A.S.Sh. Al-Tamimi1*, H.A.A.H. Al-Shamri2 and H.N.H. Aldoori3
(1) Salah El-Din General Directorate for Education, Yathreb Education Division, Iraq; (2) Scientific Research Authority, Agricultural Research Center, Baghdad, Iraq, (3) Biology Department, Faculty of Education, Samoraa University, Iraq.
*Email address of the corresponding author: [email protected]
The study aimed to prepare nanocapsules for the pesticides neem oil, Bacillus thuringiensis Bt bacteria and abamectin, and determine their properties as well as test their effects on the functional response of the egg parasitoid Trichogramma evanescens at different densities of host eggs Ephestia cautella. The size and distribution of particles were determined by Dynamic Light Scattering (DLS) examination for the nanocapsules of neem oil, Bt and Abamectin, amounted to 760.9, 180.6 and 140.4 nm, respectively. The results of the Zeta Potential test to measure pesticide stability were -19.1, -9.0, and -39.7 mV, respectively. The results of the Field Emission Scanning Electron Microscopy (FESEM) showed that the diameters of the nanocapsules were 208.22, 226.99 and 179.1 nm, respectively. The results obtained also showed that the female parasitoid had a functional response of type III according to the Holling equation at all egg densities treated with nanocapsules, whereas the eggs of the fig moth insect parasitized by females were reduced at the beginning, however, the number of parasitized eggs increased at high densities with the increasing number of eggs provided or were available, compared to the control group that showed a Type II response where mortality rate was higher at low densities and lower at high densities. The results also showed that the value of the attack rate (b) and the اandling time (Th), for the nanocapsules pesticides (neem oil, Bt bacteria and abamectin). The estimated values of the attack rate (b) were 0.0388, 0.0404 and 0.0412 eggs/hour, for the three nanocapsule pesticides, respectively, whereas the value of the control was 0.0427 eggs/hour. The estimated handling time values (Th) were 0.0585, 0.0902 and 0.0967 hours, for the three nanocapsule pesticides, respectively, and the Th value of the control was 0.0653 hours.
Nano-capsules, nano-pesticides, functional response, biological control, egg parasitoid, Trichogramma evanescens.
https://doi.org/10.22268/AJPP-001439