Grain legumes (beans, pulses and oilseeds) are protein rich and energyrich dry seeds which are often called as pulses. Protein sourced from grain legumes costs one- fifth of protein from milk. In addition, the amino acid balance of grain legume protein complements that of cereals when eaten together, greatly improving the protein quality of the combined food and sometimes referred as “poor man’s meat”(
Ali and Gupta,2012). Grain legumes are also vital sources of micronutrients such as iron, reducing wide spread anemia caused by the lack of diversity in the starch based diets of the poor. Leaves, stems (hulms) and pod walls of these pulses are also valuable as livestock feed and also soil fertility restorers. India is an important pulse growing country contributing 28 per cent to the global pulse basket from an area of about 37per cent (
MasoodAli and Shivkumar, 2000).
The commonly grown major pulse crops in India are pigeonpea, mungbean, urdbean, chickpea, horsegram, cowpea and some of the minor pulse crops are drybean, mothbean, lathyrus, lentil and peas. Cultivation of pulses in India takes place under diverse agro ecological nitches such as
kharif/rabi, rainfed/ irrigated, mixed/ monocrop, low /high input conditions, traditional/ progressive farming etc., posing a highly variable spectrum of pest problems. The insect pest spectra that infest these pulse crops include more than 40 species on blackgram or greengram and 300 species on pigeonpea
(Mahalakshmi et al., 2016). The sucking pests like aphid,
Aphis craccivora Koch; jassid,
Empoasca kerri Pruthi; whitefly,
Bemisia tabaci Gennadius, thrips,
Thrips palmi Karny and flower thrips,
Megalurothrips usitatus Bagnall are known to cause significant damage to grain legume crops
(Soundararajan et al., 2013). The repeated use of conventional insecticides to combat the sucking pests resulted in development of resistance to insecticides. Now, several novel insecticides with their novel mode of action and are very effective at lower doses against target pests and safe to natural enemies. The present review deals with the bioefficacy of certain new molecule insecticides having unique mode of action, against the sucking pests on grain legumes.
DAMAGE POTENTIAL OF SUCKING PESTS ON GRAIN LEGUMES
The annual yield loss due to the insect pests has been estimated to the tune of 30 per cent in greengram (
Soundararajan and Chitra, 2011) and urdbean and greengram
(Gailce, et al., 2015). Pigeonpea (
Cajanus cajan L. Millsp.) is attacked by number of pests which are quite varying according to different agro-climatic conditions. Several insects have been reported to infest pigeonpea crop at different stages during its growth period in different parts of the country
(Priyadarshini et al., 2013, Chakravarthy and Agnihotri, 2016,
Khamoriya et al., 2017). Srilaxmi and Ravindra Paul (2010) observed that
C. cajan is infested by insect pests belonging to 6 orders and 16 families of these orders and the pests belonging to Lepidoptera cause maximum damage followed by members of Coleoptera, Diptera and Hemiptera.
Chickpea is the second largest pulse crop produced in the world and play important role in human nutrition as source of protein. Area occupied by chickpea is about 7.29 million ha with production of 5.77 million tones which accounts for 30 % and 38 % of the national pulse acreage and production, respectively. Insect pests pose greater threat to chick pea production and results in poor yields (
Suneelkumar and Sarada, 2015). Blackgram is attacked by 40 to 60 insect species at different stages of the crop growth
(Mohanraj et al., 2012). The sucking pests like aphid,
Aphis craccivora Koch; jassid,
Empoasca kerri Pruthi; whitefly,
Bemisia tabaci Gennadius, thrips,
Thrips palmi Karny and flower thrips,
Megalurothrips usitatus Bagnall are known to cause significant damage to urdbean
(Ramu et al., 2018). Mungbean is attacked by different species of insect pests but sucking insect pests (aphid, jassid, leafhopper and whitefly) are of the major importance and whitefly, a potential vector of mung bean yellow mosaic virus (MYMV), can cause losses ranging from 30 to 100 per cent in green gram and black gram (
Panduranga et al., 2011).
Thrips cause damage to tender shoots, leaves, buds and flowers resulting in curling of leaves, dropping of flower buds and flowers and reported that thrips caused at least 40 per cent yield loss in greengram,besides direct injury by feeding, thrips also act as vectors of different plant viruses that cause leaf curl and bud necrosis (
Sreekanth et al.,2003). Cow pea is infested by 21 insect pests and cause about 65-100 per cent losses among the insect pests cowpea aphid,
Aphis craccivora causes significant yield losses (20-40 %) in Asia and upto 35 per cent in Africa (
Kotadia and Bhalani, 1992). The Indian bean,
Lablab purpureus L. is one of the important pulse crops of Gujarat widely grown in dry, warm arid region of the state. The crop is attacked by various sucking pests
viz; black aphid,
Aphis craccivora Koch, leaf hopper,
Empoasca kerri Pruthi, whitefly,
Bemisia tabaci Genn., thrips,
Megaleurothrips distalis Karny
(Chaudhari et al., 2015).
