1. To undertake research work on biology, behaviour, physiology and ecology of the major species of white grubs in
different regions of the state.
2. To evolve effective, economical and practicable technology for the management of white grubs in different cropping
systems and regions.
3. To undertake co-ordinated trials on the management of white grubs in different regions and cropping systems.
4. To undertake research work on biology, ecology, behaviour and management of other soil arthropods.
History of whitegrub project in Himachal Pradesh:
Himachal Pradesh has a history of white grub infestation in several agricultural crops and fruit/ forest nurseries. The first documented epidemic of white grubs was noticed during 1980s and caused about 70 per cent damage to potato in Shimla hills. Some reports of defoliation of fruit trees by scarab beetles are also available during 1970s. After 1980, there are frequent outbreaks of white grubs in different crops and keeping in view the magnitude of the problem All India Coordinated Project on White Grubs was approved for Himachal Pradesh. The project was formally implemented in 1995 in the Department of Entomology at CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur. Initially the survey work was conducted in few locations using light traps up to the year 2000. After 2000 more areas were surveyed through out the state and several other species were collected on their host trees. To control white grubs, systematic experiments have been conducted in potato, maize and peas. Recently work on local entomo
pathogens have been started to exploit them successfully in IPM programme of white grubs under hilly conditions of entire north western Himalaya.
Scientists Associated with the Project:
Important species of Whitegrubs in Himachal Pradesh:
||Name & Designation
||Date of Joining in the Project
||Dr PK Mehta
Professor & Head
||CSK Himachal Pradesh Krishi Vishvavidyalaya
PALAMPUR, Himachal Pradesh - 176062
Tel.: 01894-230385 (O)
Fax: 01894-230511, 230406
Email: firstname.lastname@example.org , email@example.com
||Dr RS Chandel
||CSK Himachal Pradesh Krishi Vishvavidyalaya
PALAMPUR, Himachal Pradesh - 176062
Tel.: 01894-230385 (O)
Fax: 01894-230511, 230406
Email: firstname.lastname@example.org , email@example.com
More than 100 species of white grubs have been reported to cause damage in Himachal Pradesh, out of which about 10 species are among the most destructive and troublesome soil insects threatening production of various crops in Himachal Pradesh. Principal among them are the members of sub family Melolonthinae and some members of sub family Rutelinae and Dynastinae. A brief account of some important species is given below.
Brahmina coriacea (Hope):
B. coriacea is more abundant in mid and high hills of Himachal Pradesh. This species alone comprises about 90 per cent population in apple orchards in Shimla hills. The grubs inflict heavy damage on various fruit/forest trees, their nurseries, vegetables, lawns and field crops. In potato, the tuber damage exceeds 50 per cent in endemic areas. In forest nurseries up to 50 per cent infestation has been reported in mid hills. The life stages are found in the top 10 cm of the soil and suffer higher moralities from tillage operations. The beetles emerge during June and feed on apple, wild rose, walnut, apricot, Robinia, Polygonum and Kathi ( Indigofera sp.) bushes. The length of full fed grubs is 27 mm. The adults are well known black beetles of apple with an average length and width of 15 mm x 7.8 mm, respectively (Fig.1).
This species has been observed in Shimla, Mandi and Kullu districts of Himachal Pradesh. The greatest damage occurs in Janjheli area of Mandi district in potato and pea. The estimated time for peak emergence of adults in flight trees is mid April. Larval length is about 22-24 mm. The body of beetles is elongate and oval, color yellowish, length 13-14 mm and breadth 7-8 mm (Fig. 2).
Brahmina crinicollis Burm:
It is a small beetle and is most common in March-April in Kullu valley, when it feeds upon the petals of pear and occasionally the apple. Although, the beetles do some feeding on foliage of some pome fruits, the economic importance of this pest is due to the damage it causes to pear flowers reducing the fruit set. Investigation has not yet shown on what tree the grubs of this species feed. They may feed on roots of oats or upon those of clovers growing in this locality. The beetles are reddish brown. The length is 8-9 mm and breadth is 4-5 mm (Fig. 3).
