Semiochemical and Communication Ecology of the Emerald Ash Borer, Agrilus planipennis (Coleoptera: Buprestidae)

Abstract

Knowledge of buprestid chemical ecology is sparse but the appearance of the invasive pest Agrilus planipennis Fairmaire in North America has provided the impetus to study in detail the semiochemistry and ecology of this important buprestid. The macrocyclic lactone (3Z)-12-dodecenolide [(3Z)-lactone] is identified as a key antennally-active compound that is produced by females and attracts males. Though a weak trap attractant alone, when combined with the host kairomone (3Z)-hexenol and the important visual cue of a green canopy trap, significant increases in male trap capture occur, thus defining (3Z)-lactone as both a sex pheromone of A. planipennis as well as the first and only known buprestid pheromone. The non-natural stereoisomer (3E)-12-dodecenolide and the saturated analog, 12-dodecanolide also exhibit mimetic activities towards male A. planipennis, suggesting a notable plasticity in this pheromonal structural motif. Efficient synthetic routes to these compounds have been developed. A series of fluoro-12-dodecanolides has also been synthesized containing CF2 groups as a strategy to bias the conformational space accessed by these macrolides and to assess if the analogs may act as mimetics for 12-dodecanolide pheromones associated in A. planipennis. These compounds also afford a unique opportunity to study the binding affinities of lactone surrogates with A. planipennis chemosensory proteins and olfactory receptors. Some progress has also been made in identifying the genes involved in the reception, processing and degradation of volatiles in this invasive insect. It is now evident that the behavior and ecology of A. planipennis involves a complex pattern of sensory modalities, including visual, tactile, olfactory and potentially acoustic components. Earlier reviews focused on studies of attractive host volatiles in development of a trapping system for early detection and visual and contact phenomena in A. planipennis mate finding. This review will update the semiochemistry and chemical ecology of A. planipennis and discuss studies on chemistry and behavior that have identified female-produced pheromone components and host kairomones.

Analyses of structural dynamics revealed flexible binding mechanism for the Agrilus mali odorant binding protein 8 towards plant volatiles

“…These studies clearly show that natural compounds like host plant volatiles can be used to develop eco‐friendly and sustainable measures for management of insect pests. There is evidence that Agrilus planipennis , which belongs to the same family as our target pest A. mali , can be strongly attracted by the green leaf volatile ( Z )‐3‐hexenol 13 . In addition, host volatiles like 2,6‐dimethyl‐2,4,6‐octatriene, geranyl formate, ( Z )‐3‐hexenyl hexanoate, decanal and tetradecanol were shown to be attractive for A. mali in our previous studies 3 .…”

“…There is evidence that Agrilus planipennis, which belongs to the same family as our target pest A. mali, can be strongly attracted by the green leaf volatile (Z)-3-hexenol. 13 In addition, host volatiles like 2,6-dimethyl-2,4,6-octatriene, geranyl formate, (Z)-3-hexenyl hexanoate, decanal and tetradecanol were shown to be attractive for A. mali in our previous studies. 3 Thus, new control means for A. mali may be developed, based on the manipulation of its olfactory system.…”

Function and Characterization Analysis of BodoOBP8 from Bradysia odoriphaga (Diptera: Sciaridae) in the Recognition of Plant Volatiles and Sex Pheromones

“…More recently, a series of studies showed that insect olfaction could distinguish various hosts based on plant volatiles and insect pheromones [4][5][6][7][8][9], and host plant volatiles and insect pheromones to control insect pests have been widely used. For example, the host plant volatiles undecan-2-one, nonan-2-one, and 2-nonyl acetate have been applied as repellents for Aedes aegypti [10], and (Z)-3-hexenol, (Z)-3-hexenyl acetate, (Z)-3-hexenyl hexanoate, decanal, and tetradecanol have been used in detecting Sitona lineatus [11], Agrilus planipennis [12], and Agrilus mali [13], respectively. The compounds 2-nonanone and 2-undecanone could stimulate a positive oviposition response to Ceratitis capitata [14].…”

Optimizing early detection strategies: defining the effective attraction radius of attractants for emerald ash borer Agrilus planipennis Fairmaire

“…Symptoms of infestation such as canopy dieback and epicormic shoots are not apparent until trees are heavily attacked, by which point populations of emerald ash borer in the area are quite high (Poland & McCullough, 2006;McCullough et al, 2009). Fortunately, emerald ash borers exhibit positive phototaxis to wavelengths of light in the green (540-560 nm), blue (420-430, 460 nm) and red (640-650, 670 nm) ranges, which has led to the use of both green and purple prism-shaped sticky traps (Francese et al, 2008;Crook et al, 2009;Crook & Mastro, 2010;Silk et al, 2019b). These traps are often baited with lures composed of volatiles found in ash leaves ((3Z)-hexenol) and tree oils, such as manuka oil (from the New Zealand tea tree, Leptospermum scoparium J.R. and G. Forst (Myrtaceae)) and phoebe oil (from the Brazilian walnut tree, Phoebe porosa Mez (Lauraceae)) (de Groot et al, 2008;Crook & Mastro, 2010;Grant et al, 2010;Poland et al, 2011).…”