Estimating development and temperature thresholds of Scolothrips longicornis (Thysanoptera: Thripidae) on eggs of two-spotted spider mite using linear and nonlinear models

Abstract

The development rate of the predatory thrips, Scolothrips longicornis Priesner, fed on Tetranychus urticae Koch was determined at 15, 20, 26, 30, 35, and 37°C. No development occurred at 40°C. The total development time from egg to adult emergence for females was estimated to be 48.1, 22.8, 13.6, 10.6, 8.3 and 9.6 days, respectively. The development time decreased with increasing temperature from 15 to 35°C. In the temperature range of 15-37°C, egg and larval mortality varied between 10% and 48% and 1.92% and 11.1%, respectively. The sex-ratio of S. longicornis was in favor of females at all tested temperatures and remained uninfluenced by temperature in the range of 15-35°C with an average of about 75% females. The lower temperature threshold for the entire development period and the thermal constant for female S. longicornis using the common linear model were estimated to be 11.1°C and 200 degree-days (DD), and 10.8°C and 204 DD using the Ikemoto and Takai model. Data were fitted to four nonlinear development rate models and the thermal thresholds (T min and T max ) and optimal temperature (T opt ) estimated. The Briere-1, Briere-2, and Ikemoto and Takai linear models provided adequate descriptions of temperature-dependent development of S. longicornis. The upper temperature threshold was estimated to be about 42°C. Temperaturedependent development data, thermal requirements and temperature thresholds can be used to predict the occurrence, number of generations and population dynamics of S. longicornis, an important biocontrol agent of T. urticae.

Lethal and Sublethal Effects of Fenpropathrin on the Biological Performance of <I>Scolothrips longicornis</I> (Thysanoptera: Thripidae)

“…For spider mites, biological control could be based on a variety of natural enemies (Helle and Sabelis 1985) including predatory thrips such as Scolothrips longicornis Priesner (Thysanoptera: Thripidae) (Li et al 2006), which occur commonly in bean (Aydemir and Toros 1990), cucumber, and eggplant (Pakyari et al 2009) in, among other places, the Middle East (Priesner 1950, Pakyari et al 2011. Predatory thrips may be exploited in biological control strategies based on conservation through habitat manipulation combined with the use of selective pesticides (Hopper 2003) that are effective against spider mites but at the same time relatively harmless to predatory thrips (Desneux et al 2007).…”

Effect of Different Temperatures on Consumption of Two Spotted Mite,Tetranychus urticae, Eggs by the Predatory Thrips,Scolothrips longicornis

“…The temperatures were chosen to cover the range suitable for development and survival of the predator (Pakyari et al 2011a). The effect of temperature on prey consumption was determined for all feeding life stages (first and second instar larvae, adults) of S. longicornis by following cohorts of individuals.…”

“…The different larval instars were distinguished based on larval size, and on the presence of larval exuviae. The data on juvenile development and duration of the female phases were reported in Pakyari et al (2011a) and Pakyari et al (2011b), respectively, but are included here in order to be held in comparison with the results on consumption.…”

“…S. longicornis occurs in the Middle East, India, and North America (Priesner 1950; Gilstrap and Oatman 1976; Alavi and Kamali 1996). In Iran, this species is a commonly recorded predator of spider mites in outdoor bean, cucumber, and eggplant (Aydemir and Toros 1990; Pakyari et al 2011a, b; Pakyari and Fathipour 2009). Some aspects of the biology of S. longicornis (functional response, mutual interference, life table characteristics, and feeding activity) have been studied (Gerlach and Sengonca 1986; Sengonca and Weigand 1988; Pakyari et al 2009; Pakyari and Fathipour 2009), but the influence of temperature on prey consumption has not been examined to date.…”

Traditional and modern methods for the identification of thrips (Thysanoptera) species

“…The ensuing two or three pupal stages are non-feeding, and these stages occur either in the soil or on plants, depending on the thrips species. The resulting adults may be winged or wingless, depending on both the sex and the species (Palmer et al 1989;Oetting et al 1993;Mound and Kibby 1998;Whitfield et al 2005;Pakyari et al 2011).…”