Molecular detection of pathogens in the ova and unfed larvae of Rhipicephalus annulatus and Haemaphysalis bispinosa ticks infesting domestic cattle of south India

•Pathogen detection in the engorged female ticks, their ova, and unfed larvae infesting domestic cattle in south India.•Babesia bigemina in engorged female Rhipicephalus annulatus ticks, their eggs, and unfed larvae.•Anaplasma marginale in engorged female Rh. annulatus ticks, their eggs, and unfed larvae.•A. phagocytophilum, and Rickettsia spp. similar to R. raoultii in engorged female Rh. annulatus and Haemaphysalis bispinosa ticks, eggs, and unfed larvae.•Theileria orientalis detected in engorged female Rh. annulatus, but not in their egg masses or progenies.•Mixed infections of B. bigemina and A. phagocytophilum, B. bigemina, and A. marginale in engorged female Rh. annulatus ticks and their progenies. This study aimed to investigate the presence of pathogens in the engorged ticks infesting domestic cattle, their ova, and unfed larvae. The engorged female ticks infesting domestic cattle of Wayanad district of Kerala, south India were collected and kept for oviposition. The dead females after the complete oviposition, their egg masses, and unfed larvae were screened for the presence of various pathogens by specific PCRs. The presence of Babesia bigemina, Anaplasma marginale, A. phagocytophilum, and Rickettsia spp. similar to R. raoultii was confirmed in Rhipicephalus annulatus ticks, their egg masses, and unfed larvae. Theileria orientalis was detected in Rh. annulatus females, but not in their egg masses or progenies. The presence of A. phagocytophilum and Rickettsia spp. similar to R. raoultii was confirmed in Haemaphysalis bispinosa ticks, their egg masses, and unfed larvae too. The presence of coinfections of B. bigemina with A. phagocytophilum and A. marginale were detected in Rh. annulatus ticks and their progenies.