Some aspects of the behavior and biology of Phaedon confinis Klug, 1829 are evaluated on the host plant Senecio brasiliensis (Spreng.) Less. The adult insects were collected in Ponta Grossa (Paraná, Brazil) and were kept in an average temperature of 20.03ºC. The eggs of P. confinis are elongated and yellowish, with an average total amount of 756.75 ± 50.19 eggs / female with an average of 7.54 ± 0.99 eggs / chutch. The average incubation period was 7.38 ± 0.21 days and the average viability of the eggs were 44.69% ± 7.45. The larva has dark brown coloration, with short bristles distributed on the body and the form was similar in the three larval instars, with size increasing in each ecdisys. The three instars lasted on average 5.81 days, 4.82 days and 21.84 days, respectively; and the average survival reached in the thirth instar was 5.27%. The pupal period presented average duration of 5.58 days and average survival of 3.88%. The average longevity of the females was 229 days and of the males 213.75 days.
Biological control; immature development; Phaedonini; Senecio brasiliensis
