|
[9000693.] رقم البحث : 9000693 - |
|
Vertical Distribution Of Bemisia Tabaci (Genn.) Immatures And Their Parasitoids On Unsprayed And Sprayed Cotton Plants / |
| تخصص البحث : General |
| |
Agricultural Research Journal Suez Canal University / |
| |
A.H. Mesbah |
| |
R.A.Abo-Aiana |
| |
A. El-Zoghbey Amal |
| |
Bemisia tabaci - vertical distribution - Encarsia lutea |
| |
Field study of the vertical distribution of the cotton whitefly Bemisia tabaci (Genn.) immatures and their larval and pupal parasitoids was carried out at Sakha Agricultural Research Station, Kafr El-Sheikh Governorate, Egypt during 2000 and 2001 cotton seasons. The results revealed that the highest numbers of B. tabaci eggs and larvae were found on the upper level of the cotton plant during August in both seasons in the treated and untreated fields. The overall means of eggs and larvae on upper level were 166, 67, 496.2, 65.0/160 in2 in 2000 and 121.8, 37, 683 and 168.8/160 in2
Key words: Bemisia tabaci, vertical distribution, parasitism, Eretmocerus mundus, Encarsia lutea. in 2001 on untreated and treated cotton plants, respectively. They represented 59.1, 23.8, 82 and 10.7% in 2000, and 72.5, 22.1, 79.4 and 19.6% in 2001 of the total immatures on upper level on untreated and treated cotton plants, respectively. For pupae, the highest numbers were found on middle and lower levels during August and September. The overall means of pupae on middle and lower levels represented 67.1, 89.8, 39.2, 67.2% in 2000, and 73.4, 75.1, 57 and 71.6% in 2001 of the total immatures on untreated and treated cotton plants, respectively. Two parasitoid species, Eretmocerus mundus Merct. and Encarsia lutea (Mas.) were recorded on larvae and pupae of the pest. Percents of parasitism were lower in the treated field compared with the untreated one and were higher on B. tabaci pupae than on larvae in both fields. Highest rates of parasitism on larvae and pupae were recorded during August and September on the upper level of the untreated cotton plants, and on the middle level on treated ones. The overall means of parasitism on upper level on untreated plants were 16.4 and 23%, while they were 6.4 and 15.6% on treated one on middle in 2000 and 2001, respectively. The total parasitism percentages on untreated and treated cotton were 5 and 13% in 2000, and 12.7 and 18.3%, in 2001 respectively. |
| |
 Download Paper |
تسجيل دخول 
