Foliar Aphid Research Articles

Tillage Intensity Influences Insect-Pest and Predator Dynamics of Wheat Crop Grown under Different Conservation Agriculture Practices in Rice-Wheat Cropping System of Indo-Gangetic Plain

Tillage can alter the soil habitats wherein many insect pests and their natural enemies reside during at least part of their life cycle. To enhance crop productivity and reduce climate change effects, conservation agriculture (CA) with reduced-tillage or no-tillage practices have been advocated to farmers. However, information relating to the effect of CA on insect pests and their natural enemies is very scarce, at least in the Indo-Gangetic region. In this study, the effect of tillage on the abundance of, and damage by, major insect pests (foliar aphids, root aphids, termites, and pink stem borer) and their natural enemies in wheat managed under three tillage practices, i.e., zero-till (ZT), reduced tillage (RT), and conventional tillage (CT) with (protected) and without (unprotected) insecticide protection scenarios, was investigated. Foliar aphid and termite numbers were lowest in the ZT-protected system, and highest in the CT-unprotected system. Pink stem borer damage was significantly higher in the ZT-unprotected system, whereas the root aphid number was maximum in the RT-unprotected system. The natural enemies of these four major insect pests of wheat showed variable trends under the studied tillage systems. The abundance and damage of these major insect pests showed a positive correlation with the normalized difference vegetative index (NDVI) and canopy temperature. The dynamics of the insect pests and their predators were driven by soil habitat-related changes (direct) as well as crop growth-related effects (indirect). A fine-tuning of insect-pest management tactics based on these relations would enhance the success of CA systems.

Bio-efficacy of some modern insecticides as seed treatment against foliar aphid complex in wheat

A field experiment was conducted to evaluate the bio-efficacy of imidacloprid 48% FS (Gaucho 600 FS) along with thiamethoxam 30% FS against foliar aphid complex in wheat. Keeping a no treatment control, chlorpyrifos 20% EC was also used as a standard check. Seed treatment application was carried out using three doses of imidacloprid 48% FS i.e. 250 ml, 300 ml and 350 ml/100 kg seeds alongwith one treatment each of thiamethoxam 30% FS @ 330 ml/100 kg seeds and chlorpyrifos 20% EC @ 400 ml/100 kg seeds. Of all the pesticides tested, imidacloprid 48% FS @ 300 ml/100 kg seeds and 350 ml/100 kg seeds significantly reduced the population build up (27.90 -40.79%) of corn leaf aphid followed by 16.16 -33.56% in thiamethoxam 30% FS @ 330 ml/100 kg seeds and 12.93 -25.66% in chlorpyrifos 20% EC @ 400 ml/100 kg seeds. Regardless of the doses and type of the pesticide molecules used in the experiment, no phytotoxic effect such as epinasty, hyponasty, scorching, chlorosis and wilting were observed on wheat plants.

Efficacy of few selected insecticides for the management of foliar aphid complex in barley

Efficacy of few selected insecticides for the management of foliar aphid complex in barley

Influence of sowing time and weather factors on seasonal dynamics of aphids in three wheat growing zones of India

A study was conducted to evaluate the relative population abundance of foliar aphid on wheat at three locations (Karnal, Niphad and Kharibari) sown on three different dates during rabi season of 2013-14 and 2014-15.The highest seasonal average population of aphids of 44.5 and 61.5 aphids per tiller at Karnal and Niphad, respectively were recorded on the crop sown during Ist fortnight of November and the lowest seasonal average population of 4.3 and 2.7 aphids per tillerat Karnal and Niphad, respectively were recorded on crop sown during 2nd fortnight of December. The studies indicated that early planted crop during November month provided the congenial weather conditions for aphid proliferation during crop growth period.

