Exigências térmicas e tabela de vida de fertilidade de Phytoseiulus macropilis (Banks) (Acari: Phytoseiidae)

Abstract

-Thermal requirements of Phytoseiulus macropilis (Banks) fed with Tetranychus urticaeKoch at five constant temperatures (18, 20, 23, 26 and 30°C), and the effect of three constant temperatures (20, 23 and 26°C) on the adult stage were studied. The data were used to produce the fertility life tables. The stages of egg, larva, protonymph, deutonymph and adult egg corresponded to the temperature thresholds of 12.6, 13.1, 11.6, 13.4 and 12.7°C, respectively, and thermal constants of 26.65, 10.27, 16.04, 13.31 and 66.04 DD, respectively. The average duration of a generation (T) varied from 24.3 to 18.5 days at the temperatures from 20°C to 26°C. The highest net reproduction (R 0 = 35,3) and the intrinsic rate of increase (r m = 0,19) were obtained at 23ºC. The highest fecundity rate was registered at 26ºC.KEY WORDS: Mite, biology, Phytoseiid, thermal constant RESUMO -Estudaram-se as exigências térmicas de Phytoseiulus macropilis (Banks) alimentado com Tetranychus urticae Koch em cinco temperaturas constantes (18, 20, 23, 26 e 30°C), e determinouse o efeito de três temperaturas constantes (20, 23 e 26°C) sobre os parâmetros biológicos da fase adulta do ácaro. Os dados foram utilizados para construir tabelas de vida de fertilidade. Os estágios de ovo, larva, protoninfa, deutoninfa e período de ovo-adulto apresentaram temperaturas base de 12,6; 13,1; 11,6; 13,4 e 12,7°C, respectivamente, e constantes térmicas de 26,65; 10,27; 16,04; 13,31 e 66,04 GD, respectivamente. A duração média da geração (T) variou de 24,3 a 18,5 dias entre as temperaturas de 20°C e 26°C. A maior taxa líquida de reprodução (R 0 = 35,3) e a maior capacidade intrínseca de aumento populacional (r m = 0,19) foram obtidas a 23ºC. A maior fecundidade foi verificada a 26ºC.

Reproductive parameters of Phytoseiulus macropilis (Banks) fed with Tetranychus urticae Koch (Acari: Phytoseiidae, Tetranychidae) in laboratory

“…This result was less than the 2.57 days found in the present study at 25 °C. However, at the same temperature (26 °C), Silva et al (2005) reported values higher than the current study for the other stages: oviposition, post-oviposition, and fecundity, as well as both female and male longevity.…”

“…At 26 °C, duration periods of 2.0, 1.1, and 1.0 days were found for the stages of egg, protonymph, and deutonymph, respectively, and the adult-egg lasted 4.8 days. Similar results were obtained in the present study, except for the larvae stage that in Silva et al (2005) lasted 0.8 days and in the present study lasted around 0.4 days. The different results found in the larvae stage could be related to the elapsed time between evaluations; in the present study, observations were done at 8:00 a.m. and 4:00 p.m. while in Silva et al (2005) they were done every 12 hours nevertheless, in both studies the larval stage period was less than one day.…”

“…Although the specie P. fragariae investigated by Vasconcelos (2006) is different from the specie investigated in the present study, the similar results found can be related to the fact that both species belong to the same genus. Silva et al (2005) also found that at 26 °C the pre-oviposition stage lasted 1.9 days. This result was less than the 2.57 days found in the present study at 25 °C.…”

“…Davies et al (2009) found values for P. persimilis of 0.6 and 1.4 days for the larvae and protonymph development, respectively, when fed with T. urticae. Silva et al (2005) investigated thermal requirements at five constant temperatures of P. macropilis fed with T. urticae. At 26 °C, duration periods of 2.0, 1.1, and 1.0 days were found for the stages of egg, protonymph, and deutonymph, respectively, and the adult-egg lasted 4.8 days.…”

“…The same can be observed for periods of pre-oviposition, oviposition, post-oviposition, female fertility and longevity of females and males. These differences may be related to different temperatures as in Silva et al (2005), different phases of de pray supplied to the predatory mite as Ali (1998) and also the different mite species studied as Escudero and Ferragut (2005), Vasconcelos et al (2008), and Abad-Moyano et al…”