New host detection of the parasitic mite, Erythraeus pistacicus (Trombidiformes: Erythraeidae) from Iran and indication of possible infection with bacterial symbionts

During a survey of gall-inducing aphids on pistachio trees in Razavi-Khorasan Province, larvae of a parasitic mite were collected inside the galls of Forda hirsuta (Aphididae). The mite was identified as Erythraeus (Erythraeus) pistacicus Haitlinger, Mehrnejad & Šundić based on morphological, and molecular data. This is the first record of this mite from the host aphid, F. hirsuta, and also the third record of the occurrence of the mite in Iran. The survey of possible infections with bacterial symbionts in natural populations of E. (E.) pistacicus from Mashhad and Feizabad localities in northeastern Iran revealed the presence of three bacterial symbionts, Wolbachia, Planomicrobium, and Cardinium at different infection rates (55%, 30%, and 10% respectively), while Arsenophonus, Rickettsia, and Spiroplasma were not detected. Investigating bacterial symbionts in predatory insects/mites provide a valuable framework for better understanding the complex interactions between symbionts and their hosts and will lead to developing more efficacious biocontrol strategies particularly, those seeking to decrease reliance on chemical pesticides.