First record of parasitized Trithemis pallidinervis (Kirby) from Tamil Nadu, India by Arrenurus larvae, with a description of larval morphology (Anisoptera: Libellulidae; Acari: Hydrachnidia)

Out of a total of 20 adult T. pallidinervis specimens (Odonata), collected in Tamil Nadu, India, 164 larvae of Arrenurus sp. were found; prevalence; 57.5%, intensity: 5-12. They were attached to the mesostemum and metasternum. Their morphology is very similar to that of A. cuspidator and A. maculator, but differs by the absence of Mpl tripartite seta, V2 seta and secondary seta in Pill 1 and the presence of secondary setae on both sides of V3 setae. They also differ from A. maculator by the absence of hairbrush on the base of Cl seta.