Attraction of the tea aphid, toxoptera aurantii, attraction to combinations of volatiles and colors related to tea plants

Authors: HAN, BAOYU - TEA RSRCH INSTITUTE,CHINA; CHEN, ZONGMAO - TEA RSRCH INSTITUTE,CHINA; ZHANG, QING-HE - STERLING INTNL,SPOKANE,WA; Byers, John

Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/10/2012
Publication Date: 7/27/2012
Citation: Han, B., Zhang, Q.H., Byers, J.A. 2012. Attraction of the tea aphid, Toxoptera aurantii, to combinations of volatiles and colors related to tea plants. Entomologia Experimentalis et Applicata. 144:258-269.

Interpretive Summary: The tea aphid, Toxoptera aurantii Boyer (Homoptera: Aphididae), is a major pest of the tea plant, Camellia sinensis. Fourteen volatile compounds were identified by gas chromatography and mass spectrometry (GC-MS) from air passed over intact tea shoots (ITSV). Electrophysiological and behavioral responses of the winged tea aphids to ITSV as well as to synthetic blends of individual, partial mixture (GLV) and full blend of 14 synthetic compounds (FB) were studied by using electroantennography (EAG) and Y-tube olfactometer. In the olfactory assays, all tested compounds (alone or combined) were attractive; they were also strongly EAG active, with ITSV being the strongest, followed by FB, GLV, and (Z)-3-hexen-1-ol. A decrease in dosage of any of the individual components, FB, or GLV from 10'2 g/ml to 10'6 g/ml, increased aphid EAG responses. In the laboratory and in tea gardens, six colors of sticky boards strongly attracted winged tea aphids, with rape-flower yellow and Chinese olive-yellow-green being the most attractive, followed by calcedony green, malachite green, blue green and snow'white sticky boards. Furthermore, the rape-flower yellow or calcedony green sticky boards combined with the open ITSV solution vials more strongly attracted winged tea aphids than the corresponding colored sticky boards alone. In the laboratory, plastic tea seedling models baited with (Z)-3-hexen-1-ol or GLV mixture significantly attracted winged tea aphids. This study demonstrates that general green leaf volatiles, such as (Z)-3-hexen-1-ol, (E)-2-hexenal, 2-penten-1-ol, and n-hexanol from tea shoots are stimulatory; and the combination of these volatiles with light yellow and green, and the shape of tender tea shoots results in orientation flight and landing of winged tea aphids onto host tea shoots. Bright yellow sticky boards with GLV mixture may have the potential to effectively trap and suppress tea aphids in tea gardens.

Technical Abstract: The tea aphid, Toxoptera aurantii Boyer (Homoptera: Aphididae), is a major pest of the tea plant, Camellia sinensis. Fourteen volatile compounds were identified by GC-MS from air passed over intact tea shoots (ITSV). Electrophysiological and behavioral responses of the winged tea aphids to ITSV as well as to synthetic blends of individual, partial mixture (GLV) and full blend of 14 synthetic compounds (FB) were studied by using electroantennography (EAG) and Y-tube olfactometer. In the olfactory assays, all tested compounds (alone or combined) were attractive; they were also strongly EAG active, with ITSV being the strongest, followed by FB, GLV, and (Z)-3-hexen-1-ol. A decrease in dosage of any of the individual components, FB, or GLV from 10'2 g/ml to 10'6 g/ml, increased aphid EAG responses. In the laboratory and in tea gardens, six colors of sticky boards strongly attracted winged tea aphids, with rape-flower yellow and Chinese olive-yellow-green being the most attractive, followed by calcedony green, malachite green, blue green and snow'white sticky boards. Furthermore, the rape-flower yellow or calcedony green sticky boards combined with the open ITSV solution vials more strongly attracted winged tea aphids than the corresponding colored sticky boards alone. In the laboratory, plastic tea seedling models baited with (Z)-3-hexen-1-ol or GLV mixture significantly attracted winged tea aphids. This study demonstrates that general green leaf volatiles, such as (Z)-3-hexen-1-ol, (E)-2-hexenal, 2-penten-1-ol, and n-hexanol from tea shoots are stimulatory; and the combination of these volatiles with light yellow and green, and the shape of tender tea shoots results in orientation flight and landing of winged tea aphids onto host tea shoots. Bright yellow sticky boards with GLV mixture may have the potential to effectively trap and suppress tea aphids in tea gardens.