Maize stem borer (Chilo partellus)

1. A REVIEW ON BIOLOGY AND MANAGEMENT OF MAIZE STEM BORER, Chilo partellus ( Swinhoe , 1885 ) PRESENTER: Madan Subedi Msc.Ag . Entomology Roll no. R-2018-ENT-01M Agriculture and Forestry University

2. INTRODUCTION One of the most severe insect pests of maize in Nepal ( Neupane , 1986 ) Damage results dead heart which in extreme case renders the plant earless ( Neupane , Bhandari, Sharma, Yadav, & Subedi , 2016 ) Cause loss range from 20-80% in maize (Thakur , Shrestha, Bhandari, & Achhami , 2013) A total of 28% more harvest from uninfested fields as compared to the fields infested with maize stem borer (Sharma & Gautam , 2010)

3. SCIENTIFIC CLASSIFICATION Kingdom : Animalia Phylum : Arthropoda Class : Insecta Order : Lepidoptera Super-family : Pyraloidea Family : Crambidae Sub-family: Crambinae Genus : Chilo Species : C. partellus Binomial name : Chilo partellus ( Swinhoe , 1885)  

4. GEOGRAPHICAL DISTRIBUTION Native to Asia ( Kalaisekar , Padmaja , Bhagwat, & Patil , 2017 ) First recorded in Africa from Malawi in 1932 (Tams, 1932 ) Currently, widespread in Asia and Africa ( Bleszynski , 1970; Jepson, 1954; Panwar , 2005; Sallam & Allsopp, 2008; Sharma, Kumar, & Sharma, 2006) Dominant and economically most important stem borer species at elevations below 1800 m in Africa ( Seshu , 1983 ) Evidences of displacement of Chilo orichalcociliellus (Strand) by Chilo partellus in Africa ( Ofomata , Overholt , Lux, Huis, & Egwuatu , 2000)

5. IDENTIFICATION Eggs Shape : flat and oval (scale-like ) Colour : creamy-white Size : about 0.8mm long Form of appearance : Overlapping batches of 10-80 eggs Fig. Egg batch of Chilo partellus

6. ……IDENTIFICATION Larva Have only 4 pinkish stripes , the median stripe being absent, the lateral stripes passing above the abdominal spiracles Fig. Chilo partellus larva

7. ……IDENTIFICATION ….Larva Arrangement of seta and tubercles Fig. Setal arrangement in thorax Fig. Setal arrangement in abdominal Fig . Setal arrangement in ( meso and metathorax ) segment (1-7) eight abdominal segment

8. ……IDENTIFICATION ….Larva Fig. Chaetotaxy of the head of Chilo partellus

9. ……IDENTIFICATION Pupa Fig. Lateral view of pupa Fig. Arrangement of spines on the dorsum of 5th abdominal segment of the pupa

10. ……IDENTIFICATION ….Pupa Fig. Dorsal and ventral views of the cremaster of the pupa of Chilo partellus

11. ……IDENTIFICATION ….Pupa Fig. P upa of Chilo partellus

12. ….IDENTIFICATION Adult Fig. Adult Chilo partellus )

13. ….IDENTIFICATION ….Adult Fig. Forewing of Chilo partellus Fig. Hindwing of Chilo partellus )

14. LIFE CYCLE Eggs laid in batches on both host and non-host plants (10-80 per batch) Freshly hatched larva search for host plants Leaves enclosed in whorl – preferred by larva Larva use mechanism of ballooning/walking for movement (Berger, 1992) Larva undergoes 6 instars molting 5 times (Patel , Devananda , & Korak , 2018 ) Pupation- Inside larval tunnel or outside plant (exit holes are evident) ( Achhami , BK, & Bhandari, 2015 ) Most favourable temperature for development: 30 C 5 generations per year in Chitwan conditions ( Neupane , Chapman, & Coppel , 1986 )

15. ….LIFE CYCLE Fig. Summary of life cycle of Chilo partellus (Source: Magara, 2016) )

16. NATURE OF DAMAGE Leaves enclosed in whorls- damaged by scrapping by early instar larva Symptoms evident as symmetrical holes when leaves come out of whorl (Reddy, 1998) Two types of holes: P in holes (small, pin head size) Window panes (large than pin head, leaves tend to tear apart ) Dead heart- Central leaves damaged and growing points killed Late instar larvae- Move to collar region, develop feeding tunnels Entry of larva in cobs damage grains

17. ….NATURE OF DAMAGE Overall effect on plant- Poor growth and reduced yield Infested plants- Highly susceptible to wind damage and secondary infections (Berger, 1989 ) Damage to crop stages (Fletcher & Ghosh, 1920) 100% damage may take place at early stage Matured plants show some degree of tolerance

18. ….NATURE OF DAMAGE Fig . Larval tunnel Fig. Larval tunnel Fig. Dead heart Fig . Pin holes Fig . Window panes

19. HOST PLANTS Primary host plants ( Bleszynski , 1970 ) Zea mays (Maize) Sorghum bicolor (Sorghum) Oryza sativa (Rice) Saccharum officinarum (Sugarcane) Other host plants (CABI, 2007; Kfir , Overholt , Khan, & Polaszek , 2002) Pennisetum glaucum (Pearl millet) Sorghum vulgare sudanense (Sudan grass) Pennisetum purpureum (Napier grass)