Compatibility of insecticides with propiconazole against foliar aphid Rhopalosiphum maidis (Fitch) and yellow rust in wheat

Occurrence of foliar aphid infestation and yellow rust infection is often simultaneous in wheat growing areas of North-Western Plains Zone (NWPZ). Farmers usually apply insecticides and fungicides separately for their management. Combined application of pesticides can be practiced saving cost, time and labour. Hence, a study was conducted during 2014–15 and 2015–16 to determine efficacy of two insecticides, imidacloprid @ 100 ml/ha and thiamethoxam @ 50 ml/ha, and one fungicide, propiconazole @ 500ml/ha alone as well as in combinations using two spray volumes of 250 and 500 l against foliar aphid and strip rust. The aphid population during 2014–15 after 15 days of spraying was observed to be the least (2.5 aphids/earhead) in sole application of imidacloprid @ 100 ml/ha, while during 2015–16, the least population (1.9 aphids/earhead) was in combination treatment of propiconazole with thiamethoxam @ 50 ml/ha in 250 l of water. The strip rust severity in combination treatments was 5–10% as compared to 40–60% in control plots. Coccinellid population in combination treatments ranged from 13.0–19.6/plot as compared to 39.6–42.3/plot in control plots. The studies indicated that mixing of broad spectrum fungicide, propiconazole did not influence the efficacy of two insecticides against foliar aphid.

Evaluation of new insecticides against wheat foliar aphid complex

An insecticide efficacy trial was carried out during 2013–14 at four locations viz., Karnal, Ludhiana, Niphad and Pantnagar for evaluation of six new insecticides against foliar aphid complex in wheat. Aphid counts were made on five randomly selected plants, one day before spray and then after 1, 2, 7 and 15 days after spray. After one day of spraying, flubendamide 480 SC @20g a.i./ha resulted in the least number of aphids at Karnal (4.33/shoot) and Ludhiana (1.06/shoot). However, thiamethoxam 25WG @12.5g a.i./ha and chlorantranilipride 18.5 SC @20g a.i./ha were observed as the best at Niphad (1.50/shoot) and Pantnagar (17.53/shoot), respectively. The maximum yield of 45.42 q/h and 58.31 q/ha at Karnal and Ludhiana was obtained with acetamiprid 20SP @20 g a.i./ha, respectively, whereas at Niphad and Pantnager, highest yield was obtained with clothianidin 50 WDG @15g a.i./ha and imidacloprid 17.8 SL@20g a.i./ha.

Multiple Diseases, Insect Pests Resistant Genotypes and Their Utilization in Breeding for Resistance in Wheat and Triticale

A total of 347 numbers of genotypes of Triticum aestivum , 66 of T. durum , 8 of T. dicoccum and 18 of triticale possessing resistance against multiple diseases and insect pests resistance were taken for the study. These were identified resistant to biotic stresses through rigorous evaluation under artificially inoculated conditions at hot spot locations in six agro ecological zones of India during 1998-99 till 2011-12 cropping seasons. The diseases and insect pests targeted were three rusts (stem, leaf and stripe rust), Karnal bunt, flag smut, leaf blight, powdery mildew, loose smut, brown wheat mite, root aphid, foliar aphid and shoot fly. The seeds of these genotypes along with passport data on disease resistance were shared with breeders at 30 main wheat and triticale breeding centres in India. The percentage of centres utilized these genotypes for hybridization and resistance breeding ranged from 4.0-63.6%. The per cent utilization was maximum in case of T. aestivum followed by T. durum, T. dicoccum . The most preferred genotypes of T. aestivum were, ‘DBW 18’, ‘DBW 32’, ‘GW 276’, ‘HD 2851’, ‘HD 2964’, ‘HD 2997’, ‘HP 1872’, ‘HW 2044’, ‘HW 3027’, ‘HPW 42’, ‘HPW 155’, ‘HPW 237’, ‘HPW 285’, ‘HUW 620’, ‘HS 295’, ‘HS 318’, ‘HS 345’, ‘HS 375’, ‘HS 420’, ‘HS 468’, ‘HS 493’, ‘HW 2045’, ‘HW 3083’, ‘HW 5037’, ‘HW 5208’, ‘K 9351’, ‘K 9441’, ‘MACS 295’, ‘MACS 2959’, ‘NW 3087’, ‘NW 1012’, ‘PBW 373’, ‘PBW 475’, ‘PBW 521’, ‘PBW 550’, ‘PBW 554’, ‘PBW 573’, ‘PBW 589’, ‘Raj 3765’, ‘Raj 4012’, ‘RAJ 4120’, ‘RAJ 4131’, ‘UP 2425’, ‘UP 2719’, ‘VL 801’, ‘VL 868’ and ‘VL 907’. In case of T. durum, 66 genotypes were utilized by 4.0-36% centres and most liked were, ‘AKDW 4155’, ‘CDW 04’, ‘GW 1139’, ‘HD 4696’, ‘HI 8498’, ‘MACS 3313’, ‘PDW 267’ and ‘PDW 312’. Likewise, out of eight genotypes of T. dicoccum , ‘MACS 2956’ (32.0%) and ‘MACS 2971’ (15.0%) were used most. Utilization of 18 numbers of triticale genotypes was 4.0-14.8% only. It may be due to lesser preference of triticale as compared to bread and durum wheat for breeding. The major preference of breeders was on genotypes having resistance against three or two rusts depending on agro climatic zones. The genotypes having Lr34 gene which is known for providing resistance to leaf rust were also found to be resistant to other diseases and aphids. The incorporation of resistance genes from resistant genotypes shared in breeding programme has helped greatly in management of diseases and insect pests using host resistance and avoided or reduced application of costly fungicides on wheat and producing pesticide free wheat in India. The deployment of resistant cultivars strategically in areas of prevalence of diseases and insect pests helped to further curtail losses in yield and quality of wheat and outbreak of rusts and other diseases thus ensure food self sufficiency as well as export of surplus wheat in future. These genotypes will be good source for molecular studies related to multiple disease and insect pests.

