2024, Vol. 7, Special Issue 6

The field investigation was carried out during kharif 2022, on the blackgram the experiment was conducted on research farm of entomology section of Agriculture Research Station, Badnapur in the guidance of research guide, Department of Agricultural Entomology, College of Agriculture, Badnapur, Vasantrao Naik Marathwada Krishi Vidyapeeth (VNMKV), Parbhani with the objective to study population dynamics of major insect pest of black gram, to record the activities of natural enemies in black gram ecosystem and to screen the black gram genotypes against major insect pest. The experiment was conducted under Randomized Block Design (RBD) with the 22 genotypes and three replications. The highlight of findings are given below.

The investigation on population dynamics of major insect pests of blackgram showed that the attack of thrips, whitefly, aphids, leaf hopper, green semilooper, gram pod borer and spotted pod borer commenced from 31th SMW first fortnight of August. The population of insect pest on black gram was observed in the range viz., aphid (5.1to 9.0), whiteflies (1.3 to 2.0), thrips (1.2 to 3.6), leaf hopper (1.2 to1.8), H. Armigera (0.7 to 1.4), M. vitrata (0.7 to 1.2) and green semilooper (2.4 to 3.5). Whereas population of aphid, whitefly, leaf hopper and green semilooper reached at its peak in 33rd SMW (9.0 aphids/trifoliate leaf), (2.0 whiteflies/trifoliate leaf), (1.8 leaf hopper/trifoliate leaf) and (3.5 larve/plant) while thrips reached at its peak in 34^th SMW (3.6thrips/trifoliate leaf), M. vatrata at its peak in 35th SMW (1.2 larve/plant) and H. armigera in 36th SMW (1.4 larve/plant) respect-tively.The activities of natural enemy LBB varied from (0.7 to 2.7 LBB/plant) and commenced from 31^st SMW. Whereas LBB reached at its peak in 33^rd SMW.

In regard correlation among Aphid, white fly, leaf hopper, green semilooper, M. vatrata and LBB had negative significant correlation with relative humidity at morning. The investigation on screening, 22 genotypes were screened against major pest of black gram.ie, aphid, whiteflies, thrips, leaf hopper, H. armigera, M. vitrata and green semilooper. The lowest population recorded with genotypes AKU 15 (ch) (6.11 aphid/trifoliate leaves), TPU 4 (ch) (0.83 whiteflies/trifoliate leaves), AKU 15 (ch) (0.72 thrips/trifoliate leaves), TPU 4 (ch) (1.27) AKU 15 (ch) (0.93 larvae/pant), AKU 15 (ch) (0.86 larvae/plant), AKU 15 (ch) (1.38 larvae/plant) respectively. The highest population observed genotypes ATU-2205 (9.55 aphid/trifoliate leaves), PU 62 (2.55 whiteflies/trifoliate leaves), BDU 2021-1 and AKU 11-15 (2.22 thrips/trifoliate leaves) respectively, AKU 18-2 (3.61 leaf hopper/trifoliate leaves), ATU-2205 (3.40 larvae/plant), BDU 2021-1(3.26 larvae/plant) and ATU-2205 (4.50 larvae/plant). In respect percent pod damaged by pod borer ranged between 3.85 to 20.24 percent. The genotypes TPU 4 (ch) recorded the lowest pod damaged (3.85 percent) while BDU 2021-1 recorded highest pod damaged (20.24 percent).