تأثير بعض الصفات المظهرية و الفسلجية في حساسية بعض أشجار الحور للإصابة بحشرة من أوراق الحور Chaitophorus euphraticus Hodjat

Abstract EN

The results of the susceptibility poplar species for infestation with poplar leaf aphid ‘ Chaitophorus euphraticus Hodjat.

Showed that the morphology and physiology characteristics of poplar leaves have a great role.

Concerning t the leaves thickness it appeared that there were a good association between the thickness of leave and the numbers of insects on them ‘The averages thickness of leaf / mm for Populus.

euphraticat P.

nigrat P.

deltoids were higher than these for Salix acmophylla ‘Rhobinia pseudoacacia and Eucalyptus camaldulensis ‘ they were 0.230‘ 0.159 ‘ 0.154 ‘ 0.084 ‘ 0.068 ‘ 0.180 and 0.236 ‘ 0.169 ‘ 0.160 ‘ 0.087 ‘ 0.073 and 0.186 / mm associated with at the averages; 31.026 ‘ 21.234 ‘ 18.986 ‘ 7.835 ‘ 3.093 ‘ 1.279 and 32.815 ‘ 23.316 ‘ 20.634 ‘ 8.579 ‘ 4.484 and 2.228 insect respectively.

It has been shown ‘ that ‘ physiological characters of the leaf attributes to the variation among the type of trees have a role in this respect.

It is noted that there has been an increase in the average number of insects on the leaves of different trees as a result of increase in water and chlorophyll percentage.

It is noticed that averages numbers of maxing of insects were 31.026 ‘ 21.234 ‘ 18.986 ‘ 7.835 ‘ 3.093 ‘ 1.279 and 32.815 ‘ 23.316 ‘ 20.634 ‘ 8.579 ‘ 4.484‘ 2.228 per leaf on P.

euphratica ‘P.

nigra‘ P.

deltoids ‘ Salix acmophylla, Rhobinia pseudoacacia and Eucalyptus camaldulensis when the averages of chlorophyll percentage were 8.823, 4.147 ,11.374 ,6.429 ,4.755, 7.324 and 9.651, 4.856, 11.793, 6.702, 5.063, 8.039 % for both seasons respectively.

while the percentages of water content in the leaves were 59.225 ‘ 43.950 ‘ 43.887 ‘ 37.572 ‘ 41.743 ‘ 49.870 and 64.211, 50.621,46.493, 42.247, 39.871, 53.913 %.

With the regard to the number of hairs /mm of leaf, the results have shown that the averages number of hairs/ mm on P.

euphratica, P.

nigra, P.

deltoids ‘ Salix acmophylla ‘ Rhobinia pseudoacacia and Eucalyptus camaldulensis 18.293, 4.957,2.403, 7.518, 27.593 and 19.266, 6.079, 3.232, 8.229, 28.729 hairs for both seasons respectively.

While there were no hairs could be found on the leaves of Eucalyptus camaldulensis trees.