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Chrysoperla carnea (Stephens) is an important biological control agent currently being used in many integrated pest management (IPM) programs to control insect pests. The effect of post-treatment temperature on insecticide toxicity of a spinosyn (spinosad), pyrethroid (lambda cyhalothrin), organophosphate (chlorpyrifos) and new chemistry (acetamiprid) to C. carnea larvae was investigated under laboratory conditions. Temperature coefficients of each insecticide tested were evaluated. From 20 to 40 °C, toxicity of lambda cyhalothrin and spinosad decreased by 2.15- and 1.87-fold while toxicity of acetamiprid and chlorpyrifos increased by 2.00 and 1.79-fold, respectively. The study demonstrates that pesticide effectiveness may vary according to environmental conditions. In cropping systems where multiple insecticide products are used, attention should be given to temperature variation as a key factor in making pest management strategies safer for biological control agents. Insecticides with a negative temperature coefficient may play a constructive role to conserve C. carnea populations.

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Abiotic stresses including drought are major crop production constraints. However, specific functional phenotypic markers induce resistance against these stresses. Therefore, a study was initiated to study the variability, inheritance and selection of epicuticular waxes (EW) and leaf hairiness (LH) along with low cell membrane injuries (CMI) within F2 populations derived by crossing H. annuus×H. argophyllus lines. These traits have been shown to be associated with drought tolerance of Helianthus argophyllus and thus study aims to introgress these traits in Helinathus annuus. The studied parent populations showed contrasting values of the traits. The drought susceptible line CMS-14 and CMS-20 showed lower epicuticular waxes (0.79, 0.69 mg g−1), leaf hairiness (0.75, 1.53) and higher cell membrane injury (40.90, 55.76 %) respectively while drought resistant line Argo 1802 and 1806 showed higher epicuticular waxes (2.28, 3.18), leaf hairiness (3.71, 3.80) and lower cell membrane injury (14.22, 21.54 %) respectively. The F1 hybrids had mean values of the three studied parameters i. e. epicuticular waxes (1.50 mg g−1), cell membrance injury (32.54 %) and leaf hairiness (2.74) in the range of parent lines, but some of F2 individuals extend beyond this range (Parents and F1s). The two-step selections maintained high variability especially of LH for set of F2 individuals (H. annuus CMS-20×H. argophyllus 1806). Simultaneous selection of F2 individuals with high values of LH or EW with low CMI was possible. The selected plants were further studied for narrow leaf, high fertility and silver canopy color. Selected material was promoted as the candidate of inbred line. Plant (F4) having introgressed traits (silver canopy) showed lower yield (19 %) than green leafed plants (53 %) and commercial hybrids under drought stress (63 % and 53 %). The study could help to increase the abiotic stress tolerance, minimize the yield losses under drought stress and increase functional diversity within sunflower.

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Background As different biogeographic strains and isolates of entomopathogenic fungi vary in their genetic, enzymatic and pathogenic characteristics, this study assessed the virulence of 2 indigenous strains of Beauveria bassiana (Balsam) Vuillemin and Metarhizium anisopliae (Metschn.) Sorokin (Ascomycota, Hypocreales: Clavicipitaceae), isolated from naturally infected insect cadavers, against the 3rd instar nymphs of Myzus persicae (Sulzer) (Hemiptera: Aphididae) and 3rd instar larvae of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) using leaf-dip and larval-dip methods, respectively. Results Both fungal isolates exhibited considerable pathogenicity against M. persicae and S. frugiperda. Mortality in all bioassays was conidial concentration and exposure time dependent and increased significantly along with both factors (R2 = 0.86–0.99 for B. bassiana and 0.82–0.94 for M. anisopliae). Moreover, M. anisopliae isolate appeared more virulent to S. frugiperda larvae than B. bassiana isolate, while the later fungal isolate was more lethal to M. persicae nymphs than the former one. At the highest conidial concentration (1.0 × 109 conidia/ml), M. anisopliae caused maximum mean mortality of S. frugiperda (88%) and M. persicae (65%) and B. bassiana exhibited maximum mean mortality of S. frugiperda (76%) and M. persicae (94%). Moreover, probit regression analyses showed LT50 values for M. persicae of 4.57 and 6.86 days at 1.0 × 109 conidia/ml for the isolates of B. bassiana and M. anisopliae, respectively, while LC50 values were 7.75 × 106 and 8.70 × 107 conidia/ml after 10th day of application, for the isolates of B. bassiana and M. anisopliae, respectively, against M. persicae. Similarly, LT50 values for S. frugiperda were 7.75 and 7.03 days for 1.0 × 109 conidia/ml concentration and LC50 values were 2.84 × 107 and 8.84 × 105 conidia/ml at 10th day data for the isolates of B. bassiana and M. anisopliae, respectively. Conclusion Overall study results demonstrated the effectiveness of B. bassiana and M. anisopliae against M. persicae and S. frugiperda, respectively. However, field evaluations of these indigenously isolated promising fungal strains against these insect pests.