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Browsing by Author "Ramachandran Nair, K."

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Additions to the Natural Enemy Complex of the Coconut Caterpillar Opisina arenosella Wlk.
(2007-02-08) Pillai, G.B.; Ramachandran Nair, K.
Brachycoryphus nursei (Cameron) (Hymenoptera: Ichneumonidae), A parasitoid of Opisina arenosella Wlk. on coconut in Kerala, India
(2007-02-08) Pillai, G.B.; Ramachandran Nair, K.
The cotton boll worm parasitoid Brachycoryphus nursei (Cameron) has been observed to occasionally parasitise the prepupae and pupae of the coconut leaf eating caterpillar Opisina arenosella Wlk. in coconut gardens around Kayangulam, Kerala State. This Indo-Pakistani species of solitary ectoparasitoid shows some peculiarities in host acceptance, ovipcsition and development. It attacks the larvae, prepupae and pupae, always deposits numerous eggs on the host, eventually to produce only one individual parasitoid. Occasionally, it develops internally in the host pupae. It has high fecundity but possesses low searching ability, thereby causes only negligible percentage parastism in O. arenosella. Eggs are laid after keeping the ovipositor touching the paralysed host. Feeding on the hosts haemolymph is observed throughout the long life span of the female parasitoid. The larvae of B. nursei are cannibalistic. This parasitoid produces more female progeny than males in the field. The females are polyandrous and males are very vigorous. Method of rearing, oviposition, development and life cycle of the parasitoid are discussed.
A check list of parasitoids and predators of Opisina arenosella Wlk. on coconut
(2007-02-08) Pillai, G.B.; Ramachandran Nair, K.
Two species of parasitoids, Antrocephalus sp.? maculipennis CAM. and Trichospilus diatraeae CHERI AN & MARGABANDU and four species of predators, Ankylopteryxoctopunddta FAB., Geocoris sp., Physopleurella sp. and Cardiastethus sp.? pygmaeus pauliniae CARAYON were recorded by the authors on the leaf eating caterpillar, Opisina arenosella WLK. on coconut, for the first time. Including these, the pest supports 40 species of parasitoids and 20 predators. Among the parasitoids, 34 belong to Hymenoptera, 5 to Diaptera and one to Acarina. The hymenopterans fall under 9 families. Fourteen species belong to Chalcididae, seven species to Ichneumonidae, four species to Braconidae, three to Eulophidae, two to Eurytomidae and one species each to Elasmidae, Bethylidae, Eupelmidae and Trichogrammatidae. Three species of tachinids and two phorids constitute the dipterans. Among 40 species of parasitoids, ten are larval, two larval-pupal, two prepupal and twenty five species pupal. Bracon hebetor SAY (B. brevicornis WESM.) Bracon serinopae (CHERIAN), Goniozus nephantidis (MUES.), Elasmus nephantidis ROHWER, Trichospilus pupivorus FERR., T.diatraeae and Jetrastichus israeli (M. & K.) are the seven gregarious parasitoids of 0. arenosella. Twenty species of the predators fall under four orders: I. Coleoptera (Carabidae-4, coccinellidae-4) II. Heteroptera (Anthocoridae-7, Reduviidae-1, Lygaeidae-1) III. Neuroptera (Chrysopidae-2) IV. Psocoptera (Peripsocidae-1) The dipteran, Stomatomyia bezziana BARANOFF which is a common parasitoid in some parts of the eastern and south-eastern tracks of Sri Lanka is not at all present in India. The Sri Lankan biotype of Eriborus trochanteratus (Morley) attacks O. arenosella caterpillars on coconut and this biotype is established at Coimbatore (Tamil Nadu) and Thottappally (Kerala) in India. B. hebetor becomes adapted to Corcyra cephalonica ST., when reared continuously on its larvae in the laboratory and such adults quite often do not exert any high degree of suppression of 0. arenosella in the field. Xanthopimpla pundata F. and x. nana nana SCHULZ. appear in the field only in the latter half of the year. Both species select breeding sites close to the sea shore, back waters, streams and paddy fields and congregate in such sites without uniformly dispersing to all pest-infested regions Bradiymeria sp. dominate the parasitoid complex of 0. arenosella in Kerala and Bradiymeria nosatoi HABU has several desirable attributes of an ideal parasitoid. Larval and pupal parasitism vary from locality to locality and region to region. A thorough survey for the natural enemies of O. arenosella in different tracts of the country would be rewarding.
Distribution of spear rot disease of oil palm (Elaeis guineensis Jacq.) and its possible association with MLO diseases of palms in Kerala, India
(2007-02-08) Kochu Babu, M.; Ramachandran Nair, K.
