Functional response and predatory potential of coccinellid predator, Oenopia kirbyi Mulsant (Coccinellidae:Coleoptera) on rose aphid, Macrosiphum rosae L. (Aphididae: Hemiptera)

The investigations were carried out to evaluate the predatory potential and functional response of Oenopia kirbyi Mulsant (Coccinellidae: Coleoptera) against rose aphid, Macrosiphum rosae L. (Aphididae: Hemiptera). The experiments were carried out in vitro condition at 25 +/- 1 degrees C, 70 +/- 5% R.H and 14L:10D photoperiod under laboratory conditions. The freshly emerged coccinellid larvae were reared individually in test tubes containing assorted populations of second and third instar nymphs of M. rosae. The predatory potential of 1(st), 2(nd), 3(rd) and 4(th) instar coccinellid larvae was 8.70, 20.70, 28.10 and 31.40 aphids, respectively. The lifetime consumption rate of adult female was 560.16 aphids which varied from 544 to 580 aphids and adult male consumed 491 aphids which varied from 472 to 516 aphids. The predation efficiency of O. kirbyi against M. rosae increased with the developmental stage of the predator which is illustrated by parameters of attack rate (a) and handling time (T-h). The predation rate (k) of 1(st), 2(nd), 3(rd), 4(th) instars and adult were 19.17, 27.69, 30.63, 32.49 and 34.27 aphids, respectively, in 24 h. The fourth instar coccinellid larvae and adults (both male and female) of O. kirbyi were recorded as voracious feeders and can successfully be exploited in interated pest management programme(IPM) against rose aphid along with other natural enemies as a biocontrol agent of M. rosae.