Seasonal Abundance of the Oleander Aphid Aphis Nerii Boyer De Fonscolombe (Homoptera, Aphididae) in Relation to the Primary and Hyper-Parasitoids on Duranta in Egypt.

Abstract

Seasonal abundance of the oleander aphid, Aphis nerii Boyer de Fonscolombe and its associated parasitoids on duranta plants were studie in Zagazig and Mansoura during the three seasons 2004/05, 2005/06 and 2006/07. Obtained data revealed that: A. nerii infestation of duranta started by late September and early October, respectively. It continued to late March in the three season. The aphid numbers ranged between 10.88-48.04, 9.40-38.16 and 8.44-39.52 individuals/leaf, respectively in Zagazig during the three seasons. While, in Mansoura the infestation started earlier in the first half of September. It continued to early March. The aphid numbers ranged between 16.08-52.16, 15.72-37.56 and 14.00-41.00 individuals/leaf, respectively during the three seasons. In Zagazig, the aphid abundance showed three peaks in the three seasons of study. The mean numbers of aphids/leaf was 25.64, 25.04 and 22.75, respectively during the three seasons, meanwhile in Mansoura the aphid abundance showed three peaks in first season, four peaks in second season and two peaks in third seasons. The mean numbers of aphids/leaf were 26.63, 24.91 and 24.83, respectively during the three seasons. Five hymenopterous parasitoids, Diaeretiella rapae (M`Intosh), Aphidius sp. (Aphidiidae), (primary parasitoids) Pachyneuron sp. (Pteromalidae), Alloxysta sp. (Cynipidae) and Aphidencyrtus sp. (Encyrtidae) (Hyper parasitoids) were recorded..

Effects of Temperature, Relative Humidity and Some Biological Aspects on Parasitoids Performance Agsinst Oleander Aphid, Aphis Nerii Boyer De Fonscolombe (Homoptera, Aphididae)

“…Aphids were fed on their host plant and kept in Petri dishes (50 aphid/Petri dish) until formation of mummies. The mummies were isolated and kept in small glass tubes until emergence of adult parasitoids (Saleh and Gatwary, 2007).…”

“…Parasitism of aphids has been shown to be density dependent (Walker et al, 1984). Saleh and Gatwary, (2007)…”