Holotrichia longipennis Blanch:
This species is distributed in entire Himachal Pradesh except in zone - I. It causes damage to various crops but ginger and potato are badly infested. The larvae are also reported to be injurious in the nursery beds of deodar in Himalaya. The beetles emerge from soil in late May and its preferred hosts are walnut, Rubus ellipticus, chestnut, apple, plum and toon. The full fed third instar grubs are about 38 mm long. The adults are brown in colour (Fig.4). Body length varies from 19-24 mm.
Holotrichia problematica Brenske:
The beetles appear on the wings during severe winter right from last week of February in Solan area. Maximum activity occurs during last week of March - first week of April especially on Olive. The beetles are dark colored, slightly iridescent above, with a thick white pubescence beneath. The length x width measures 16 mm x 8 mm. The grubs are white, crinkled, with a yellow head and length is about 25 mm. The grubs feed on the bark of the younger roots, eating it away in patches and often completely girding the roots of Sal. The grub spends major portion of the year feeding on the roots of the tree, descending deeper into the soil to hibernate during winter months. Larvae, pupae and beetles are all found in the upper 10 cm of soil. This insect only passes through one life cycle during the year.
Melolontha furcicauda Ancey:
This species occurs mainly in association with coniferous forests up to an altitude of about 3000 meters. The adults are on wings during the late half of June and feed on stone fruits and Ficus spp. The beetles are brown-red, covered all over with pale scales. Pygidium is long and projected behind into a bifurcated tail. The length x width is 32.0 x 15.0 mm. The grubs damage potato and other vegetable crops. They also feed on roots in seed beds of deodar nurseries and the grubs cut through roots of seedlings and young plants or more often gnaws away the bark all round, thus girdling them. The grubs are very large, heavy, yellowish white with a light brown head. Length is about 40-50mm (Fig. 5).
Granida albosparsa Moser:
This is one of the most common and largest cockchafer grubs, occurring commonly in the seed beds and nurseries of deodar and pines at higher elevations of up to 3000 meters in the entire himalayan range. Larvae feed on roots in nurseries and the damage caused is so serious that it may lead to failure of regeneration patches. The damage is most serious during May-June. The life cycle is believed to be of two years at higher altitudes beyond 2000 meters. Length of larva is about 45 mm.
Lepidiota stigma (F.):
It is a large beetle reported from Hamirpur, Bilaspur and Una districts. The beetles were noticed sitting on leaves and twigs of Shisham trees, eating out holes in the leaves. Elytra are convex and finely punctuate. Under surface is shining where pubescence has been rubbed off. The beetles are dull brown in color with a length of 45-46 mm and breadth is about 25 mm. The grubs are very large, robust and measure 70-80 mm in length. Evidences lean toward a biennial life cycle. The white grubs cause extensive damage to maize in river bed areas having loose sandy soil. The damage occurs in alternate years and vulnerable period for maize occurs during the seedling stage from May - June (Fig. 6).
Anomala dimidiata Hope:
The adults are strongly phototactic and cause severe crop damage throughout state. The grubs damage rice, maize and potato. Beetle emergence starts by the end of May. Adults feed on apple, walnut, plum, toon, poplar, and Shisham. The adults are shiny, metallic green beetles (Fig. 7). The length and width of beetles range from 20-22 mm and 12-15 mm, respectively.
Anomala lineatopennis Blanch:
This beetle is found in entire Himachal Pradesh except dry temperate region. The grubs damage potato and many other Kharif crops. The full fed grubs are 23-26 mm in length and the width range from 6-9 mm. The adults are dark brown with black thoracic region (Fig.8). They feed on apple, peach and apricot. The beetles are 18-19 mm in length while the width ranges from 9-10 mm.
Phyllognathus dionysius (F.):
The beetles are chest nut red and shining. Body length varies from 16-23 mm and breadth ranges from 9.5 - 13.0 mm. In male beetles, cephalic horn is broad strongly inclined backwards triangular at extremely with acute apex. Adult emergence takes place in May. The white grubs are said to be committing damage to maize, more especially to the roots of young seedlings in Kullu valley. Apparently full fed grubs cut through the roots of maize plants just below the surface level, thus killing the young plants (Fig 9).
