Temperature Effects on the Survival and Development of Two Pest Bark Beetles Hylurgus ligniperdaF. (Coleoptera: Curculionidae) and Hylastes aterPaykull (Coleoptera: Curculionidae)

Hylurgus ligniperda(F.) and Hylastes ater(Paykull) are secondary bark beetles that have successfully spread beyond their native range, particularly into Pinusspp. plantations in the Southern Hemisphere. They feed on the phloem and cambial regions of highly stressed and recently dead Pinusspp. Here H. ligniperdaand H. ateregg, larval, and pupal survival and development rates were modeled. Survival was variably influenced by temperatures depending on the life stage, but general trends were for H. ligniperdato tolerate warmer temperatures in comparison to H. ater. Nonlinear models showed 26, 29, and 34°C are the optimal temperature (maximum development rates) for the development of eggs, larvae, and pupae of H. ligniperda. In contrast, optimal temperature predictions were lower for H. ater, with estimates of 26, 22, and 23°C for the development of eggs, larvae, and pupae, respectively. H. ligniperdapre-imaginal stages were more tolerant to high temperatures, and H. aterpre-imaginal stages were more tolerant to low temperatures. Understanding the thermal requirements and limits for development for these two pests can assist in modeling emergence times, their current and potential species distribution and have potential phytosanitary applications.