How male tobacco budworm moths found their perfect cologne
Various animals and plants will use any means to reproduce, ranging from “wingmen” dolphins to pee-sniffing Giraffes and daisies that fool insects into pollinating them. Scientists have identified the specific pheromone blend chemicals and a recently revealed sexual aphrodisiac used by male moths to court. The results were published on August 1 in the scientific journal Current Biology. They will provide more information about this complex blend of chemical compounds utilized for short-range communication between female and male moths.
The male pheromone combination used for matting was first identified nearly three decades ago. However, the aphrodisiac male moth found in this study contains a chemical known as methyl salicylate. It comes from plants and is released when herbivores come in to attack and consume them. Methyl salicylate serves as a plant healing mechanism and a call for assistance to the enemies of the herbivores who eat the plants. It alerts them to the fact that there could be food available.
The moth family studied in this study eats around 350 plant species from North and South America, including the tobacco budworm, the corn earworm, and the autumn armyworm. The male Chloridea virescent moths, also known as the moth with the tobacco budworms, the chemical methyl salicylate as part of their pheromone mixture, which the researchers in the study believe assists the male to show dominance. The essence of this natural fragrance proves that the moth can defy the plant’s defenses. It is a way to indicate that it is a suitable mating choice.
“These close-range interactions provide valuable insight into both species recognition– how females recognize males of the same species–and female choice in mate selection,” study co-author and North Carolina State University entomologist Coby Schal declared in an email. “This interaction gives females some insight into a particular male’s history.”
The female moths start mating by releasing an attractive mix of pheromones composed of fat acids across a wider distance. The males respond by flying closer to the females. When they are close enough, males emit their unique blend of pheromones composed of various alcohols. Females use the male’s mix to decide if the male is a suitable partner.
For the study, they utilized a method in which chemicals are separated within an oven-controlled gas chromatography to determine the chemical components of the male pheromone mix. A few of these ingredients were absent in the first characterization developed by scientists over three decades ago.
They observed that the salicylate methyl produced a massive response from females in the lab, especially because females’ moth antennae contain two receptors for smell specifically designed to detect the chemical.
The group also reduced the amount of methyl salicylate that males produced and found that mating success suffered. If these males were given less of the chemical, mating rates returned to normal, showing how the chemical acts as an Aphrodisiac.
Furthermore, the team discovered tiny amounts of methyl salicylate in moths feeding on an artificial food source in their lab; however, those caught in North Carolina soybean fields had vast quantities of this chemical. This chemical is stored inside hair pencils. Hair pencils are male organs that release their pheromone blend for mating. Incorporating the chemical into the food of the male moths by drinking a drink of sugar that resembled nectar revealed that male moths absorbed the chemical and then hid it within their hair pencils. If they were urged to court females aggressively, these hairpins had less methyl salicylate because the males absorbed a significant amount of it in their Pheromone cocktail.
“It was surprising to find methyl salicylate in male moth pheromone blends, but the evidence from this paper suggests that male moths take up and sequester methyl salicylate as larvae while chewing up plants or as adults by drinking flower nectar,” Schal explained. “Males may have evolved sexual signals that match the sensory bias exhibited by females in responding to methyl salicylate.”