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Open Access
Bionomics and ecological management of coconut eriophyid mite
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 2001) Vidya, CV; KAU; Ranjith, A M
The bionomics and ecological management of coconut eriophyid mite, Aceria guerreronis (Keifer) was studied under the Department of Entomology, College of Horticulture, Vellanikkara. The preference of mites to bunches of different maturity, symptoms of damage, population dynamics, relationship of mite population with weather factors and the distribution pattern of mites based on plant morphology were considered for the study. Some ecological management practices were also tried along with this. The experiment was laid out as completely randomised design. Mites were absent in male and female flowers and also on buttons of first bunch. Initiation of infestation starts from buttons of second bunch and population increases further and maximum population is noticed in buttons of third and fourth bunches and thereafter it decreases. This is because after fourth bunch, the meristematic tissue becomes necrotic due to feeding of mites and hence mites cannot feed further easily. Traces of population were noticed even on nuts of ninth bunch. Predatory mites were also seen along with eriophyid mites even though they are very negligible. Symptoms of damage were seen outside from second bunch onwards. The symptom initially appears as whitish streak or triangular patch and it increases further in length and breadth and becomes brownish and later necrotic. In some cases, cracks, cuts and gummosis can be seen on the husk. The relationship between surface damage and mite population was worked out. Maximum mite population was noticed when the surface damage was 1-3 and 3-6 cm2 before and after the removal of perianth respectively and the percentage of damage was 1-3 per cent. Mite population was found to vary with different weather parameters. Minimum temperature of current week, current, -1 and -2 fortnights and maximum temperature of -2 fortnight were positively related with mite population. Morning humidity is also positively related with mite population. Mite population was negatively related with wind speed of zero current, current, -I and -2 fortnights. There is no direct relation between mite population and rainfall, number of rainy days, evening humidity and sunshine hours. Mite infestation was irrespective of the height of the palm, crown shape and perianth arrangement. The intensity of infestation varies between each inner tepals. Maximum infestation was under fourth tepal followed by fifth and sixth tepa\. The preference of mites to different portions under each tepal also varies with maximum entry through the 'outer edge' of fourth tepal followed by 'outer edge' of fifth tepal, 'middle' portion of sixth tepal, 'middle' portion of fifth and fourth tepal, and 'inner edge' of sixth and fifth tepa\. Infestation was found to be less in round shaped nuts compared to oval and oblong nuts. Maximum incidence was in green coloured nuts followed by greenish yellow and orange coloured nuts. There was no reduction in mite damage by different water regimes (rainfed, channel and drip irrigated) fertilizer regimes (0.34:0.17:0.68 kg NPK/palm, 0.5:0.32:1.2 kg NPKlpalm and 0.25:0.32:1.2 kg NPKlpalm) micronutrients (MgS04, ZnS04, MnS04, Borax and Micronutrient mixture) and crown cleaning (once and twice in an year).
Open Access
Management of coconut eriophyid mite Aceria guerreronis Keifer using ecofriendly methods
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2001) Amritha, V S; Saradamma, K
Experiments were conducted in the Department of Agricultural Entomology and in the Instructional Farm, College of Agriculture, Vellayani during 2000-2001, to generate eco-friendly components in developing a sustainable long term strategy of pest management against coconut eriophyid mite. The treatments included the laboratory screerung of various oils, botanicals and synthetic acaricides. The promising treatments and innovative farmer practices were evaluated in a field experiment. The results of laboratory screening revealed that Neem oil three per cent followed by Neemazal 0.4 per cent and castor oil three per cent were promising among the botanicals while fenazaquin 0.05 per cent followed by sulphur W.P 0.4 per cent were found to be effective among the synthetic acaricides. The field evaluation using promising natural products and synthetic acaricides, showed that fenazaquin 0.05 per cent was effective followed by sulphur W.P 0.4 per cent. Maximum protection was observed after the third round of spraying. Sprays applied at the critical stage of infestation afforded maximum protection to the bunches. Results of the field evaluation experiment using natural products and innovative farmer practices revealed that starch solution five per cent was the most effective among the various treatments.
