As is generally the
case with nocturnal Arctiidae moths, males of
Cosmosoma teuthras are
attracted by pheromones emitted by the females. As the male approaches
a female he hovers above her and discharges a burst of very fine
filaments which swirl in the air around her, and envelop her body.
American biologists Conner and Boada
found that Cosmosoma males are attracted
to Eupatorium plants, and sequestered
alkaloids from juices seeping from the stems. Such pyrrolizidine
alkaloids are sequestered by a wide variety of butterfly genera
Pteronymia, Lycorea and
Danaus; and by several genera of moths in
the family Arctiidae. The PAs stored in the bodies of the insects
render them toxic or unpalatable to birds, and are a primary defence
method in aposematic species.
The researchers found that in the case of
Cosmosoma the toxins seemed to be
directed mainly at predatory spiders. Moths caught in the webs of
Nephila clavipes were cut free from the
webs by the spider, but moths which had been deprived of the
opportunity to sequester PAs were consumed.
Conner and Boada
found that PAs were passed to females via the discharged filaments,
and also via spermatophores delivered during copulation. The toxins
conveyed to females were found to provide them with protection against
predators during the following nights, enabling them to lay their eggs
unmolested. It was also demonstrated that the toxins were passed to
the eggs, and provided them with protection against ants, Coccinellid
beetles ( ladybirds ) and Chrysopid larvae.