Major crops infested by whitegrubs in Himachal Pradesh:
This is a polyphagous pest both in grub and adult stage and damages almost all crops grown during rainy season. The economic importance of the chaffers is primarily due to feeding activity of third instar grubs which inflict heavy damage to potatoes, maize, pea, ginger, cole crops and fruit/forest nurseries in Himachal Pradesh. They also suppress the yields of the other crops but this generally goes undetected.
The potato crop grown during summer as rain fed under long day conditions in higher hills is more prone to the attack of white grubs. In Himachal Pradesh, about 9 species of white grubs are reported to damage potato in different areas. The important ones are; B coriacea
, H. longipennis
, Melolontha sp.
and A. dimidiata
Initially young grubs feed on mother tuber, roots of developing potato plants, but after tuber formation, the older second instar and third instar grubs feed on the under ground potato tubers by making large, shallow and circular holes into them and thus rendering them unfit for marketing. They live concealed while feeding on tubers and plants continues to grow normally without any reflection of injury on aerial parts.
The grubs of B. coriacea
are smaller in size and more number of grubs can seen feeding on a single tuber. This results in the formation of numerous holes on all sides of tubers (Fig. 10a). However, incase of Melolontha sp.
, the grubs are large in size and a single grub usually feed on a tuber making large circular hole in it (Fig.10b). The extent of damage varies from 40-50 per cent, 17-28 per cent and 23-34 per cent in Shimla, Mandi and Sirmour, respectively. In endemic pockets like Shilaroo, up to 80 per cent infestation has been recorded.
In Himachal Pradesh , 11 species of white grubs viz. Melolontha furcicauda
(Ancey), M. nepalensis
Blanchard, A. dimidiata
, A. rufiventris
Redt., A. lineatopennis
Blanchard, Phyllognathus dionysius
Fabr., Heteronychus robustus
Arrow., Holotrichia longipennis
Blanchard, Xylotrupes gideon
(Linn.), Brahmina coriacea
(Hope) and L. stigma
have been observed causing damage to maize during Kharif
season. The extent of damage and species composition varies from place to place. On an average 10-35 per cent damage have been observed by white grubs in low and mid hill areas. P. dionysius
and H. robustus
cause maximum damage in Kullu and Solan districts, whereas, maize grown along river bed areas of river Beas in Sandhol and Kheri areas suffer the most due to ravages of L. stigma.
Certain areas of district Bilaspur are also suffering from the attack of this pest. The symptom of injury is root pruning by grubs, such plants show varying degrees of yellowing, browning and wilting and eventually death. The grubs destroy the root system completely and such plants can be easily pulled out. There is uneven crop growth and the infested fields present a devastated appearance (Fig. 11).
Pea is a leading off season vegetable of the state. There are certain ecological niches providing environmental conditions congenial for growing peas during Kharif
in higher hills. In Sangla valley of Kinnaur, white grubs cause 20-25 per cent plant mortality in off season crop in the month of June-July. The major species which were collected from different localities in the valley were H. longipennis
, B. coriacea
, M. furcicauda
and Anomala sp.
The damage was most serious in fields located in the vicinity of apple orchards. There was patchy growth in the infested fields and the damaged plants showed varying degree of yellowing, browning and wilting (Fig.12 ). The population of white grubs was very high and 4-5 grubs were found feeding on a single plant. The roots were totally pruned and the infested plants can be pulled out very easily. The pea crop fetches premium price during off season, hence white grub damage incurs heavy losses to farmers in that area.
