Larval Development of Otiorhynchus sulcatus (Coleoptera: Curculionidae) and Effects of Larval Density on Larval Mortality and Injury to Rhododendron 1

The 6 larval instars of Otiorhynchus sulcatus (F.) completed development from eggs inoculated to container-grown rhododendron in 84 or 211 days when grown indoors or outdoors, respectively. Larval mortality was greatest during instars I–III. During instars IV–VI, mortality increased with increasing insect density. Underground stem tissue was fed on exclusively by instars IV–VI and the amount of tissue removed increased with larval density.