Browsing by Author "Mammen, K V"

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Biology of the brown plant hopper, nilaparvata lugens (stal) (delphacidae, hemiptera)
(Kerala Agricultural University, 1975) Nalinakumari, T; Mammen, K V
Biology of the pea leaf roller, Nacoleia vulgalis Guence. (Lepidoptera :Pyralidae)
(Kerala Agricultural University, Vellanikara, 1964) Mammen, K V; Joseph, K V
Control of major pests of copra with phosphine fumigation
(Kerala Agricultural University, 1998) Nalinakuinari, T; Visalakshi, A; Mammen, K V
Effect of oilcakes on the incidence of rootgalls and the yield of bhindi in nematode-infested soil
(Kerala Agricultural University, 1972) Mammen, K V
Impact of insecticides on the flora and fauna in the soil ecosystem of banana plantation
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 1993) Alice Renta Packia Sujeeth, J; Mammen, K V
Possible adverse effects of the insectisides recommended for the control of pests/diseases of banana in Kerala, on the useful soil organisms and the consequent impact on the banana ecosystem were studied in detail through a field experiment and follow up laboratory investigations. The results revealed: (1) Earthworm population was adversely affected with HCH even in low doses upto two months after the treatment. With carbofuran soon after the first and second application the population declined but restored with in two months. In the case of phorate the first treatment alone caused significant adverse effect while the second and third did not cause any significant effect on the earthworms. Even in carbofuran and phorate treatments earthworms. Even in carbofuran and phorate treatments earthworm population came on par with control two months before the harvest. (2) Parasitic nematodes were unaffected by HCH treatment. With carbofuran significant reduction in the population of parasitic nematode was noted after two applications of the insecticide. The nematicidal effect was seen lost throughout the period of observations from the eighth month. In phorate treatment significant reduction was observed only after three consecutive applications of the toxicant. The overall reduction caused by phorate was not adequate. Carbofuran was hence better to control parasitic nematodes than phorate. In both the cause the low level of nematode population in soil may be attributed to the lack of response to the nematicides recommended for the control of the pest. (3) HCH treatment was not at all toxic to non-parasitic nematodes. In the case of carbofuran and phorate low population was observed throughout, while significant reduction was observed for a short while after the first application of the insecticides only. (4) Collembolan and mite population was not reduced by HCH treatment. Significant reduction was observed for two months after the first and second applications of carbofuran and phorate. Adverse effect was then lost and the population was maintained on par with control till harvest. (5) The bacterial count was low throughout in HCH treatment. Though the carbofuran reduced the bacterial population it was revived in two months time. Phorate suppressed the bacterial population after first two applications, while with the third application slight enhancement was observed on the population and it was restored on par with control before harvest of the crop. (6) In fourth and eighth month a suppressing effect of HCH on actimycetes was noted and a stimulatory effect was observed during the sixth month. In carbofuran no significant reduction was observed upto three months and later on no reduction was noted. In phorate significant reduction was observed after the first and second application and the actinomycets population was then restored and remained unaffected till harvest. (7) Significant reduction of fungi was observed during the third and fourth months after planting in HCH treatment. In carbofuran slight reduction was noted after first and second application. The population was then restored. In phorate slight reduction was noted after two applications and it was restored in the next month itself. The third application showed stimulatory effect and the population was higher than that observed in control in subsequent observations. (8) The organic matter content in treatments and control remained on par and hence the humification process in banana ecosystem, through the activity of the soil organisms, was not seen affected by the application of insecticides. The variations in pH and moisture content of a soil in control plots and treatments also were not statistically significant. (9) Changes in the correlation of soil parameters with the beneficial organisms in control and treatments also did not show any definite trend. This may be due to low variability in the data on the population levels as well as the soil parameters. In general the treatments did not alter the population of the soil fauna and flora in the ecosystem to cause any adverse persistent effect.
Influence of climatic factors on populations of the brown plant hopper in Kuttanad, Kerala
(Kerala Agricultural University, 1980) Nair, K P V; Mammen, K V; Pillai, K B; Nair, S S
Studies carried out at the Rice Research Station, Moncompu, Kerala, during 1974-76 showed that in the Kuttanad rice tract, brown plant hopper Nilaparvata /ugens (Stal.) is present in the field throughout the year with a major population peak during January to March for themain crop (winter crop) and a minor peak during August to September for the second crop {autumn crop). Correlation studies revealed that the hopper population was significantly influenced by climatic factors. Rainfall in association with relative humidity and and maximum temperature played a decisive role in regulating the population of the insect.