Open Access
Eco-friendly insecticides for the management of major pests of amaranths
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 2001) Leena, M K; KAU; Suma Paulose
There has been increasing reports on health hazards in human beings from the unscientific and intensive use of pesticides in crops, especially vegetables. It was in this backdrop, a scientific investigation was designed to evolve safer and eco-friendly methods in pesticide use to control the major pests of the popular leafy vegetable amaranths. Field experiments were conducted at the college of Horticulture, Vellanikkara during 2000-2001 to identify the safer, eco-friendly insecticides. For the first experiment, thirteen different commercial formulations of neem, microbial and chemical pesticides were evaluated for the control of amaranths leaf webbers viz., H. recurvalis, P. basalis, weevil H. truncatulus and grasshopper A. crenulata. The best six effective components were further screened at lower doses, so as to identify the most promising one in the second experiment. The effect of the tested components on the natural enemies and other bio control agents were also studied.. Organoleptic quality evaluation of cooked amaranths leaves was done to know, whether the applied insecticides have any effect on the taste, appearance, colour, flavour, texture and bitterness. Of the insecticides tested in the first experiment, Econeem, N eem Azal, Halt, Dipel, Delfin and Nuvan were the most effective in controlling the pest population. The results of the second experiment indicated that the plots treated with Dipel @ 0.7 ml r' gave better control of both the leaf webbers. Halt @ 0.7 g r' gave comparably good results for the control of weevil. All the microbial insecticides tested were found ineffective to grasshopper. No disease symptom or deformities were observed in any of the natural enemies and other bio control agents. In the field, though Nuvan was found to control the pests, it was not effective in the long run. All the microbial products were found to protect the crop for a longer period of time. The crop sprayed with Delfin @ O.7g r' gave an yield of 5481 kg green leaves per acre compared to untreated control (2963 kg). Organoleptic quality evaluation of cooked amaranths leaves revealed that, there was no significant difference in qualities of cooked amaranths due to treatments compared to untreated control.
Open Access
Distribution of phytonematodes and their management in ornamental crops in Thiruvanantharpuram district
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2001) Mahesh, T; Arthur Jacob, J
A random survey was. conducted in Thiruvananthapuram district to gather information about the nematodes associated with cut flowers( anthurium and orchid), traditional flowers( rose and jasmine) and ornamental foliage plants ( begonia and croton). The root - knot nematode M incognita and burrowing nematode, R. similis were found associated with these plants. Other nematodes observed were the lance nematode Hoplolaimus spp.,spiral nematode Helicotylenchus spp. and ring nematode Criconemoides sp. Among the cut flowers, anthurium was found to be highly susceptible to root - knot nematode. In ornamental foliage, begonia and traditional flowers, jasmine were found susceptible to the nematode. Small terminal galls were seen in anthurium whereas comparatively large sized galls spread throughout the root system were seen in begonia and croton . Histopathological studies were conducted in anthurium, jasmine and begonia .The xylem vessels were highly damaged in these crops due to nematode attack affecting translocation of nutrients and water. Studies on nematode management conducted in anthurium revealed no significant difference in the biometric characters of the plant. Significant reduction in root weight was observed in plants receiving different treatments. Treatment of soil with carbofuran 2 kg ai ha' gave maximum reduction of nematode population in soil. Neem cake 0.5 per cent w/w ,carbofuran lkg ai ha+ neem cake 0.25 per cent w/w and carbofuran 1 kg ai hal+neem cake 0.25 per cent w/w +G.fasciculatum 200 spores per pot were equally effective in reducing population of nematode in the soil. G. fasciculatum 200 spores per pot +neem cake 0.25 per cent w/w gave maximum reduction of nematode in root. A low gall index of 1.25 was observed in plants treated with carbofuran @ 2 kg ai ha:' and carbofuran @ 1 kg ai hal+neem cake 0.25 per cent w/w.
Open Access
Eco-friendly management of root-knot and burrowing nematodes associated with kacholam (Kaempferia galanga Linn.)