BIO EFFICACY OF CHEMICAL INSECTICIDES AGAINST MAJOR SUCKING PESTS ON GRAIN LEGUMES
Several reports are available on the insecticide based management of major sucking pests on pulses at different locations which are reviewed group wise hereunder.
Organophosphates and synthetic pyrethroids
Foliar spray of cypermethrin @ 0.01%, deltamethrin @ 0.028% and dimethoate 0.03% were effective against whitefly on greengram (
Borah,1995). Monocrotophos @0.04% and dimethoate @ 0.03 % had been found effective against jassids and thrips in greengram and cow pea (Oyewale
et al.,2014). Dimethoate @ 0.03% showed effectiveness in reducing aphid population (88.4%) in greengram
(Vikram et al., 2015). Malathion and chlorpyriphos were least effective against sucking pets in pulses
(Shiloskar et al., 2015). Acephate@ 0.037% and profenophos @0.05% are moderately effective against jassid and whitefly on greengram
(Manju et al., 2016).
Carbamates
Patel and Srivastava (1990) reported the phytotonic effect and effectiveness of carbosulfan 25 E C as a seed dresser @ 5.00 a.i/100 g seed and carbofuran 3 G @ 0.5 and 1 Kg a.i/ha against aphids in green gram. Carbosulfan 25 EC @1000ml/ha and 500 ml/ha failed to control the whitefly population, YMV and YVMV diseases in blackgram and mesta, respectivevely
(Gopalaswamy et al., 2012 and
Yadav et al., 2012). Indoxacarb @ 500 ml/ha was highly toxic to the natural enemies (ladybird beetles, Green lace wings and spiders) of soybean pests at Parbhani, Maharastra (
Ilyas et al., 2015). Thiodicarb @0.10% recorded lower number of leafhopper population (1.04/leaf) in blackgram
(Parmar et al., 2015).
Neonicotinoids
Neonicotinoids are the newest major class of insecticides, have outstanding potency and systemic action for crop protection against piercing-sucking pests. These were developed in the 1980s, and the first commercially available compound, imidacloprid, has been in use since the early 1990s
(Kollmeyer et al., 1999). Their common names are acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid and thiamethoxam. They possess lower mammalian toxicity, less resurgence problems, environmental protection, pest management selectivity and less toxicity to natural enemies
(Kunkel et al., 1999). Neonicotinoids are broad-spectrum, systemic compounds exhibit activity against sucking insects (e.g. aphids, whiteflies, leafhoppers) and several species of flies and moths. Neonicotinoids are used primarily as plant systemic, applied to seeds, soil, or foliage; they move to the growing tip and afford long-term protection from piercing-sucking pests
(Kundoo et al., 2017).
Imidacloprid
Imidacloprid @ 0.75 l/ha was highly effective in controlling the thrips infesting field bean resulting in 85.97% reduction over control
(Cermeli et al., 2002). Seed treatment with imidacloprid 600 FS @ 5 ml/ kg seed in blackgram was effective in reducing the whitefly population (2.53/leaf)
(Men et al., 2005). Two sprays of imidacloprid 17.8SL @ 0.24 ml/l along with imidacloprid 70WS @ 5 g/kg seed treatment and two sprays of imidacloprid 17.8SL @0.24 ml/l alone recorded least disease incidence of 30.2 and 30.3% with minimum vector population of 1.87 and 1.73 whiteflies per leaf, respectively
(Salam et al., 2009). Imidacloprid treated plot gave a less severity of yellow mosaic virus disease (9.22%) when compared to untreated control (21.84%) at 40 DAS in greengram
(Hossain et al., 2010). Higher efficacy of imidacloprid was also reported in cowpea
(Khade et al., 2014). Seed treatment with imidacloprid @ 5g/kg seed + foliar spray with imidacloprid @0.05% was very effective in reducing whitefly population (88.11%) and thrips on moth bean
(Naga et al., 2015). Seed treatment with imidacloprid 600 FS @ 10ml/kg seed significantly recorded lowest population of whitefly, leafhopper and thrips with highest gross and net returns
(Anusha et al., 2016).
Thiamethoxam
Foliar application of thiamethoxam @100 g/ha was found significantly effective over control which recorded 1.25 whiteflies/leaf followed by seed treatment with thiamethoxam 500 FS @ 4.0 ml/kg seed in soybean (
AICRP report on Soybean, 2005-06).
