A Model for Predicting Boll Weevil (Coleoptera: Curculionidae) Overwintering Survivorship

• Published in: Environmental entomology 2001-06, Vol.30 (3), p.550-555
• Main Authors: Parajulee, M. N, Slosser, J. E, Carroll, S. C, Rummel, D. R
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Anthonomus grandis; Anthonomus grandis grandis; Biological and medical sciences; cotton pest management; Curculionidae; Demecology; diapause; Fundamental and applied biological sciences. Psychology; overwintering survivorship; Phytopathology. Animal pests. Plant and forest protection; POPULATION ECOLOGY; Protozoa. Invertebrata; Protozoa. Invertebrates; Records, symptoms, damages, economic importance, population surveys; USA, Texas
• ISSN: 0046-225X; 1938-2936
• DOI: 10.1603/0046-225X-30.3.550

Boll weevil, Anthonomus grandis grandis Boheman, overwintering survivorship was quantified monthly throughout the overwintering period (October to May) in Texas High Plains and Rolling Plains for 12 yr. A negative exponential model was developed to dynamically predict survivorship throughout the overwintering months. Survivorship was modeled as a function of the number of days that weevils were in the habitat, negative degree-days (6.1°C), rainfall, and mortality during the first month of overwintering. First month mortality was modeled as a function of overwintering survival potential of weevils determined by dissection examination of their body lipid content and gonad atrophy. A nonlinear iterative multiple regression analysis showed that the model explained 94% of the variability in parameterization-verification data; a goodness-of-fit test showed that 97% of the estimated survival values did not significantly depart from their corresponding observed values. With independent validation data, 94% of the variability was explained by the survival model; a goodness-of-fit test for validation data showed that 96% of the predicted survival values did not significantly depart from their corresponding observed values. This model offers a greater understanding of boll weevil overwintering biology as it demonstrates a link between biological and climatic parameters. The model can be used to forecast weevil survivorship throughout the overwintering period in the Texas Plains.