IAN 26, 2006 29

Table 1. White grub species recorded on groundnut inSaurashtra region in Gujarat, India.

ColeopteranWhite grub species family

Phyllognathus sp DynastinaeApogonia rauca Fabr. MelolonthinaeHolotrichia consanguinea Blanch. MelolonthinaeHolotrichia fissa Br. MelolonthinaeHolotrichia serrata Hope. MelolonthinaeMaladera sp MelolonthinaeSchizonycha ruficollis F. MelolonthinaeAdoretus bicolor Br. RutelinaeAdoretus deccanus Ohaus RutelinaeAdoretus versutus Harold RutelinaeAdoretus sp RutelinaeAnomala bengalensis Blanch. RutelinaeAnomala dorsalis Fabr. RutelinaeAnomala varicolor Gyll. Rutelinae

Sciences, GKVK, Bangalore, India for identification ofthe white grub species.

References

Nandagopal V and Prasad TV. 2004. World list of insect andnon insect pests of groundnut and their natural enemies.Junagadh, Gujarat, India: National Research Centre forGroundnut. pp. 10–14.

Yadav CPS. 1987. Whitegrub – A national pest and strategiesof its management. Pages 1–20 in Recent advances in entomology(Mathur YK, Bhattacharya AK, Pandey ND, Upadhyaya KDand Srivastava JP, eds.). Kanpur, Uttar Pradesh, India: NewGopal Printing Press.

Grub stages

Pupa Adult

Figure 2. Different growth stages in white grub.

Occurrence of White Grubs inGroundnut Crop in Uplands of SouthVietnam: A New Report

GV Ranga Rao1*, Ngo Thi Lam Giang2, Phan Lieu2

and Nguyen Thi Hoai Tram2 (1. ICRISAT, Patancheru 502324, Andhra Pradesh, India; 2. Oil Plant Institute,HoChiminh City, Vietnam)*Corresponding author: g.rangarao@cgiar.org

Groundnut (Arachis hypogaea) is an important crop inSouth Vietnam covering more than 125,000 ha underdifferent cropping systems. Crop surveys, and the on-farm research organized in Trang Bang, Cuchi, Duc Hoaand Go Dau during the past (until 2000), brought out theimportance of the foliage feeding insect pests (Spodoptera,Helicoverpa) as economically important in farmers’ fields(Ranga Rao 1995). Field visits during the last week ofMay 2004 and interactions with the farmers in Tra Vinhprovince, villages around Cau Ngang town revealed theoccurrence and importance of white grubs in this region.This soil-inhabiting pest is a menace in this area, which isin the heart of Mekong delta mostly covered by irrigatedrice (Oryza sativa) cultivation with multiple croppingsystem.

During field visits, white grub adults were foundfeeding on nearby trees. Discussions with the farmers ofMy Thap village (Mai Van Tiep and colleagues) clearlybrought out the importance of white grubs in their groundnutcrops. According to farmers, these grubs infest cropssuch as groundnut, sugarcane (Saccharum officinarum),cowpea (Vigna unguiculata), cassava (Manihot esculenta)and maize (Zea mays) in uplands. The adults cause foliardamage in orchards particularly mango (Mangifera indica),cashew (Anacardium occidentale), litchi (Litchi chinensis),guava (Psidium guajava), etc. Among the various crops,groundnut and sugarcane were most severely affected.Though the adults were active during the nights, searchfor few hours in nearby mango and cashew orchardsduring daytime may yield several hundred adults.

Population dynamics of white grubs in TraVinh province

Based on the field observations and the farmers’ experience,it was concluded that adults emerge soon after thesummer rains (April–May) from their pupation sites (soil).The adults feed and mate at their feeding sites (cashewand mango trees). After feeding and mating, the adultsreturn to their ovipositon sites (groundnut or any other

30 IAN 26, 2006

Table 1. Calendar of events in white grub biology in TraVinh province, Vietnam.

Stage of the insect Month of activity

Adults May–JuneYoung grubs June–JulyWell-grown grubs September–OctoberGrub developmental period June–NovemberPupae November–April

upland crops). The young grubs are seen during June–July while weeding the groundnut crop. Generallygroundnut is sown in these villages in the last week ofMay, which coincides with the adult emergence. Sincethe adult feeding sites are nearby the groundnut crops, itis easy for adults to locate the oviposition sites. After theharvest of May-sown crops, farmers takeup anothergroundnut crop in October. Thus two groundnut crops aregrown in a year in the same field.

The adults are dull brown in color, measure about 25mm in width and 40 mm in length with white markings onthe posterior end of the elytra. The adults are identified asLepidiota signata (Fig. 1). According to the farmers, thegrub damage to May-sown groundnut crop was notsevere, probably because the crop would be harvestedbefore the grubs reach considerable size to inflictdamage. The October-sown crops are affected severelybecause the crop is sown directly into grub-infested fields

Figure 1. Lepidiota signata adult.

and the well-grown grubs kill groundnut plants. Farmersobserved grubs until November. Hence it is clear that thegrub period extends from June to November (Table 1).However, detailed studies are required to define thedevelopmental biology of this species in this region.According to farmers, total loss due to severe infestationon groundnut was not uncommon.

Though information is available on the importance ofwhite grubs in North Vietnam pertaining to groundnutcrop (Tran Huy Tho et al. 2001), the occurrence and theimportance of white grubs in South Vietnam was notknown. In view of the importance of Mekong delta foragricultural productivity and stability, the informationpertaining to this pest is of immense value for sustainingthe agricultural productivity in the upland areas of this region.

