›› 2011, Vol. 54 ›› Issue (2): 238-245.doi:

• RESEARCH PAPERS • Previous Articles     Next Articles

Behavioral responses of Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae) to cruciferous vegetables

GUO Xiang-Ling, HE Yu-Rong, WANG De-Sen, PAN Fei   

  • Online:2011-02-20 Published:2011-03-10

Abstract: In order to clarify the effects of different volatiles of cruciferous vegetables on the host parasitoid searching behavior of Trichogrammatoidea bactrae Nagaraja, the olfactory behavioral responses of T. bactrae to six common species of host plants (Brassica oleracea, Brassica alboglabra, Brassica juncea, Brassica parachinensis, Raphanus sativus and Nasturtium officinale) of Plutella xylostella L. and four varieties of Brassica oleracea plants were investigated with Y-tube olfactometer in the laboratory, and the chemical compositions of six intact vegetable volatiles were analyzed by GC-MS. The results indicated that olfactory responses of T. bactrae were influenced not only by the species of cruciferous vegetables, but also by different varieties of the same vegetable. Female wasps were attracted to six intact plants, and the degree of attraction to different species of plants was significantly different (P<0.05). The female wasps showed the strongest attraction to N. officinale, less attraction to B. oleracea, B. parachinensis and B. juncea, and the least attraction to R. sativus and B. alboglabra. Attractiveness of the undamaged plants of Yashilü variety of B. oleracea to parasitoid was significantly stronger than that of Japan chunxiaqiu variety (P<0.01). GC-MS results showed that the majority of the six plant volatiles were alkane compounds, the next were alkenes, and others included aldehydes, alcohols, esters, acids, ketones and thiazoles compounds. Five aldehydes compounds (2,3-dimethyl-benzaldehyde, octanal, nonanal, undecanal, and dodecanal) accounting for 4.90% of the total volatiles were the unique components from N. officinale. The contents of alkanes (33 kinds) and alcohols (6 kinds) in N. officinale were 47.42% and 5.66%,respectively, higher than those in other vegetables. Of the six species of vegetables, B. oleracea had the highest contents of alkenes (9 kinds, 5.52%) and acids (4 kinds, 12.20%). The research may provide a theoretical basis for the reasonable layout of vegetable varieties and screening attractants of parasitic wasps.

Key words: Trichogrammatoidea bactrae, Plutella xylostella, cruciferous vegetables, behavioral responses, plant volatiles, attraction