Mating and Host Paralysing Behaviours of Goniozus (Parasierola) Nfphantidis (Mues.) (Hymenoptera:Bethylidae) on Opisina Arenosela Wlk. of Coconut
(1985) Pillai, G.B.; Ramachandran Nair, K.
Goniozus (= Parasierola) nephantidis (Muesebeck) (Hymenoptera: Bethylidae), the gregarious ectoparasitoid of the coconut leaf eating caterpillar, Opsina arenosella Wlk., is one of the widely used larval parasitoids for biological suppression of the pest in south India. Sequence of the courtship and mating behaviours of the parasitoid and its host paralysing behaviour are discussed. It was noticed that excessive mating and inbreedirg had little adverse effect on the progeny of the parasitoid. Details such as time taken for subduing the host, location of stinging, its effect on the host and the time taken for oviposition on the paralysed host caterpillars of O. arenosella are also discussed. It was observed that the parasitoid attacked the host caterpillar 12 to 36 hours after the same was offered for parasitisation. Once the host caterpillar was stung between the head and thorax, paralysis of the same took place in three minutes and cessation of muscular movementsin another 55 minutes.Normally, oviposition commenced 10 hours after the paralysis of the host caterpillar.
Mating Behaviour and Biology of Elasmus Nephantidis Rohw. (Hymenoptera: Elasmidae),A Parasitoid of Nephantis Serinopa Meyrick
(2007-02) Ramachandran Nair, K.; Pillai, G.B.
Courtship and mating behaviour of Elasmus nephantidis Rohw., the monophagous ectoparasitoid on the prepupal caterpillars of Nephantis serinopa Meyrick include wing vibration, licking the antennae of the female with mouth parts, antennal stroking, leg tapping and post-copulatory biting on the females abdomen. The female adopts a copulation posture by raising the abdomen and exposing the genital pocket on receiving sexual stimulation from the courting male. Males are capable of mating at very close intervals. Females allow courtship even when they are non-receptive and actually do not require further matings. Eggs are laid inside the hosts cocoon one by one in groups after stinging and paralysing the host. Egg to adult stages are completed in 11 days and longevity is shorter in summer than in winter. Sex ratio is normally female-biased. The merits and demerits of E. nephantidis as a biocontrol agent of N. serinopa are discussed.
A Method to Estimate the Intensity of Natural Pupal Parasitism of Opisina Arenosella Wlk. (=Nephantis Serinopa Meyrick)
(2007-02) Pillai, G.B.; Ramachandran Nair, K.
The nature, size and position of the emergence holes made in the host pupal cases by different species of pupal parasitoids of the coconut caterpillar Opisina arenosella Wlk. (-Nephantis serinopa Meyr.) were studied. These criteria were used in developing a method to estimate the intensity of natural parasitism of the pest and the relative contribution of individual species of parasitoids in the natural suppression of the pest. The advantages of the method of examination of empty pupal cases are that it is less time-consuming, less cumbersome and more accurate than the currently adopted method of collecting sample pupae at periodic intervals and observing the emergence of parasitoids and evaluating the intensity of parasitism.
Mushroom Cultivation on Oil Palm Factory Wastes 1. Scope for Oyster and Paddy Straw Mushrooms
(2007-02) Kochu Babu, M.; Ramachandran Nair, K.; Thankachy, S.
Two species of oyster mushroom (Pleuroius sajorcaju and P. llorlds) and paddy straw mushroom (Volvariella volvacea) were evaluated on oil palm factory wastes viz., mesocarp waste and bunch leluse, by different methods. The highest yiald on mesocarp waste was oblained In the case of Plaurolus llorids(37.3% conversion). Volvariella volvacos recorded a conversion of 4.97% on bunch refuse. The scope tor bio-utillzation of these wastes by mushroom cultivation Is discussed.
Norms for Release of Larval, Prepupal and Pupal Parasitoids of Opislna Arenosella Wlk., the Leaf Eating Caterpillar of the Coconut Palm
(1987-12) Sathiamma, B.; Pillai, G.B.; Jose Abraham; Keshava Bhat, S.; Jayapal, S.P.; Ramachandran Nair, K.
