Agrl. Entomology


Unit of Entomology

          The unit of entomology of Tamil Nadu Rice Research Institute, the university includes Agricultural entomologists, engaged in diverse research focusing on plant pests and their interaction with rice ecosystem.

Main Objectives

  • To conduct research on screening rice varieties for major pests and epidemiology of insects and evaluation of plant protection on rodents and insects on rice and rice fallow crops.
  • Field and green house screening of rice resulted in identification of resistant donors to many pests.

FUTURE THRUST AREA

  • Identification of resistant varieties from different source material.
  • Designing screening methodology for plant hopper resistant
  • Incorporation of high resistance gene in to common back round (MAS)
  • Understanding insect plant interaction metabolite chemicals in isogonics resistant lines.(Chemical Ecology)
  • Field testing of the new resistant lines through multi location trial .
  • Understanding the tritrophic interaction involving resistant lines- BPH – Green mirid bug, a potential bio control agency.
  • Improvement of integrated pest management methods with the emphasis on cost reduction and environmental safety and sustainability.
  • Generating data for safer environmentally friendly pesticides for management of insects .
  • Develop pest management strategies that enhance natural enemy effectiveness. Intensification  and generation of data under cultural methods of control,
  • Develop and updating surveillance and forecasting system for rice pest.
  • Generation and intensification of data through bio diversity indices and to correlate with IPM strategies.
  • Developing a pheromone product for stem borer a key component for IPM.
  • Participatory  adoption  and improvement of key new technologies in IPM for short to medium term delivery for sustainable future cereal based systems.
Yellow stem borer (YSB)

MANAGEMENT

  • Stem borers can be managed using cultural control measures, biological control agents, the use of resistant varieties, and chemical control.
  • Cultural control measures include proper timing of planting and synchronous planting. The crops should be harvested at ground level to remove the larvae in stubble.
  • Likewise, stubble and volunteer rice should be removed and destroyed.
  • Plowing and flooding the field can kill larvae and pupae in the stubbles.
  • At seedbed and transplanting, egg masses should be handpicked and destroyed.
  • The level of irrigation water can be raised periodically to submerge the eggs deposited on the lower parts of the plant.
  • Before transplanting, the leaf-top can be cut to reduce carry-over of eggs from the seedbed to the field.
  • Application of nitrogen fertilizer should be split following the recommended rate and time of application.
  • Insecticides such as fipronil applied as granules to the paddy water or soil can help to protect plants at vegetative stage, but granular insecticides are generally not effective at the reproductive stage. 

BROWN PLANT HOPPER

Management

  • Draining the rice field for 3-4 days is recommended during the early stage of infestation. Nitrogen application can be split to reduce BPH buildup.
  • Synchronous planting within 3 weeks of staggering and maintaining a free-rice period could also decrease the build-up of BPH.
  • The common parasites of the eggs are the hymenopteran wasps.
  • Eggs are preyed upon by mirid bugs and phytoseiid mites. Both eggs and nymphs are preyed upon by mirid bugs.
  • Nymphs and adults are eaten by general predators, particularly spiders and coccinellid beetles.
  • Hydrophilid and dytiscid beetles, dragonflies, damselflies, and bugs such as nepid, microveliid, and mesoveliid eat adults and nymphs that fall onto the water surface.
  • Fungal pathogens also infect brown planthoppers.
  • There are varieties released by IRRI, which contain genes for BPH resistance, like IR26, IR64, IR36, IR56, and IR72.
  • BPH is a secondary problem due to insecticide spraying for leaf-feeding insects in the early crop stages.
  • To reduce the risk of hopperburn, application of early season insecticide should be avoided.
  • WBPH population can be regulated by natural biological control agents. For example, small wasps parasitize the eggs.

