Characterizing potential repelling volatiles for “push-pull” strategy against stem borer: a case study in Chilo auricilius

Abstract

Background Massive techniques have been evaluated for developing different pest control methods to minimize fertilizer and pesticide inputs. As “push-pull” strategy utilizes generally non-toxic chemicals to manipulate behaviors of insects, such strategy is considered to be environmentally friendly. “Push-pull” strategy has been extraordinarily effective in controlling stem borers, and the identification of new “pushing” or “pull” components against stem borers could be significantly helpful. Results In this study, the results of field trapping assay and behavioral assay showed the larvae of C.auricilius, one kind of stem borers, could be deterred by rice plant under tilling stage, its main host crop. The profiles of volatiles were compared between rice plants under two different developmental stages, and α-pinene was identified as a key differential component. The repelling activity of α-pinene against C.auricilius was confirmed by Y-tube olfactometer. For illuminating the olfactory recognition mechanism, transcriptome analysis was carried out, and 13 chemosensory proteins (CSPs) were identified in larvae and 19 CSPs were identified in adult of C.auriciliu, which was reported for the first time in this insect. Among these identified CSPs, 4 CSPs were significantly regulated by α-pinene treatment, and CSP8 showed good binding affinity with α-pinene in vitro. Conclusions Overall, C.auricilius could be repelled by rice plant at tilling stage, and our results highlighted α-pinene as a key component in inducing repelling activity at this specific stage and confirmed the roles of some candidate chemosensory elements in this chemo-sensing process. The results in this study could provide valuable information for chemosensory mechanism of C.auricilius and for identification of “push” agent against rice stem borers.

Olfactory Proteins and Their Expression Profiles in the Eucalyptus Pest Endoclita signifier Larvae

“…Behavior, physiology, and molecular result indicated olfactory proteins of larvae play a role in pheromone or volatile recognition. For example, four CSPs in Chilo auricilius larvae (Yi et al, 2019 ) were significantly regulated by α-pinene treatment. Pre-exposure larvae to single volatile organic compounds can upregulate ORs in Spodoptera exigua larvae strongly and non-specifically (Llopis-Gimenez et al, 2020 ).…”

The Structure of Rice Stemborer Assemblages: A Review of Species’ Distributions, Host Ranges, and Interspecific Interactions

“…Some early reports as primary species [61]; more recently regarded as a secondary species [22,62]; shows little preference among crop hosts [63]; but is more commonly regarded as a sugarcane pest [64] Prevalent in rice that is adjacent to other crop hosts, with the 2nd generation attacking rice [65,66] Chilo polychrysus (Meyrick)…”

“…Cont. : See TablesS2 and S3for full information on potential host plants and related references[9,10,33,37,38,41,45,46,55,56,58,[63][64][65][66][67]83,[88][89][90][94][95][96]100,101,107,123,128,129,140,141,; 2 : Includes crop species.…”

Fungal volatile organic compounds: mechanisms involved in their sensing and dynamic communication with plants

“…Finally, the ‘Push–Pull’ system has been successfully implemented in Africa to control lepidopteran pests ( Pickett et al., 2014 ). The purpose of this technology is keeping out herbivorous insects away from the crop of interest, by combining the crop with other plants that repel or attract a specific herbivore ( Stenberg et al., 2015 ; Yi et al., 2019 ). For instance, maize is intercropped with Desmodium uncinatum as the repellent plant, and Pennisetum purpureum as the attractive plant in the crop-field border ( Figure 2E ).…”

“…The challenge for the implementation of the “Push-Pull” system with other crops is finding the pair of plants that repel or attract the same pest in combination with a crop of interest ( Yi et al., 2019 ). Another possible limitation of the “Push-Pull” system is the lack of protection against pathogen microorganisms since the system protects plants against insect pests only ( Pickett et al., 2014 ).…”