Samira A. Khlaywi ⁽¹⁾,  KhloodAbid-AlelahAlkhafaji ^{(1) *}, Mahdi S. Hameed⁽¹⁾, Mohamed Abid al- Rahem Abiallah ⁽¹⁾ and Ahmed Fawzi Abbas ⁽¹⁾

(1). Ministry of Science and Technology. Baghdad, Iraq.

(*Corresponding author: KhloodAbid-AlelahAlkhafaji, E-Mail khlooodalkhafaji@yahoo.com)

Received: 29/07/2022         Accepted: 28/10/2022

Abstract: 

Two field experiments were conducted to evaluate the efficacy of some local Bacillus thuringiensis isolates which included a local isolate that were B. thuringiensis KS 3 and two imported isolates, (Spanish and Indian No. 13). In addition to the chemical pesticide bifenthrin EC 10) TALSTAR in the control of the melon aphid or cotton aphid Aphis gossypii Glover on the cucumbers crop and grapes. First experiment was conducted at al-Twiatha/ Baghdad (24/5/ 2018) on a field grown cucumbers and grapes. The results showed that the three isolates of B. thuringiensis  have a good efficiency reducing the average number of live nymphs/ leaf, especially after 6 days of treatment, it reached to 3.75, ‎2.25, ‎and 4.25 nymphs/ leaf, respectively. These results are similar to the results of the pesticide Telastar which achieved a decrease in the population density of live nymphs to 2.5 nymphs/ leaf. It is worth noting that these isolates continue to be effective in the field, especially when it was supported by spraying more than once compared to the gradual decrease in the effectiveness of the chemical pesticide after 9 days of treatment. The results of the experiment showed that Bt bacteria was effective on the grape. Local isolate No. 3 and Spanish led to decrease population density of this pest insect to 23.4 and 32.4 nymphs /2 cm² respectively after 6 days of treatment, while this rate decreased Indian isolate to 71.2 nymphs / 2 cm² as compared to control treatment (143.8 nymphs / 2 cm²).

Key words: Biological Control, crystal protein, cotton Aphids، Aphis gossypii ، Bacillus thuringiensis

Full paper in Arabic: pdf