Search

The non-persistent impact of biocontrol agents can be revealed for pest control when associated entomopathogenic fungi (EPFs) negatively affect the natural enemies. In this assay, impacts of Beauvaria bassiana (Balsamo) Vuillemin, and Metarhizium anisopliae (Metschnikoff) Sorokin were studied for their compatibility or side effects on life table parameters of an important generalist predator, Coccinella septempunctata L. The results indicated non-significant impacts of both EPFs on life table parameters of C. septempunctata. The development time (egg-adult) was not significantly different in control (69.79 days) and EPFs treated C. septempunctata (69.35–80.07 days). Both fungi did not induce any significant changes in the fecundity, adult pre-oviposition period (APOP), total preoviposition period (TPOP), and mean generation time (T) as compared to control treatment. Similarly, no difference in fecundity rate of C. septempunctata was observed after EPFs treatment (287.7–288.5) compared to control (290.0). The highest net reproductive rate (R0) occurred in control (87.05 offspring individual−1) and M. anisopliae (86.31 offspring individual−1) as compared to B. bassiana treated beetles (76.97 offspring individual−1). The age-specific fecundity curves indicated that the C. septempunctata had a similar fecundity rate in both EPFs treatments and control. This study demonstrates no significant side effects of B. bassiana and M. anispoliae on the performance and biology of C. septempunctata. Considering the compatibility of both EPFs with C. septempunctata, their combinations can be recommended in various integrated pest management programs. [ABSTRACT FROM AUTHOR]

Chemical control of Bactrocera cucurbitae in crops biomagnifies toxic residues in fruits and vegetables imposes health-hazard effects on consumers and demands for eco-friendly approaches. Present research assessed the bio-efficacy of Beauveria bassiana, Metarhizium anisopliae, Verticillium lecanii and Bacillus thuringiensis by adult-diet-bioassay at eleven concentrations (1 × 108, 5 × 107, 1 × 107, 5 × 106, 1 × 106, 5 × 105, 1 × 105, 5 × 104, 1 × 104, 5 × 103 and 1 × 103 CFU ml−1) of each entomopathogen against B. cucurbitae at three post-exposure-intervals (PEI) under controlled conditions. The results revealed that the maximum concentration (1 × 108 CFU ml−1) of B. bassiana, M. anisopliae, V. lecanii and B. thuringiensis caused 5.3 to 7.7, 7.4 to 9.2, 5.3 to 6.7 and 5.1 to 11.2 times higher mortality in B. cucurbitae, respectively at 10 d PEI as compared to mortality demonstrated by the same concentration at 3 d PEI. All tested microbial-insecticides induced statistically similar mortality in both male and female B. cucurbitae at each concentration for the same PEI. Correlation coefficient (r) values reveal that concentrations of each microbial-insecticide had a high positive correlation with mortalities of male and female B. cucurbitae [r(B. bassiana) = 0.691 to 0.865, r(M. anisopliae) = 0.643 to 0.849, r(V. lecanii) = 0.508 to 0.886 and r(B. thuringiensis) = 0.591 to 0.812]. Regression-parameters reveal that concentrations of tested microbial-insecticides had significant linear-relationship with and explained significant variability in B. cucurbitae mortality (P < 0.05). At maximum PEI (10 d), B. bassiana exhibited least LC50 (4.10 × 101 to 1.87 × 102 CFU ml−1) and proved highly toxic followed by M. anisopliae (1.16 × 102 to 3.55 × 102 CFU ml−1), B. thuringiensis (2.97 × 102 to 5.92 × 102 CFU ml−1) and V. lecanii (4.50 × 102 to 7.64 × 102 CFU ml−1). In conclusion, B. bassiana incorporated adult-diet proved highly effective against B. cucurbitae followed by M. anisopliae, B. thuringiensis and V. lecanii. Hence, B. bassiana can be recommended for incorporation in bait-traps to develop attract-and-kill technology for B. cucurbitae. [ABSTRACT FROM AUTHOR]

Copyright of Gesunde Pflanzen is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)