Temperature-dependent development and mortality of Australian cockroach, Periplaneta australasiae (Fabricius) (Blattodea: Blattidae

Abstract

The effect of temperature on the development of the 1 st instar of Periplaneta australasiae (Fabr.) was studied at the four constant temperatures of 21°C, 24°C, 27°C and 30°C in temperature-controlled chambers. Mortality was 50% at 30°C, and 10% at 21°C, 24° and 27°C. Thermal constants were established by plotting linear regression to development rate. The thermal threshold for the development was 17.1°C and the thermal constant for 1 st instar larvae was 147.1 day-degrees. As "safe temperature" (t s ) -the temperature to be maintained in stores or food premises to prevent the development of a pest species -we recommend 16°C.

Differential development and survival of Blattella asahinai and Blattella germanica (Blattodea: Ectobiidae) at six constant temperatures

“…The LDTs and degree days presented are merely estimations based only on three constant temperatures. Stejskal et al (2003) calculated the LDT for the first instar of B. germanica to be 16.2 °C, which is higher than 11.75 °C, the LDT for the first instar of B. germanica determined in the present experiment. Xu et al (2017) reported the LDT of 1st to 5th instar of B. germanica was 14.…”

“…Stejskal et al (2003) calculated the LDT for the first instar of B. germanica to be 16.2 °C, which is higher than 11.75 °C, the LDT for the first instar of B. germanica determined in the present experiment. Xu et al (2017) reported the LDT of 1st to 5th instar of B. germanica was 14.3 ± 3.2, 13.7 ± 2.3, 14.6 ± 3.6, 16.6 ± 2.4, and 18.5 ± 1.4 °C, respectively.…”

“…Linear regression was performed for each instar and for the average nymphal development period using the mean number of days required for completion and the temperature within each species. To calculate degree days and the lower development temperature (LDT) for each life stage, the formula y = ax + b or = aT + b was used, where 1/ D , the reciprocal of the number of days required to complete the life stage, is the development rate, and T is the temperature (Stejskal et al 2003, Wu et al 2017). The LDT was calculated as the temperature ( T ) at which the development rate (1/ D ) is 0, or – b / a .…”

“…This temperature range was selected because, in Alabama, the hottest month of July has an average high temperature of 32.6 °C (National Weather Service Forecast Office 2018). The LDT for B. germanica was reported to be 16.2 °C (Stejskal et al 2003), but because Alabama can experience average low temperatures of −1.4 °C in January (National Weather Service Forecast Office 2018), 10 °C was used as the lowest temperature for this experiment. Six different incubators were used for each of the six temperatures.…”

“…One method to experimentally determine the number of degree days required for each life stage, as well as estimate the lower threshold, is to record development at a series of constant temperatures and calculate the number of degree days required for each life stage (Marco et al 1997, Wu et al 2017). This information can be used to create simple linear models through linear regression of days and experimental temperatures (Stejskal et al 2003, Wu et al 2017). The resulting models can be applied in the field by tracking the number of degree days accumulated since a certain event or day (e.g., January 1, biofix, or the date to begin accumulating degree days) to predict the date of important life cycle events, such as spring emergence or generational egg hatch (Marco et al 1997, Liu et al 2002).…”