Insect chemical defense

Research on the defensive chemistry of insects during the last decade is reviewed, with special emphasis on non-volatile compounds. The isolation and structure determination of defensive chemicals, of glandular and non-glandular origins, are first discussed, followed by an overview of the synthesis and biological/pharmacological activities of some of them. Biosynthesis has been largely omitted since this topic has been addressed in a recent review. During the period covered, beetles (e.g., coccinellids and chrysomelids) and ants have undoubtedly been the most prolific producers of repellent and/or toxic compounds. This survey also shows that alkaloids are the most frequently encountered defensive compounds in insects.