Arthropods associated with some medicinal plants under field conditions in Sindh province of Pakistan

Present studies were carried out on the insect pests associated with medicinal plants i.e., rib grass, Plantago ovata, linseed Linum usitatissimum, fennel, Foenoculum vulgare, fenugreek, Trigonella foenum and cumin seed, Cuminum cyminum under field conditions. Twenty plants were selected at random and these plants were observed on weekly intervals for recording field observations weekly. Results showed that pest’s population was appeared on different crops from 2nd week of February 2009 and insects continued their activities till the harvest of crops. Pest-wise mean population per plant on rib grass were aphid, Aphis gossypii 0.89+0.08; thrips, Thrips tabaci 0.74+0.09 and whitefly, Bemisia tabaci 0.73+0.01. Similarly, different insect pests recorded on linseed were jassid, Amrasca devastans and aphid, Aphis gossypii and their mean populations found 0.79+0.05 and 0.98+0.02 per plant, respectively. While, fenugreek was infested by thrips, Thrips angusticeps 2.23+0.037; aphid, Aphis craccivora 1.39+0.20, jassid, A. devastans 0.75+0.06 and B. tabaci 0.84+0.09. The cumin seed was attacked by thrip, T. tabaci 3.39+0.60, jassid, A. devastans 0.74+0.19 and aphid, A. gossypii 1.64+0.23. Predatory arthropods found associated with these pest insects were predatory beetle, Coccinilla septempunctata, mite, Typhlodromus spp., and spider, Pardosa spp.