Surface-active millipedes (Diplopoda) and associated mites (Acari, Mesostigmata) in Pigeon Valley Nature Reserve in Durban, South Africa

Abstract

Surface-active millipedes and associated mites were surveyed during two rainfall seasons in Pigeon Valley Nature Reserve (PVNR) in Durban, South Africa. Four millipede species, Doratogonus cristulatus (Porat, 1872) and Orthoporoides pyrhocephalus(C. L. Koch, 1865) (Spirostreptida, Spirostreptidae), Centrobolus anulatus (Attems 1934) (Spirobolida, Pachybolidae) and Sphaerotherium giganteum Porat, 1872 (Sphaerotheriida, Sphaerotheriidae) were recorded. All the species, except D. cristulatus, were arboreal. The sex ratio in D. cristulatus was strongly male-biased compared to O. pyrhocephalus and Centrobolus anulatus. Adult Neomegistus julidicola Trägärdh 1906 (Acari, Mesostigmata) were recorded only on males of D. cristulatus and O. pyrhocephalus. Incidence of mites on D. cristulatus and O. pyrhocephalus was 50 % and 6 %, respectively. The abundance, incidence and infestation intensity of mites on millipedes were higher at the beginning of the rainfall season when millipedes emerged than at any other time during the season. Surface-active females of D. cristulatus were uncommon and N. julidicola was found only on males. Most (50 %) of the mites were found on the anterior third of the male millipede body. The association between O. pyrhocephalus and N. julidicola is a new record. Although the results may not reflect the diversity of millipedes in PVNR because the sampling strategy did not include searching in the soil, they highlight the importance of carrying out surveys in urban reserves to provide data to inform biodiversity and conservation research.