Arthropod-Plant Interactions (2018) 12, 575-589

Huilin Yu, Yongjun Zhang, Yunhe Li, Ziyun Lu and Xiangju Li (2018)
Herbivore- and MeJA-induced volatile emissions from the redroot pigweed Amaranthus retroflexus Linnaeus: their roles in attracting Microplitis mediator (Haliday) parasitoids
Arthropod-Plant Interactions 12 (4), 575-589
Abstract: The redroot pigweed Amaranthus retroflexus Linnaeus (Caryophyllales: Amaranthaceae), an annual weed, is a host plant of the cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae). Microplitis mediator (Haliday) (Hymenoptera: Braconidae) is a parasitoid of H. armigera. Here, the electrophysiological and behavioral responses of M. mediator to induced redroot pigweed volatiles were investigated. Female parasitoids were significantly attracted to odors from plants induced by H. armigera damage, H. armigera continuous feeding, and 10 mM methyl jasmonate (MeJA) spray. The gas chromatography–mass spectrometry (GC–MS) results demonstrated that there were significant changes in volatiles from these three treatments in comparison with the control. When the constitutive compound 6-methyl-5-hepten-2-one was emitted in significant amounts from treated plants, it could elicit a medium electrophysiological response (0.2 < value < 0.8) , a significant behavioral response of M. mediator females. β-Elemene, emitted from two treatments (plants damaged by H. armigera, plants with H. armigera continuous feeding), showed a very weak electrophysiological response (value < 0.2), but was significantly attractive to M. mediator. The results showed that 6-methyl-5-hepten-2-one and β-elemene might play important roles in mediating the foraging behavior of M. mediator. Further work will be conducted to evaluate the function of these two compounds under semi-field and field conditions and exploit them as attractants for M. mediator to control H. armigera.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Yong-Jun Zhang

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Helicoverpa armigera
	Amaranthus retroflexus (weed)
Microplitis mediator (parasitoid)	Helicoverpa armigera