An experiment was conducted to work out the dosages for release of the larval, prepupal and pupal parasitoids of Opisina arenosella under field conditions. Parasite releases were madeat three doses Viz. Zero, 25 and SOX of the target stages of the pest population at fortnightly intervals. Observations revealed that the releases of the parasites effected varying levels of reduction in population density of O. arenosella. The reduction obtained was significant in plots in which the larval parasitoid Goniozus nephantidis and the prepupal parasitoid Elasmus nephantidis were released. The doses worked out were 20.5% for G. nephantidis, 49.4X for E. nephantidis and 31.9% for B. nosatoi, when the parasitoids were released individually, and 40.4% when a combined release was made.
A Note on the Biology of Xanthopimpla Nana Nana Schulz. (Hymenoptera: Ichneumo Nidae), A Pupal Parasitoid of Opisina Arenosella Wlk. on Coconut
(2007-02) Pillai, G.B.; Ramachandran Nair, K.
The association of Xanthopimpla nana nana schulz with Opisina arenosella WLK is seasonal from August to January. Like Xanthopimpla punctata F.,X. nana nana also selects brooding sites close to the sea shore, back waters, rivers, etc. Maximum parasitism by it was 31.6% during November, 1984. Egg period was 26-28 hours, larval period 5 to 9 days and pupal period 6 to 9 days. Females survived for 24 to 95 days. X. nana nana is difficult to rear in the laboratory during summer months. Short descriptions of the immature stages and their distinguishing features are also provided.
Nursery Disorders and Abnormalities
(1998) Kochu Babu, M.; Ramachandran Nair, K.; Nampoothiri, K.U.K.
Observations on Eriborus Trochanteratus (Morley) (Hymenoptera : Ichneumonidae), A Larval Parasitoid of Opisina Arenosella Wlk.
(2007-02) Pillai, G.B.; Ramachandran Nair, K.
The populations of Eriborus trochanteratus (Morley) occurring in India and Sri Lanka, are morphologically identical, but belong to two biotypes. A method to rear the Sri Lankan biotype of E. trochanteratus using Opisina arenosella Wlk. as host in the laboratory was developed. Additional information on the mating behaviour, oviposition and life history of the parasitoid on O. arenosella and Corcyra cephalonica caterpillars was collected. Attempts on field colonisation of the laboratory reared parasitoids in Opisina infested coconut gardens in the West Coast of Kerala resulted in establishment and recovery. However, hyperparasitism by the chalcidid Brachymeria nephantidis Gahan was observed in a few cocoons of E. trochanteratus collected from the release site. The possible reasons for the slow build up of population of E. trochanteratus in the field are also discussed.
Observations on Eurytoma Albotibialis Ashmead (Hymenoptera: Eurytomidae), A Hyperparasitoid of the Coconut Leaf Eating Caterpillar, Opisina Arenosella Wlk.
(1985-10) Pillai, G.B.; Ramachandran Nair, K.
Eurytoma albotibialis Ashmead, recorded as a hyperpaiasitoid as well as a primary parasitiod of the coconut leaf eating caterpillar, .Opisina arenosella Wlk., is predominantly a hyperparasitoid parasitising the larval/ pupal stages of several species of primary parasitoids of the pest. Its importance as a secondary parasitoid in minimising the role of Brachymeria spp. has been overlooked so far. The peak activity of E. albotibialis synchronised with that of Brachymeria spp. and O. arenosella during April and May. Consequently, the build up of population of Brachymeria spp. was checked considerably at a time when the pest was likely to multiply rapidly taking advantage of the high temperatures of the summer season and the low levels of population or total absence of certain other species of parasitoids It was observed that during April and May, E. albotibialis suppressed 13.11% and 43.48%, respectively, of Brchymeria spp. populations in the field. Mating behaviour, ovipcsition and development of the hyperparasitod and its population abundance in the field are also discussed. Egg to adult stages of the hyperparasitoid were completed in 13-19 days(egg period 24-28 hours, larval 6-9 days and pupal period 6-9 days). Longevity of adults ranged from 30-105 days and the sex ratio was always female-biased (male : female ratio :16). The life cycle of the secondary parasitoid was almost comparable to that of Brachymeria spp., which constitute the dominant species of pupal parasitoids of the pest.
Observations on Xanthopimpla Punctata Punctata F. (Hymenoptera:Ichnemonidae), A Pupal Parasitoid of Opisina Arenosella Wlk
(2007-02) Pillai, G.B.; Ramachandran Nair, K.
