Evaluation of Reduced-Risk Insecticides to Control Chilli Thrips (Thysanoptera: Thripidae) and Conserve Natural Enemies on Ornamental Plants

Abstract

Ornamental plants provide valuable services that benefit people and the environment. Herbivorous insects, particularly invasive pests with little resistance from natural enemies or plant defenses, damage plants and reduce the beneficial services they provide. Reduced-risk insecticides are valuable tools to selectively reduce target pests and protect plants while presumably conserving natural enemies. Herein, we conducted 2 separate tests of a new reduced-risk insecticide, cyantraniliprole, and industry standards for the control of Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), a damaging invasive insect pest of ornamental plants. We also evaluated each insecticide's compatibility with Orius insidiosus Say (Hemiptera: Anthocoridae), an important natural enemy of S. dorsalis. During laboratory evaluations, we found that spinosad was superior in acute toxicity to S. dorsalis and compatibility with O. insidiosus. Cyantraniliprole was consistently moderately toxic to S. dorsalis and O. insidiosus under lab conditions. In the field study, we found that all reduced-risk insecticides had no detectable effect on natural enemy abundance. Cyantraniliprole provided the best plant protection, with 70% less damage than the untreated control. Importantly, the effect of cyantraniliprole on S. dorsalis and plant protection depended on the application rate, such that the lowest rate tested did not reduce damage. This study demonstrates IPM tactics for managing an important invasive pest with a combination of chemical and biological control. As non-target effects of commonly used insecticides are becoming better understood, safer tools are needed to protect beneficial organisms, ornamental plants, and their services.

Spatio-Temporal Distribution and Fixed-Precision Sampling Plan of Scirtothrips dorsalis (Thysanoptera: Thripidae) in Florida Blueberry

“…Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) is invasive to the United States [ 1 ], as it was accidentally introduced from South Asia and became established in south Florida in 2005 in Knock Out ® rose plants ( Rosa X ‘Radrazz’: Rosaceae) [ 2 ]. Since then, S. dorsalis has become a pest of vegetable, ornamental, and fruits crops, and minor pest of landscape plants in Florida and Texas [ 1 , 3 , 4 , 5 , 6 , 7 ]. It has also been reported in other southern US states including Louisiana, Georgia, Alabama, Mississippi, and South Carolina, with a potential to expand up to western and northeastern US states and southern Canada [ 1 , 8 , 9 ].…”

“…It has also been reported in other southern US states including Louisiana, Georgia, Alabama, Mississippi, and South Carolina, with a potential to expand up to western and northeastern US states and southern Canada [ 1 , 8 , 9 ]. In Florida, S. dorsalis is a significant pest of pepper ( Capsicum spp., Solanaceae) [ 10 ], rose [ 11 ], strawberry ( Fragaria × ananassa Duchesne, Rosaceae) [ 12 ], blueberry ( Vaccinium sp., Ericaceae) [ 13 ], and landscape plants [ 5 ]. Scirtothrips dorsalis is minute (1–2 mm long) with yellow-colored body, dark-fringed wings, and dark stripes on dorso-abdominal segments [ 14 ].…”

Risk Assessment of Insecticides Used in Tomato to Control Whitefly on the Predator Macrolophus basicornis (Hemiptera: Miridae)

“…Many are broad-spectrum and can kill a wide range of many natural enemies [22,23], including M. basicornis. Other, reduced-risk insecticides are more selective to the predators and cause no or low lethal effect [18,20,24].…”

Monitoring of Diaphorina citri populations from Florida reveals reduced susceptibility to cyantraniliprole and thiamethoxam

“…Anthranilic diamides are a relatively new class of insect control chemicals and were developed to selectively activate insect ryanodine receptors resulting in uncontrolled release of calcium ion stores causing insect mortality (Lin et al, 2020;Little & Umina, 2017;Selby et al, 2013;Tiwari & Stelinski, 2013). Anthranilic diamide insecticides have been shown to effectively control a large number of insect pest species including European crane fly, Tipula paludosa Meigen (Diptera: Tipulidae) (Peck et al, 2008); chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) (Dale & Borden, 2018); stem borer, Tryporyza incertulas Walker (Lepidoptera: Pyralidae) (Sarao & Kaur, 2014); Eastern subterranean termite, Reticulitermes flavipes Kollar (Isoptera: Rhinotermitidae) (Barwary et al, 2015); Asian citrus psyllid, D. citri Kuwayama (Hemiptera: Psyllidae) (Qureshi et al, 2014;Stansly et al, 2013;Tiwari & Stelinski, 2013); and rice water weevil, Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae) (Lanka et al, 2015). Cyantraniliprole, a systemic anthranilic diamide, has been used to control hemipteran pests (Sattelle et al, 2008;Tiwari et al, 2011).…”