Steampunk-ish novel containing drug secreting insectoids and mechanical computers?

Question

I remember reading a very peculiar novel that I really enjoyed about 10 years or so ago. The novel might have been significantly older than that.

I remember the plot was about a scientist / inventor who was working on some form of mechanical computer / artificial intelligence. He found an insectoid creature that was responsible for the secretion of a certain kind of drug. That insect had the capacity to hypnotize other creatures or something similar.
If I recall, the solution they found to solve the problem was by designing some sort of artificial intelligence that was harnessed in a mechanical computer (or something with punch card inputs) that fought the drug secreting insects.

Answer 1

This is Perdido Street Station by China Miéville, published 2000.

From its Wikipedia article, here's your scientist and insectoid creature that feeds on a hallucogenic (rather than secretes it) and hypnotises victims.

Isaac Dan der Grimnebulin is a scientist living in the city of New Crobuzon. He is approached by Yagharek, a member of a birdlike species known as garuda, who has had his wings removed as a punishment in his native land. He asks Isaac to allow him to fly again. Isaac agrees and starts collecting samples of flying creatures for his research with the aid of Lemuel Pigeon, a fence with links to the criminal underworld. One sample he receives is a large and unusual caterpillar, stolen from a government research lab. The caterpillar sickens until Isaac realises that it can feed on a popular hallucinogenic drug. It grows and starts to pupate. After reaching maturity, it emerges as a monstrous flying beast known as a slakemoth with the power to paralyse its victims using its wings. It escapes after eating the mind of one of Isaac's colleagues, leaving him catatonic. Isaac, Yagharek and Lemuel resolve to re-capture or destroy it.

Your other details, including the mechanical computer, mostly match.