Immature stages and life cycle of a Megalopyge Hübner, [1820] causing dermatitis in the city of Córdoba, Argentina (Lepidoptera: Megalopygidae)

Abstract

During the last decades in Argentina, the cases of erucism have increased notably, with some outbreaks of epidemiological importance. In December 2019, a resident of the city of Córdoba reported a case of erucism caused by contact with caterpillars of Megalopyge Hübner, [1820] present in a shrub in the sidewalk. Taking into account the little information available in the literature about the family in general, and in this region of the country in particular, and the potential health risk that these caterpillars could represent, our goals were to know what species it is, to describe the immature stages and the development times of this species, and to evaluate the possibility of the caterpillars using some common tree species as alternative hosts. Adults and immatures reared in the laboratory are more similar to those described as Megalopyge undulata vulpina Berg, 1882 than any other species of the genus, but some morphological and chromatic differences lead to the proposition that these are two related but different taxa. According to our observations, at the latitude of Córdoba the species seems to be bivoltine, with an average embryogenesis time of 6 days and 58 days of larval development time for the second generation. The time spent inside the cocoon was highly variable. On the other hand, the limited success in the development of the larvae with the alternative hosts that we offered them would indicate that the species does not represent, at the moment, an emerging health problem.