What type of material is toxic to insects through contact and/or stomach poisoning?

Insecticide is the correct choice because it is specifically designed to target and control insect populations. These substances operate either through direct contact with insects or through ingestion, effectively disrupting their biological functions. Insecticides can act on the nervous system of insects, leading to paralysis or death, making them a crucial tool in pest management for agriculture, landscaping, and gardens.

Herbicides are intended to control unwanted plants or weeds, so they do not affect insect populations in the same way. Fungicides are used to combat fungal infections and diseases, which are unrelated to insect control. Acaricides are similar to insecticides but are specifically formulated to target mites and ticks rather than a broader range of insects. Therefore, insecticides remain the primary solution for toxic effects on insects through either contact or stomach poisoning.