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2001) Nisha, M S; KAU; Sheela, M S
Field experiments were conducted to evaluate the efficacy of bioagents (Pseudomonas fluorescens, arbuscular mycorrhizal fungi, Trichoderma vir i dae (3 per cent w/w) plant products (nee m oil (2%), neem leaf extract (S%), neem oil + garlic (2%), neem leaf extract (4%)+ garlic (l %), botanical pesticide, nimbecidine (0.2%), hot water treatment (SSoC) and organic amendments (neem cake (200g/m2), coir pith (SOOg 1m2), sawdust (SOOg/m2), neem leaf (7S0 g/rn ") as rhizome and main field treatments for working out an eco-friendly management strategy against the nematodes (Meloidogyne inco gnit a and Radopholus si milisi in the medicinal plant, kacholam, Kaempfer ia galanga Linn. The efficacy of green leaf mulching was also tested using locally available green leaves (neem, glyricidia, mangium, clerodendron, calotropis, chromolaena) @ Skg 1m2 as mulch, to maximise the natural resource utilization in the context of low cost farmer friendly technology. To establish the potential of rhizome treatment with bioagents, botanicals, plant products and hot water treatment a micro plot study (2 m x 2 m) was conducted at College of Agriculture, Vellayani in sick plots having an initial population range of 100 to 160 M. incognita and 4S-6S R. similis per 100 g soil. The effect of the above treatments were compared with the chemical, dimethoate (0.1 %) and untreated. The results showed that maximum improvement in biometric characters like fresh plant weight and root weight of kacholam plants was observed in rhizome treatment with P. fluorescens. Next best treatments were AMF and hot water treatment and the effect of these two were significantly better than the chemical, dimethoate. The improvement in biometric characters due to above three treatments increased the yield of kacholam to the tune of 87 to cent per cent. Regarding the reduction in nematode population in root (root-knot count and number of females), P. jluorescens and AMF were the best treatments. Next effective ones the hot water treatment and T. viride were also better than the chemical, dimethoate. There was no significant variation in the R. similis population in soil due to rhizome treatments. The results on the effect of application of bioagents and organic amendments in soil at the time of planting revealed that neem cake (200 g I m2) and AMF (300 g inoculum I m") were on par in leaf production and nee m cake established its superiority in improving the shoot weight also. Neem cake, AMF, sawdust and coir pith were statistically on par in improving the fresh weight of plant. In all these cases effect of the above treatments were on par with the chemical, carbofuran (lkg a.i.lha). Regarding the improvement in yield also the best treatments (neem cake, AMF, sawdust, P. jluorescens and coir pith) were on par with the chemical, carbofuran. The superiority of carbofuran was maintained in reduction of nematode population only in root (number of females and larvae). In all other cases (nematode population in soil at different periods) the effect of nee m cake, AMF, neem leaf were on par with the chemical. The results on the. effect of mulching with green leaves revealed that neem and chromolaena leaves improved the fresh plant weight and yield of kacholam. Reduction in nematode population in soil was observed 111 glyricidia leaves also along with neem and chromolaena. The effect of nee m and chromolaena @ Skg 1m2 leaves were on par in reducing the root-knot count and number of larvae in root. There was no significant variation in population of R. similis due to mulching with different leaves but minimum population was recorded in neem leaf (4 MAP). Even the application of mangium @ 5 kg/rn ' significantly reduced the nematode population in soil, but the effect was inferior to other leaves, but superior to the untreated.
