Question

what is the main excretory product of terrestrial insects ??☺☺

Answer 1

excretory products are of three types
ammonotelic
ureotelic
uricotelic
you asked for terrestrial insects it excreates in the form of dry pellets it is ureotelic 

Answer 2

URIC ACID is important excretory product of terrestrial insects.

Explanation:

Usually the organisms excretes three types of products namely, “Ammonia, Urea, and uric acid”. The aquatic animals like bony fish excrete ammonia as waste products. Other living species such as mammals, Amphibians, sharks and humans excretes Urea as waste product.  

Organisms such as birds, reptiles and all types of insects gives out waste in form of Uric acid. The terrestrial insects gives away uric acid due to adaptation of water conservation in the terrestrial habit.