European Corn-borer

• It is the pest the first Bt transgenic maize was designed against, producing a bacterial insecticidal protein; its widespread planting in North America has cut populations so far that growers of conventional maize benefit too.
• There are two races that use different pheromone blends and do not recognise one another, a much-studied case of speciation under way within a single species.
• The larva overwinters inside the stems and crop residues, so shredding and ploughing in the stubble is a basic control measure.
• It is the costliest maize pest of the temperate world: the caterpillar bores through the stalk from within, weakening it until it snaps, and it also attacks the cob.
• It reached the United States around 1917, probably in millet brooms imported from Europe, and within a few decades it had colonised the entire Corn Belt.
• It is the main reason Bt maize exists: the transgenic varieties that produce the Bacillus thuringiensis toxin were developed above all against this species.
• And the result has been measured: a 2010 study calculated that Bt maize in the United States had generated some 6.9 billion dollars in accumulated benefit over fourteen years, and that most of it went to growers of conventional maize, because the reduction of the pest across the landscape benefited them too.
• What is known as Ostrinia nubilalis is in fact two races separated by the sex pheromone they use, which scarcely interbreed.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat & environment

Crops of maize, pepper and other thick-stemmed herbaceous plants

Sources consulted: https://es.wikipedia.org/wiki/Ostrinia_nubilalis