Chitin synthesis inhibitors

Definition

A class of insect growth regulators (IGRs) that disrupt formation of the exoskeleton by blocking enzymes or transport processes required to polymerize N-acetylglucosamine into chitin. Affected insects typically fail to molt successfully, die during ecdysis, or develop with soft, malformed cuticle. The two main chemical groups are benzoylureas (e.g., diflubenzuron, lufenuron) and newer non-benzoylureas such as buprofezin and cyromazine.

Etymology

From chitin (Greek khitōn, tunic) + synthesis (Greek synthesis, putting together) + inhibitor (Latin inhibēre, to restrain)

Example

Diflubenzuron, a benzoylurea chitin synthesis inhibitor, is applied to larval mosquito breeding sites; exposed larvae cannot produce functional cuticle and die trapped in their old exoskeleton during the next molt.

Synonyms

• CSIs
• chitin synthesis inhibitor (singular form)

Related Terms

• insect growth regulator
• Benzoylurea
• ecdysis
• Molting
• chitin
• exoskeleton
• cuticle
• Buprofezin
• Diflubenzuron

Usage Notes

Often abbreviated CSIs in pest-management literature. Distinguished from juvenile hormone analogs and ecdysone agonists, which also disrupt development but through different endocrine pathways. Activity is generally limited to arthropods, making these compounds relatively safe for vertebrates and many non-target organisms.