Factors affecting distribution pattern of the white mango scale insect, Aulacaspis tubercularis (Newstead)‎ (Hemiptera : Diaspididae)‎ on mango trees at Esna district, Luxor governorate, Egypt

Abstract EN

The present work was carried out throughout two successive years (2017/2018 and 2018/2019) to determine effect of different tree cardinal directions, strata of tree, leaf surfaces and orchard depth (distances from boarders of orchard) of mango trees on distribution of A.

tubercularis at Esna district, Luxor governorate.

The obtained results showed that there significant differences between the population means at the four cardinal directions and highly significant differences between the different stratums of tree and between surfaces of leaf and also between different distances from boarders of mango orchard during the two successive years.

The results obtained that the grand means were relatively higher at the south direction (86.40 ± 4.85 and 82.74 ± 4.14 individuals per leaf), followed by east site (84.35 ± 5.00 and 82.34 ± 4.14 individuals per leaf).

In contrast, north direction was the least infested by insect (83.18 ± 4.92 and 79.84 ± 4.24 individuals per leaf).

While, the west direction was moderately infested with this insect as mean (84.01 ± 4.67 and 81.06 ± 3.96 individuals per leaf) for the two years of study, respectively.

Also, the middle stratum leaves of tree was the most preference parts and highest infestation by insect as mean (105.36 ± 6.06 and 99.96 ± 5.03 individuals per leaf), followed by the bottom stratum leaves of mango tree (97.04 ± 5.57 and 91.49 ± 4.55 individuals) for the two years, respectively.

The top stratum leaves was the least infestation by insect as mean (51.05 ± 2.98 and 53.03 ± 2.84 individuals) during the two successive years, respectively.

Generally, it can be concluded from the current investigation that that the insect population occurred on different tree directions in all stratums of mango tree and on surfaces of leaf on the all year round during the two years of investigation.

A.

tubercularis prefers the upper surface on the middle stratum of tree in east southern side where its population was always abundant allover the year and mango trees which far from the orchard boarders were more heavily infested by pest than the nearby trees from the boarders during the two years of study.