Field evaluation of methoxyfenozide and chromafenozide, ecdysone agonists against cotton leaf worm, sugar beet moth and preservation their predators

Abstract EN

Due to the significant economic losses of the sugar beet crop caused by the cotton leaf worm Spodoptera sp.

(littoralis and exigua) and the sugar beet moth Scrobipalpa ocellatella (Boys.) (Lepidoptera : Gelechiidae), as well as the desire to reduce the use of traditional insecticides for their harms, this study was conducted during seasons; 2017/2018 and 2018/2019 at shenno village, Kafr El-Sheikh Governorate .The aim was to evaluate alternatives to traditional insecticides represented by five ecdysone agonists.

It also assesses its role in maintaining the presence of arthropod predators associated with these pests in the field.

Results showed that the tested ecdysone agonists and the tested insecticides were similar in reducing the number of Spodoptera sp.

larvae.

The all tested insecticides induced above 92% reduction in Spodoptera sp.

larvae number in the both study seasons.

As for the arthropod predators associated with Spodoptera sp., the maximum overall mean reduction was 31.59% and 11.57% during the first and second seasons respectively Compared to traditional insecticides (99.38% and 98.68% in 2017/2018 and 2018/2019 seasons respectively).

Ascendancy reducing the number of S.

ocellatella larvae, overall mean of reductions to all tested insecticides took the same trend.

They caused above 87% reduction in S.

ocellatella larvae numbers.

Concerning the arthropod predators numbers associated with S.

ocellatella, the maximum overall mean of reduction caused by the tested ecdysone agonists were 12.41% and 14.40% in the first and second seasons respectively.

While, that recorded when using traditional insecticides 99.20%in 2017/2018 season and 99.54% in 2018/2019.