sub fatal effects of new chemistry insecticides
Abstract
This research was performed to determine the efficacy of 8 insecticides viz., dimethoate, profenofos, lamb-dacyhalothrin, monocrotophos, indoxacarb, endosulfan, chlorpyriphos andmultineem against the discovered bollworm, Earias vittella (Fabricius) on okra cultivars viz., Arka Anamica, Prabhani Kranti, Selection-9, Seed Tech-71, NBR-1, Hari Rani, Deepti, Green Gold, Ajeet-121, Ajeet-311 (Hybrid) during summertime of 2005-06. The highest reductions of fruits borer invasion was with lambda-cyhalothrin 13. 60% and 27. 07% while the cheapest with multineem was twenty six. 91 and 32. 64 % when compared with untreated control with forty. 41 and 36. 09% infestation during 2005 and 2006. The highest seed produce was discovered with application of dimethoate (234. 9g) and lamb-dacyhalothrin (244. 9g) as well as the lowest was with multineem (226. 1g) and endosulfan (241. 3g/10 plants) during2005 and 06\. All the insecticides proved substantially effective in controlling At the. vittella pests and the seedling yield between treatments differed significantly in all cultivars of okra during both the years.
Introduction
Cotton is an essential cash crop in Pakistan, which makes up 11. 7% of value added in culture and about installment payments on your 9% of GDP. Pakistan is third largest cotton lint maker in the world following China and U. T. A. Bollworms cause about 30 to 40% failures of yield of seed cotton. Between bollworms, American bollworm, Helicoverpa armigera (Hub. ), noticed bollworm, Earias insulana (Boisd. ) and spinny bollworm, E. vietella (Fab. ) are important unwanted pests of silk cotton. Bollworms generally feed on fruiting parts of natural cotton resulting in substantial losses at quality and quantity and 20-60% damage to and a decrease in their market value of dietary fiber. American bollworm tunnels in small pieces, terminal pals and large bolls from the bottom by departing posterior fifty percent portion of the entire body outside the bolls. This may trigger abnormal non-reproductive growth. The larvae of Earias spp. attack soft and developing tissues especially terminal bud of key stem, floral buds and bolls, which will ultimately shed. To defeat the loss and to increase the yield, insect poison application is definitely utmost important.
In Pakistan during 2000-2001, about 16402 tons of pesticides had been imported approximately 70-80% of the were sprayed for controlling the cotton infestations. Previous investigation about the evaluation of different insecticides for the power over cotton bollworms were done by Patil et al. [1990], Talpur et al. Muhammad Aslam, Muhammad Razaq, Saher Rana and Muhammad Faheem 18 [1993], Ravi et approach. [1997], Sherma et al. [1997], Akber and Hassan [1999], Naveed et al. [1999] and Allen et ‘s. [2000]. It is important to compare the efficacy of insecticides against pests for effective pest management and also to reduce the indiscriminate use of insecticides. Thus, the modern day study was conducted to evaluate different products available in the market for his or her efficacy against bollworms intricate. Spotted bollworms are generally known as serious pests of natural cotton and okra in India and this popular name is normally applied to bug belonging to genus Earias (Lepidoptera: Noctuidae).
The common species of spotted bollworms are: Electronic. vittella (Fab. ), and E. insulana (Boisd. ). These two kinds are widely distributed in North The african continent, India, Pakistan and other countries. The major owners of Earias spp. happen to be cotton and okra in which it causes immense destruction and other website hosts are sonchal (Malva parviflora), gulkhaira (Althaea officinalis), hollyhock (Althaea rosea) and some additional malvaceous plant life. Apart from all their marked capacity to bore in the terminal portion of the locations they causes drooping of shoots, flaring and shedding of pals and other fruiting bodies of cotton as well. For the control of these kinds of pests in the field, a number of insecticides belonging to different groups possess proved successful but the continuous and indiscriminate use of these kinds of insecticides to get the power over lepidopterous unwanted pests may result into the development of amount of resistance in Earias spp. to be able to insecticides.
