What are some examples of parasites that use chemicals to form relationships with thier host?

Question

Some examples that I have come up: gall wasps that inject a chemical into the host leaf to cause the leaf to form a gall. The wasps larvae can then grow inside the gall.
Also monarch butterfly larvae eat leaves from the milkweed plant, so they can absorb the poisonous chemical. They then carry this chemical into thier adult form.

Answer 1

There's a parasditic barnacle that changes the hormonal balance of a crabs body so that it is emasculated, can't reproduce and cares for the parasites egg sac as though it was its own egg mass - how's that?

Answer 2

The large blue butterfly in its larva stage will produce sugar and entice ants to carry it back to the nest where it will feed on the ants larva. It produces sugar to keep the ants from being concerned about it and while it feeds on the larva it is protected by the smell of pheromones form the queen larvae that it picks up while feeding. This is an example of parasitism.

Answer 3

The example that comes to mind is the human female. She plies her lover with alcohol until he proposes marriage. After that she will absorb the total life force he has until he is nothing but an empty shell. Does he die? Not usually but he sometimes wishes he was dead.

Answer 4

Leeches secrete a substance that acts as a painkiller so that the host doesn't feel the bite and knock them off.

Answer 5

i believe there is a parasite in the gut of a termite that uses chemicals in its system to breakdown the food a termite eats and the dissolved substance is digested by the termites system. i dont believe a termite can digest cellulose.

Answer 6

Men who slip drugs into womens' drinks. Sarcastic. Yes. But sadly kinda true.

Answer 7

you also have sulpur bacteria