Fig. 4.

Effect of chemotaxis on hermaphrodites of A) young (YH) and B) old hermaphrodites (OH) of Bursaphelenchus okinawaensis (Bok) or females of C) unmated (UF), and D) mated females (MF) of B. xylophilus (Bxy) by the chemical cue of male of Bok or Bxy as compared to the water control. Chemotaxis index (CI) was calculated as in Fig. 3. A positive CI indicates attraction, while a negative one indicates repulsion. (+) or (−) in each set indicates sperm status of hermaphrodites or females which used for chemotaxis assay. Sperm (+) indicates hermaphrodite having self-produced sperm or female having sperm supplied by male, while sperm (−) indicates hermaphrodite or female have no sperm at the beginning of chemotaxis assay. Error bars indicate standard error. **Indicates significant difference (P < 0.01) in CI between the tested chemical cue and water control based on Dunnett’s test.