|RAJASTHAN AGRICULTURAL RESEARCH INSTITUTE (RARI)
(SRI KARAN NARENDRA AGRICULTURE UNIVERSITY, JOBNER, JAIPUR)
DURGAPURA, JAIPUR, RAJASTHAN, INDIA
History of whitegrub project in Rajasthan:
The light sandy soil of Rajasthan has a history of whitegrub, Holotrichia consanguinea
infestation in all most all the kharif crops. The damage in different crops ranges from 20 to 100 per cent. Durgapura is the oldest and main lead center of the project where the coordinating cell is situated. Initially the project center was started at Jobner (District, jaipur) in 1980 and later on it was shifted to Dugapura, jaipur in 1986. the basic and strategic research have been conducted at this center for the management of whitegrub, Holotrichia consanguinea
, which is the predominant species of Rajasthan, Gujarat, M.P.,U.P., Haryana, Punjab, Bihar. Hitherto known as minor species, Maladera insanabilis have attained a major status in last few years due to the spread of canal irrigation system and the work for its management is in progress.
Scientists associated with the Project:
Major crops infested by whitegrubs in Rajasthan:
|Name of the Scientist
||Date of Joining in the Project
|Dr. V.K. Agrawal
Network Coordinator &
Professor and Head
Division of Entomology, RARI, Durgapura
||AINP on Soil Arthropod Pests, Division of Entomology, RARI, Durgapura, Jaipur 302018
Tele No.: 09460380103 (M)
|Dr. A. S. Baloda
||AINP on Soil Arthropod Pests, Division of Entomology, RARI, Durgapura, Jaipur 302018
Tele No.: 09414065091 (M)
All crops grown in the rainy season (kharif), Groundnut, Pearl Millet, Moong bean, Maize, vegetables etc.
Important species of whitegrubs in Rajasthan:
Holotrichia consanguinea is the most serious scarab pest in India. It finds loose, sandy well drained soil to be quite suitable for its survival and multiplication. It is a dominant whitegrub species in the states of Rajasthan, Gujarat, Haryana, Punjab, U.P. and Bihar. It feeds on all kharif crops but the damage is more evident on plants having tap roots and so in many parts of the country, it is the main constraint in groundnut cultivation. The beetles of Holotrichia consanguinea emerge from the soil during dusk after good pre monsoon or monsoon rain in mid May or later, Any rain received prior to mid-May does not initiate emergence of beetles as they are not sexually mature. If there is good premonsoon rain, two peaks of beetle emergence are observed, Once active, the beetles follow the daily rhythm of emergence, congregation on host trees at dusk, and return to soil, at dawn.
The beetles are polyphagous, and may feed on the foliage of a wide variety of host trees and bushes found in the close vicinity. However, they do exercise some preference for certain hosts like jujube (ber), Prosopis cineraria (khejri) neem, cluster fig (gular), jambolana (Jamun) and drumstick (sainjana). In some situations, large number of beetles settles on a non-host tree, only for mating and just after, shift for feeding to nearby preferred hosts. The host preference depends on the combination of hosts available in a particular locality.
The beetles usually after emergence, do not fly long distances in the evening but try to avail the short twilight hour for mating and selecting a suitable host as they are unable to see clearly in dark. It is the female which first comes out of soil, settles on a host and secretes a pheromone which attracts the male for mating. If a female fails to mate in first 10 to 15 minutes of setting on the host tree, she tries mating next evening. The process of congregation of beetles on host continues every evening for a period of about three weeks to ensure mating of all females. The mated females return to soil in early morning and start egg laying within 2 to 3 days of mating. However, some females, depending upon the condition of maturity of their ovarioles, may lay eggs upto 10 days or more after mating. The female prefer light sandy soil for egg-laying. The longevity of the emerged beetles varies from 35 to 49 days, during the period daily host visits are made for feeding.