Control

Generally farmers apply basudin 10H at 10 kg ha-1 asbasal application in groundnut to manage this pest. Somefarmers are also aware that soil application of carbofuran(furadan) granules 3 G at 1 kg ai ha-1 controls the pest.However, the farmers are not clear about the efficientmanagement of this pest.

Conclusions

• White grubs occur in upland areas of Mekong delta.• Lepidiota signata causes loss to groundnut crops in

Tra Vinh province of South Vietnam.• Adults emerge in April–May soon after the summer rains.• White grubs cause severe plant mortality in groundnut

crop sown in October than in the crop sown in May.• Basal application of basudin at the time of sowing

gave satisfactory control.• Several dryland crops such as sugarcane, cassava and

maize are also infested by white grubs.

• Studies on the detailed biology, crop loss assessment,taxonomy and potential management strategies ofwhite grub species are of high priority.

• We suggest to have a nation-wide white grub researchproject for effective control.

• Since the grubs pupate by November, delaying groundnutsowing to December wherever possible can help toovercome this menace.

IAN 26, 2006 31

References

Ranga Rao GV. 1995. Groundnut entomological work duringspring 1995–96. Summary of sabbatical work on insect pestsassociated with peanut crop in Vietnam. ICRISAT Project Report.Patancheru 502 324, Andhra Pradesh, India: InternationalCrops Research Institute for the Semi-Arid Tropics. 109 pp.

Tran Huy Tho, Pham Thi Vuong, Nguyen Thi Mao, NguyenChuc Quynh and Pham Chi Hoa. 2001. Some results ofresearch on whitegrubs in upland crops and their management.Plant Protection Research and Extension Scientific Report.Vietnam: Oil Plant Institute of Vietnam. pp. 27–29.

Assessment of Integrated PestManagement Modules in Groundnuton Farmers’ Fields

DA Shambharkar*, PK Dharne, TM Bahale, AnjaliDeshmukh, RT Surywanshi and RB Jadhav (OilseedsResearch Station, Mahatma Phule Krishi Vidyapeeth(MPKV), Jalgaon 425 001, Maharashtra, India)*Corresponding author: da_ shambharkar@rediffmail.com

Currently India is facing shortage of edible oils which isbeing met through large-scale imports. To meet thegrowing requirement of oil and to ensure nutritional securityto the population of over one billion in the country,groundnut (Arachis hypogaea) has to play a pivotal role.Groundnut is a principal oilseed crop that suffers severeyield losses due to insect pests and diseases at differentstages of crop growth. The defoliating caterpillarsSpodoptera litura, Helicoverpa armigera and Amsactaalbistriga, groundnut leaf miner (GLM) Aproaeremamodicella, sucking pest Aphis craccivora, jassids andthrips attack the crop and cause economic loss. Early andlate leaf spots, rust and blight are serious foliar diseases.Seedling crown rot, collar rot, stem and pod rot, and dryroot rot are important soilborne diseases. Bud necrosisdisease is one of the serious viral diseases of groundnut.When groundnut is grown in poor soil under inadequategrowing condition, the crop becomes highly affected bythese pests and diseases. Since groundnut is raisedpredominantly under rainfed conditions by resource-poorfarmers who cannot afford the expensive agrochemicals(Rabindra 2004), intensive use of chemical pesticides aspracticed during the era of green revolution is not asustainable practice.

Though chemical pesticides have played an importantrole in increasing groundnut production, their indiscriminateuse for the control of pests has led to several environmentalproblems such as development of resistance in pests topesticides, pesticide residues and the destruction ofbeneficial parasites and predators of pests. Thus, a holistic,integrated pest management (IPM) program was developedin groundnut based on six years of independent researchon entomological, pathological and weed managementaspects conducted by the scientists of the NationalResearch Centre for Groundnut (NRCG), Junagadh,Gujarat and All India Coordinated Research Project(AICRP) on groundnut at various centers in India. ThisIPM technology gave control of major insect pestsranging from 24 to 46% and diseases from 28 to 48%with an average increase in yield by 19% (Ghewande etal. 2002).

Integrated pest management options include disease-free seeds of resistant/tolerant varieties, cultural practices[viz, use of castor (Ricinus communis) as a trap crop andintercropping system], usage of pheromones as monitoringtool, biocontrol agents, biopesticides and economic thresholdlevel (ETL)-based chemical pesticides application. TheIPM modules for groundnut based on production systemcan lead to higher crop production and conservation ofbiotic fauna. In shifting from chemical control tomanagement of pests and diseases, IPM has to play acrucial role (Amerika Singh et al. 2004).

To attain high production level with minimum risk ofpesticides contamination and risk of crop failure, this attempthas been made to assess and demonstrate the profitableviable intercropping system of groundnut and soybean(Glycine max) followed by utilization of IPM modules incomparison with farmers’ practice.

Materials and methods

Field demonstrations were conducted through frontlinedemonstrations in non-replicated trial on farmers’ fieldsin Jalgaon and Dhule districts of Maharashtra, India forthree years in 2003, 2004 and 2005 during rainy season(July–November). Groundnut variety JL 286 (PhuleUnap) and soybean variety JS 335 were sown in 0.2 haarea with a spacing of 30 cm × 10 cm. A total of fifteendemonstrations (five in each year) was conductedincluding one at Oilseeds Research Station, MahatmaPhule Krishi Vidyapeeth (MPKV), Jalgaon Maharashtra.

The sowing was completed in 2nd week of July and thetrials were harvested in 2nd week of November in eachseason. Two rows of castor were sown around the plot as