Study on the Insect Pest-complex and Its Correlations with Environmental Factors on Fenugreek (Trigonella Foenum Graecum L.)

Abstract

The present investigation was carried out during November 2022 to February 2023. The field experiment was conducted in Randomized block design with eight treatments and three replications at Experimental farm, Department of Entomology, SAS, Medziphema. The outcomes of the experiments revealed that, during period of investigation, ten insect pests and two natural enemies were observed. The activity of aphid (Aphis craccivora) infestation on fenugreek started in the 45th SMW (1.5 aphids/ three leaves) and reached its peak during 52nd SMW (23.36 aphids/ three leaves). The thrips (Scirtothrips dorsalis) was observed from 46th SMW (0.8 thrips/ three leaves) and reached its peak during 2nd SMW (9.32 thrips/ three leaves). The population of Spodoptera litura on fenugreek started appearing from 47th SMW (0.1caterpilar/ plant) and the highest incidence was recorded during 1st SMW (2 caterpillar/ plant). The serpentine leaf miner was observed from 49th SMW (0.56 maggot/ plant) and reached its peak during 2nd SMW (2.3 maggot/ plant). The population of flea beetle on fenugreek started appearing from 48th SMW (0.8 adult/ plant) and the highest incidence was recorded during 1st SMW (2.03 adult/ plant). The correlation studies with weather parameters revealed that aphid, thrips, Spodoptera litura, serpentine leaf miner and flea beetle population had significant negative correlation with maximum temperature, minimum temperature but non-significant with other remaining weather parameters.