Synergistic Action of Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae) and Spirotetramat against Asian Citrus Psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae) under Field Conditions

Abstract Background The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae) is an insect pest species responsible for damages of citrus fruit quality and tree health. This insect is a vector of bacteria ‘Candidatus Liberibacter’ spp. a putative causal agent of citrus greening disease known as Huanglongbing (HLB), considered one of the most destructive diseases of citrus orchards worldwide. Disease management is mainly based on vector control using pesticides which can affect natural enemies that play an important role in pest control. The entomopathogenic fungi (EPF) Beauveria bassiana (2067 and 2121) and Metarhizium anisopliae (2411) were achieved by applying a suspension of 1 × 107 spores against D. citri nymphs and artificially infected the citrus seedlings under controlled and semi-field conditions. Also, the activity of these EPFs on the coccinellid and lacewing predators was evaluated. The effects of the main chemicals used in citrus plantations on the selected fungi for possible combined use was also investigated. Results The obtained results showed that under controlled conditions, the percentage of insect mortality produced by EPF varied between 82.8 and 85.9%. Under semi-field conditions, the infection and mortality of D. citri caused by the M. anisopliae 2411 strain was significantly higher than that of B. bassiana 2067, 78.9 and 51%, respectively. Non-significant effect of EPF on the natural enemies of D. citri was observed, suggesting that EPF and predators had compatible effects. Conclusion This study clearly demonstrated that EPF were able to kill D. citri and can be explored as a promissory biocontrol candidate. Simultaneous use in an integrated pest management program could be possible by applying EPF combined with pesticides.

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Evaluation of Three Commercial Biopesticides for the Reduction of Diaphorina citri (Hemiptera: Liviidae) Populations

HortScience ◽

10.21273/hortsci13349-18 ◽

2018 ◽

Vol 53 (10) ◽

pp. 1453-1460

Author(s):

Augusto Ramírez-Godoy ◽

María del Pilar Vera-Hoyos ◽

Natalia Jiménez-Beltrán ◽

Hermann Restrepo-Díaz

Keyword(s):

Integrated Pest Management ◽

Pest Management ◽

Beauveria Bassiana ◽

Chili Pepper ◽

Field Conditions ◽

Asian Citrus Psyllid ◽

Diaphorina Citri ◽

Citrus Industry

Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is the most serious threat to the global citrus industry, and its management has mainly depended on the application of chemical insecticides. The use of biopesticides can play an important role in regulating this pest. In a first test, two separate experiments were conducted in two different municipalities (Apulo and Jerusalen, Cundinamarca, Colombia) to evaluate the effect of foliar Beauveria bassiana and imidacloprid sprays on ACP populations in 2015 and 2016, respectively. In a second test, two separate tests were carried out in commercial Tahiti lime orchards to evaluate the efficacy of three different commercial biopesticides (Beauveria bassiana and extracts of Sophora sp. and garlic-chili pepper). In test 1, imidacloprid-treated trees showed a reduction (60% and 80%) in cumulative ACP adults in 2016. ACP cumulative nymphs were also diminished by foliar imidacloprid and B. bassiana application, between 40% and 65% in 2015 and 2016, respectively. ACP cumulative eggs showed lower individuals in imidacloprid-treated flushes at 3 and 4 weeks after treatment 9 (WAT) in 2016. In test 2, the results obtained showed ACP adults and eggs unaffected by biopesticide treatments; nymphs were reduced 50% to 75% in trees treated with the three biopesticides in comparison with control trees. All three biopesticides tested can be considered useful tools in integrated pest management (IPM) programs for ACP, since these products reduced immature ACP individuals between 50% and 75% under field conditions.

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