The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) is a species complex, including at least 24 biotypes which express different ecological and physiological characteristics. B. tabaci is one of the most serious pests in the horticultural crops in worldwide level. B. tabaci infests over 600 plant species and also indirectly damages plants by the honeydew excretion. Moreover, whiteflies transmit more than 100 plant viruses, especially begomoviruses. Tomato yellow leaf curl virus (TYLCV) which infested severely in tomato cultivars is transmitted by the vector insect, B. tabaci. Here, we demonstrated whether gene expression of B. tabaci is regulated by the oral ingestion of dsRNA. Double strand RNA (dsRNA) of heat shock protein 70 gene (hsp70) was produced from cDNA by using the specific primer. Whitefly adults were allowed to ingest sugar solution containing dsRNA for 3 hr in the two-layered parafilm feeding tube. Quantitative realtime PCR showed that whiteflies which ingest hsp70 dsRNA completely knockdown its transcript expression. Whiteflies ingestded dsRNA increased mortality by heat shock but not by cold shock. Further research will focus the role of hsp70 in various environmental stresses against insects.

• Jae-Kyoung Shim(College of Agriculture and Life Sciences, Kyungpook National University)
• Duck-Oung Jung(College of Agriculture and Life Sciences, Kyungpook National University)
• Bong-Gi Choi(College of Agriculture and Life Sciences, Kyungpook National University)
• Kyeong-Yeoll Lee(College of Agriculture and Life Sciences, Kyungpook National University, Institute of Plant Medicine, Kyungpook National University)