Temperature-Dependent Development ofOtiorhynchus ovatus(Coleoptera: Curculionidae) Pupae

Temperature-Dependent Development and Prediction of Emergence of the Summer Generation of Plum Curculio (Coleoptera: Curculionidae) in the Southeastern United States

“…This was not unexpected, for it is well known that development tends to proceed more rapidly at ßuctuating temperatures than would be expected based on model predictions at constant temperatures with the same mean, especially at relatively low temperatures (Kauffmann 1932, Wagner et al 1984b). This phenomenon has also been described for other coleopteran insects (Fan et al 1992, Lerin and Koubaiti 1998, Umble and Fisher 2000. Because the outdoor validation trials were carried out between late September and late November, when daily minimum temperatures were below the lower thresholds for development (Table 3), a signiÞcant deviation between observed and predicted degree-day requirements for emergence is not surprising.…”

“…This approach differs from developmental period models for other coleopteran insects where either mean (Fan et al 1992, Lerin and Koubaiti 1998, Lapointe 2000 or median (Umble and Fisher 2000) emergence times were used. In our experiments, the peak of plum curculio emergence occurred when Ϸ15Ð30% of the insects had emerged (data not shown).…”

“…Results showed that a simple linear degree-day model predicted development more accurately than a more complex biophysical model. Umble and Fisher (2000) developed nonweighted and weighted linear degreeday models for pupal development of the strawberry root weevil (Otiorhynchus ovatus L.) in constant temperatures. Weights were based on the proportional occurrence of these temperatures in the Þeld and calculated from historical weather records.…”

Overwintering ofTrichogramma funiculatumCarver (Hymenoptera: Trichogrammatidae) Under Semi-Natural Conditions

“…Degree-day (or degree-hour) models are commonly used as the basis for insect development models (e.g., Judd and Gardiner 1997, Godin and Boivin 1998, Ro et al 1998, Umble and Fisher 2000, Kim et al 2001). The value of such models lies in their ability to successfully predict the timing of an insectÕs life cycle.…”