Identification of Volatile Compounds Involved in Host Location by Anthonomus grandis (Coleoptera: Curculionidae)

Abstract

Phytophagous insects rely on plant volatiles to locate suitable hosts upon which to feed or oviposit. The boll weevil, Anthonomus grandis, is the main pest on cotton crops in the Neotropical region and is attracted to host plant volatiles, especially herbivore-induced volatiles from reproductive cotton. Behavioral and electrophysiological responses of the boll weevil were evaluated with the aim of identifying the compounds responsible for host location. Ten compounds elicited antennal responses from A. grandis, but only six were required to elicit a full behavioral response, namely: (R)-linalool, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), methyl salicylate, (E)-(1R,9S)-caryophyllene, geranylacetone and (E-E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT). A synthetic blend comprising these six compounds was as attractive as the sample of cotton reproductive stage volatiles. These data are discussed in the context of insect host location and crop protection.

Identification of Lathyrus sativus plant volatiles causing behavioral preference of Aphis craccivora

“…A number of studies have demonstrated that the attraction of insects towards plant volatiles has used a fixed natural ratio of compounds in synthetic blends resembling the natural volatiles of host plants. 31,[52][53][54][55][56][57][58][59][60] This study demonstrates that the fixed natural ratio of compounds for either a synthetic blend of four compounds (benzyl alcohol, 1,3-diethylbenzene, thymol, and 1-hexadecene) at similar amounts to those present in volatile extracts of ID 100 NIR plants or a synthetic blend of 11 compounds (diacetone alcohol, benzyl alcohol, p-cymene, 1,3-diethylbenzene, acetophenone, linalool oxide, 1-nonanol, ethylacetophenone, p-cymen-7-ol, thymol, and 1-hexadecene) at similar amounts to those present in volatile extracts of ID 100 BIO plants acted as an attractant of A. craccivora. Therefore, both these blends could be used to develop baited traps in IPM strategies for A. craccivora.…”

Priming of indirect defence responses in maize is shown to be genotype-specific

“…Previously we reported that this parasitoid responded to a blend of maize HIPVs with fifteen compounds induced (Sf 12-24 h) (Michereff et al 2019). Further studies could evaluate the importance of these components for the foraging behaviour of this egg parasitoid to evaluate the presence of redundant information in the blend of maize HIPVs (Tasin et al 2007;Bruce and Pickett 2011;Magalhães et al 2019). The response to mixtures of HIPVs from the same source, and not only to one specific compound or blend, helps to overcome problems with signalling detectability.…”

Olfactometer Responses of Convergent Lady Beetles Hippodamia convergens (Coleoptera: Coccinellidae) to Odor Cues from Aphid-Infested Cotton Plants Treated with Plant-Associated Fungi

“…The air was monitored, checking the flowmeter during the whole observation to ensure it was not escaping and interfering with the assay. After five individuals were tested, we changed the Y-tube, the jars, and the treatment sides to avoid positional bias [52,53]. Jars were cleaned with fragrance-free soap, rinsed with water, and dried in an oven at 80 °C to sterilize and avoid residuals from the previous treatment [50].…”

“…We recorded the insect responses as a choice when they entered at least halfway up into one arm of the Y-tube and remained there for at least 20 s [51]. Within the 10 min, we recorded the first choice, latency (time to make a choice), and residence time (time spent in an arm) [52,53]. If an individual did not choose within five minutes, it was recorded as "no choice" and excluded from the statistical analysis [57][58][59].…”