Field trials to control Thrips tabaci (Thysanoptera: Thripidae)‎ infesting onion crop

Abstract EN

Thrips tabaci Lindeman (Thysanoptera: Thripidae) attack many vegetable crops specially onion causing grate economic damage on onion crops.

Individuals of thrips are protected between the inner leaves of the plant where the pupal stage is spent in the soil.

Field trial were conducted during two seasons 2017 and 2018 at Moshtohor, Toukh district, Qalubiya Governorate, to evaluat the efficacy of entomogenous fungus bioranza (Metarhizium anisopliae), two insecticide tracer 24% Sc (Spinosad) and marshall 25% EC (Carbosulfan ), agriculture soap (potassium salts os fatty acids 49% Liquid) and two releasing rates (i.e.

3000 and 1000 pred./20m2) of phytoseiid predatory mites, Neoseiulus californicus (McGregor) and Neoseiulus arundonaxi Metwally and Sanad (Acari: Phytoseiidae) for controlling T.

tabaci infesting onion crop.

Two applications were carried out during March and April during the two seasons.

The results showed that all treatments reduced thrips populations compared to control.

The maximum reduction in thrips population 73.42% for the predatory mite N.

californicus at rate 3000 pred./ 20m2 followed by N.

arundonaxi at rate 3000 pred./ 20m2.

However, the minimum reduction in thrips population 57.27% for soap at rate 500ml/ 100 liter of water.

Reduction percentage of thrips was highly in the second season 69.11% and 65.42% in the first year.

The results indicate the potential of using N.

californicus, N.

arundonaxi, M.

anisopliae and soap for the control of T.

tabaci, there are safe enough to be used in an integrated pest management programs (IPM).