Seasonal Abundance of Icerya aegyptiaca (Douglas) on Mandarin Trees and its Associated Predators at Giza Governorate

Abstract

The present work was carried out in Giza Governorate to study the seasonal abundance of the Egyptian mealybug Icerya aegyptiaca (Douglas) (Coccoidea : Monophlebidae) during (2016)(2017) which attacking mandarin trees Citrus reticulata Blanco (Rutaceae) and its main associated predatory insects. Also, study effect of biotic and abiotic factors on the seasonal abundance of its stages. The obtained data showed that, nymphs, adult females, ovipositing females and the total population of I. aegyptiaca recorded three peaks on mandarin trees during (2016 -2017). These peaks of total population of I. aegyptiaca, occurred on June, August and December. The highest peak recorded in 15 th August (2016 -2017).The results revealed that, three peaks were recorded for Rodolia cardinalis (Mulsant) (Coleoptera: Coccinellidae) and Chrysoperla carnea (Steph.) (Neuroptera: Chrysopidae), during the two successive years of study. Simple correlation coefficient indicated that, the relationship between I. aegyptiaca and its associated predators assured that, a highly positive significant effect during (2016)(2017). The temperature showed a positive significant effect on the population of I. aegyptiaca. The common effect of biotic and abiotic factors was 90.56% and 92.92% of the nymph stages, adult females was (87.11% & 88.36%), ovipositing females was (94.16% & 90.09%) and total populations was (94.16% & 84.35%) during (2016)(2017).

Pest categorisation of Icerya aegyptiaca

“…It also egests honeydew which induces sooty blotch that covers leaf surface and, make fruits unmarketable (Liu and Shi, 2020 ). However, in Japan, I. aegyptiaca is found to egest little to no honeydew and, this monophlebid species is rarely associated with sooty mould, (Uesato et al., 2011 ; Helmy, 2021 ). In Kiribati and some other Micronesian atolls, the greatest impact of I. aegyptiaca is on the breadfruit tree ( Artocarpus altilis ) with crop loss as high as 50% or more (Waterhouse, 1991 ).…”

“…Harmonia arcuate, Coelophora inaequalis, Cryptolaemus montrouzieri, Nephus includens, and Steatococcus samaraius were found attacking this species (Beardsley, 19,559;Abdel-Salam et al, 2010). Rodolia cardinalis found to be an effective predator of I. aegyptiaca in Egypt (Ragab, 1995;Ghanim et al, 2013;Awadalla and Ghanim, 2016;Helmy, 2021).…”

“…It is reported that I. aegyptiaca populations have been significantly reduced by Chrysopa spp., in the Marshall Islands, Fais Island, at Lae Atoll, and Egypt (Beardsley, 1955;Helmy, 2021). Harmonia arcuate, Coelophora inaequalis, Cryptolaemus montrouzieri, Nephus includens, and Steatococcus samaraius were found attacking this species (Beardsley, 19,559;Abdel-Salam et al, 2010).…”