تأثير بعض المبيدات الكيميائية و معلق الكونيديات للفطر beauveria bassiana (L)‎ في مكافحة عنكبوت الغبار oligonychus afrasiaticus على نخيل التمر (acari: tetranchidae

الملخص EN

The results of lab study showed that the treatments by the mixture (Byby5%20EC insecticide + fungal isolate Beauveria bassiana(BI)) & Byby%20EC insecticide alone was the best treatments in eggs mortality which amounted to % 41.9 & 44.5 respectively 72 hrs after treatment as well as those treatments gave the best results in killing the immatures which was about % 68.3 & 69.8 (24) hrs after spraying &% 87.3& 85.9 (72) hrs after spraying ,& those treatments gave the same results for the nymph killing percentage which was % 87.1& 85.2 (72)hrs after spraying, respectively .

while concerning the adult stage ,the rate of killing reached %85.3& 86.3 (72)hrs after spraying ,using the mixture (Byby%20EC insecticide + fungal isolate B.

bassiana(BI)) and byby%20EC insecticide alone, respectively .

In terms of field results , treatment by the mixture ( byby%20EC insecticide + B.

bassiana(BI)isolate)) showed the best results in eggs number reduction , from (50)eggs/fruit to 18.7, 24, 23.7, 25& 26.7 egg/fruit after 1, 3, 7, 14 & 30 days of treatment respectively with a morel significant difference .

while there was no significant difference between the two treatments to limit population density of adults 1,3,7 & 30days after treatment, where there was a moral significant difference between the two treatments (14) days after spraying .

the treatment by mixture (byby%20EC insecticide + B.

bassiana(BI)isolate ) and Byby%20EC insecticide gave the best results in decreasing the adults number ,decrease percentage was 16, 19 & 17.6 mite/fruit , respectively in compare with the average of its density prior to the treatment which was 58.7, 47.3 & 51 mite/fruit , respectively.