Used by many natural history museum curators in the preparation of animal skeletons for display, dermestid beetles feed on the decaying flesh of animal carcasses, pulling with its mouthparts to strip the bone of any residual fat or muscle tissue.

dermestid beetles feed on the decaying flesh of animal carcasses, pulling
dermestid beetles feed on the decaying flesh of animal carcasses and pull
the dermestid beetle feeds on the decaying flesh of animal carcasses in order to pull
the dermestid beetle feeds on the decaying flesh of animal carcasses, pulling
the dermestid beetle feeds on the decaying flesh of animal carcasses and it pulls

OA - D

I understood that the sentence contains the singular noun and plural verb error. But I am stuck on the usage of 'the' with 'dermestid beetle'
I feel the should not be used here because it is not the second reference to beetles in the sentence. Only if there is some prior reference 'the' should be used.

how about -

dermestid beetle feeds on the decaying flesh of animal carcasses, pulling

is there some other reason for which 'the' has been used in the sentence???