Clothianidin, a new neonicotinoid insecticide for the management of foliar aphid complex of wheat in India and its safety to coccinellid predators

Foliar aphid complex is becoming a major constraint of wheat production in India. The only option available to manage them is the use of insecticides. In this endeavor, the All India Coordinated Wheat and Barley Improvement Programme (AICW&BIP) has recommended traditional insecticides viz., dimethoate, oxydemeton methyl etc. Insecticide resistance and dearth of new molecules created a need to identify newer molecules for wheat aphid control. Recently, the neonicotinoids, viz., imidacloprid and thiamethoxam were recommended for the control of foliar aphids by the AICW&BIP. To broaden the base of these molecules, clothianidin, a new molecule, belonging to the neonicotinoids was evaluated at three locations viz., Ludhiana, Karnal and Niphad for two years. It was found that the new molecule was highly effective at 35 g/ha in controlling the foliar aphids and reducing the yield losses. The new molecule was found safe under field conditions but in vitro studies showed that it was relatively toxic to the coccinellid beetles. The feeding preference study showed that the treated leaves were not fed by aphids up to seven days after treatment. No phytotoxicity was observed on the plants even when they were sprayed at very high concentrations.

Efficacy of Selected Insecticides for Aphid Control on Cotton, 1997

Abstract Cotton was planted on 26 Apr on 30-inch rows near Weldon in Northampton Co., NC. Recommended practices for fertility and weed management were followed. Disyston 15 G at the rate of 0.75 lb (AI)/acre was used at planting for thrips control. On 19 and 28 May, cotton was sprayed with a banded application of 0.25 (AI) Orthene 75 S for thrips control. The banded foliar aphid treatments were applied on 15 Jun via a CO2-pressurized sprayer calibrated to deliver 8.0 gpa at 50 psi with a single TX-8 Spray Systems nozzle 9 inches over the row. Plots were 6 rows X 20 ft with 4 reps and arranged in a RCBD. On 20 Jun, treatments were evaluated by randomly collecting 10 plants in each plot and counting the aphids. On 30 Jun, treatments were evaluated by randomly collecting 10 expanded terminal leaves in each plot and counting the number of aphids. Plots were harvested from the middle 2 rows with a 2-row John Deere picker on 22 Oct. Seed cot-ton yields were converted to lint cotton/acre using 40% gin turnout. All data were analyzed via ANOVA and DMRT.