Akademik Veri Yönetim Sistemi
JOURNAL OF CROP HEALTH, cilt.76, sa.4, ss.811-820, 2024 (SCI-Expanded, Scopus)
Entomopathogenic nematodes (EPNs) are obligate parasites of insects that cooperate with insect-pathogenic bacteria to kill their hosts. Recently, the symbiotic bacteria of EPNs have attracted considerable attention due to their potential use in the control of agricultural pests without their nematode partners. However, the efficacy of these bacteria on the citrus mealybug, Planococcus citri (Risso) (Hemiptera: Pseudococcidae) remains unknown. In the present study, the separate and joint action of insecticide (spirotetramat) and cell-free supernatants (CFSs) of four bacterial endosymbionts of EPNs (Xenorhabdus bovienii, X. budapestensis, X. nematophila, and Photorhabdus luminescens subsp. kayaii) was evaluated on P. citri (nymphs and adults) and its coccinellid predator, Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) (adults) under controlled conditions (25 +/- 1 degrees C, 65 +/- 5% RH). The contact application of CFSs of all tested bacteria has resulted in significant mortality in the nymphs and adults of P. citri ranging between 80 and 97.5% four days after treatment (DAT) while inducing the same mortality (27.5%) on the adult of C. montrouzieri. The combination of the CFSs with full (100 ml/100 l) and half doses of spirotetramat caused similar mortalities in the nymphs and adults of P. citri compared to spirotetramat treatments alone. The nymphal stage of P. citri was more susceptible to all treatments than the adults. The highest mortality was 52.5 and 100% 4 DAT when the adults and nymphs of P. citri were exposed to the CFSs-Spirotetramat combinations, respectively. The results indicate that the CFSs of symbiotic bacteria of EPNs can be as effective as chemical insecticides and enable the reduction of the insecticide application in the control of P. citri.