RICE LEAF FOLDER  

Management

  • In cultural control, it is advised not to use too much fertilizer.
  • It was observed in a field experiment that highly fertilized plots attract females. Surrounding grass habitats should be maintained because these serve as temporary reservoirs of natural enemies like crickets, which are egg predators of leaffolders. Herbicide spraying and burning of these non-rice habitats might not be useful.
  • Among the biological control agents, there are small wasps and crickets that attack the eggs.
  • The larval and pupal stages are parasitized by many species of wasps. Damselflies, ants, beetles, wasps, mermithids, granulosis virus, and nucleopolyhedrosis virus prefer the larval stages. Spiders and mermithids attack the adults.
  • There are many varieties from the Philippines, Korea, United States, Honduras, Taiwan, Vietnam, and the former USSR that show resistance to the rice leaffolders.
  • Control of the rice leaffolders using chemicals during the early crop stages is not advisable.
  • A general rule-of-thumb is “spraying insecticides for leaffolder control in the first 30 days after transplanting (or 40 days after sowing) is not needed.”
  • The rice crop can compensate from the damage when water and fertilizer are well managed. Pyrethroids and other broad-spectrum insecticides can kill the larvae but can put the crop at risk because of the development of secondary pests, such as the brown planthopper.
  • If infestations of the flag leaves are extremely high (>50%) during maximum tillering and maturity stage, insecticide sprays may be useful. Such applications may stop further defoliation and may avoid losses.

EXTERNALLY FUNDED SCHEME 

Sl.No

Title

Sponsor

Duration

PI/Co PI

Budget (Lakhs)

1.

Investigations on beneficial safety of Pymetrozine 50 WG, a new molecule identified effective against rice brown plant hopper (BPH), Nilaparvata lugens

F-Private agencies 37-scheme – sponsor by M/S Syngenta India Ltd, Coimbatore

Sept.2009 to Aug.2010

 

Dr.G.Ravi/

Dr. S. Mohamed Jalaluddin

01.36

2.

Base line toxicity for new insecticide molecule GF 2032 against rice brown plant hopper Nilaparvatha  lugens

M/S Dow Agro Science India Pvt. Ltd, Mumbai

June 2008 to August 2010

Dr.G.Ravi/

Dr. S. Mohamed Jalaluddin

06.05

3.

Out reaching pheromone technology in Tamil Nadu.

.

 

IICT, Hyderabad

June 2010 to May 2010

Dr.G.Ravi

 

1.20

4.

FLD- Pheromone technology 

AICRIP

2010-2011

Dr.G.Ravi

 

Diversion or separate fund expected from AICRIP

RESEARCH HIGHLIGHT
a. Host Plant Resistance
 Plant Hoppers
  • In the  Plant hopper screening trial (PHS) of the 60 entries four  derived  from  Dhobanumberi  and  one  from  Salkathi    were promising and  entries  viz.,  ACC  3739,  CB  05-022,  MTU  1114,  TU 1115, MTU 1123, MTU 1126, MTU 1128 recorded were found ressitance to BPH damage< 5.0 damage score. In the net house assay (SSST)entries CRRI entries derived from   Dhobanumberi and Salkathi were found resistance to BPH (Score 1).

Leaffolder

  • In NSN  of the 220 entries (IET Nos  21189,  20556,  21247,  20625,  21199,  21208 and  20262 were promising against BPH and ten  cultures  viz.,  IET  20892,  20901,  20902,  20923,  20925,  21176,21201, 20773, 21229, 20863 were promising against leaf folder.
  • Of the 40 Leaf folder screening trial entries screened RRH-2, PSD3 a RP 4687-52-1-1182 were found free from Leaffolder incidence.
  • Entries namely PTB 33, VL 96-36-38, VL 96-36-56, Vikramarya, Balguna, TNAU LFR 831311 and a wild accession Oryza brachiantha were found consistently less attractive to rice leaffolder species Marasmia patnalis both in net house screening and filed condition.

Whorl Maggot

  • Leaffolder folder screening trials entries namely   RP 686-48-1-937, RP 4681-16-2-569, RP 4684-35-1- 732, DRRH-2, RP 4684-35-1-739, Sahyadri-4  were found free from whorl maggot damage .

