EAG Responses of <I>Apis cerana</I> to Floral Compounds of a Biodiesel Plant, <I>Jatropha curcas</I> (Euphorbiaceae)

Abstract

The Eastern honey bee, [Apis cerana (F.)], is an important and common pollinator for an important biodiesel tree, [Jatropha curcas (L.)]. To understand sensitivity of A. cerana to different floral compounds, we quantified volatile floral compounds of J. curcas, then determined electroantennogram (EAG) responses of A. cerana to 11 compounds each at five doses (0.4, 4, 40, 400, and 4,000 microg) of six most active floral compounds. Our results demonstrated that floral compounds of J. curcas differ in variety and quantity while linalool is always a major constituent in floral blends from three different plantations. Antennae of A. cerana responded to all 11 floral compounds, implying a broad sensitivity of A. cerana to different floral compounds of J. curcas. Antennae of A. cerana were most sensitive to six compounds, including all aldehydes (decanal, hexanal, nonanal, and octanal), linalool, and an alcohol (3-hexenol), suggesting that A. cerana possesses chemoreceptors to aldehydes, linalool, and alcohol on the antenna. Furthermore, low doses elicited a zero EAG response and high doses a positive one under all of six most active compounds. Thus, EAG responses of A. cerana were both chemical specific and dose-dependent. Our results here suggest that A. cerana is senstive to various floral compounds, and linalool in the floral blends of J. curcas plays a key role to attract A. cerana.

Electrophysiological and Behavioral Responses of Plodia interpunctella (Hübner) Females to Aldehyde Volatiles from Dried Fruits

“…Ukeh et al showed that a synthetic blend of hexanal, octanal, and (E)-2-heptanal identified from maize seed volatiles was significantly attractive to Sitophilus zeamais (Coleoptera: Curculionidae) . Similar studies have been reported on various insect species, for example, Triatoma infestans (Hemiptera: Reduviidae), Dinoderus minutus (Coleoptera: Bostrichidae), and Apis cerana (Hymenoptera: Apidae). − Our results are consistent with these findings, showing that aldehydes are attractive to insect target insects. Uechi et al showed that hexanal was not attractive to P.…”

Linalool: A ubiquitous floral volatile mediating the communication between plants and insects

“…Generally, flowering plants attract pollinators by promising reward, floral mimicry or sexual deceptive, and the well‐developed sensory bias response for distinct volatiles is crucial (Raguso, 2008; Schiestl, 2015). Electroantennogram (EAG) is an electrophysiological technique used to detect insect responses to volatile compounds, and it has been experimentally confirmed that a variety of insects exhibit significant electrophysiological responses to linalool, which is an important elicitor of insect pollination behavior (Raguso et al, 1996; Johnson et al, 2007; Luo et al, 2013; Braunschmid et al, 2017; Lukas et al, 2019).…”

“…In many cases, researchers have found that flowers that release linalool also attract bees, like Paullinia cupana , Silene otitis , and Medicago sativa (Henning et al, 1992; Dötterl et al, 2012; Krug et al, 2018; Table 2). The electrophysiological response test of insect antennae is often used to detect whether the insect is sensitive to a certain chemical compound, which has been employed to confirm that multiple bees like Lasioglossum , Andrena , Nomada , and Apis cerana are all sensitive to linalool (Luo et al, 2013; Braunschmid et al, 2017; Lukas et al, 2019). However, it is worth noting that whether a higher concentration of linalool exhibits stronger attraction to insects.…”