Open Access
Eco-friendly pest management in snakegourd
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2001) Sivakumar, T; KAU; Jiji, T
A study was conducted to document farmers' practices for pest control, record the population of pests of snakegourd and their natural enemy complex in farmers' field, as well as to evolve an eco - friendly package of practices for pest management. The survey conducted in the farmers' field revealed that the farmers were resorting to indiscriminate use of pesticides. The recommended pesticide/ fertilizer dosage was not practised by the farmers. Quinalphos was the most widely used pesticide followed by carbaryl. The frequency of spraying was the highest at fruiting stage. The major pests observed in the field were B. cucurbitae, A.peponis, D. indica, E. septima, Aulacophora sp. A. gossypii and L. trifolii. A very low population of pests and their natural enemies were present in the farmers' fields compared to untreated plot maintained in the Instructional Farm, Vellayani. In the untreated plot there was ten fold population of natural enemies compared to farmers' field. Fruit flies were found to be serious pests causing 63.63 per cent loss in unprotected field and this emphasised the importance and necessity for fruit fly management in snakegourd fields. Three fruit fly traps viz., were tested to assess their efficacy in catching fruit flies. Among the three traps tested, banana traps consisting of palayamkodan fruit pieces and carbofuran were the best. Three snakegourd varieties viz., Kaumudi, T.A. -19 and Local, were tested against insect infestation. Kaumudi had the lowest infestation by pests like pumpkin beetle (Aulacophora sp.), leaf eating caterpillar (Diaphania indicas, snakegourd semilooper (Anadevidia peponis) and fruit fly (Bactrocera cucurbitae). Kaumudi recorded the minimum fruit fly damage and consequently, the highest yield. Field evaluation of fourteen treatments was carried out at the Instructional Farm, Vellayani during 1999-2000. Chemical insecticides were found to be very . effective in controlling the pests of snakegourd at vegetative and flowering period, but the pest population build up was the highest with them. Neem oil - garlic emulsion was the best in controlling the pest menace with the least impact on natural enemies. Population build up of pests was also low in case of neem oil - garlic emulsion. The practice of covering fruits was very effective in preventing the flies from attacking the fruits. Covering the fruits and setting up of banana traps at the rate of two traps for three plants gave the best protection against the fruit flies. The treatments involving neem oil - garlic 2.5 per cent spray at vegetative stages + covering the fruits and banana trap setting at flowering and fruiting stages gave the highest yield and benefit - cost ratio (1.938). Spraying neem oil -garlic emulsion 2.5 per cent, on need basis, at vegetative stages and setting up of banana fruit fly traps and covering the fruits with reusable polythene covers was found to be the best eco- friendly and economical package for the management of major pests affecting snakegourd.
Open Access
Bio-ecology of coconut eriophyid mite, aceria guerreronis keifer and yield loss due to its infestation on popular coconut cultivars
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2001) Ambily Paul Thomas; KAU; Biju Mathew
Studies were conducted to understand the biology, ecology, population dynamics and rr .te-host interactions of A. guerreronis and to assess the yield loss on popular cultivars of coconut as influenced by nut characters and weather parameters. An abstract of the work done and the results are given below. Biology of A. guerreronis was studied under both laboratory and field conditions. The study indicated that a total period of 9.8 days was required for completing one generation under laboratory condition. Population dynamics of A. guerreronis in young buttons of susceptible and tolerant palms of variety WeT and Komadan was studied from February 2000 to January 2001. Population of mites under each tepal was counted by using cello tape embedding method. The results revealed that the population was the highest in nuts sampled from fifth bunch followed by fourth and sixth bunches in both susceptible and tolerant palms. The present study indicated that age of developing nut was the most critical factor in the study of population dynamics. Monthly mean population of A. guerreronis was correlated with weather parameters viz., temperature, relative humidity and rainfall prevailed during the time of sampling, probable time of mite entry and the total duration of critical age of the bunch. The results indicated that the relative humidity prevailed at the probable time ofmite entry alone had a positive correlation with population in the susceptible type of Ko mad an. The length to circumference ratio of young nuts and its influence on mite injury was observed. The results showed that round nuts having a length to circumference ratio of 1 :1.90 to 1 :2.29 suffered less damage. The study gave an indication that elongated nuts were more susceptible to mite attack than round ones. The expansion of feeding scar on coconut husk due to mite injury in relation to growth of nuts was studied in young nuts with different degree of injury in terms of number of triangular lesions. The study indicated that the age of buttons / nuts at which the colonization started w~ the most critical factor in deciding whether the nut will finally become economically damaged (category 4 and 5) or not. Yield loss studies were carried out from the nuts obtained from ten consecutive harvests by categorizing them into five damaged categories and the yield loss was calculated by deducting actual yield from potential yield. No significant variation was observed among the five varieties studied, viz. WeT, Komadan, T X YD, Laccadive Ordinary and Dwarf Orange Yield loss in terms of reduction in weight ofcopra ranged from 11 to 39 percentage and reduction in weight of husk ranged from 12 to 40 percentage. Additional labour requirement for de husking infested nuts was studied in a separate experiment. Study revealed that an extra time of 25.05 to 41.75 minutes was required to dehusk 100 damaged nuts over healthy nuts. Another experiment was conducted to assess the effect of mite injury on the quality and quantity of fibre and coir. Husk obtained from fifty harvested nuts representing the damage categories 1 to 5 were subjected to natural retting practices. Fibre obtained from nuts coming under damage category 4 and 5 resulted in 47-53 per cent reduction in length.
