Region: South America > Brazil
Categorized: Biological control
Tagged: Biological control Egg parasitoid Talenomus remus
The influence of temperature on the development of FAW's eggs parasitoid, Telenomus remus Nixon.
The main hosts of Teleomus remus Nixon, 1937 (Hymenoptera: Plastygastridae) are eggs of lepidopterans of the family Noctuidae, especially species of Spodoptera. Eggs of Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae) and Spodoptera litura (Fabricius, 1775) (Lepidoptera: Noctuidae) are the most frequently parasitized, although T. remus has been recorded parasitizing species of Pyralidae and Arctiidae.
Several investigators have studied the biology of this egg parasitoid, as reviewed by Cave (2000). Teleomus remus develops over a wide range of temperatures, from 15.5 to 30 °C.
Thermal-requirements experiments determined that the parasitoid’s development time at 15.5 °C is 18 to 24 hours in the egg phase, 7 days for the larval period, and 15 days for the pupal phase. At 30 °C, the egg phase lasts 10 hours, the larval phase 4 days, and the pupal phase approximately 4.6 days.
The effects of temperature and RH on the biology of T. remus have been assessed, for example, by Bueno et al. (2008) and Pomari et al. (2015). The temperature, besides influencing the development time, also strongly affects the percentage of emergence (viability). The relative humidity does not affect biological attributes of the parasitoid when it develops in S. frugiperda eggs. According to Pomari et al. (2015), RH is more important when T. remus is reared on factitious hosts, a subject addressed in another note in this portal (Reis, Coelho Jr, Parra).
The results obtained by Bueno et al. (2008) concord with those summarized by Cave (2000), again indicating a wide temperature range for development of 15 °C to 31 °C. However, insects that developed at 15 °C had lower viability, and at 35 °C failed to develop.
Females of this parasitoid emerge from eggs approximately 1 day after the males emerge, a phenomenon known as protandry. The length of the life cycle ranges from 8.1 days at 31 °C to 46.8 days at 15 °C for males and 8.3 to 47.2 days, respectively, for females. The thermal constant (K) and the base temperature (Tb) for females are 158.88 degree-days and 12.52 °C, and for males are 154.12 degree-days and 12.59 °C.
References used.
Bueno, R. C. O. de F., T. R. Carneiro, D. Pratissoli, A. de F. Bueno, and O. A. Fernandes. 2008. Biology and thermal requirements of Telenomus remus reared on fall armyworm Spodoptera frugiperda eggs. Ciência Rural 38: 1–6.
Cave, R. D. 2000. Biology, ecology and use in pest management of Telenomus remus. Biocontrol News Inf. 21: 21–26.
Pomari-Fernandes, A., A. P. de Queiroz, A. De F. Bueno, A. W. Sanzovo, and S. A. De Bortoli. 2015. The Importance of Relative Humidity for Telenomus remus (Hymenoptera: Platygastridae) Parasitism and Development on Corcyra cephalonica (Lepidoptera: Pyralidae) and Spodoptera frugiperda (Lepidoptera: Noctuidae) Eggs. Ann. Entomol. Soc. Am. 108(1): 11–17.
