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Identification, symptoms and nature of damage: beetles and wireworms. Dr. S.K. Dutta & Dr. Badal Bhattacharyya Department of Entomology Assam Agricultural University,Jorhat-13. Epilachna Beetles:. Identification:.
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Identification, symptoms and nature of damage: beetles and wireworms Dr. S.K. Dutta & Dr. Badal Bhattacharyya Department of Entomology Assam Agricultural University,Jorhat-13
Epilachna Beetles: Identification: • The adult beetle is medium sized (8-9 mm in length), yellowish brown globular insect bearing 12-28 spots on the elytra • The grubs are about 6 mm long, yellowish in colour and bear spines all over the body Fig. Grubs of Epilachna beetle Fig. Adults of Epilachna beetle Source: http://www.infonet-biovision.org Source: http://www.agroatlas.ru/pests/ /default/ct/116/crops Epilachna_vigintioctomaculata_en.htm
Symptoms: • Scrapping of epidermis leading to skeletonised leaves Fig. Leaf skeletonization caused by Epilachna beetle Source: http://www.ipmimages.org/browse/detail.cfm?imgnum=1326153
Nature of Damage: • Both adults and grubs feed on the upper surface of the leaves. They eat up regular areas of leaf tissue, leaving parallel bands of uneaten tissue in between • The infested leaves are skeletonized which later turn brown, dry up and fall off Fig. Leaf skeletonization caused by Epilachna beetle Source: http://www.organicgardeninfo.com /mexican- bean-beetle.html Fig. Epilachna beetle Source:http://www.avrdc.org/LC/eggplan t/epilachna.html
Wireworms/ Click Beetle Identification: • Wireworms are very thin, yellow, pink or orange worms (larvae) of click beetles. Young wireworms are initially white and about 1.5 mm long • Adults are slender beetles whose appearance varies greatly according to the species Fig. Grub of wireworm Fig. Adult of wireworm (click beetle ) Source: www.bayercropscience.co.uk
Small feeding scars or feeding tunnels in potato tubers Symptoms: Fig. Wireworm infested potato plant Fig. Wireworm infested potato tuber Source : instruct1.cit.cornell.edu/pest_defects.html
Nature of Damage: • The larvae (wireworms) damage potato by feeding primarily on tubers. The damage appears as straight, round holes with smooth walls • Wireworm can also feed on young sprouts, underground stems and roots • Wireworm infestation may also lead to secondary infection by soft rot disease Fig. Potato tuber infected with soft rot Source:http://www.omafra.gov.on.ca/english/crops/hort/news/hortmatt/2003/20hrt03a7 .htm