Open Access
Management of the sucking pest complex coconut eriophyid mite, coreid bug and button mealy bug infesting coconut bunches
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2001) Priya Mohan; KAU; Faizal, M H
A study was conducted at the College of Agriculture, Vellayani from April 2000 to July 2001 to investigate the nature and extent of damage caused by the sucking pest complex, coconut eriophyid mite (CEM), coconut coreid bug (CCB) and coconut button mealy bugs (CB M) infesting coconut bunches and to devise suitable chemical and biological management measures against them. CEM, CCB and CBM attack coconut bunches singly or in combinations, the combined attack of CEM and CCB being the most predominant. The coconut palms suffered heavy loss due to the combined infestation of" these pests by way of premature nut fall , varying degrees of damage in retained nuts, distortion and stunting of nuts and formation of barren nuts. An annual premature nutfall of 101.5 nuts palm" was observed due to sucking pest infestation, the share of nut fall due to CEM, CCB and the combined infestation of CEM and CCB being 35.96 per cent, 36.45 per cent and 27.59 per cent respectively. Maximum nutfall was observed in November. 5.81 nuts bunch" palm" were rendered barren or stunted due to infestation of button mealy bugs, singly or in combination with other pests. The infestation of CEM in retained nuts was more or less uniform all through the year whereas CCB showed wide fluctuation with maximum infestation in bunches that opened in November. A new scoring technique was developed, based on surface damage by the pests to assess the loss incurred due to combined infestation of CCB and CEM. Significant negative correlation was observed between surface damage and nut characteristics like weight of whole nut, weight of dehusked nut, weight of dewatered nut, volume of nut water and weight of copra. Significant reduction in the above nut characters was observed in higher scores with high intensity of surface damage as compared to healthy nuts (Score 1). Reduction in weight of whole nut, dehuskednut and copra ranged between 17 to 46 per cent, 13 to 50 per cent and 11 to 53 per cent respectively. Among the various pesticides evaluated against the sucking pest complex, neem oil - garlic emulsion (2 %), quinalphos (0.05 %) + wettable sulphur (0.4 %), endosulfan (0.1 %) + wettable sulphur (0.4 %) and endosulfan (0.1 %) + neem oil garlic emulsion (2 %) were found to be effective in reducing the yield loss. Verticillium suchlasporium (Goddard) and Metarhizium anisopliae (Metch.) Sorok. were found to be infective to CEM and CCB respectively . . Four entomopathogenic fungi Penicillium purpurogenum Stoll., Acremonium strictum Gams., Fusarium solani (Martius) Sacc. and Paecilomyces varioti (Bainer) were identified causing natural mortality CEM population and one fungus, Fusarium moniliforme Wollenw and Reink, to CBM. Two egg parasitoids viz., Chrysochalcissa oviceps Boucek and Gryon homeoceri (Nixon), hitherto unknown to parasitise the eggs of CCB were identified.
Open Access
Biocontrol of mites on yard long bean (Vigna unguiculata ssp. sesquipedalis (L.) verdcourt) and chilli (Capsicum annuum L.)
