Single-Insect NMR: A New Tool To Probe Chemical Biodiversity

Abstract

Because of analytical limitations, multiple animals or plants are typically required to identify natural products. Using a unique 1-mm high-temperature superconducting NMR probe, we directly examined the chemical composition of defensive secretions from walking stick insects. Individual milkings were dissolved in D2O without purification and examined by NMR within 10 min of secretion. We found that Anisomorpha buprestoides secretes similar quantities of glucose and mixtures of monoterpene dialdehydes that are stereoisomers of dolichodial. Different individual animals produce different stereoisomeric mixtures, the ratio of which varies between individual animals raised in the same container and fed the same food. Another walking stick, Peruphasma schultei, also secretes glucose and a single, unique stereoisomer that we are naming "peruphasmal". These observations suggest a previously unrecognized significance of aqueous components in walking stick defensive sprays. Single-insect variability of venom demonstrates the potential importance of chemical biodiversity at the level of individual animals.

Chemical signals associated with life inhibit necrophoresis in Argentine ants

“…These analyses confirmed that extracts of live ants contained substantial amounts of trans,transdolichodial (referred to as ''peruphasmal'' in ref. 13) and cis,transiridomyrmecin, whereas these compounds were virtually absent in extracts of 1-h-old dead ants (Fig. 3B).…”

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).…”

Survey of the Color Forms of the Southern Twostriped Walkingstick (Phasmatodea: Areolatae: Pseudophasmatidae: Pseudophasmatinae: Anisomorphini), With Notes on Its Range, Habitats, and Behaviors

“…These insects are well known for their ability to defend themselves by spraying a particularly odoriferous and irritating chemical secretion from prothoracic glands. Numerous publications have dealt with its systematics and geographical range (Caudell 1903, Rehn and Hebard 1916, Conle and Hennemann 2002; external anatomy (Littig 1942, Happ et al 1966; behavior, habitats, and host plants (Hetrick 1949a,b;Gunning 1987;Thomas 2001); chemical analysis of its defensive spray termed anisomorphal (Eisner 1965;Meinwald et al 1962;Dossey et al 2006Dossey et al , 2008, or injuries to the human eye caused by this secretion (Albert 1947, Stewart 1937, Paysse et al 2001. Some studies have stated the adults show considerable color variability among populations.…”