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

Abstract

The study was performed to declare the effects of temperature and relative humidity on the population density of Aphis nerii, and the parasitoids, Diaeretiella rapae and Aphidius sp. at two districts, Zagazig and Mansoura (Sharkia and Dakahlia Governorates, respectively) throughout two seasons, 2005-2006 and 2006-2007 on Difla plants. The results indicated a highly significant positive correlation between temperature and population density of A. nerii in the second seasons at the two districts, while relative humidity showed negative significant at Mansoura district in the last season. On the other hand, the data cleared highly significant correlation between temperature and D. rapae during the two seasons at the two districts. Results indicated a highly negative significant between temperature and Aphidius sp at Mansoura district during two seasons. A significant negative correlation was obtained between the two parasitoids, D. rapae & Aphidius sp and A. nerii during two seasons at two districts.The parasitoid, D. rapae accepted the stages of oleander aphid, A. nerii, with average number of mummies per female parasitoid 64.2. Results indicated insignificant effect on incubation period of eggs, larval and pupal durations between the two parasitoids, D. rapae and Aphidius sp., but the total developmental period of two parasitoids had a significant effect on A. nerii, the averages were 19.38±0.57 and 22.09±0.54 with D. rapae and Aphidius sp., respectively. The work showed that leafarrival time decreased with increasing host density. Meanwhile, the first sting-time, numbers of oviposition and mummies increased with increasing host density.

Potential Impact of Lysiphlebus fabarum (Marshall) Parasitoid against Cowpea Aphid

“…According to Saleh et al, (2009) and Maghraby (2012), who showed that D. rapae, L. fabarum, and Ephedrus sp. were parasitoids on A. craccivora in Egypt, the current findings are consistent with earlier studies.…”

“…Cowpea has long been used as an economic crop, and its global relevance is growing due to its high economic significance (Saleh et al, 2009 andSalman et al, 2022). Cowpea is susceptible to pest infestation, which can result in significant losses (Saleh 2008 andMaghraby 2012).…”

“…Piercingsucking insects are among the insect pests that cause notable harm to sweet basil plants (Ali 2014, Kumar et al, 2022 Aphids, A. craccivora inflict damage by directly ingesting on plant sap (EI-Defrawi et al, 2000;Kolaib et al, 2016) or by injecting poisonous salivary secretions and spreading viral infections ( Harrison et al 1997and Ali 2014 ) Chemical insecticide use upsets the natural equilibrium between insects and their natural enemies (Abdul Rehman and Powell (2010) and Woltz and landis 2014) and has resulted in the development of insect resistance, phytotoxicity, and environmental contamination (Saleh 2008 andAhmad et al, 2011). Biological control is an effective approach that is useful in pest control (DeBach andRosen 1991 andSaleh et al, 2009) and is a viable, environmentally friendly, and economically sound alternative to insecticide-based agricultural pest management measures (Heimpel andMills 2017 andSaleh et al,2020).…”