On an average 20 eggs are laid by mated females in instalments, starting from third day after mating. The eggs are laid at the depth of 6 to 10 cm inside the soil. Freshly laid eggs are white, elliptic, about 3.22 mm in length and 1.95mm in width. Prior to hatching the eggs become brownish black and globular, and measure about 3.27 mm in length and 2.73 mm in width. The incubation period under laboratory conditions ranges from 7 to 13 days.
Life Cycle of Whitegrub
The newly hatched grubs are creamy white in colour and may feed on organic matter for some time till they come in contact with living roots. On an average, the first instar grub measures 15.1 mm in length; while, the head length and width are 4 mm and 3 mm, respectively. The average duration of first instar grub is 16 days. The second instar grub measures 34.5 mm in length; the head length and width being 6 mm and 5 mm, respectively. The average duration of second instar grub is 32 days. The third instar grub measures 40.7 mm in length; the head length and width being 8 mm and 7 mm, respectively. The average duration of third instar is 49.5 days. Total grub duration ranges from 82 to 113 days.
For feeding, the grub makes chamber by compressing the surrounding soil particles and then eats the rootlets exposed into the chamber; thereafter it moves vertically, a little, to eat more of the same root. After this, the grub moves horizontally making chambers and feeding on the exposed toots. The grubs continue active feeding from July to mid - October.
All the grubs pupate by the beginning of November. Before pupation the grubs enter deep into the soil to the depth of 40 to 70 cm or more in search of suitable moisture Zone. The average pupal length and width is 27.3 mm and 14.2 mm, respectively. A short prepupal period is spent before entering into pupation, during which, the grub prepares and earthen chamber for pupation. The average pupal period is 14.2 days.
The freshly emerged beetle is white in colour but with the lapse of time it becomes dull brown with light brown abdomen and dark brown legs. The average beetle length and width is 21.3 mm and 11.8 mm, respectively. The beetles remain in the soil in inactive state upto middle of May at a depth of about one meter. The average duration of one life cycle is 122 days and there is only one generation in a year.
Holotrichia serrata (F):
Holotrichia serrata is prevalent in Karnataka, Maharashtra, Andhra Pradesh, Tamil Nadu, kerala, South Rajasthan, Tarai belt of UP and South Bihar. It survives happily in well drained, heavier, red alluvial and black cotton soils. The grubs of this species cause extensive damage to vegetables, pulses, oilseeds, cereals, millets, tobacco, sugarcane and sorghum.
Like, H. consanguinea, the beetles of H. serrata also emerge from soil after the first good premonsoon or monsoon shower. The adults are attracted to neem, palas (Buttea monosperma), babul (Acacia Arabica), guava, grapevine etc. After emergence the beetles settle on the host plants where mating occurs for 5 to 7 minutes. Unmated females continue their efforts to mate in subsequent evenings and this process goes on for about three weeks.
Egg lying may commence 2 to 3 days after copulation; a gravid female may lay from 5 to 40 eggs in her life time. Freshly laid eggs are creamy white, oval and measure on an average 3.0 mm in length and 1.7 mm in width,. After 2 to 3 days, the eggs turn spherical, smooth, and measure on an average 2mm in diameter. In 6 to 8 days, the chorine becomes slightly transparent towards one end and milky white towards the other, and the developing embryo is visible with its cephalic appendages. The incubation period ranges from 12 to 15 days. The colour changes as the development advances and the egg swells upto 4.0 mm in diameter, one or two days before hatching.
The newly hatched grubs are creamy white in colour and measure about 10.8 mm in length and 2.7 mm in width, the head capsule being 2.1 mm. The head turns brown in colour in a few hours and the grub becomes active in about 4 hours. The first stage larva comes out of the earthen cell if there is sufficient moisture; under drought it remains inside the cell until favorable conditions occur. The average duration of first instar grubs is 22.5 days. The second instar grub on an average measures 20.0 mm in length and 7.0 mm in width; the head capsule measures 5.6mm. The duration of second instar grub on an average is 35 days.