Shah et al. (2007) reported that thiamethoxam 25 WS @ 0.005 % was highly effective by recording lowest population of 2.60 whiteflies per plant and also recorded lowest MYMV incidence (10.7%) in greengram.
Verma and Kanwar (2009) reported that the lowest leafhopper population (0.84/ plant) was observed in seed treatment with thiamethoxam 70 WS @ 3 g /kg seed (0.84/plant) at 20 DAS in green gram. Seed treatment with thiamethoxam 25WS @0.0035% and imidacloprid 70WS @0.0035% protected the mungbean crop from whiteflies upto 25DAS but later resulted in more vector population (6.00 &7.33/5 plants) and high MYMV incidence (19.8% & 24.3%) than in other treatments
(Panduranga et al., 2011). Thiamethoxam 70 WS @ 3 g/ kg seed and imidacloprid 70 WS @ 3 g/kg seed were moderately effective against thrips resulting in a population of 2.36 and 19.6 thrips/ 10 terminal buds of blackgram and greengram
(Kabir et al., 2014). Seed treatment with thiamethoxam 25 WG @ 3 g kg
-1 of seed + spray with thiamethoxam 25 WG @ 0.4 g l
-1 was found to be effective against sucking pests of blackgram by recording lowest population of leafhoppers (2.36 per plant) over untreated control (8.03)
Gailce et al., (2015). Mahalakshmi et al., (2015) reported that Thiamethoxam 25 WG @ 0.2 g l
-1 was effective in recording the lowest per cent population of whitefly (45.15) and 30.38 per cent YMV disease incidence in blackgram.
Shlokeshwar and Dhremendra (2015) conducted a field experiment on competitive studies of insecticides for the control of sucking pests in urdbean in relation to yield during
kharif season 2012 and 2013 and reported that thiamethoxam @ 125g ha
-1 gave significantly good control of whiteflies(2.11 in 2011 and 2.6 in 2013 per 6 plants).
Yadav et al., (2015) revealed that thiamethoxam (0.025%) proved to be effective in reducing the leafhopper, whitefly and aphid population by 81.32%, 87.78% and 92.61%, respectively over untreated control in cluster bean.
Sujatha and Bharpoda (2017) conducted an experiment and reported that thiamethoxam 25WG (0.01%) was found to be more effective against the sucking pests by recording lowest population of 0.38 aphids and 0.08whiteflies per three leaves, respectively on greengram.
Imidacloprid(0.05%) and thiamethoxam (0.025%) were found to be most effective against whitefly and thrips resulting in highest reduction of population in soybean, greengram, urdbean, cow pea, clusterbean and groundnut
(Iqbal et al., 2013, Nataraja et al., 2014, Kaushik et al., 2015, Ahirwar et al., 2016, Singh et al., 2016) at Varnasi, Junagadh and other locations.
Acetamiprid
Kumawath and Kumar (2007) reported that acetamiprid @ 80 g a.i/ha provided significantly superior control of leafhoppers in soybean. Acetamiprid 20 SP @ 40 g a.i./ha resulted in highest reduction in whitefly population over untreated control and least incidence of yellow vein mosaic virus (YVMV) disease (<6.4 %) in mesta
(Seetharamu et al., 2011). Acetamiprid @ 180g a.i/ha were found to be effective against jassid and thrips population in mungbean
(Singh et al., 2014). Acetamiprid (0.3g/l) effective against whitefly in green gram
(Singh et al., 2015, Sasmal and Kumar, 2016). Acetamprid 20SL @ 0.125g/l proved to be highly effective against cowpea aphid
A. craccivora with mortality percentage of 98.33
(Gowtham et al., 2016). Acetamiprid @ 0.004 per cent was effective in reducing the whitefly population by recording 87.67% reduction over untreated control in cowpea at Junagadh
(Anandmurthy et al., 2017).
Thiacloprid
Palumbo (2001) conducted an experiment on evaluation of neonicotinoid insecticides for the control of whiteflies and reported that thiacloprid recorded excellent control as a foliar spray with a residual effect upto 14-21 days after spraying in melons.
Mahalakshmi et al., (2015) stated that thiacloprid 21.7 SC @ 1.25 ml l
-1 was effective in reducing 50.22 per cent population of whitefly by recording 30.38 per cent YMV disease incidence in blackgram. Thiacloprid @ 60 g a.i./ha was found superior with a reduction of 88.07% in whitefly population after 7DAS in urdbean
(Indrajeetsingh et al., 2017). Thiacloprid 21.7 SC @ 0.0325% was found to be highly effective against thrips by recording 74.80 per cent reduction in thrips population followed by acetamiprid 4% + fipronil 4% @ 2ml l
-1 with 70.81 per cent reduction in thrips population over untreated control in blackgram (
Swathi, 2018).
