Two novel alkaloids, 2-(12-aminotridecyl)-pyrrolidine and its 1-(2-hydroxyethyl) derivative, are characterized from extracts of adult Mexican bean beetles. These pyrrolidines, together with a previously identified homotropane alkaloid, euphococcinine, account for 90% of the alkaloids present in this beetle. A number of piperidine derivatives are also identified as minor components. The total mixture represents the most complex bouquet of alkaloids reported hitherto from any coccinellid beetle.