Susceptibility of soybean varieties to infestation of cotton leaf worm Spodoptera littoralis (Boisduval)‎ (Lepidoptera : Noctuidae)‎ and their relation to climatic factors with emphasis on leaves characteristic

Abstract EN

Susceptibility of five soybean varieties (Giza 21, Giza 22, Giza 35, Giza111 and Crawford) to infestation of cotton leaf worm Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) were studied under natural field conditions at the experimental farm of the Faculty of Agriculture, Benha University, Egypt during two successive seasons, 2015 and 2016.

The relationship between phytochemical components and anatomical characters of leaves were also studied.

Results showed that, Crawford variety was highly infested by S.

littoralis as number of larvae/100 plants and rate of leaflets soybean feeding damage.

While the susceptibility of Giza 21 variety recorded the lowest number of larvae/100 plants and rate of leaflets soybean feeding damage during the two successive seasons.

Statistical analysis showed positive correlation between population of S.

littoralis with minimum and maximum temperature during the two seasons.

On the other hand, the relative humidity had insignificant negative effects in both seasons.

Phytochemical analysis had significant positive effect among the leaflet of the five studied varieties and the total of protein, carbohydrates and phenols.

While there was insignificant negative effect between leaflet contained of phosphate and potassium and insect population.

The anatomical characters of the leaflet of five soybean varieties and the population of S.

littoralis were correlated significantly positive for all leaf morphological and anatomical characteristics on the five soybean varieties.