none Blood development and adult activity of Pissodes nemorensis Germar were studied in slash pine (Pinus elliottii Engelm. var. elliottii) plantations in northern Florida in 1977-78. The insect is basically univoltine in this area, but immatures are present in infested hosts or almost 9 mo during the cooler part of the year. Eggs were present in the field from late August until mid March; most oviposition occurred from October through February. Development from egg to adult within hosts required 7-25 wk depending on date of oviposition. Most adults emerged from late March to mid May. Some adults emerged before December from eggs laid in later summer, but it is not known whether these reproduced during the same season. Adults were caught in sticky traps next to trap trees, in window traps, and in pheromone traps from August until early April, with a major peak in October or November and a smaller peak in March. Most adults trapped were apparently mature (i.e., had developed in the previous season), for trap catches declined as new adults emerged. Adults were not observed in the summer months and were not caught in traps. P. nemorensis has five instars. At constant temperatures of 15, 20, and 25 degree C, egg-to-adult development required ca. 180, 70, and 58 d, respectively. Principal causes of mortality to weevil brood were the parasite Coeloides pissodis (Ashmead) (Hymenoptera: Braconidae) and woodpeckers. Disease and competition, principally with Ips spp., also appeared to be important.