In India, integrated level of resistance management approaches include solid recommendations for the alternation of chemical organizations in effective spray times. It is hard to escape the conclusion that insecticide centered control of lepidopteran pests in India, anxiously needs new chemistries with different resistance status. New chemistries showing guarantee for the control of insect pests include avermectin (abamectin) and certain oxadiazines (indoxacarb) happen to be gaining importance.
Considering that the use of these types of new elements is increasing day by day in cotton for controlling bollworm complex, you will find chances pertaining to the development of resistance in insect pests. Though the advancement resistance by pests to new insecticides may be postponed, the possibility pertaining to development of level of resistance cannot be fully denied. Thus, the insecticide resistance should be continuously supervised and need to form a fundamental element of chemical control, to enable the detection of resistance as early as possible (Regupathy, 1996) and to take necessary actions thereof. Furthermore, a base collection data about the toxicity of these insecticides against important unwanted pests would help in understanding the level of resistance developed by the pest and virtually any possible cross-resistance there in, could be evaluated in advance.
Review of literature
“Patil and Pokharkar (1977) tested the residual toxicity of some widely used insecticides viz, carbaryl, endosulfan, endrin, quinalphos, malathion, fenitrothion and an assortment of DDT and toxaphene for the first-instar larvae of At the. vittella following releasing them on dispersed okra plant life. All the substances tested gave complete or perhaps almost total mortality right after spraying yet carbaryl was observed to be the most persistent, giving thirty seven. 93 percent kill of larvae following 15 days of spraying. On the basis of LT50 carbaryl was a lot more than twice as poisonous as fenitrothion. Residual degree of toxicity of eight commonly used insecticides viz, carbaryl, endosulfan, endrin, quinalphos, malathion, fenitrothion and a mixture of DDT + toxaphene to the adults of discovered bollworm, Electronic. vittella was tested by simply Patil and Pokharkar (1981). Endrin noted the highest mortality (86. 6 %) the moment released about the same day in the treatment but was on equiparable with endosulfan, fenitrothion and DDT + toxaphene.
Quinalphos was least harmful and was on doble with malathion and carbaryl. In case of discharge of moths on sixth day after treatment, maximum mortality (28. 5 %) was recorded with endrin and DDT & toxaphene whereas no fatality was noticed in moths the moment released 10 days after treatment. Ovicidal a result of some insecticides on the eggs of the noticed bollworms, Earias spp. collected from okra was based on Singh et al (1982).
Diazinon at zero. 02 per cent was the best compound, leading to 97. 5 per cent egg mortality, and was substantially superior to the 5 additional treatments with the exception of cypermethrin at 0. 009 per cent (95. 0 % egg mortality). The order of efficiency of the leftover compounds was 0. 01 per cent fenvalerate (92. 5 % mortality), 0. 05 per cent phenthoate, 0. 03 per cent phosphamidon and zero. 08 % malathion (90. 0 %), 0. goal per cent monocrotophos and 0. 05 per cent fenitrothion (87. 5 %), 0. 015 per cent permethrin (85. zero %), zero. 03 percent parathion-methyl (80. 0 %), 0. goal per cent dimethoate and zero. 03 % thiometon (77. 5 %), 0. goal per cent chlorpyrifos (52. five %) and 0. goal per cent vamidothion (50. 0 %).
Singh and Sircar (1986) studied the evaluation of synthetic pyrethroids for inhibitory effect on the hatching of eggs of E. vittella. On the basis of LC50 values, the order of toxicity of synthetic pyrethroids against eventually old eggs was decamethrin >cypermethrinA >cypermethrinB >fenvalerate >permethrin, the relative toxicity principles being 99. 34, 33. 14, 6th. 05, four. 77 and 1 . 00, repectively. While the purchase of toxicity of insecticides against two day older eggs was decamethrin >cypermethrinB >cypermethrinA >permethrin >fenvalerate and out of five pyrethroids simply three viz, decamethrin, cypermethrinB and cypermethrinA were found to be fifty-one. 34, 20. 27 and 8. seventy two times, correspondingly more effective than permethrin.
