The agricultural industry is so obsessed with keeping weeds and insects away from its crops (usually through genetic modification and dangerous chemical pesticides), that it might seem counter-intuitive to look for the secret to increased crop yields among the pests themselves.
But a study soon to be published in Ecological Applications found that larvae of one of the most troublesome potato pests in Latin America—the Guatemalan potato moth (Tecia solanivora) were the source of dramatically increased potato yields in Colombia.
In some areas of Columbia, farmers apply pesticides twice a week in an attempt to keep these spud-munchers at bay.
According to a researcher from Georg August University in Germany, the larger, more abundant potatoes were a result of chemical elicitors in the larvae saliva, which are produced in its foregut (EcoTone).
When moth larva infested one of the tubers (potatoes are stem tubers) of a Colombian Andes potato plant (Solanum tuberosum), the rest of the plant, including the remaining tubers, increased in size and abundance. The resulting yield (when infested potatoes were removed) weighed 2.5 times more than the yield from completely undamaged plants.
Researchers are fascinated by the underlying molecular and metabolic mechanisms at work in their study, and hope that the isolation and application of the herbivore-derived elicitors can provide promising tools for managing the impact of herbivores on crops.
No word yet on whether or not drool from other species could have a similar effect.
Image Credit: Flickr Creative Commons - tibchris