Intrinsic rate of increase of Aphidius colemani Vier. (Hym., Braconidae), a parasitoid of Aphis gossypii Glov. (Hom., Aphididae), at different temperatures

Abstract

Increasing problems with chemical control of cotton aphid, Aphis gossypii Glov., in vegetable crops necessitate development of a biological control programme. An endoparasitoid of cotton aphid, Aphidius colemani Vier., is one of the candidate control agents. Data on longevity, reproduction, and development of A. colemani with A. gossypii as host are presented in this paper. The parasitoid has a fecundity of 302 eggs per female at 20°C and 388 eggs per female at 25°C, a developmental period of 12.7 days at 20°C and 10.0 days at 25°C, and an immature mortality of 14.1 % at 20°C and 27.8 % at 25°C. The intrinsic rate of increase of the parasitoid is both at 20 and at 25°C comparable to the intrinsic rate of increase of the cotton aphid. Aphidius colemani seems, therefore, a promising candidate for biological control of cotton aphid. Zusammenfassung Untersuchungen zur Wachstumsrate von Aphidius colemani Vier. (Hym., Braconidae), einem Parasitoid von Aphis gossypii Glov. (Hom., Aphididae), in Abhängigkeit von der Temperatur Zunehmende Probleme bei der chemischen Bekämpfung der Baumwoll‐Laus, Aphis gossypii, in Gemüsekulturen machen die Entwicklung von biologischen Bekämpfungsverfahren notwendig. Der Endoparasitoid Aphidius colemani ist ein möglicher Kandidat für ein biologisches Bekämpfungsverfahren. In der vorliegenden Untersuchung werden Ergebnisse zu Lebensdauer, Reproduktion und Entwicklung von A. colemani mit A. gossypii als Wirt dargestellt. Der Parasitoid hatte bei 20°C eine Fekundität von 302 Eiern bzw. 388 Eiern/♀ bei 25°C; die Entwicklungszeit betrug 12,7 Tage bzw. 10,0 Tage und die Larvenmortalität 14,1 % bzw. 27,8 % bei 25 °C. Die Wachstumsrate des Parasitoiden entsprach bei beiden Temperaturen der der Baumwoll‐Laus. Aus diesem Grunde scheint A. colemani ein geeigneter Kandidat für die biologische Bekämpfung von A. gossypii zu sein.

Fertility, longevity and intrinsic rate of increase of Aphidius gifuensis Ashmead (Hymenoptera: Braconidae) on the green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae)

“…Similar patterns were found in the other aphidiids, e.g., A. colemani and Diaeretiella rapae (M'Intosh) (van Steenis, 1993;Bernal and González, 1997). These cases can also be explained as proovigenic: no ovarian egg production during the adult stage, as discussed in Bernal and González (1997).…”

“…It thus should be noted that proovigenic parasitoids including A. gifuensis released as biological control agents in greenhouses seem to be effective during relatively short periods following adult emergence even though they have long life spans. This implies that the method of their introduction has to be adapted in such a way that a continuous presence of the female parasitoids can be assured (van Steenis, 1993): a multiple release with short intervals or the utilization of banker plants to maintain their alternative hosts.…”

Praon volucre (Hymenoptera: Braconidae: Aphidiinae), a natural enemy of Macrosiphum euphorbiae (Hemiptera: Aphididae): Life table and intrinsic rate of population increase

“…That a small proportion of the hosts was superparasitized when ample hosts were available is also recorded for A. colemani (van Steenis, 1993;Torres et al, 2007) and L. testaceipes (van Steenis, 1994;Rodrigues et al, 2003;Silva et al, 2008b). Although P. volucre shows intraspecific discrimination, it is apparently not able to discriminate interspecifically as Sidney et al (2010a) show it is unable to distinguish between unparasitized hosts and hosts already parasitized by A. ervi.…”

Tabela de vida de fertilidade de Lysiphlebus testaceipes (Cresson) (Hymenoptera, Braconidae, Aphidiinae) em Rhopalosiphum maidis (Fitch) e Aphis gossypii Glover (Hemiptera, Aphididae)

“…Após esse período, as ninfas foram transferidas para um "freezer" a 5ºC, para promover a paralisação do desenvolvimento da larva. A quantidade de ovos colocados por fêmea do parasitóide foi estimada em função do número de larvas dentro de indivíduos de cada espécie de pulgão hospedeiro, os quais foram dissecados com o auxílio de estilete, sob microscópio estereoscópico, em solução de cloreto de sódio 1%, conforme Steenis (1994) e Rodrigues et al (2003).…”