20. DIAPAUSE Facultative diapause is reported in C. partellus Summer diapause ( Scheltes , 1978) Winter diapause (Dhillon & Hasan, 2017 )

21. ….DIAPAUSE (Source: Dhillon & Hasan, 2017) Characteristics Non-diapause Diapause (Aestivation/Hibernation) Size of larvae Large Reduced Body colour and pigmentation Light brown with dark brown pigmentation Creamy to milky white with reduced or no pigmentation Asetose tubercles (AT) Present Absent Head capsule colour Dark brown to black with clear epicranial suture Reddish brown sometime with distinct epicranial suture Color of prothorasic shield Dark brown Light brown to creamy Symptoms to enter diapause (diapause chamber) No diapause chamber Fail to pupate and construct diapause chamber Supernumerary moults No supernumerary moults >2 supernumerary moults Pupal size Larger Smaller Adult colour and size Light brown and larger in size Dark brown and smaller in size

22. ECONOMIC INJURY LEVEL (EIL) EIL - insect pest abundance or amount of damage that results in economic yield loss ( Pedigo , 1991 ) Most vulnerable period for borer attack: 10-17 days ( Sarup et al., 1977 ) EIL for kharif and rabi maize - 2.42 and 2.09 larvae per plant ( Chouraddi & Mallapur , 2017) EIL for 20- and 40- day old plants- 3.2 and 3.9 larvae/plant (Reddy & Sum, 1991) EIL for insecticidal application - 20 % and 2% of plants with visible symptoms of whorl damage, for the resistant and susceptible genotypes (Berg , Rensburg , & Westhuizen , 1997)

23. MANAGEMENT PRACTICES

24. Cultural control Good crop hygiene D estruction of crop residues (stems and stubbles) R emoval of volunteer crop plants and/or alternative hosts of diapausing larvae and active populations ( Verma & Singh, 1989 ) Intercropping of maize with cowpea in the ratio 1:1 (Singh, Jaglan , & Verma , 2018 )

25. Biological control Biological control agents - Cheap and effective ( Kfir , 1992) Spinosad 45% EC prepared from bacteria Saccharopolyspora spinosa ( Neupane et al.,2016; Devanapalli & Kumar, 2018) Beauvaria bassiana - an effective fungus ( Maniania , 1993) Formulations of the protozoan Nosema marucae and Nosema partelli ( Odindo & Opondo, 2009; Walter & Kfir , 1993 ) Commercial preparations of bacterium Bacillus thuringiensis ( Brownbridge , 2001)

26. ….Biological control Table 2. Common parasitoids used for management of MSB ( Kfir , 1997) Parasitoid Order Family Allorhogas pyralophagus Hymenoptera Braconidae Cotesia chilonis Hymenoptera Braconidae Cotesia flavipes Hymenoptera Braconidae Descampsina sesamlae Diptera Tachinidae Mallochia pyralidi Hymenoptera Ichneumonidae Meloboris sinicus Hymenoptera Ichneumonidae Metagonistylum minense Diptera Tachinidae Paratheresia claripalpis Diptera Tachinidae Sturmiopsis inferens Diptera Tachinidae Tetrastichus howardi Hymenoptera Eulophidae Trichogramma chilonis Hymenoptera Trichogrammatidae Trichogramma ostrinia Hymenoptera Trichogrammatidae Xanthopimpia stemmator Hymenoptera Ichneumonidae

27. Pheromonal cont rol Mating disruption preferred to mass trapping (Campion & Nesbitt, 1983) Major chemical components of pheromone (Hansson, Blackwell, Hallberg, & Lofqvist , 1995) Z)-11-hexadecenal (Z )-11-hexadecenol (Z)- 10-pentadecenal

28. Botanical control Methanolic extracts of Bougainvillea spectabilis flowers and distilled water leaf extracts of Nerium oleander (Anuj & Sharma, 1999 ) Chloroform and methanol leaf extracts of Cymbopogon martinii and Eucalyptus globulus kill larvae up to 5 days after treatment (Bhatnagar & Sharma, 1999 ) E xtracts from Azadirachta indica and Annona squamosa kernels (Sharma , Sankaram , & Nwanze,1999 )

29. Chemical control Timing of application of chemical insecticides is crucial ( Nwanze & Mueller, 1967 ) Effective in early growth stage of the crop (i.e. up to 10 ± 12 days ) Best when applied at egg hatching and the first three instars , before the larvae enter the stem O rganochlorines , organophosphates, carbamates and synthetic pyrethroids - widely used against the pest ( Dharmasena , 1993; Teli , Chavan , Ankalkoppe , Khot , & Harers , 2007 ) C hloropyrifos 10% EC @ 1.5 ml L -1 of water, chloropyriphos 50% EC+cypermethrin 5% EC @ 1.5 ml L -1 of water, imidachloprid 17.8% @ 0.5 ml L -1 of water commonly used in Nepal ( Neupane et al., 2016)

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