Sherasiya and Chari (1987) evaluated tough luck insecticides because of their ovicidal actions on the ovum of discovered bollworm, Elizabeth. vittella. The results suggested that cyfloxylate 0. 005 per cent, cypermethrin 0. 01 per cent, decamethrin 0. 0014 per cent, benefit 0. 01per cent, permethrin 0. 0125 per cent and methamidophos 0. 16 percent exhibited ovicidal action. Of most the insecticides tested diflubenzuron (0. 0125 %) proven least in ovicidal actions with simply 6. ninety six per cent egg mortality.
Ovicidal real estate of several insecticides against spotted bollworm, E. vittella were looked into by Deshmukh et ‘s (1988). The order of toxicity from the insecticides was ethylparathion (parathion) >phosphamidon >phosalone >endosulfan >carbafuran >monocrotophos >carbaryl >formothion, which in turn gave egg mortalities of 69. 43, 64. 43, 55. ninety five, 49. seventy nine, 46. 71, 44. 39, 42. seventy eight and thirty six. 51 percent, respectively.
Ovicidal and larvicidal actions of diflubenzuron on Electronic. vittella was studied simply by Samraj and Jesudasan (1989). The results revealed that inhibited in hatching was upto the extent of 91 per cent in 100 ppm diflubenzuron cared for eggs followed by 84, 65 and 57 per cent in 75, 60 and twenty-five ppm diflubenzuron, respectively. The larvicidal activity of diflubenzuron on E. vittella causes the most larval fatality of ninety-seven per cent in 500 ppm. The percent larval mortality varied by 26 to 62 when ever diflubenzuron was applied in concentrations starting from 75-250 ppm.
Hirano et ‘s (1993) monitored the susceptibility of At the. insulana in Multan, Pakistan from 85 to 1991 to fenvalerate and fenpropathrin by a simple dipping method. The LC50 value of fenvalerate up against the Multan colony of E. insulana was 0. 00015 per cent while the LC50 value of fenvalerate and fenpropathrin against the Hyderabad colony was reported as 0. 00018 and 0. 000046 per cent, respectively.
Brar et al (1998) researched insecticidal power over spotted bollworm, E. insulana on American cotton. Of the number of insecticides tested against E. insulana which given on cared for cotton pals in cup battery containers, alphamethrin [alpha-cypermethrin], fenvalerate, cypermethrin, chlorpyrifos and triazophos at equivalents of 250, 250, five-hundred, 1000 and 1500 cubic centimeters ha-1, correspondingly, were the very best, causing 75 per cent fatality after seventy two hours of spraying. A variety of 1 % deltamethrin and 35 % triazophos gave the same impact.
The interaction a result of diflubenzuron with two man-made insecticides viz, profenophos and alphacypermethrin upon spotted bollworm, E. vittella was studied by Srinivasan and Uthamasamy (2001). Alphacypermethrin recorded a LC50 of 0. 00023 per cent followed by 0. 00499 per cent in profenofos. Diflubenzuron needed a better dose (0. 03548 %) to give 50 per cent result when compared with conventional insecticides. The toxicity of alphacypermethrin was increased due to addition of diflubenzuron in 1: 1 ratio which recorded a LC50 of 0. 00017 per cent followed by 0. 00247 per cent in diflubenzuron + profenophos blend.
Verma et al (2004) researched the relative toxicity of nine commonly used insecticides against first intar larvae of E. vittella. Based on the LC50 beliefs, the buy of toxicity of different insecticides was chlorpyriphos + cypermethrin >indoxacarb >chlorpyriphos >endosulfan >quinalphos >carbaryl >fenvalerate >cypermethrin >monocrotophos. Correspondingly, the above insecticides were 94. 25, 80. 12, 17. sixty four, 10, 82, 9. 79, 2 . 16, 1 . 93 and 1 . 22 instances more dangerous than monocrotophos.
Relative toxicity of novel substances and standard insecticides against spotted bollworm, E. vittella was worked out by Gupta et ‘s (2005). Based upon the LC50 values, abamectin, betacyfluthrin, emamectin benzoate and spinosad were found being highly poisonous to the check insect with LC50 beliefs 0. 0001 per cent for abamectin and betacyfluthrin and 0. 0004 per cent for 7 spinosad and emamectin benzoate”