Insecticidal control of the pod borers of cow pea
(Kerala Agricultural University, Vellanikara, 1968) Mammen, K V; Nair, M R G K
Insecticidal dusts to control pests of stored paddy
(Kerala Agricultural University, Vellanikara, 1968) Mammen, K V; Visalakshi, A; Nair, M R G K
Meloidogwe javanica (Treub, 1888) Chitwood, 1949 and Hoplolaimus indicus, Sher, 1963 associated with sugarcane in Kerala
(Kerala Agricultural University, 1974) Mammen, K V
Occurrence of Nilaparvatha lugens (Stal.) (Delphacidae: Homoftera) as a serious pest of paddy in Kerala
(Kerala Agricultural University, 1972) Das, N M; Mammen, K V; Christudas, S P
On the occurrence of Coccinella Arcuata fabricius (Coleoptera:Cocci nellidae) as a predator of rice thrips in Kerala
(Kerala Agricultural University, 1977) Mammen, K V; Vasudevan Nair, K P
On the occurrence of white grub Schizonycha Ruficollis F. (Melolonthinae Scarabaeidae Coleoptera) as a pest of sugarcane in Kerala
(Kerala Agricultural University, 1981) Mammen, K V
Plant parasitic nematodes associated with different field crops in Kerala
(Kerala Agricultural University, 1973) Mammen, K V
Protection of stored cowpea seeds (Vigna unguiculata (L) (Walp) from infestation by the pulse beetle Callosobruchus maculatus F. (Bruchidae : Coleoptera)
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 1982) Purnamma, B; Mammen, K V
Review of the insect pests of pulsecrops and studies on the biology of the pea leaf roller Nacoleia vulgalis Guence (Pyralidae)
(Division of Entomology, Agricultural College and Research Institute, Vellayani, 1963) Mammen, K V; Joseph, K V
Literature on the insect pests of the important pilse crops, with special reference to the work done in India has been reviewed. The biology and bionomics of the pea leaf roller Nacoleia vulgalis Gn. (Pyralidae) have been worked out in detail. The moths mate a day after emergence. The female moth lays creamy yellow, oval, scale like eggs during night in rows, generally on tender leaves . On an average , about 542 eggs are laid by one female. Incubation period is 4 days. Larval period lasts 13 to 15 days, the larva undergoing five instars. Durations of the different instars are 3 to 4 , 2 to 3, 2 to 3, 2 to 3 and 4 to 6 days respectively. The first instar caterpillars nibble and feed on the green matter on the undersurface at the base of the leaves and the later stage caterpillars web the leaves together and feed from inside skeletonising the leaves.
Studies on the extent of damages caused by pests of stored copra and controle of the important pests
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 1989) Nalina Kumari, T; Mammen, K V
The magnitude and intensity of insect pest attack in stored copra, in the Southern Districts of Kerala, were assessed in an elaborate survey, adopting a random sampling technique for two years. The survey revealed that insects cause significant damage even in well preserved good quality copra stocked for more than five months. N. rufipes, O. surinamensis, A. advena and L. serricorne were the major pests recorded. The immature stages of N. rufipes, adults and immature stages of the other pests were seen inside the tunnels made between the endosperm and testa. N. rufipes and O. surinamensis were distributed widely, while the predominant insects observed at Nedumangad were A. advena and L. serricorne. All the insects were found breeding on copra from June to October. A positive correlation between moisture content of copra and the insect incidence was observed in the studies. The influence of A. flavus on the extent of damage caused by these pests showed that the presence of the mould was not a predisposing factor for insect attack. The extent of damage in copra due to the infestation by N. rufipes was 12.2 per cent at the end of sixth month whereas O. surinamensis caused only three per cent damage. When combind with fungus, the damage caused by N. rufipes was reduced by 50 per cent. This effect was not observed on O. surinamensis. The infection by the fungus adversely affected the oil content of copra and this effect was not altered by the preceeding or succeeding infestation of the insect. The insect attack alone caused significant reduction in oil yield of copra during the sixth month after exposure only. The quality of oil was adversely affected when infested by insects and fungus independently. The infestation of insects preceeding or succeeding fungal infection did not alter the adverse effect caused by them independently. The quantitative loss caused by the attack of N. rufipes and O. surinamensis to copra obtained from different varieties of coconut did not show significant variations. Among the different varieties tested LM and LO were more favourable to N. rufipes and DxT and TxD to O. surinamensis. Two to six fold increase in the longevity of the adults of N. rufipes was observed when they were provided with immature stages in addition to copra for feeding. N. rufipes and O. surinamensis caused significantly greater damage to copra under eight per cent and six per cent moisture levels respectively. The development of N. rufipes was totally arrested in copra with four per cent moisture content. The development of immature stages and adult population of N. rufipes were higher in copra containing eight per cent moisture level and those of O. surinamensis in copra containing six per cent moisture. The response to moisture fluctuations was more conspicuously seen in O. surinamensis than in N. rufipes. Though the population of insects were found to be high in reused gunny bag followed by heap storage, the extent of damage was higher in heap storage than in reused gunny bags. High populations of N. rufipes and O. surinamensis were recorded from heap and reused gunny bags respectively. Low populations of insects were recorded in copra stocked in polythene/alkathene lined gunny bags and netted polythene bags. But the oil extracted from copra stored in these types of bags gave significantly higher acid values. In the trials done to find out a safe prophylactic method of control against pests of copra, malathion and phoxim proved more toxic to N. rufipes and malathion and fenitrothion to O. surinamensis. When these insecticides were evaluated for their persistence on gunny bags, malathion 0.4 per cent gave protection up to five months and fenitrothion 0.8 per cent up to six months. The residues of malathion and fenitrothion came below tolerance limits, 15 and 60 days after treatment respectively . For complete control of the major pests of copra 4.5 g/m (2.5 g ai/m ) of aluminium phosphate with one day exposure period was found adequate. The residue of phosphine in the copra fumigated as above was below tolerance limit.
