There are about 950,000 species of insects known but estimates range as high as 2-10 million which means that there are probably many species not yet known which have probably gone undetected so far in perhaps more remote parts of the world.
I think the relationship is Commensalism ( relationship between two organisms in which one benefits and the other does not benefit nor is harmed ) because the bird benefits and the cow does not benefit nor is harmed. Hope this helped ☺
The answer is C. Pheromones are hormones (which are proteinous) produces by individuals of the same species and are a means to send communication signals for social interactions. They signal alarm, food and even sex. Sex pheromones are released by females beetles into the environment to signal their availability for mating. The pheromones are picked up by receptors on the male beetles and this is how they find the females.