Xanthopimpla punctata. F. the solitary, potyphagous, pupal parasitoid has been so fat Considered as an insignificant species in the biological suppression-of the coconut leaf eating caterpillar, Opisina arenosella Wlk. (Lepidoptera:Cryptophasidae). Recent observations carried out in Tamil Nadu and Kerala revealed that X. punctata breeds in O. arenosella during July to December with a peak period of activity during September - October. Without uniformly dispersing in all the Opisina - infested coconut gardens, the adult parasitoids congregated in some localised tracts close to the sea, back waters or other water ways or in irrigated coconut plantations and effected a high degree of parasitism, suppressing even the dominant species of pupal parasitoids like Brachymeria nosatoi Habu. Other ichneumonid parasitoids such as Zanthopimpia sp. and X. nana nana Schulz. were not found to build up their populations in the territory occupied by X. punctata.. Host feeding is present prior to opposition, which is continued in every one to three days, through out the long life span of the female parsitoid. A method for rearing this parasitoid in the laboratory, its mating behaviour life history, intensity of natural parasitism etc. are also discussed.
Oil Palm Seed and NurseryDiseases
(1998) Kochu Babu, M.; Ramachandran Nair, K.; Nampoothiri, K.U.K.
On the Biology of Calleida Splendidula (F) (Coleoptera: Carabidae), A Predator of the Coconut Leaf Eating Caterpillar, Opisina Arenosella Wlk.
(2007-02) Pillai, G.B.; Ramachandran Nair, K.
A method for rearing the carabid predator, Callefda splendidula (F) in the laboratory is described. Short descriptions of the adult and immature stages of the beetle and feeding potential of the predator on Opisina arenosclla WLK. caterpillars are also fiirnished. The adult beetle, on an average, consumed one fully grown caterpillar of O. arenosella i n every three days. Eleven to thirteen second instar caterpillars of O. arenosella were consume by each grub during the entire grub phase. The adult beetle lived for6 to 14 months in laboratory cages. A comparison between C. splendidula and Parena nigrolineata (CHAUDOIR) also is furnished.
Phytosanitary Seed Treatments in Oil Palm Elaeis Guineensis.
(2007-02) Kochu Babu, M.; Ravindran, P.S.; Ramachandran Nair, K.
The seeds of oil palm harbour several fungi on the mesocarp remnants. To prevent the spoilage of seeds by fungi and to check their spread to new areas (when germplasm introductions are made) the effects of methyl bromide fumigation and five fungicides were tried before preheating the seeds. The seed micro-flora, germination and seedling vigour were monitored. Methyl bromide fumigation reduced germination and had no effect on external microflora. Hence it cannot be recommended for seed treatment. Fungicide treatments increased seed germination and seedling vigour. Wet fungicide treatments with Emisan 6 (Methoxy Ethyl Mercury Chloride) 0.1% and Foltaf 80W (Captafol 80% WDP) 0.2% for 20 min. before preheating were effective in eliminating external microflora and helped in increasing seed germination and seedling vigour. Thus seed treatment with fungicides was the best for phytosanitary treatment of oil palm seeds.
Role of Ichneumonid Parasitoids in the Biological Suppression of the Coconut Leaf Eating Caterpillar, Opisina arenosella Wlk.
(1990) Pillai, G.B.; Ramachandran Nair, K.
Role of Pupal Parasitoids in the Natural Suppression of the Coconut Caterpillar Nephantis Serinopa Meyrick
(1981) Pillai, G.B.; Ramachandran Nair, K.
Evaluation of the intensity of natural parasitisation of Nephantis serinopa pupae in the Quilon and Alleppey districts of Kerala State for two years (1979 and 1980) revealed that more than 50% of natural pest suppression was due to the pupal parasitoids, of which the chalcidids Brachymeria spp. were the major ones and among them, B. nosatoi was the most dominant species followed by B. nephantidis. Activity of B. nosatoi was more during the summer season, which is also the peak period of the pest. The intensity of natural parasitisation by Trichospilus pupivora (Eulophidae) was meagre, being 1.6% only.
Studies on spear rot disease of oil palm in Kerala, India I. Establishment of phytoplasma etiology and yellow leaf disease affected arecanut as the source of inoculum
(2004-12) Kochu Babu, M.; Ramachandran Nair, K.; Solomon, J.J.; Nambiar, K.K.N.; Geetha, L.
Experimental transmission of phytoplasmas (Mycoplasma-like organisms) associated with spear rot disease (SRD) of oil palm in Kerala. India from oil palm to oil palm and yellow leaf disease (YLD) affected arecanut to oil palm was attcmptcd using dodder laurel, Cassytha filiformis L. Positive transmission by symptom reproduction was observed in five oil palm seedlings after 10- I8 months of bridging to SRD-affected oil palm and two out of four oil palm seedlings bridged to YLD affected Areca palm. Electron microscopic detection of phytoplasmas in all the seedlings which have expressed symptoms confirmed the transmission of this disease.

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