The third instar grub is creamy white in colour, measuring on an average 47.0 mm in length and 12.0 mm in width; the width of head capsule is 7.8 mm. This instar is an active root feeder with powerful mandibles. The average duration of third instar is 124.5 days while the total grub duration on an average is 185.5 days.
The grubs become full grown in the month of October when they stop feeding and burrow deeper in the soil and construct an earthen cell for pupation. The pupa on an average measures, 32.0 mm in length and 15.0 mm in width. The average pupal period is 15.5 days.
The freshly emerged beetle is white in colour but with the lapse of time it becomes dull brown with light brown abdomen and dark brown legs. The body length and width of the beetle is 22.4 and 14.0 mm, respectively. The average duration required to complete one life cycle is 220 days and there is only one generation in a year.
Maladera insanabilis Brenske:
Maladera insanabilis is a prevalent scarab species in the entire country, and is attaining pest status in western Rajasthan. The adults as well as grubs are polyphagous in nature. The beetles assemble in large numbers and defoliate the tender leaves, buds and flowers of the shrubs and trees growing in an around the cultivated fields. The grubs feed upon the tender roots, rootlets and root hairs of the plants. The crop plant attacked by the grubs is groundnut, chilli, orkra, brinjal, pearl millet, Lucerne, alfalfa onion and cucurbits.
The adults emerge twice in a year, first prior to rains, from middle of March to May, and again with rains, from middle of June to end of August. After emergence, the beetles settle on the nearby host plants like, Lucerne, cucurbits and trees like, rose wood, khejri, (Prosopis cineraria), babul (Acacia nillotica), ber (Zizyphus mauritiana) etc. The mating occurs in the initial 10 to 15 minutes of emergence, during the twilight, and the duration ranges from 10 to 15 minutes.
The mated females lay from 2 to 25 eggs (avg. 8.5 eggs) at the depth of 1.5 to 5 cm in the soil. They prefer to lay eggs in cropped field in moist, loose soil, near the root zone. The oviposition period of the species ranges from 5 to 7 days. The freshly laid eggs are white in colour, oval in shape and on an average measure 1.16 mm in length and 0.82 mm in width. The eggs gradually swell and at the time of hatching become globular, dirty white in colour and measure 1.55 mm in length and 1.12 mm in width. The incubation period varies from 4 to 8 days (avg. 5 days).
Newly hatched grubs are milky white in colour and about 2.5 to 3.0 mm in length. The average duration of first instar grub is 13 days. The second instar grubs measure 7 to 9 mm in length and the instar duration is 31 days. The length and width of third instar grubs range from 11 to 18 mm and 3 to 4 mm, respectively. The average duration of third instar is 20 to 30 days in first generation and 182 days in second generation. The duration of second generation grub is prolonged as they pass the winter in larval stage. The first instar grubs usually feed on organic matter and humus, while the second and third instars feed on roots.
The full grown grub constructs an earthen cell in the soil and pupates. The pupa measures about 9 mm in length and 4 mm in width. The pupal period ranges from 5 to 10 days. The size of beetles ranges from 6.5 to 8.5 mm in length and 2.5 to 4.0 mm in width.
Salient research achievements:
. An integrated pest management technology for whitegrub, Holotrichia consanguinea
, the predominant species of Gujarat, Rajasthan, U.P., M.P. Punjab, Haryana, Bihar was developed by Durgapura centre of the project. The pheromone from the female adults of Holotrichia consanguinea
was isolated and identified. Subsequently, refinement in the whitegrub, (H. consanguinea
) management technology through pheromone technique was done. Practical utility of whitegrub management technology through pheromone was successfully demonstrated in the whitegrub endemic area of Rajasthan for four consecutive years under National Agricultural Technology Project covering an area of more than 1000 hectare. During four years, 27 on campus and off campus training programmes were organized for farmers and extension functionaries.
