4-Methyl-1-hepten-3-one, the Defensive Compound from Agathemera elegans (Philippi) (Phasmatidae) Insecta

Abstract

Insects of the genus Agathemera (Phasmatidae) live in the Chilean Andes over 1500 m above sea level. On disturbing, the insects release a spray that can cause temporary blindness in humans. Very little is known on the composition of chemicals used for defense by South American phasmids. Here we show that both female and male defensive secretion of Agathemera elegans is made up of 4-methyl-1-hepten-3-one. The compound is reported for the first time as a natural product.

Alkyldimethylpyrazines in the Defensive Spray of Phyllium westwoodii: A First for Order Phasmatodea

“…The first analysis of a phasmid defensive spray was published in 1934 on Agathemera crassa (Schneider 1934) (referred to by Schneider as Paradoxomorpha crassa ). Possibly due to analytical limitations of that time, the chemical structure obtained in that study was likely incorrect, as the defense compound of another species in that genus ( Agathemera elegans ) was more recently determined to be 4-methyl-1-hepten-3-one (Schmeda-Hirschmann 2006). Subsequent to the work by Schneider in 1934, the next species studied was Anisomorpha buprestoides in classic works by Eisner, Meinwald, and co-workers (Eisner 1965; Meinwald et al 1962).…”

“…However, the chemical composition of defensive sprays from only a few species has been analyzed to date (Bouchard et al 1997; Chow and Lin 1986; Dossey et al 2007; Dossey et al 2006; Eisner et al 1997; Eisner 1965; Ho and Chow 1993; Meinwald et al 1962; Schmeda-Hirschmann 2006; Schneider 1934; Smith et al 1979). The first analysis of a phasmid defensive spray was published in 1934 on Agathemera crassa (Schneider 1934) (referred to by Schneider as Paradoxomorpha crassa ).…”

“…Since then, other phasmids have been shown to produce monoterpenes such as: iridodoal ( Graeffea crouani ) (Smith et al 1979), nepetalactone ( Graeffea crouani ) (Smith et al 1979), actinidine ( Megacrania alpheus (Chow and Lin 1986) and Megacrania tsudai (Ho and Chow 1993)), limonene ( Sipyloidea sipylus ) (Bouchard et al 1997), parectadial (a novel monoterpene first identified from the phasmid Parectatosoma mocquerysi (Dossey et al 2007)), dolichodial (isomer of anisomorphal found in young A. buprestoides (Dossey et al 2008)), peruphasmal (isomer of anisomorphal from Peruphasma schultei ) (Dossey et al 2006), and others as minor components (Bouchard et al 1997; Ho and Chow 1993). In addition to monoterpenes, 4-methyl-1-hepten-3-one (as mentioned above) (Schmeda-Hirschmann 2006) and quinoline (from Oreophoetes peruana ) (Eisner et al 1997) have also been found in phasmid insect defense gland sprays. Besides these secondary metabolites, glucose has also been reported in the defensive spray of A. buprestoides (Dossey et al 2007; Dossey et al 2006; Zhang et al 2007), P. schultei (Dossey et al 2006), and P. mocquerysi (Dossey et al 2007).…”

Multiple Identified Neurons and Peripheral Nerves Innervating the Prothoracic Defense Glands in Stick Insects Reveal Evolutionary Conserved and Novel Elements of a Chemical Defense System

“…In species displaying chemical defense, the paired defense glands produce the defense fluid from a secretory epithelium lining the inner gland muscle layers (Happ et al, 1966;Strong, 1975;Eisner et al, 1997). The defense secretions have been studied for the biochemical components in detail in different species of stick insects (e.g., Meinwald et al, 1962;Smith et al, 1979;Chow and Lin, 1986;Ho and Chow, 1993;Bouchard et al, 1997;Eisner et al, 1997;Dossey et al, 2006Dossey et al, , 2008Schmeda-Hirschmann, 2006;summarized in Dettner, 2015). In Anisomorpha species, the principle component of the defense spray is anisomorphal, a monoterpene dialdehyde (Meinwald et al, 1962) which occurs in three diastereomers in Anisomorpha buprestoides (Dossey et al, 2006).…”

Defensive Spiroketals from Asceles glaber (Phasmatodea): Absolute Configuration and Effects on Ants and Mosquitoes

“…However, many species produce a chemical spray from a pair of tegumental glands in their prothorax when disturbed (Bedford 1978; Dossey 2010; Dossey 2011; Scudder 1876) (and references therein). The chemical composition of defensive sprays from only a few species has been analyzed (Bouchard et al 1997; Chow and Lin 1986; Dossey 2011; Dossey et al 2009; Dossey et al 2007; Dossey et al 2006; Eisner et al 1997; Ho and Chow 1993; Meinwald et al 1962; Prescott et al 2009; Schmeda-Hirschmann 2006; Schneider 1934; Smith et al 1979). Besides the various secondary metabolites, glucose has been reported in the defensive sprays of A. buprestoides ,(Dossey et al 2006), P. schultei (Dossey et al 2006), P. mocquerysi (Dossey et al 2007), P. westwoodii (Dossey et al 2009) and M. nigrosulfurea (Prescott et al 2009).…”