What's the noun for parasiticides? Here's the word you're looking for.
parasite
(pejorative) A person who lives on other people's efforts or expense and gives little or nothing back. [from 16th c.]
(biology) An organism that lives on or in another organism, deriving benefit from living on or in that other organism, while not contributing towards that other organism sufficiently to cover the cost to that other organism.
(literary) A climbing plant which is supported by a wall, trellis etc. [from 19th c.]
“When doubt remains, an experienced cytologist, pathologist, or parasitologist should review the smear.”
“This text is one that will please the experienced pathologist and parasitologist, as well as being a comprehensive starting point for those entering the field.”
“When Canadian parasitologist Leo Margolis read of Kabata's work he immediately began to correspond with him.”
“These typically include malnutrition, anaemia, malaria parasitaemia, or HIV infection.”
“The occurrence of other illnesses and malarial parasitaemia was not significantly affected by iron administration.”
“Firstly, because the level of parasitaemia in malaria varies from hour to hour, blood should have been examined several times a day for two or three days.”
“The carrier to noise ratio optimization, or the minimisation of the parasitics signals, is crucial, together with the system reliability.”
“The very low profile offering low parasitics inductances makes this product range a component of choice when space, electrical performance, weight and cost are a concern.”
“Parasitics become more problematic as the circuitry becomes more sophisticated and smaller and as it runs at higher frequencies.”