BIOLOGY AND DESCRIPTION OF IMMATURE STAGES OF PENTISPA-SUTURALIS (BALY) (COLEOPTERA, CHRYSOMELIDAE) ON BACCHARIS-BIGELOVII (ASTERACEAE)

The chrysomelid Pentispa suturalis (Baly) feeds on leaves of Baccharis bigelovii Gray (Asteraceae) in Arizona. There is one generation per y ear. Adults emerge from soil debris in April and feed for about a mont h before mating. Eggs are laid within the leaf tissue and are covered with fecal material. Most are laid in the tip of the leaf and 93.6% ar e found on the lower side. Larvae are present from July to September; they feed in blotch-type mines and each consumes one to three leaves. Teneral adults emerge in September and feed before overwintering in le af debris below the plant. Taxonomic descriptions of third-instar larv a and pupa and a key to aid larval identification are given.