TEMPERATURE TOLERANCE OF PRONYMPHS AND PUPAE OF THE LARCH SAWFLY,PRISTIPHORA ERICHSONII(HYMENOPTERA: TENTHREDINIDAE)

Abstract

The effects of temperature on survival during postdiapause development of the pre-imaginal stages of the larch sawfly,Pristiphora erichsonii(Hartig), were investigated in the laboratory using Manitoba material. Pronymph mortality increased progressively between 10° and 30 °C. Developmental arrest occurred in pronymphs exposed to 35 °C for periods up to 10 days prior to their transfer to 15 °C for completion of development. Pupae were more tolerant of high temperatures than were pronymphs.The results are discussed in relation to the possible physiological mechanism involved and the ecological implications for survival in the field.