Studies on the nature and extent of damage caused by insect pests to stored tapioca chips
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 1988) Ramla Beevi, S; Mammen, K V
A survey on tho population of different stages of insect pests and the extent of damage caused by these insect to stored tapioca chips were conducted at monthly intervals for a period of four months from August 1984 to November 1934 in ten centres of Trivandrum District via. Palode, Parasala, Nedumangad, Venjaramood, Pothencode, Chirayinkil, Vembayon, Chalai, Sreekaryam and Mangalapuran, where tapioca chips wore stored. Among the various posts recorded three species viz. tapioca weevil
Taxonomic key for the identification of Indian delphacidae
(Kerala Agricultural University, 1974) Mammen, K V; Menon, M R G
Taxonomic observations on the family Delphacidae with special reference to wing venation and male genitalia
(Kerala Agricultural University, 1971) Mammen, K V; Ramdas Menon, M G
Taxonomic studies of leaf and plant hoppers associated with paddy in Kerala
(Department of Entomology, College of Horticulture, Vellanikkara, 1984) Abdulla, K; Mammen, K V
Taxonomic study on the leaf and plant hoppers of paddy was conducted to find out the various specious of leaf and plant hoppers associated with paddy in Kerala. Paddy fields from two important paddy growing tracts of Kerala viz., Trichur and Palghat were selected and weekly collections of hoppers were made. Collections were made with a fine mesh hand net for the entire cropping season from transplanting upto harvest. Fixed numbers of sweeps were taken from the same field in order to get an idea about the population fluctuations. Collections from each field for each week were separately preserved in homeopathic vials with collection data. Later insects in all vials were sorted out, number of specimens collected in each week were noted, sexes separated, and each species were preserved in separate vials. Vials were serially numbered and collection data were noted under each serially numbered species. Genitalia of males as well as general form and colouration of all species were stidied. However genitalic studies of Exitianus indicus (Dist.) and Nisia nervosa (Motsch.) could not be conducted for want of male specimens. Altogether nine species were collected viz., Nephotettix Virescens (Dist.), N. nigropictus (Stal), Recilia dorsalis (Motsch.) and Exitianus indicus (Dist.) coming under Cicadellidae, Nilaparvata lugens (Stal), Sogatella furcifera (Horv.),Matutinus pusanus (Dist.) belonging to Delphacidas and Nisia nervosa (Leth) under Meenoplidas. Among these species all but M. pusanus were reported to be occurring on paddy in India and other East Asian countries, while E. indicus and N. nervosa were not observed by earlier workers from Kerala. Apart from these, two male and two female specimens of Nephotettix showing variations in characters from N. nigropictus and N. virescens were also obtained. These may be natural hybrids between N. virescens and N. nigropictus. Certain morphometric studies were conducted using head measurements viz., eye diameter to interocular distance and /or vertical distance next to eye to median length of Vertex. It was found that there is difference between male specimens of N. virescens and N. nigropictus with regards to the ratio of vertical distance next to eye to median length of vertex; and in females of these species there is difference between the ratios of eye diameter to interocular distance. Similarly there is difference between male specimens of N. lugens and S. furcifera with regards to the ratio of eye diametor to interocular distance. Studies on the seasonal abundance of leaf and plant hoppers revealed that there is variation in the predominant species present in each area.