Millipedes in and Around Structures in Florida

Abstract

The 2 millipedes which most commonly become nuisances around structures in Florida are the greenhouse millipede, Oxidus gracilis Koch, and the tropical millipede, Orthomorpha coarctata (Saussure). Several others are bothersome more sporadically. The greenhouse millipede is more widespread, but is generally less of a problem because it appears to breed only in wild and overgrown areas where there is much decaying leaf litter from which it occasionally disperses to nearby structures. The tropical millipede apparently breeds in the thick lawngrass thatches common in south Florida. The biology of the tropical millipede was found to be much like that of the better known greenhouse millipede. Egg to adult time for Orthomorpha coarctata was 119 to 187 days, with apparently 2 generations a year. Development continued slowly through the winter, but mating and egg laying appeared to begin in March. These millipedes were active through the night, but peak activity was reached in mid-morning and with the least activity during afternoon and early evening hours. Oxidus gracilis fed on decaying organic matter, and could not be forced to eat grass or bean plants. In cross-mating tests, gracilis males attempted to mate with coarctata females, but no eggs were produced from these pairings. In laboratory-scale control tests, the carbamates methomyl, carbaryl, and propoxur provided complete and quick kill of greenhouse millipedes.