Clothianidin
Parmar et al., (2015) reported that clothianidin 50WDG @ 0.03% was found to be very effective against jassids by recording lowest population of 0.45 jassids/leaf in blackgram and greengram. Clothianidin@0.2g/l was found to be effective against aphids in greengram (
Sasmal and Kumar, 2016). The potency of neonicotinoids
viz., imidacloprid, acetamiprid and clothianidin against
B. tabaci and leafhoppers on cowpea, Indian bean and okra
(Gurjar et al., 2007, Preetha et al., 2009 and
Chaudhari et al., 2015).
Flonicamid
Flonicamid - a pyridine carboxamide compound and a novel systemic insecticide with selective activity against hemipterous pests, such as aphids, whiteflies and thysanopterous pests. It has better action through ingestion than contact. It is found effective in controlling aphids resistant to various conventional insecticides (
Hancock, 2003). The effectiveness of flonicamid against aphids and other sucking pests has been well documented in other systems (
Baugh and Kerns, 2010). Flonicamid was more selective against soybean aphid
A. glycines (
Pezzini and Koch, 2015).
Chaudhari et al., (2015) observed that the plots of Indian bean treated with flonicanid 50WG @ 0.015% showed comparable reduction in the incidence of thrips, hoppers and whiteflies at Anand.
Anandmurthy et al., (2017) stated that flonicamid 50WG @ 0.02% was effective in reducing the whitefly population by recording 58.21 per cent reduction in population over untreated control in cowpea.
Swathi (2018) reported that flonicamid 50 WG @ 0.0325% was very effective against the population of whitefly by recording 72.19 per cent reduction and lowest per cent disease incidence (17.66%) in rice fallow balckgram.
Kalyan et al., (2017) concluded that the maximum (69.72%) reduction in whitefly population over untreated control was recorded with flonicamid 50 WP@ 100g a.i. ha
-1.
Spinosad
Spinosad is a macrocyclic lactone developed from an actinomycete (
Saccharopolyspora spinosa) fermentation culture that was originic acetyl choline receptors and has been reported to be effective on a wide variety of insect pests, especially lepidopterans and dipterans
(Sparks et al., 2001). Spinosad @ 0.005% was significantly superior by recording 120.12 per cent increase with a pod yield (14.66 q ha
-1) over untreated control in blackgram
(Lakshmi et al., 2002). Spinosad 45 SC was least effective in reducing the whitefly population (29.98) and recorded highest YMV incidence (31.76%) in blackgram
(Mahalakshmi et_al2015). Spinosad 45 SC at 60 g a.i. ha
-1 and 70 g a.i. ha
-1 was highly effective in controlling the incidence of sucking pests and pod borers on blackgram, and reported it to be very safe to the coccinelid beetles, Green lacewings and Syrphids
(Lalbabu et al., 2017). Spinosad 0.009 per cent was found least effective against the jassid population in summer cowpea
(Anandmurthy et al., 2017).
Novel groups of insecticides
The higher effectiveness of diafenthiuron on whiteflies was reported by
Gopalaswamy et al., 2012 and
Mandal (2015) in greengram and
Parmar et al., (2015) in blackgram.
Meena and Raju (2014) reported that fipronil @ 2ml/l was found effective in reducing whitefly population.
Mahalakshmi et al., (2015) concluded that spiromesifen 240 SC @ 0.4 ml/l was the most effective treatment with more than 75 per cent mean reduction in nymphal population of whiteflies on blackgram at Guntur, Andhra Pradesh. Acetamiprid 4% + fipronil 4% @ 2ml l
-1 was effective against thrips by recording (70.81%) reduction over untreated control (
Swathi, 2018). These findings of actemiprid + fipronil are in agreement with
Roshan et al., (2018) against BPH and GLH in paddy.
Swathi (2018) and
Tatagar et al., (2014) as they documented the effectiveness of flubendiamide 19.9% + thiacloprid 19.9% @ 1ml l
-1 against thrips infesting blackgram and chilli, respectively. Pre mixed formulations like flubendiamide 24%+ thiacloprid 24% @175ml/ha or chlorantraniliprole 10% + thiamet- hocxam 20% @180 ml/ha or emamectin benzoate 5% + fipronil 15% @ 750 g/ha were effective combinations for the sustainable management of spotted podborer and all stages of
Aphis craccivora on cowpea
(Roy et al., 2017).