosts belong to the superfamily

Generic diagnosis
Female: Cephalic extremity formed by single annulus and simple second annulus. Oesophagus consisting of a cylindrical corpus, an isthmus which may be distinct or indistinct and a valvular bulb. Cardia lobed or simple. Vulva in the posterior third of body, vagina directed anteriorly. Gonads amphidelphic. Eggs elongate, elliptical, flattened on one side, fused in pairs or more along their flattened surfaces with ridges and furrows or simply attached to one another forming a chain. Polar egg filaments present or absent. Tail conical or with a terminal spike.
Male: Cephalic extremity formed by single annulus. Oesophagus consisting of a cylindrical corpus, distinct or indistinct isthmus with a bulb. Spicule single or absent. Caudal papillae comprising 3-5 pairs. Tail very short, rounded, with or without a spine like process on its ventral side.

Generic diagnosis
Female: Cephalic extremity formed by circumoral annule and enlarged second annule. Mouth surrounded by eight labial papillae. Amphids present. Lateral alae present or absent. Buccal cavity simple. Oesophagus consisting of an anterior cylindrical corpus, an isthmus and a posterior valvular bulb. Excretory pore pre-or post-oesophageal bulb or at the level of the base of the bulb. Tail long filiform about one-third to one-fourth of the total body-length. Vagina short, muscular and anteriorly directed with well developed vulval lip. Vulva at or posterior to mid-body. Eggs broadly oval.  Male: Cephalic extremity formed by single expanded annule. Lateral alae present or absent. Tail elongated and filiform. Four pairs of caudal papillae, consisting one pair pre-anal, one pair ad-anal and one median duplex post anal papillae on genital cone. One pair of papillae on caudal appendage some distance away from the anus. Testis single. Spicule present or absent.

Generic diagnosis
Female: Cephalic extremity formed by two annules. Lateral alae present. Eggs large, elongate and crescent-shaped. Female tail long, filiform or attenuated. Oesophageal corpus divided into narrow anterior and broad posterior portions of roughly equal length, isthmus short, and bulb spherical. Intestine with blind diverticulum. Vulva near midbody.
Male: Cephalic extremity formed by single expanded annule. Lateral alae present or absent. Spicule present or absent. Caudal extremity in males abruptly truncate with or without short terminal spine (spine-like process on its ventral side) or with several protuberances. Caudal papillae 3-5 pairs.

Species
Leidynema appendiculatum (Leidy,    Male: Cephalic extremity formed by single expanded annule. Caudal extremity with prominent genital cone. Caudal papillae 3-6 pairs, single median papilla present or absent. Spicule single. Caudal appendage, narrowing abruptly posterior to last pair of caudal papillae, rest of the papillae borne on genital cone.

Diagnosis
Mouth with or without trilobed circumoral elevation. Cuticle without spines. Anterior region may or may not possess transverse striations. Oesophagus consisting of corpus which may be clavate or cylindrical, isthmus distinct or indistinct and a posterior valvular bulb. Vulva anterior to base of the oesophagus. Gonads amphidelphic. Eggs with or without cuticular crest or grooves. Tail of female attenuate to conical terminating in narrow spine or short and subconical or short and rounded with two cuticular wing like projections. Male caudal extremity tapering posterior to anus and ending in digitiform appendage or short and subconical or narrowing, with long appendage or short and bluntly rounded or subconical. Caudal papillae 3-8 pairs or completely absent. Spicule single or absent.

Diagnosis
The family Pseudonymidae is diagnosed by the presence of filaments coiled around egg shell and in the absence of polar egg filaments.

Generic diagnosis
Female: Cephalic extremity formed by circumoral annule and simple second annule. Oesophageal end bulb gently clavate with or without pseudobulb. Isthmus a constriction between corpus and bulb. Cardia may or may not be modified into a branch-like structure posteriorly. Vulva with protruding anterior lip near posterior-third of the body. Vagina short, anteriorly directed. Gonads amphidelphic. Eggs broadly oval with filaments coiled around shell. Tail conical Male: Cephalic extremity formed by single annule. Corpus cylindrical. Caudal extremity conical. Spicule present. Caudal papillae consisting of one pair pre-anal sub-ventral, one pair adanal sub-lateral, three pairs circumanal of which one pair pre-anal, one pair adanal and one pair post-anal and two pairs on tail, of which one is sub-lateral and one sub-ventral.

Generic diagnosis
Cephalic extremity formed by a circumoral ring and short second annule. Lateral alae present or absent in both sexes. Isthmus distinct or it is a constriction between corpus and bulb with or without a ring-like sub-ganglion at its middle of isthmus. Buccal cavity absent or present in females. Vulva posterior to midbody. Gonads amphidelphic. Eggs broadly oval with polar filaments deposited in capsules containing 2-3 eggs or non-encapsulated and laid in pairs. Tail conical or rounded with short or long caudal appendage or flagella-like, with or without fine striations near its tips. Caudal extremity in male conical to subulate or filiform or spike-like. Caudal papillae 5-10 pairs. Single median papilla present or absent.    Cephalic extremity formed by prominent cephalic annule. Oral opening surrounded by three lips, one dorsal and two subventral. Buccal cavity long, tubular, formed by two distinct parts of almost equal length. Oesophageal corpus very long, widest at its anterior end, shaped like an inverted club, isthmus short and bulb spherical. Excretory pore anterior to the base of the oesophagus. Vulva near posterior-third of body. Vagina short, muscular and anteriorly directed. Amphidelphic. Eggs oval shaped, attached to one another by polar filaments, laid in mucus capsules, each capsule containing two-five eggs. Tail short, blunt or rounded or subulate, with or without spine-like appendage. Lateral alae absent in female. Gonads two, ovaries reflexed at both ends, the anterior one extends upto the middle of the corpus and the posterior one a little above the anus. Caudal extremity in male rounded. Caudal papillae four to seven pairs. Spicule absent. Pointed cuticularized accessory piece present immediately behind the anus.