Calicut District Research Articles

A new species of entomopathogenic nematode Oscheius gingeri sp. n. (Nematoda: Rhabditidae) from ginger rhizosphere

A new species of entomopathogenic nematode (EPN) of the genus Oscheius was isolated from the rhizosphere of ginger (Zingiber officinale Rosc.) cultivated in Indian Institute of Spices Research Experimental Farm, Peruvannamuzhi, Calicut District, Kerala, India. This species is described as a new species on the basis of morphometrics study. Entomopathogenicity of this nematode was also tested against greater wax moth Gallaria mellonella larvae. O. gingeri sp. n. is diagnosed by the presence of leptoderan bursa and crochet needle-shaped spicules, presence of 10 lateral lines, didelphic female reproductive system, double-flapped epipytigma and nine genital papillae. The characteristics of the new species are: male; body ventrally curved, “C”-shaped upon fixation, leptoderan bursa, tail short rounded conoid and nine pairs of genital papillae, female; body almost straight upon fixation, female reproductive system is didelphic, double-flapped epipytigma present on the vulval opening and tail is short conoid with pointed tip and infective and juvenile; body thin elongate, tail elongate attenuated, gradually tapering at tip and spine-like projection present. It closely resembles with O. carolinensis but differs in smaller length (vs. L = 1728 μm), larger “a” value (vs. a = 18.2); smaller “b” value (vs. b = 7.0); and larger “c” value (vs. c = 11.0), vulval opening (vs. V = 50.3%), number of lateral lines (vs. = 4) and male body posture “C” shaped (vs. elongate). This new species also closely resembles with O. columbiana but differs in higher body length (vs. L = 1288 μm), smaller “b” value (vs. b = 6.5), smaller stoma length (vs. SL = 23) and number of lateral lines (vs. = 4). O. gingeri sp. n. also resembles with O. andrassyi but differs in size of the body (vs. L = 1601 μm), larger “b” value (vs. b = 8.2), smaller “c” value (vs. c = 14.4), vulval opening (vs. V = 50.3%) and number of lateral lines (vs. = 6). This new species is capable to kill ginger shoot borer larva Conogethes punctiferalis and G. mellonella within 24–72 h under laboratory conditions. This opens a new hope of utilising Oscheius gingeri sp. n. as a biopesticide for management of the shoot borer and other insect pests of ginger.

A new species of Philautus Gistel (Amphibia: Anura: Rhacophoridae) from southern Western Ghats, India

A new species of the oriental shrub frog genus Philautus is described from Kakkayam Reserve Forest of Calicut district, Kerala state, in the southern Western Ghats. This species is distinguished from congeners by the combination of characters such as body small, elongate, squat and flat; head arched, wider than long; snout short rounded, equal or sub equal to diameter of eye; canthus rostralis rounded; tympanum indistinct but visible; eyes protruding, pupil with striking golden yellow dentition like marks; belly granular; vocal sac unpigmented; fleshy brown to cream yellow dorsum with two distinct golden yellow lateral bands bordered by dark brown from upper eyelid to the posterior part of flanks. A description of the advertisement calls and ecology and natural history notes are also provided for the new species which so far is only known from the type locality.

The prevalence and associations of reading difficulties in a population of South Indian children

A random sample of 1192 children aged 8–12 years living in Calicut District, Kerala, South India, underwent testing with the Malayalam Graded Reading Test as part of an epidemiological study of neuropsychiatric disorders. The prevalence of reading difficulty was 8.2% and it was associated with younger age, male sex, poverty, less‐educated parents, psychiatric disturbance, school failure, poor school attendance, physical ill‐health, poor motor co‐ordination and impaired vocabulary and visuo‐spatial reasoning. The findings support a multifactorial causal model of reading difficulties in this child population.

The Prevalence and Associations of Psychiatric Disorder in Children in Kerala, South India

This study aimed to identify the prevalence and associations of childhood psychiatric disorder in Calicut District, South India. Among 1403 children aged 8 to 12 years selected by random cluster sampling, a projected prevalence of 9.4% (95% CI 7.9-10.8%) was found. Associations of disorder with male sex, the Muslim religion, lower social class, less parental education, school failure, and impaired reading and vocabulary were found, but not with malnutrition or perinatal problems. The similarity to associations of disorder in Western studies was noted. The discussion focuses on the validity of comparisons of prevalence across cultures.

The prevalence and associated factors of epilepsy in children in Calicut District, Kerala, India.

To determine the prevalence of epilepsy and its association with indices of malnutrition, infection and perinatal complications in children in Calicut District, Kerala, India, a door-to-door two-stage survey was conducted in two local government districts. Among the random sample of 1172 children aged 8-12 y, 26 conformed to the definition of epilepsy giving a 5-y period prevalence of 22.2/1000. A history of perinatal complications, low BMI and recent physical symptoms were independently associated with active epilepsy. The results suggest epilepsy is highly prevalent in this population of children and that further research is needed into its cause.

Febrile seizures in a south Indian district: incidence and associations.

One thousand four hundred and three children participated in a home-based survey of psychiatric disorders in 8- to 12-year-old children in Calicut District, Kerala, India. One thousand one hundred and ninety-two consecutive children underwent neurological and psychometric assessments. The projected number of children with a history of febrile seizures was 120 giving a lifetime incidence of 10.1%. Recurrent febrille seizures predominated and these were strongly associated with a history of perinatal adversity. Febrile seizures were independently association with indices of infective illness and mothers' education. Epilepsy developed in 2.7% of children with febrile seizures, but no evidence was found that febrile seizures had adverse intellectual or behavioural sequelae.

A New Species of Nymphoides (Menyanthaceae) from South India

The plant described in this note was first collected in December, 1964, from fresh-water paddy-fields at Badagara, Calicut District, Kerala, south India, and again in September, 1965, from Alwaye, Ernakulam District. In spite of a close similarity to Nymphoides indicum (L.) Kuntze in vegetative characters, the flowers were strikingly different. Detailed studies indicated that the plant was a distinct and undescribed species. Sketches and plant material, both dried and preserved, were sent to Kew, where this was confirmed. The description and drawings below are based on fresh specimens.