Insect Resistance in Citrus and Mango Sneka.pptx

Agricultural Entomology: Host plant resistance- Insect Resistance in Citrus and Mango Key pests

1. ENT 507 – HOST PLANT RESISTANCE Insect Resistance in Citrus and Mango Sneka A 227080013 M.Sc.,(Ag.) Entomology

2. 1.Introduction- Citrus spp , As of 2021, Citrus fruit production in China stands top with 46.7 million tonnes (28.77 %) . Citrus fruit production for India - 14.3 million tonnes (2021). Oranges (Brazil) - half of world citrus production - followed by Mandarin (China) , lemons (India and Mexico) and grapefruits (China) . The  ICAR-Central Citrus Research Institute  at Nagpur, Maharashtra.

3. Citrus psyllid Diaphorina citri   . Fruit sucking moth Otheris materna , O. ancilla , O. fullonica Citrus leaf miner Phyllocnistic citrella 3 Key pests of Citrus Black aphid Toxoptera aurantii Brown aphid Toxoptera citricida

4. Diaphorina citri   Germplasm screening: Field screening of citrus germplasm (32 Nos.) against ACP was conducted during 2008-2010 at Experimental Farm of National Research Centre for Citrus, Nagpur. The exotic germplasm collections (21 Nos.) and Indigenous germplasm (11 Nos.) used for the study. 4 RAO et al ., 2013

5. C. reshni  volatiles were attractive to  D. citri ,  based on the high number of entries, which result in reduced oviposition. Ni Cleopatra mandarin,  C. reshni and Japanese bitter orange,  Poncirus trifoliata  L. have been cited as unsuitable hosts for  D. citri  development, survival, and reproduction. Poncirus trifoliata  and Palestinian sweet lime, have been cited as extremely tolerant to psyllids and tolerant to HLB, respectively, under greenhouse conditions. 5 TOLERANCE Mechanism of Resistance Folimonova et al ., 2009 ANTIBIOSIS ANTIXENOSIS Westbrook et al ., 2011 Rogers et al ., 2010

6. Areas of focus Biophysical ​ Hardness of citrus flush shoots ( M amoudou et al., 2013 ) Biochemical ​ The presence of aromatic aminoacids in the flowers plays a major role ( Broadbec k et al ., 2001). Terpenoids- plant defense volatiles (i.e. as repellents) 6 Bases of Resistance

7. Toxoptera aurantii Germplasm screening: Relative susceptibility of 78 citrus var. to T. aurantii - no variety was completely free from aphids. The varieties Nagpur Mandarin and Ikeda Unshiu among mandarins, acid citrus group, recorded significantly least mean number of aphids per flush. 7 Bhumannavar et al ., 2013

8. Feeding behavior and population development experiments showed Eureka exhibits obvious resistance to  T. citricida , while Yuzu and Rough Lemon were susceptible host plants. The total duration time of waveform per aphid on Rohde Red and Eureka was significantly longer than on Yuzu and Rough Lemon. Antibiosis Zhoa et al ., 2021

9. Schwarzkopf et al ., 2013

10. Areas of focus Biophysical ​ Leaf surface/epidermis structural traits (trichomes, surface waxes, hardness or thickness of leaf tissues). Biochemical ​ Chemical cues (emission of volatiles, many forms of terpenes) easily disturb insects feeding behaviors. Raphides 10 Bases of Resistance Zhoa et al ., 2021

11. Phyllocnistic citrella Germplasm screening: 23 genotypes screened and used lime ‘ Rugoso ’( Citrus jambhiri ) as the susceptibility standard. Artificial: Trifoliata‘Limeira’ and hybrid C x R315- seedlings were kept in a greenhouse. 11 Santos et al ., 20 20

