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Background: To better inform conservation biological control of aphids multitrophic interactions between aphids, coccinellids and their parasitoids in natural and managed plant systems were examined over 4 years. Methods: Coccinellid larvae found naturally feeding on aphids on two non-crop plants growing in agricultural landscapes in Pakistan; Aphis nerii (Boyer de Fonscolombe) feeding on Calotropis procera L. and Nerium oleander L.; and four crop host; Lipaphis erysimi (Kalt) feeding on Eurica sativa Mill. and Brassica campestris L., Uroleucon compositae (Theobold) feeding on Carthamus tinctorius L., and Diuraphis noxia (Mordvilko) feeding on Hordeum vulgare L.; were collected throughout the aphid season and reared on their respective aphid-plant combination in the laboratory to identify coccinellid species, their parasitoids and performance (survival and pupal weight).Results: Coccinellid pupal weight on different host plant-aphid combinations varied from 3.4±1.8 to 11.2±0.9 mg (mean ± SE), as did mortality of coccinellid larvae due to diseases and unknown causes (5±2.2 to 31±3.8%). Parasitism of coccinellid larvae by Homalotylus flaminus (Dalman) (Hymenoptera: Encyrtidae) ranged from ca 10±2 to 30±3% in B. campestris and E. sativa, respectively. Parasitism of coccinellid pupae by Oomyzus scaposus (Thomson) (Hymenoptera: Eulophidae) ranged between 17±2.7 (C. procera) to 41±2.9% (B. compestris). One Dinocampus coccinellae Schrank (Hymenoptera: Braconidae) was reared. Conclusions: Coccinellids were host plant and aphid selective. Some coccinellids were never or rarely recorded on a particular aphid-plant combination, suggesting that their prey selection more specific than often assumed. Management decision and conservation biological control cannot be based on superficial categories such as “aphids” and “coccinellids” but needs to be plant and species specific.

The field studies were conducted at the farmer’s field in 2015-2016 to determine the effect of three different insecticides (triazon, radiant and polytrin C) on Bt. and non-Bt. cotton varieties against pink bollworm. The results revealed that triazon was observed the most effective pesticide against PBW on both cotton varieties. The mortality reduction percent of 33.99 to 30.45% was recorded at triazon, 27.72 to 26.95% at radiant and 24.68 to 14.48% at polytrin C respectively, in 2015. However, in 2016 the mortality reduction percent decreased but effective trend of these selected pesticides were observed same with mortality reduction percent of 28.15 to 25.46% at triazon, 21.95 to 23.52% at radiant and 19.96 to 16.37% at polytrin C in Bt. and non-Bt. cotton varieties. In present investigation, triazon was observed the most effective pesticide than radiant and polytrin C on larvae of PBW in both Bt. and non-Bt. varieties.

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