Uptake of plant-derived specific alkaloids allows males of a butterfly to copulate

Abstract

Certain butterflies utilize plant-acquired alkaloids for their own chemical defense and/or for producing male sex pheromone; a trait known as pharmacophagy. Males of the danaine butterfly, Parantica sita, have been reported to ingest pyrrolizidine alkaloids (PAs) as adults to produce two PA-derived sex pheromone components, viz. danaidone (major) and 7R-hydroxydanaidal. We found, however, that not all PAs that can be precursors for the pheromone serve for mating success of males. Here we show that although the sex pheromone is regarded as a requisite for successful mating, uptake of specific PA(s) (lycopsamine-type PAs) is also imperative for the males to achieve copulation. The increase in the levels of two biogenic amines, octopamine and/or serotonin, in the brain and thoracic ganglia of males fed with specific PA(s) suggested that these alkaloids most likely enhance male mating activity. The results can present new evidence for the evolutionary provenance of pharmacophagous acquisition of PAs in PA-adapted insects.

Attraction of Brown Marmorated Stink Bugs, Halyomorpha halys, to Blooming Sunflower Semiochemicals

“…Foraging stink bugs are guided, in part, by plant semiochemicals (Ishiwatari 1974;Lockwood and Story 1987;Pareja et al 2007). Plants serve as: (i) resources rich in nutrients (House 1961;Sinclair 2015;Urbaneja-Bernat et al 2020), water (Kerkut and Gilbert 1985) and secondary metabolites (Boppré 1984;Honda et al 2018); (ii) rendezvous sites for mate encounters (Geiselhardt et al 2012;Xu and Turlings 2018); (iii) oviposition sites for gravid females (Forister 2004;Jaenike 1978;Thompson 1988); (iv) food sources for offspring development (García-Robledo and Horvitz 2012;Scriber and Slansky Jr. 1981;Via 1986); as well as (v) shelter from harsh weather and natural enemies (Jones Jr. and Sullivan 1981;Mulatu et al 2004). As most pentatomids are multivoltine and may deplete local host plant resources, they must often shift between host plants and navigate through a complex landscape in search for new hosts of varying degrees of suitability (McPherson 1982;Todd 1989).…”

“…Host plants provide a plethora of benefits to insect herbivores. Plants serve as (i) resources rich in nutrients (House 1961;Sinclair 2015;Urbaneja-Bernat et al 2020), water (Kerkut and Gilbert 1985) and secondary metabolites (Boppré 1984;Honda et al 2018),…”

Role of herbicides in the decline of butterfly population and diversity

“…These colorful distinguishing marks help them to choose partners during breeding season, but they would fail to do so if the scales are removed due to herbicidal effect. Some pheromones are also present like pyrrolizidine that help butterflies like tiger, crows during reproduction where the source of the chemical is crotalaria or Heliotropium indicum while the loss of them adversely impacts the butterfly population (Honda et al, 2018). A good source of protein is pollen from flower.…”

Kleptopharmacophagy: Milkweed butterflies scratch and imbibe from Apocynaceae‐feeding caterpillars

“…Courtship success correlates with mating success and fecundity (Edgar and Caulvenor 1974, Honda et al. 2018), and males often transfer alkaloids to females through spermatophores as nuptial gifts (Boppré 1990). While alkaloids are often ingested in leaves consumed by caterpillars during the larval stages, they may be stored as intermediary compounds (Orr et al.…”