12. Ni ​1. Hybrid C x R(4) - small pupae 2. Hybrids C x R(4) and C x R(315) - least fecundity. Lowest value for the corrected reproductive potential (CRP) - hybrid C x R(315 )- least favorable for the development and reproduction of CLM. Maximum CLM populations was found on C. sinensis -blood red and C. limonia - mayer lemon, showing infestation severities as 30.15 and 31.82 (Means). The minimum CLM population occurred on C. Reticulata - kinnow with severity of 10.49 (Means). 12 TOLERANCE Mechanism of Resistance Mustafa, et al ., 2013 ANTIBIOSIS ANTIXENOSIS 1. Trifoliata ‘Limeira’ and hybrid C x R 315  - least preferred genotypes. 2. Lime ‘ Rugoso ’ - more oviposition.   Trifoliata ‘ limeira ’ and hybrid C x R 315  are potential sources of antixenosis . Santos et al ., 20 20 Santos et al ., 2011

13. Biophysical ​ Oviposition antixenosis - trifoliolate with relatively narrow leaf surface. CLM oviposites only in soft young shoots. 13 Bases of Resistance Santos et al ., 20 20 Knapp et al ., 1995

14. 1.Introduction- Mangifera indica India - leading mango producer in the world, estimated 24.7 million tons (about 50% of the world’s mango production). Uttar Pradesh - leading in India (21% of market share). The processed mango varieties are produced in Tamil Nadu ( Malgova ), Andhra Pradesh ( Banganapalli ), Karnataka ( totapuri ) and Gujarat ( Vanraj ). ICAR-Central Institute of Sub Tropical Horticulture

15. Mango hoppers Idioscopus niveoparsus,I . clypealis , Amirtodus atkinsoni . Nut Weevil Sternochetus mangiferae Stem Borer Batocera rufomaculata 15 Key pests of Mango Fruit Fly Bactrocera ( Dacus ) dorsalis

16. Mango Hoppers Germplasm screening: Field screening of five varieties in equal age (about 15-20 years old trees) and population density of hoppers was observed at fortnightly intervals. 103 varieties of mango screened under natural and artificial released conditions against A. atkinsoni - Keshar Basti, Annanas and Pau – more resistant 16 Pandi , 2019 Singh, 1997

17. Ni ​ 1. A positive significant correlation of population density vs. the inflorescence phenology in all mango cultivars. 2. However, population of hoppers revealed a negative correlation with its development. 17 Mechanism of Resistance ANTIBIOSIS Talpur et al ., 2002

18. Biochemical ​ Chemical analysis of inflorescence –Var. Banesha Bangalora , Chinnarasam and Khader are resistant –less nitrogen, more P, K, Ca ,total phenol , Orthodihydroxy (OD) phenols and less of reducing sugars. 18 Bases of Resistance N achiappan and Baskaran, 1983

19. Bactrocera ( Dacus ) dorsalis Germplasm screening: Of the different local mango accessions screened in field, Toranjo and Monterio –no infestation Hybrid 23-6 (Neelam x Alphonsa ) : less susceptible 19 Chellapan et al ., 2001

20. Ni ​ Cis-ocimene and 3-carene (attractants to B. dorsalis ) - reduced in the headspace volatiles of treated fruit- reduced pupae formation and adult emergence . 20 Mechanism of Resistance ANTIBIOSIS ANTIXENOSIS 1. Langra and EC 95862 var. -tannins - deter females from ovipositing. 2. Effect of salicylic acid (SA) treatment - gravid females laid significantly less eggs. Rashmi et al ., 2017 Damodaram et al ., 2015

21. Areas of focus ​ 1. Fruit length and fruit diameter - positive correlations 2. Peel thickness of fruits - negative correlations with the percentage fruit infestation. Insect visit-moderately affected- flesh flavonoid content. Phenolics- prevents fruit fly herbivory. 21 Bases of Resistance Choudhary et al ., 2018 Sison et al ., 20 20

22. Sternochaetus mangiferae Germplasm screening: Screening of mango germplasm for the varietal preference towards mango nut weevil infestation was carried out under field condition (2015 and 2016). Highest damage was recorded in Panchadarakalasa followed by Paiyur 1 (57.50%), Kalepad (47.21%) and Swarna Jehangir (41.55%) with the lowest damage in Mulgoa recording 5.15 per cent. 22 Thilagam S, 2017

23. Areas of focus ​ Skin toughness and age of the fruit – susceptibility of fruit. Bases of Resistance Sundara Babu, 1969 VC: Sneka

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