Prothoracic Gland Semiochemicals of Green Lacewings

Abstract

Adult chrysopids have paired prothoracic glands (PG) that are thought to produce defensive secretions (allomones). We analyzed PG extracts of the following green lacewings from North and South America, Australia, and China: Ceraeochrysa cubana (Brazil); Chrysopa (= Co.) oculata, Co. nigricornis, Co. incompleta, Co. quadripunctata (USA), and Co. septempunctata (China); Chrysoperla (= Cl.) rufilabris (USA) and Cl. sp. (Brazil); Plesiochrysa ramburi and Mallada spp. (Australia). PG secretions are characteristic for species within a genus, except for Chrysopa spp. (Z)-4-Tridecene is ubiquitous, but (Z,Z)-4,7-tridecadiene is a major PG constituent in some Chrysopa spp. and in P. ramburi. Earlier reports that Co. oculata and Co. nigricornis produce 1-tridecene were shown to be in error. Chrysopa PG secretions are distinguished by the presence or absence of N-3-methylbutylacetamide, plus skatole (3-methylindole). Skatole is also identified for the first time from the Plesiochrysa and Ceraeochrysa. The PG secretion in Plesiochrysa ramburi is characterized by the presence of (Z)-4-undecene instead of (Z)-4-tridecene, and N-3-methylbutylpropanamide instead of the acetamide, resembling the PG secretions of Chrysopa nigricornis, Co. septempunctata and Co. incompleta. The chemotaxonomic value of PG semiochemicals is discussed, including evidence for subgroups within the genus Chrysopa as it now stands.

Aphid Sex Pheromone Compounds Interfere with Attraction of Common Green Lacewings to Floral Bait

“…Since treatments containing NEPOH and NEPONE attract C. formosa males in high numbers (Koczor et al 2010), and Chrysopa spp. are known to produce defensive compounds bearing a very specific odor (Aldrich et al 2009), it was hypothesized that the decrease in catches of C. carnea complex adults could be due to the scent emitted by the numerous C. formosa individuals caught in the same traps. However, results of the present study contradict this hypothesis: we found no effect of dead C. formosa individuals (bearing the specific 'Chrysopa odor') nor of skatole, a characteristic compound of Chrysopa defensive secretions, on catches of C. carnea complex lacewings to the ternary floral bait.…”

“…Furthermore, traps baited with NEPOH and NEPONE (either with or without the ternary floral bait) caught Chrysopa formosa Brauer 1850 in high numbers (Koczor et al 2010). Since adults of Chrysopa lacewings produce defensive chemicals when disturbed (Aldrich et al 2009), we could not exclude the possibility that defensive compounds produced by trapped C. formosa adults may have been responsible for the decrease in catch of C. carnea complex adults.…”

Revision of the green lacewing subgenus Ankylopteryx (Sencera) (Neuroptera, Chrysopidae)

“…More importantly, it remains to be discovered what the true biological significance of this trait is. Given that the baits only attract males, one immediately wonders whether these are components of semiochemicals produced by the females or if they play some other role in courtship and mating behaviors (Aldrich et al 2009). On the surface it seems as though these may act to gather males into mating leks, from which either a chemical cue or mere location attracts females.…”

Photoinduced Electron Transfer in a Ferrocene–Distyryl BODIPY Dyad and a Ferrocene–Distyryl BODIPY–C60 Triad

“…Another reasonable alternative is that trapped Chrysopa adults themselves repel carnea complex lacewings. Adults of most species of Chrysopa when disturbed emit defensive volatiles, producing an odour specific for the genus 35, 36. As the dead Chrysopa material also had this specific scent, probably dying individuals poisoned by killing agent (insecticide) also emitted defensive secretions, potentially affecting attraction of carnea complex adults to floral compounds.…”