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2001) Abhilash, B; KAU; Sudharma, K
Mass production techniques, biology, predatory potential and prey preference of predatory mites and the chrysopid predator, C. earn ea preying T. ludeni in cowpea and P. latus in chilli were studied. Further, the effect of pesticides on these bioagents and the role of these predators in the management of T. ludeni and P. latus were also assessed. A.longiyfspinosus was identified as the major predator of T. ludeni. Another species of Amblyseius (unidentified)was the major predator of P .latus in the field. In the laboratory a macrocheylitid mite, M. merdarius found in rice bran was also observed as an efficient predator of P. latus. Techniques were developed to mass multiply both species of Amblyseius and their hosts, T. ludeni and P. latus in excised leaves of cowpea. Using this technique, within a week a two fold increase of the predator was seen. Techniques were developed to multiply another predatory mite of P. latus, M. merdarius in storage mite, Tyrophagus sp. From 109 rice bran containing Tyrophagus sp., 410 M. merdarius were produced within a month. A. longispinosus when fed with pollen of A. auriculiformis and H. rosa-sinensis , survived in the diet and laid eggs. The larvae that emerged from the eggs completed development on pollen diet where .as in artificial diet , though the gravid females survived and laid eggs, the larvae that emerged from eggs did not reach adulthood. Studies on the biology of predatory mite!.A.longispinosus and Amblyseius sp preying on T. ludeni and P. latus respectively revealed that the predators completed its development within a week. In order to identify suitable hosts for mass rearing C. carnea, the predator was reared on different hosts and it was observed that developmental period was shortest when reared on Corcyra eggs. The fecundity and longevity was maximum when reared on Corcyra eggs. An assessment of predatory potential of A. longispinosus revealed that the predator fed on all stages of T. ludeni. Among the different stages of the predator ,adult was the most voracious and the most preferred stage of the prey was eggs. In the case of Amblyseius sp. preying on P. latus the larvae of the predator consumed all stages of prey mite except adult. The predatory potential of M. merdarius on P. latus was higher than that of Amblyseius sp. An assessment of predatory potential of C. carnea revealed that it was a voracious feeder of A. craccivora as well as T. ludeni, The mean daily consumption was highest for the third instar larvae in both the cases. The prey preference of the predators was assessed through multiple choice and single choice tests. Among the prey tested viz. T. ludeni , P. latus and Tyrophagus sp, maximum preference was shown towards T. ludeni. The broad mite, P.latus was also found to be preyed upon by the predator in both multiple and single choice tests, but total avoidance was shown towards bran mite Tyrophagus sp. The prey preference of C. carnea assessed through multiple choice and single choice tests revealed that A. craccivora was the most preferred prey and it was followed by T. ludeni. Spiralling white fly was the least preferred one. Effect of pesticides on predators assessed by exposing them to dry films of pesticide showed that triazophos 0.05 per cent was the most toxic chemical against A. longispinosus . In all the chemical pesticides tested none of the predators survived after 24 hours. Though 10 percent emulsified extract of A. panieulata, H.suaveolens and neem garlic emulsion 2.5 per cent were found significantly safer than chemical pesticides, mortality of the predator was observed in these treatments also indicating that negative impact of botanical pesticides on natural enemy cannot be overlooked. Similar response was shown by C. earn ea towards these pesticides, except in dicofol 0.05 percent which imparted lower mortality to the larvae. Field experiments conducted in cowpea to study the effect of bioagents and botanicals on T. ludeni, predators and yield showed that, application of neem oilS percent was the best treatment for management of T. ludeni. This was followed by application of neem garlic emulsion 2 percent, Fish oil insecticidal soap 2.5 percent and garlic emulsion 2 percent taking into consideration the benefit cost ratio. Comparatively high population of predatory mites was observed in plants released with A. longispinosus. The population of the predatory mite increased steadily and within a month the population of the predator and prey became almost equal. Though the predatory mite could check the population of T.ludeni, the treatment was uneconomical. The general predator, C. earnea could not bring spectacular reduction in population of T. ludeni which may be due to the polyphagous nature of the predator. Field experiments conducted on chilli showed pronounced effect of Amblyseius sp on P. latus from tenth day onwards at both the levels tested. The release of the predator C carnea @5 and 10 per plant, and fish oil insecticidal soap 2.5 percent was not effective in checking P. latus. Garlic emulsion 2 percent gave substantial reduction immediately after first application. Subsequently, the population increased but with repeated application significant reduction in population was noticed. There was no significant difference in the yield of chilli 111 the different treatments. However based on benefit cost ratio, it is concluded that application of nee m oil 5 percent, neem garlic emulsion 2 percent, garlic emulsion 2 percent, fish oil insecticidal soap 2.5 percent and release of Amblyseius @ 10 and 20 per plant are economically viable for management of P. latus in chilli .

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