Modeling Embryo Development of <I>Sitona discoideus</I> Gyllenhal (Coleoptera: Curculionidae) Under Constant Temperature

Abstract

The alfalfa root weevil, Sitona discoideus (Coleoptera: Curculionidae), is an important pest of alfalfa. The developmental rates of the embryo development were recorded at eight constant temperatures ranging from 8.5 to 30 degrees C. Using 10 models (1 linear and 9 nonlinear), we evaluated the relationship between constant temperature and developmental rate. Embryo development was shortest (8.5 d) and longest (69 d), at 28 and 8.5 degrees C, respectively. The threshold temperature (T0) and the thermal constant (K) were estimated using linear regression to be 4.7 degrees C and 207.7 DD, respectively. The two most efficient nonlinear models, the Lactin and the Sharp and DeMichele, gave estimates of Tmin and Tmax of 4.4 and 3.9 and 30.0 and 30.9 degrees C, respectively. This information has potential application in predicting the suitability and optimal time of release of an egg parasitoid of S. discoideus.

Influence of Host Plants on the Development of &lt;i&gt;Caryedon serratus&lt;/i&gt; Olivier (Coleoptera: Chrysomelidae, Bruchinae), Insect Pest of Groundnut Stocks in Burkina Faso

“…Our results indicate that larval stage duration varies from one stage to another; which was not the case with the results reported by some authors who found a 4 days average duration for the first three larval stages [13]. This constant duration has something to do with the climatic conditions, mainly with temperature [15]; they consider the latter as the main factor which determines insects' larval development. In addition to this factor, insect used variety and biotype can also influence this development period.…”

Estimations of the critical temperatures for development of the pistachio psylla, Agonoscena pistaciae (Hemiptera: Psyllidae)

“…The relationship between insect developmental rate and temperature reported here is an important ecological variable, which should be included in models of the population dynamics of this pest. Forecasting models can be used to predict when to start monitoring a pest in the field or the optimum time to apply control measures, such as insecticides or release of natural enemies (Akers & Nielsen, 1984;Brunner, 1984;Graf et al, 2006;Diaz et al, 2007;Arbab et al, 2008). Such a forecasting model could be incorporated into integrated pest management programs of this pest and used to predict when best to either apply an insecticide or release natural enemies.…”

“…The lower and upper temperature thresholds were estimated using these equations. The optimum temperature for development is that at which the rate of development curve reaches its maximum value (Arbab et al, 2008).…”

“…The relationship between developmental rate and temperature is an important ecological variable in models of the population dynamics of insects (Wagner et al, 1984). The relationship between temperature and developmental rate could provide useful parameters for predicting the development of this pest and for determining the optimal time to release natural enemies (Arbab et al, 2008). It is easy to calculate the minimum temperature threshold using linear regression but not the maximum and optimum thresholds.…”

Nonlinear models for describing development and fecundity of the pseudococcid predators Nephus includens and Nephus bisignatus

“…Several mathematical models have been used for describing the development of insects over a wide range of temperatures such as Logan-6, Lactin, Sharpe and DeMichele, Briere, Bieri-1 and 2, Analytis and Enkegaard equations (Lactin et al 1995, Roy et al 2002, Kontodimas et al 2004, Arbab et al 2006, 2008, Zahiri et al 2010, Ranjbar et al 2011. Similarly, some mathematical models have been used to describe fecundity or fertility at different temperatures such us the equations of Bieri-1 and 2, Enkegaard, Ydergaard and Analytis (Bieri et al 1983, Enkegaard 1993, Ydergaard et al 1997, Lanzoni et al 2004, Kontodimas et al 2007, Ranjbar et al 2011.…”