Population fluctuation and effectiveness of climate on the mango shield scale, Milviscutulus mangiferae (Hemiptera: Coccidae) in Al-Busayli, El-Beheira Governorate, Egypt

Abstract

The mango shield scale, Milviscutulus mangiferae (Green) (Hemiptera: Coccidae) is a serious polyphagous pest of mango trees and many  ornamental plants. Since the climatic conditions in Egypt are conducive to the establishment and spread of M. mangiferae, it is expected that it will have an economic impact in Egypt. The seasonal abundance of M. mangiferae was studied under the climatic  conditions during the two seasons 2021 and 2022 in El-Beheira Governorate. The present results showed that M. mangiferae population  exponentially increased from October to next January and reached the maximum peak in November and slightly increased in June and  July. The immature stages were synchronized with the population fluctuation, where crawler, first and second nymphal stages recorded  the highest peak 197.25, 107 and 112.2 in November 2021, respectively, and139.75, 98 and 97 in November 2022 seasons, respectively. The  highest rate of monthly variation in the population (R.M.V.P.) value was recorded in June 2.23 and 2.66 for 2021 and 2022 seasons,  respectively. On the contrary, the lowest value was shown in February and March. In conclusion, the changes in population fluctuation  dynamics of M. mangiferae on mango trees were mostly related to the monthly changes in climate, especially daily temperature rates.  The present findings will help in developing appropriate pest management strategies for M. mangiferae.