The pheromone technique of whitegrub management has reduced the pesticide consumption by 60 per cent, which ultimately reduced the cost of protection, labour and pesticide load on environment. The pest population and the crop damage in campaign area/demonstration villages was reduced by more than 80 per cent and increased the productivity of groundnut crop by more than 4 q/ha.
. Out of several new compounds tested viz. Thiamethoxam 70 WS and 25 WG, Fipronil 5 FS, Imidacloprid 70 WS and 200 SL, Chlorpyriphos 10 G for the management of whitegrub, Holotrichia consanguinea
in groundnut crop, the Imidacloprid 17.8 SL at 0.6 g a.i./kg seed, clothianidine 50 WDG at 2 g / kg seed, Imidacloprid 600 FS at 6.5 ml / kg seed as seed dresser, Imidacloprid 17.8 SL at 60 g a.i./ha in standing crop and chlorpyriphos 10 G at 2 kg a.i /ha as soil treatment were found most effective and were included in package of practices.
. Apart from chemicals, intensive research of biological control agents was also done for the management of whitegrub. Among the microbial control agents, fungi, Metarhizium anisopliae and Beauvaria bassiana were identified as entomopathogenic to the predominant whitegrub species of the region i.e. Holotrichia consanguinea
. Further, research indicated that fungi were more effective, when placed at soil depth of 10-15 cm. Few species of nematodes, Setainernema glaseri, Heterorhabditis species and a local strain were found to be pathogenic to several whitegrub species including Holotrichia consanguinea
. Out of the number of insecticides evaluated against termite damage in groundnut and wheat in kharif and Rabi seasons respectively, Imidacloprid 17.8 SL at 0.6 g a.i./kg seed and seed were found very effective when used as seed dresser. Furrow application of imidacloprid 0.75 G (10 kg/ha) was also found promising against termite in groundnut crop. Imidacloprid 17.8 SL at 1.5 ml / kg seed was found effective as seed treatment and fipronil 5 SC at 10 ml / kg seed was found effective against termite in chickpea.
. For organic farming two applications of calotropis leaf extract in cow urine (1:1) at 5 l/ha gave encouraging results against termite in groundnut crop.
. Inventory of soil arthropods was prepared in which about 20 different types of soil arthropods belonging to different orders were listed. Among the three ecosystems, the forest ecosystem was observed to contain maximum soil arthropods followed by agro ecosystem and fallow land. It was also found that the majority of soil arthropods were, soil mites and collembolans.
. The effect of insecticides on non-target insects was carried out and it was found that these pesticides are harmful to the soil mites, collembolans and other micro and meso soil arthropods. It was also found that population of soil arthropods specially soil mites and collembolans were restored after two months in case of chlorpyriphos and quinalphpos and three months in case of imidacloprid.
|IPM OF WHITEGRUB IN GROUNDNUT CROPPING SYSTEM
THE IPM MODULE
||What to do
||When to do
||How to do
||Identification of whitegrub host trees
||Before sowing, April-May
||Among the group of trees, selection of preferred host trees of whitegrub like Neem, Ber, Khejari, Guava, Gular etc. in the month of April-May.
||Selection and mapping of host trees to be sprayed with insecticide and loaded with pheromone dispenser
||Before sowing April-May
||Among the preferred host trees, identification and marking of only one tree within a radius of 15 metres for insecticide spraying and pheromone loading in April-May.
||Insecticidal spraying of marked host trees
||Before sowing, June
||After first rain of the season in the month of June, spraying of marked host trees with Imidacloprid 17.8 SL (0.027%) or monocrotophos (0.05%) or carbaryl (0.2%) within 3 days of the first shower.
||Pheromone loading on host trees.
||Before sowing, June
||In the evening, at the time of beetle emergence (7.30 to 7.45 PM) hang pheromone dispensers on the already sprayed, marked host trees (3 dispensers/tree) for 3-4 evenings continuously.
