Sexual differences in the response of the parasitoid wasp Anagrus nilaparvatae to rice volatiles
Author of the article:HUANG Ting-Fa MA Ying TANG Bing-Jie WANG Bing-Yang ZENG Rou-Xian ZHOU Qiang ZHANG Gu-Ren
Author's Workplace:School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China; School of Agriculture, Sun Yat-sen University, Guangzhou 510275, China
Key Words:Anagrus nilaparvatae; rice volatiles; electroantennography; sexual dimorphism
Abstract:
[Objectives] To clarify sexual differences in the response of the parasitoid wasp Anagrus nilaparvatae to rice volatiles in order to improve the effectiveness of using
parasitic wasps as biological control agents. [Methods] A potentiometric,
micro-antennae detection method was developed to measure the EAG responses of
female and male A.nilaparvatae to 9
different kinds of rice volatiles. Gradient
concentration stimulation experiments were also performed to detect significant
gender differences in the response to specific chemicals. [Results] The largest peak
amplitudes in males were recorded in response to trans-2-hexenal and the
smallest to trans-caryophyllene. Responses of males to aldehydes, esters,
alcohols and terpenes ranged from large to small. For females, the highest
response was to cis-jasmone and the lowest to linalool. Six of the 9 rice
volatiles tested elicited significantly different responses in males and
females. In the gradient concentration experiment, only 3 of the 6 volatiles
tested (trans-caryophyllene, nerolidol and trans-2-hexenol) elicited a
significant response from males, whereas all 6 compounds elicited a significant
response from females. The terpenoids linalool, trans-caryophyllene and nerolidol,
elicited the strongest responses at a
concentration of 0.01 g/L, which was the lowest concentration
used in experiments. [Conclusion] There are significant sexual differences
in the responses of A. nilaparvatae to rice volatiles; females respond to
a greater range of volatiles than males. EAG responses to rice volatiles were
detected within the concentration range of
0.01-100 g/L, which could be a preliminary indication that differences in EAG
responses to volatiles reflect different ecological functions.