ULTRASTRUCTURAL STUDIES ON THE SENSILLA OF THE MOUTH PARTS AND ANTENNAE OF THE PRE-ADULT STAGES OF SITOPHILUS GRANARIUS (COLEOPTERA: CURCULIONIDAE)

doi:10.21608/aunj.2019.221129

ULTRASTRUCTURAL STUDIES ON THE SENSILLA OF THE MOUTH PARTS AND ANTENNAE OF THE PRE-ADULT STAGES OF SITOPHILUS GRANARIUS (COLEOPTERA: CURCULIONIDAE)

Document Type : Novel Research Articles

10.21608/aunj.2019.221129

Abstract

The granary weevil S. granarius is one of the most important stored product pests on the world, because of its damage. This pest is the main reason of the post harvest losses in world production; as a result of adults and larvae infesting and feeding on stored grains. The morphology and ultrstructure of the mouth parts and antennae of the pre-adult stage of S. granarius was investigated using scanning electron microscopy. The antennae and mouth parts of the granary weevil larvae and pre-pupal stage have a number of very interesting sensillae. The antennae have one large sensillum with different morphological appearance. Pores have been noticed on both sides. This one is known as sensilla basiconica. The pores may have an auditory function. The 2^nd, 4^th, and prepupal stages have a very strong mandibles each of them have two long sensillae. On the lateral view of the distal part of maxillary palp there was a digitiform sensillum. The digitiform organ is considered as a hygrothermo-receptor and was located on the lateral surface of the last segment of the larval maxillary palp. Another type of sensillae have been present and called chaetica sensillae, sensillae like a peg (sensilla twig basiconica) and campaniform sensilla which are located on the upper surface of the antennae of the 2^nd, 4^th larval instar and prepupal stages.

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