Ginger is mainly cultivated in district Sirmour and is a cash crop of that area. Extensive survey was conducted during 2006 - 2007, and in some localities up to 30 per cent infestation was recorded. Five species were collected from ginger fields out of which H. longipennis
and B. coriacea
cause maximum damage. The damage is most serious during September-October. There are no symptoms of grub attack on ginger foliage and only rhizomes are attacked (Fig.13). The grubs make large holes in rhizomes and reduce market value of produce. In 2006, 8 locations were surveyed and maximum infestation (30 %) was recorded in Sangrah area. Likewise in 2007, the incidence was more (18.7%) in Sangrah area out of 15 surveyed localities. The healthy rhizomes of ginger are sold @ Rs. 700-800/bag of 40 kg in Dehradun market, however, white grub infested rhizomes fetches nearly 50 per cent lesser price and are sold only @ Rs. 300-350/bag
A melolonthid beetle is one of the most common cockchafer grub, occurring commonly in cabbage fields at higher elevations (up to 2500 meters) in Baragran area of Chuhar valley. Apparently full fed larvae feed on cabbage roots after transplanting in fields and the damage is so serious that it may lead to total failure of crop in certain fields. The damage is most serious during August September. Dying-off in fields usually occurs as a result of root feeding by this pest. The symptom of injury is root pruning by grubs, such plants show varying degree of wilting, yellowing, browning and eventually death. The attacked plants show stunted growth and can be easily pulled out (Fig.14). The larvae are large, thick and measure 45 mm.
Salient Research Achievements:
Detailed survey has been conducted in different parts of Himachal Pradesh and the important species of white grubs which cause economic damage have been identified as Brahmina coriacea
, B. crinicollis
, B. flavoserica
, Melolontha spp.
, Anomala lineatopennis
, A. dimidiata
, Holotrichia longipennis
and Lepidiota stigma
. The detailed life cycles of B. coriacea
, B. crinicollis
, H. longipennis
and L. stigma
have been studied. The emergence pattern of important species and their peak period of activity have been worked out in different areas of the state. The important hosts of adult beetles which favour their build up have also been identified on regional basis. For the management of white grubs in potato and maize, chlorpyriphos and quinalphos have been found effective.
Time of application is more relevant for the management of B. coriacea
in potato in Shimla hills. In maize, time of sowing and time of halod are important factors in the management of L. stigma
. In peas, seed treatment is also effective against white grubs. Among biopesticides, Beauveria bassiana, Metarhizium anisopliae, Bacillus cereus
have been tested against B. coriacea
. The mortality hardly exceeds 30 per cent with either of the biopesticides. Local isolates of entomopathogenic fungi have been found to perform better.
[A]. Lepidiota stigma in Maize:
1. Delay in sowing increases incidence of L. stigma
, therefore timely sowing be done to reduce the infestation.
2. The practice of early halod
exposes most of damaging grubs to their predators and reduces incidence.
3. In fields, application of chlorpyriphos 20 EC @ 800g a.i./ ha is recommended.
4. The chemical as mixed in sand and broadcasted in the fields prior to halod
so as to mix it thoroughly in the soil.
5. This pest causes damage in alternate year, but chemical should be applied every year for effective control.
[B]. Holotrichia longipennis in off-season Peas:
1. Treatment of pea seeds with quinalphos 25 EC or chlorpyriphos 20 EC @ 4ml/ kg seed is recommended for the control of H. longipennis
2. The required quantity of the insecticides should be thoroughly mixed with the seed in a polythene bag by adding small quantity of water (20-30 ml) and the seed should be shade dried before sowing.
[C]. Brahmina coriacea in Potato:
1. Chlorpyriphos 20EC @ 400g a.i./ ha after mixing it in the sand should be applied at the time of first earthing up operation in potato crop.
2. There should be sufficient moisture in the soil at the time of application and the insecticide should be thoroughly mixed in the soil so as to translocate sufficient quantity of insecticide to the root zone where the damage is actually inflicted.
On Going Research Projects:
At Palampur centre, major emphasis is on white grubs, however few experiments on cutworms have also been conducted. In white grubs, four projects are in operation at Palampur. In cutworm, there is one project with special emphasis on management. The projects are listed as under.
[A]. Research Projects on white grubs:
1. Monitoring of soil arthropods through light traps and on host trees.
2. Management of white grubs through chemicals.
3. Microbial control of white grubs.
4. Use of semio-chemicals for trapping and monitoring of adult beetles.
[B]. Research Projects on cutworms and other soil arthropods:
1. Management of cutworms through plant products.
2. Preparation of inventory of micro soil arthropods under different ecosystems by Tullgren Funnel Method.