Physiological Time Model for Predicting Adult Emergence of Western Corn Rootworm (Coleoptera: Chrysomelidae) in the Texas High Plains

Department of Entomology, Texas Cooperative Extension, The Texas A&M University System, 115-A Agronomy Field Laboratory, Texas A&M University, College Station, TX 77843-2488, USA.
Journal of Economic Entomology (Impact Factor: 1.61). 11/2008; 101(5):1584-93. DOI: 10.1603/0022-0493(2008)101[1584:PTMFPA]2.0.CO;2
Source: PubMed

ABSTRACT Field observations at three locations in the Texas High Plains were used to develop and validate a degree-day phenology model to predict the onset and proportional emergence of adult Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) adults. Climatic data from the Texas High Plains Potential Evapotranspiration network were used with records of cumulative proportional adult emergence to determine the functional lower developmental temperature, optimum starting date, and the sum of degree-days for phenological events from onset to 99% adult emergence. The model base temperature, 10 degrees C (50 degrees F), corresponds closely to known physiological lower limits for development. The model uses a modified Gompertz equation, y = 96.5 x exp (-(exp(6.0 - 0.00404 x (x - 4.0), where x is cumulative heat (degree-days), to predict y, cumulative proportional emergence expressed as a percentage. The model starts degree-day accumulation on the date of corn, Zea mays L., emergence, and predictions correspond closely to corn phenological stages from tasseling to black layer development. Validation shows the model predicts cumulative proportional adult emergence within a satisfactory interval of 4.5 d. The model is flexible enough to accommodate early planting, late emergence, and the effects of drought and heat stress. The model provides corn producers ample lead time to anticipate and implement adult control practices.

1 Follower
  • [Show abstract] [Hide abstract]
    ABSTRACT: The oriental fruit moth, Grapholita molesta, is becoming a large threat to Korean pear production. Timely management of the egg and early larval stages from the spring emergence is critical to reduce the G. molesta population during the pear growing season. A model was developed to precisely predict the spring occurrence of G. molesta adults as a function of accumulated degree-days. The model was validated with male moth caught in sex pheromone-baited traps placed in pear orchards at two major pear production regions (Icheon and Naju) of Korea in 2010. We applied nine distribution models to describe the cumulative proportions of G. molesta males caught relative to accumulated degree-days. The observed phenology of the G. molesta spring population was well described by the nine models. The predicted dates for the cumulative 50% male moth catches were within a 5 day period. Based on statistical information criteria (Akaike's and Bayes–Schwartz information criteria), we recommend the sigmoid function referred by Brown and Mayer, because of its ease of use and meaningfulness; the parameter “b” denotes the degree-day accumulation at 50% moth emergence. The G. molesta spring emergence model could be applied to determine optimal chemical treatment timing for controlling G. molesta in fruit tree orchards and further help to develop a full-cycle phenology model of G. molesta.
    Journal of Asia-Pacific Entomology 12/2012; 15(4):589–593. DOI:10.1016/j.aspen.2012.04.002 · 0.88 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The sum of effective temperature (SET) of adult Western Corn Rootworm (WCR) occurrence was determined based on several criteria. The risk of WCR occurrence was mapped, and the areas of continuous reproduction of WCR in the Czech Republic were identified. The daily soil SET, until the initial adult WCR occurrence was observed, ranged from 414 degree days (DD) when the lower threshold temperature (LTT) 12.5°C at 0.02 m depth to 719 DD (LTT of 10°C at a depth of 0.05 m). The daily air SET ranged from 415 DD (LTT 12.5°C at a height of 2 m) to 726 DD (LTT of 10°C at a height of 0.05 m).
    Plant Protection Science 01/2013; 49(2):89-97.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: 1 The Asian longhorn beetle Anoplophora glabripennis is highly polyphagous and widely spread over regions with different climates. Determining the key life-history traits is important for understanding how local conditions affect its successful establishment and to develop adaptive management strategies. 2 Field and laboratory studies were conducted from 2010 to 2012 on an A. glabripennis infestation in Northern Italy, aiming to determine its seasonal phenology, adult beetle longevity, density of successful emergence, infestation age and overwintering life history. 3 Adult beetle emerged from infested trees from 22 May to 28 June. Ninety percent of emergence was reached around 20 July. The rst 1% of emergence was accurately predicted by an accumulated degree-day model. 4 In the laboratory, the mean longevity of males and females developed under natural conditions was 27.8±1.7 and 24.9±1.8 days, respectively. In northern Italy, A. glabripennis largely overwinter as mature larvae in the xylem. The mean density of exit holes was 24.0±2.7 holes/m2 of bark, with successful emergence from branches as small as 3.2 cm in diameter. Although the infestation was discovered in June 2009, the oldest exit hole found in infested trees dated from 2005.
    Agricultural and Forest Entomology 12/2014; DOI:10.1111/afe.12096 · 1.56 Impact Factor