Insect is the correct spelling.
That is the correct spelling of the plural noun "insects" (bugs).
insects
Insect.
There is no actual "opposite" of an insect. However, the other insect-sized arthropods are the arachnids (spiders and scorpions).
They spell the word "tick" (a biting insect, or a clock sound).
That is the correct spelling of the insect, the silkworm.
The household insect pest is a "cockroach".
The insect is a cicada. (family includes the co-called 17-year locust)
The correct spelling of the biting insect is mosquito.
The spelling of the flying insect name is the damselfly.
Tick.
The correct spelling is "insectivores" (insect eaters).
Cicada is the name of the insect you are looking for.
That is the correct spelling of "katydid" (an insect, family Tettigoniidae).