| Evaluation of the synthetic aggregation pheromones and host plant volatiles for trapping of two sympatric species: Oryctes elegans Prell. and O. agamemnon Burmeister |
| Paper ID : 1032-3IICE (R1) |
| Authors: |
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Arman Avand-Faghih *1, Mohammad Taghi Fassihi2, Kazem Mohammadpour3 1Iranian Research Institute of Plant Protection, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran 22- Plant Protection Research Department, Bushehr Agricultural and Natural Resources Research and Education Center, AREEO, Bushehr, Iran. 31- Iranian Research Institute of Plant Protection, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran |
| Abstract: |
| Oryctes elegans and O. agamemnon matthiseseni (Col.: Scarabaeidae), are two sympatric species causing damages on date palms in South of Iran. 4-methyloctanoic acid and a blend of ethyl 4-methyloctanoate and 4-methyloctanoic acid, with the same ratio of each component, have been identified as the aggregation pheromones of O. elegans and O. agamemnon respectively. Two field trapping trials were carried out in Bushehr province in 2016 and 2017 in randomized complete block designs with factorial treatments and 4 blocks. The efficiency of the pheromones (acid and the blend of ester and acid) and the trap position (on ground and below the palm crown) were studied on the capture of these two rhinoceros beetles in 2016. The effects of the pheromones and two synergists, including date palm core tissue and a host plant-based synthetic blend, were compared in 2017. Three times more O. elegans were captured by traps baited with the blend of ester and acid than those baited with acid alone in 2016. But there was no significant difference between the capture of two pheromones for females, males and both sexes pooled together. In 2017, significantly more females of O. elegans were trapped by the blend of ester and acid than acid alone. Even if two times more beetles were caught by the blend than acid alone, the captures of males and both sexes pooled together were not significantly different by two pheromones. It seems that ethyl 4-methyloctanoate is a behaviorally active component of O. elegans pheromone, especially attractive for females. Only 8 females of O. agamemnon were trapped during both trials (7 females by acid alone), resulting serious hesitation on the behavioral activity of acid alone or mixed with the ester, for the Iranian population of this species. This result revealed the probable divergence in pheromone composition of O. agamemnon in sympatry with O. elegans in Iran. The captures of traps on the ground level and those attached below the palm crown were not significantly different for both species. No significant difference was observed between the capture of traps baited with date palm core tissue and those baited with host plant-based synthetic blend. Thus the synthetic blend can be used efficiently as the pheromone synergist of O. elegans. Regarding the possible divergence in pheromone of the Iranian population of O. agamemnon, it’s suggested to identify the pheromone composition of both sympatric species as well as the optical isomer of components. |
| Keywords: |
| Rhinoceros beetles, Pheromone divergence, 4-methyloctanoic acid, ethyl 4-methyloctanoate, date palm |
| Status : Paper Accepted (Oral Presentation) |