 Multiple Resistances

  • In the AICRIP trial RP 4688-53-2-1255 (Aganni x INRC 3021) and   donor parent INRC3021 along with TKM6 recorded grade 1 (resistance) against stem borer , BPH and leaffolder. Shyamala x Danteshwari cross and IR64  sub1 was found to possess multiple resistance to Leaffolder, Whorl maggot, Stem borer and BPH .

b Ecology, Species Complex and Natural Enemies

Leaffolder

  •  Total number of enumerated arthropods was higher in ADT  43 (227) in    Kuruvai’ 09 Nursery and population richness in terms of Margalaf’s index is significantly high for neutrals especially Back swimmer (20.85), Microvelia (9.06) and Gerrid (9.34) .
  • Observations on the natural  enemies  of  stem borer indicated   the  egg  parasitization in stem borer  was  16%  at maximum tillering phase which increased to  40% at heading stage. Two parasitoids were observed, T. japonicum  (60-75%) and T. chilonis  (25-40%) at various stages of crop  growth.  Larval  parasitization  was  36-48  per  cent.
  •  At Aduthurai the stem borer was a major problem in mansoon season crop. The common species yellow stem borer (YSB) Scirphophaga incertulas (Lepidoptera: Pyralidae) is the dominant (60%) followed by pink borer (PSB) Sesamia inferens (Lepidoptera: Noctuidae) (35%)  and  Dark headed stripped borer (DHB) Chilo polychrysus (Lepidoptera: Pyralidae) (5%) in tillering phase and at heading stage besides YSB (80%) the DHB (14%) and   PSB (6%) were also observed. In Madurai the yellow stem borer, Scirpophaga incertulas alone was recorded during November 2009 – March 2010 and in Trichy and Tirupathisaram also the yellow stem borer, Scirpophaga incertulas  alone was present both in kharif and Rabi seasons .
  • Two  parasitoids  were recorded  from  the  leaf  folder  larvae Macrocentrus  philippinensis (83%)  and Temelucha philippinensis  (17%) at maximum tillering phase and three parasitoids at heading stage - M. philippinensis (45%), T. philippinensis (33%) and Cotesia sp. (22%). Pupal parasitisation was only 4 % by Brachymeria at maximum tillering while it was 60% by Brachymeria and  40% by T. cnaphalocrocis .
  • In the leaf folders the Egg, larval and pupal parasitism ranged from  16-40,  36-48 and  4 %, respectively. Main species observed were T. japonicum (60-75%) and T. chilonis from eggs, Macrocentrus philippinensis, Temelucha philippinensis, T. cnaphalocrocis,  and  Chelonus sp., sp from larvae, and Brachymeria from pupae  
  • The number of insect species occur at vegetative stage (Kuruvai’ 09) is more favourable in transplanted crop (6) than in direct seeding (4) and the insect  species richness (Margalaf’s index) is significantly larger indirect seeding plot (9.92) when comparing transplanted crop (5.20). GLH, Thrips and stemborer show significant richness in direct seeding.
  • In samba’ 09 variety CR 1009 harbour significantly lower population of GLH (0.18 No./ hill ) when compared to other varities T. japonicum 45 DAT + +Azadirachtin 0.03% registered lower percentage of dead hearts. ADT 44 recovered significantly higher population of Coccinellids in all of the sub plot after treatment.

Black Bug

  • Peak black bug activity is seen during August’ 09 during the crop year 2009-2010 

c. Bio-pesticides and Botanicals

  •  Application of Pf 1 + AH 1 + B. bassiana @ 2.5 kg / ha significantly reduced the GLH population.
 d. Chemical Control
  • Milbemectin @ 4.5 g a.i./ha and Abamectin @ 9 g a.i./ha were superior in their efficacy against leaf mite   but, diafenthiuron @ 450 g a.i ./ha showed superiority to other treatments in terms of grain yield
  • ADT 40 (Samba’ 09) ADT 46 (Thaladi’ 09) registered significantly less white ear damage 4.04% and 1.72% respectively while ADT 38 recorded yield. Among sub plot treatments in terms of yield, Chlorpyriphos 0.05% treatment in the best