||Insecticidal spraying and pheromone loading of host trees
||Repeat insecticidal spraying and pheromone loading of host trees with the monsoon showers, if there is a gap of more than 15 days between pre-monsoon and monsoon showers.
||Mechanical collection of beetles
||In areas where the facilities of spraying does not exist mechanical collection of beetles from the host trees can be done around 9.00 PM by jerking the host trees, collecting the fallen beetles and killing them in 5% kerosenised water.
||At sowing time, June-July
||Groundnut seed treatment with Imidacloprid 17.8 SL at 3 ml/kg seed or clothianidine 50 WDG at 2 g / kg seed, Imidacloprid 600 FS at 6.5 ml / kg seed or quinalphos 25 EC at 25 ml/kg seed in monsoon sown crop.
||Post sown treatment (in early sown crops where seed treatment is not done)
||In standing crops, July - August
||Soil drenching of Imidacloprid 17.8 SL at 300 ml/ha or chlorpiriphos 20 EC or quinalphos 25 EC at 4 l/ha with irrigation in standing crop around 21 days of mass emergence of beetle. OR Insecticidal mixed soil can also be used in rainfed crops provided it rains soon after the application
||July - August
||Ploughing of summer fodder crop fields from end of July to middle of August after taking the last cutting to expose the grubs to predatory birds. If predatory birds are absent a man with a bucket in hand may follow the plough and pick up the exposed grubs. This will reduce the population pressure in coming years.
. Annihilation of whitegrub adults on host trees by application of insecticides and pheromone loading of selected host trees.
. Management of whitegrub in Groundnut crop
a. Monsoon sown:
Seed treatment either with clothianidin 50 WDG (Dantotsu) at 2g per kg seed or Imidacloprid 600 FS at 6.5 ml / kg seed or Imidacloprid 17.8 SL at 3ml per kg seed or quinalphos 25 EC at 25 ml per kg seed be done before sowing
b. Advance sown:
Standing crop treatment either with Imidacloprid 17.8 SL at 300 ml per ha. or quinalphos 25 EC at 4 lt per ha., be done, 3 weeks after mass beetle emergence (after first monsoon shower) with irrigation water.
. Management of whitegrubs in other crops:
a. Pearl millet:
I. Phorate 10G at 12 kg/ha to be mixed with required amount of seed and then the insecticide seed mixture be sown.
II. Pre sowing soil application of phorate 10G at 25 kg/ha or quinalphos 5 G at 30 kg. /ha be done in furrows.
III. In standing crop, chlorpyriphos 20 EC or quinalphos 25 EC at 4 l/ha be applied with irrigation, 3 weeks after the first monsoon shower.
b. Kharif pulses :
I. For monsoon sown, soil application of phorate 10G at 25 kg/ha be done.
II. In standing crop, chlorpyriphos 20 EC or quinalphos 25 EC be applied at 4 l/ha with irrigation, 3 weeks after the first monsoon shower.
c. Vegetables :
I. In standing crop, chlorpyriphos 20 EC or quinalphos 25 EC be applied at 4 l/ha with irrigation, 3 weeks after the first monsoon shower.
Ongoing Research Projects:
. Monitoring of Soil Arthropods
A. Species profiling of soil arthropods through light trap:
B. Population Monitoring of scarabacid beetles on host trees:
C. Monitoring of natural enemies of soil arthropods:
. Management of Whitegrubs
A. Management of whitegrubs through chemicals
I. Evaluation of granular insecticides against whitegrub:
II. Evaluation of some liquid insecticides against whitegrub:
B. Microbial Control of Whitegrubs
. Transfer of Technology
Dissemination of already generated technologies through on farm trials/large scale demonstrations for the management of soil arthropod pests.
. Location Specific Trials
1: Effect of insecticidal seed treatment against termite in groundnut.
2. Field evaluation of insecticides in standing crop of groundnut against termite
3. Biological suppression of termites