Buckwheat flower volatiles attract Peristenus spretus and enhance its field-level parasitism of Apolygus lucorum

Authors: SHIKE, XIA - Institute Of Plant Protection - China; TAO, ZHANG - Hebei Academy Of Agriculture & Forestry; Williams, Livy; YIZHONG, YANG - Yangzhou University; YANHUI, LU - Beijing Academy Of Agricultural Sciences

Submitted to: Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/13/2023
Publication Date: 4/15/2023
Citation: Shike, X., Tao, Z., Williams III, L.H., Yizhong, Y., Yanhui, L. 2023. Buckwheat flower volatiles attract Peristenus spretus and enhance its field-level parasitism of Apolygus lucorum. Plants. 12:1658. https://doi.org/10.3390/plants12081658.
DOI: https://doi.org/10.3390/plants12081658

Interpretive Summary: Plant-infesting insects are serious pests of many crops throughout the world. Beneficial insects are useful in controlling these pests, and may use odors from some plant species to find their insects to attack. For example, buckwheat is a plant that, when planted near crop plants, has the potential to attract beneficial insects to the vicinity of crops. Thus, understanding the interactions between plant odor signals and attraction of beneficial insects has important implications for pest control. Through combined studies of analytical chemistry and insect behavior, we characterized the odors of buckwheat flowers, their degree of attraction to a beneficial insect, and their effect on parasitism of an insect pest. Our results indicate that buckwheat flowers produced five odors which were attractive to the beneficial insect. Further, the beneficial insect was strongly attracted to these odors and under field conditions led to increases in parasitism. Our findings indicate that buckwheat odor signals play an important role in mediating the interactions between a plant pest and a beneficial insect, and thus help form the theoretical basis for the development of plant attractants, many of which are already commercially-produced, for use in pest management.

Technical Abstract: Volatile compounds play indispensable roles in the interactions among host plants, herbivores and natural enemies. Peristenus spretus is the dominant parasitoid of the mirid bug Apolygus lucorum. Previous studies showed that the addition of buckwheat strips in cotton fields could attract P. spretus and enhance their parasitic activity. Through the combined analysis of Y-tube olfactometer, solid-phase microextraction (SPME), gas chromatography-mass spectrometer (GC-MS) and electroantennography (EAG), our study found that male and female P. spretus responded to compounds present in buckwheat flowers. The five major components of buckwheat flowers, cis-3-hexenyl acetate (CHA), 4-methylanisole, 4-oxoisophorone, p-methylphenol and 2-ethylhexyl salicylate, all had significant attraction to P. spretus adults, and led to positive electroantennogram responses especially under 10 mg/mL 4-oxoisophorone, indicating the components played a key role in the selection behavior of P. spretus to buckwheat flowers. Additionally, field trials showed that the five volatiles could significantly increase the parasitism by P. spretus. Our results help form the theoretical basis for the development of attractants for P. spretus and conservation biological control (CBC) of A. lucorum.