PUBLICATIONS

  • Jalaluddin, S.M. and S.Jebaraj .2008. Nelil silanthiyin thakkudlai yappadi kattu paduthuvdu Daily thandi, Thanjavur edition, dated 31.07.2008 (Thursday) 66 (272) : 12
  • Jalaluddin, SM., Ravi,G & S. Jebaraj 2008.  Suppression of rice leaf mite pest.  TheHindu, Science & Technology, Agriculture, 13.12.08 PP.20 (ISSN 0971 – 751xvol.131 No.269 Pages.24) Trichy edition.
  • Jalaluddin, S.M. 2008.Science exhibition inauguration at Crescent higher secondary school at Avaniapuram 612 101, a brief note with colour photograph published in second page of the daily Hindu 23.12.2008.  
  • Jalaluddin, S.M., Ravi,G and S. Jebaraj 2009. Pest status for Rice leaf mite.  Scientists Region, The Hindu, Sunday, June 20 P-3 .
  • Ravi,G., Mohamed Jalaluddin, S and S.Jebaraj .2008. Management of spider mites in Rice (Tamil version) Dinamalar, Trichy 10.09.2008. vol. 58 (5) Page No.10
  • Ravi,G., Bhanu K.R.M., Jhansi lakshmi, Jalaluddin Md.Jayanth, K.P and Jebaraj.2008. Preliminary investigation on the sex pheromone for the management of species complex in stem borer and leaffolder in rice in National seminar on pheromone technologies development and communalization for strengthening eco – friendly Agriculture in India, September 25-26 th 2008 Chennai (Best oral presentation award).
  • Ravi,G., Jalaluddin, SM & S. Jebaraj 2008.  Electro – antennogram in host plant  resistance studies, CAS Entomology training Programme on Recent Techniques in Entomology Research, 8-28th  Dec 2008, TNAU, Coimbatore.
  • Ravi,G., Jalaluddin, SM and S. Jebaraj 2009. Pheromone for management of Rice insect pests in National conference on biotechnological approaches for Eco friendly insect pest management organized by University of in Madras (27-28 Feb 2009) Chennai published as Abstract.
  • Manimegalai, R., Chozhan, S and S. Jebaraj -2009.   Pulses production in rice fallow (Tamil) Dinamalar
  • Jalaluddin, S.M, Ravi G. and Jayaraj, T. 2010 Methods of rice leaf mite control, the Hindu, Thursday Feb 11, 2010 ISSN 0971 – 751 X, Vol. 133 No. 35, P.15, Total pages 20, Tiruchirapalli edition.
  • Ravi,G., Mohamed Jalaluddin, M and Jayaraj, T. 2010. Rat poison Zinc Phosphide. Valarum Vellanmai, Feb 2010, TNAU, Coimbatore. P52-53.
  • Jalaluddin etal.2010. Occurrence of Japanse black rice bug in Aduthurai. Revised script sent to Entomon , University of Kerela for publications.
  • Jalaluddin etal 2010.Tactis in stem borer control. Despatched for publication to the daily The Hindu.
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  • Mohamed Jalaluddin,S, Ravi , G and T.Jayaraj 2010. Mealy bug and its management. Science & Technology. The Hindu daily Tuesday.(18.03.2010).
  • Mohamed Jalaluddin, S., Ravi G., Tamilselvi. M and T. Jayaraj. 2010 Interception of Japanese black bug Scotinophora lurida (Blumeister) in rice eco system at Aduthurai, TN, India sent to Insect Environment, Bangalore.
  • Mohamed Jalaluddin, S., Ravi G., T. Jayaraj. 2010 Controlling rice stem borer. The Hindu, Science & Technology. P.15, April 29,2010.  
Dr. S. SURESH, Ph.D.,
Professor & Head





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