Effects of two types of semiochemical on population development of the bird cherry oat aphid Rhopalosiphum padi in a barley crop

Abstract

1 Field experiments were performed in barley using volatile semiochemicals affecting population density (density-related substances ± DRS) and spring migration (methyl salicylate) in bird cherry oat aphid Rhopalosiphum padi (L.). Natural infestations of aphids were used, and semiochemical dosages were chosen to be biologically relevant based on previous studies. A simple formulation method for active substances using wax pellets was developed. 2 The effect of treatments on aphid populations was analysed in terms of initial colonization of the crop, temporal dynamics of the population and maximum aphid incidence. 3 Treatments caused a significant delay in aphid establishment in the crop, and reduced the average infestation by 25±50% compared with the untreated control. At a moderate attack rate, the treatments with methyl salicylate and DRS gave a significant reduction in maximum aphid numbers. 4 The significant control effect of the treatment encourages further investigation both to increase understanding of the ecological role of the active substances, and to establish the limitations for their use in plant protection.

Tobacco overexpressing β-ocimene induces direct and indirect responses against aphids in receiver tomato plants

“…The total number of newly developed nymphs on TTT was about one-third of that on TWT. These results confirm findings with bird cherry oat aphid Rhopalosiphum padi, whose population growth in the field is reduced by treating plants with a pellet formulation releasing methyl salicylate (Ninkovic et al, 2003). Emission of ˇ-ocimene by transgenic tobacco induces attraction of aphid parasitoids in receiver tomato plants…”

Aphid Acceptance of Barley Exposed to Volatile Phytochemicals Differs Between Plants Exposed in Daylight and Darkness

“…This is in line with previous studies in which plants were exposed continuously throughout the light-dark cycle. 7,8,12,23 However, the current experiment showed that effects on aphid behavior are dependent on the presence or absence of light during the exposure. Plants exposed to volatiles from cv.…”

“…Exposure to methyl salicylate reduced acceptance and population development of Rhopalosiphum padi on barley. 12 In Arabidopsis, constitutive activation of jasmonate signalling was correlated with enhanced resistance against Myzus persicae 13 and sorghum became less acceptable to Schizaphis graminum after treatment with methyl jasmonate. 14 The aims of this study were (a) to investigate the influence of the presence or absence of light on the response of barley to phytochemicals and (b) to compare the effects of exposing barley to phytochemicals from undamaged plant neighbors and the stress-related www.landesbioscience.com Plant Signaling & Behaviorcues methyl salicylate and methyl jasmonate.…”

The potential for modifying plant volatile composition to enhance resistance to arthropod pests.

“…The potential also exists to identify the active volatile cues and apply them in crops as chemical elicitors [cf. [104][105][106] or as natural enemy attractants [107].…”