In 2020, the invasive Thrips parvispinus (Karny) was first detected in Florida, United States. In response to the implemented regulatory restrictions, we conducted laboratory experiments under containment conditions. Thrips larvae and adults were exposed to 32 products (conventional and biorational insecticides) either directly or indirectly. Direct exposure was performed using a Spray Potter Tower, while indirect exposure was conducted by evaluating residue toxicity against the thrips. Water served as a control. We assessed mortality and leaf-feeding damage 48 h post-treatment. Among the conventional insecticides, chlorfenapyr, sulfoxaflor-spinetoram, and spinosad caused high mortality across all stages in both direct and residue toxicity assays. Pyridalyl, acetamiprid, tolfenpyrad, cyclaniliprole-flonicamid, acephate, novaluron, abamectin, cyantraniliprole, imidacloprid, cyclaniliprole, spirotetramat, and carbaryl displayed moderate toxicity, affecting at least two stages in either exposure route. Additionally, chlorfenapyr, spinosad, sulfoxaflor-spinetoram, pyridalyl, acetamiprid, cyclaniliprole, cyclaniliprole-flonicamid, abamectin, and acephate inhibited larvae and adult’s leaf-feeding damage in both direct and residue toxicity assays. Regarding biorational insecticides, mineral oil (3%) and sesame oil caused the highest mortality and lowest leaf-feeding damage. Greenhouse evaluations of spinosad, chlorfenapyr, sulfoxaflor-spinetoram, and pyridalyl are recommended. Also, a rotation program incorporating these products, while considering different modes of action, is advised for ornamental growers to avoid resistance and to comply with regulations.

Originating in northeastern Mexico and southern Texas, the hibiscus bud weevil (HBW), Anthonomus testaceosquamosus Linell 1897, was discovered infesting China rose hibiscus (Hibiscus rosa-sinensis L.) in south Florida in May 2017. Although the biologies of the congeneric boll weevil, A. grandis Boheman 1843, and pepper weevil, A. eugenii Cano 1894 are well documented, no data are available regarding the biology of HBW. Here, we present a comprehensive study on the biology of this pest when reared at 10, 15, 27 and 34 °C and on different food sources. This weevil has three larval instars and its life cycle was completed only at 27 ± 1 °C. Weevil development was similar on an artificial diet when compared with a diet of hibiscus buds. Adult HBW could survive solely on pollen, but reproduction did not occur. Without water, HBW survived for ≈15 days; survival times reached nearly 30 days when water was accessible. Our results suggest that if left unmanaged, HBW has the potential to cause significant economic damage to the hibiscus industry. Given that a comprehensive understanding of a pest’s biology is critical for development of effective integrated pest management, our results provide a foundation for future research endeavors to mitigate the impact of this weevil in south Florida.

In 2017, the hibiscus bud weevil (HBW), Anthonomus testaceosquamosus Linell (Coleoptera: Curculionidae), was found outside of its native range of Mexico and Texas, infesting hibiscus plants in Florida. Therefore, we selected 21 different insecticide and horticultural oil products to evaluate their effects on the reproductive rate, feeding, and oviposition behavior of the HBW. In laboratory experiments, significant mortality was observed in adult weevils exposed to diflubenzuron-treated hibiscus leaves and buds, and hibiscus buds treated with diflubenzuron contained the fewest number of eggs and feeding/oviposition holes. Among horticultural oil products, significant mortality was only observed in experiments in which adult weevils were directly sprayed (direct experiments). Pyrethrins and spinetoram plus sulfoxaflor reduced the oviposition rate and caused significant mortality in direct experiments. Diflubenzuron, pyrethrins, spinetoram plus sulfoxaflor, and spirotetramat were further tested via contact toxicity experiments and greenhouse experiments. Contact toxicity experiments demonstrated that the tested insecticides (except diflubenzuron) were highly toxic to HBW adults. In greenhouse experiments, only those hibiscus plants treated with pyrethrins had significantly fewer feeding/oviposition holes and larvae within their flower buds when compared to control (water-treated) plants. These results constitute an important first step in the identification of effective chemical control options for the HBW.

Thrips parvispinus (Karny) is an invasive pest of vegetable and ornamentals in the United States. To support ornamental growers to control T. parvispinus infestations, we tested seven conventional (spinosad, chlorfenapyr, sulfoxaflor–spinetoram, pyridalyl, tolfenpyrad, abamectin, and cyclaniliprole–flonicamid) and two biorational insecticides (mineral oil and sesame oil) under greenhouse conditions on mandevilla (Mandevilla splendens) and gardenia (Gardenia jasminoides), primary T. parvispinus ornamental hosts. Two insecticide applications were performed: a curative, treating an existing infestation, and a prophylactic, treating a plant prior to the thrips release. In the curative application, ten larvae and ten adults were released two weeks prior to treatment. Three leaves from the upper, middle, and lower canopy were collected 24 h, 7-, and 14-days post-treatment to assess thrips mortality. In the prophylactic application, plants were first sprayed with insecticides, and thrips were introduced 24 h later, but followed the same sampling method. In mandevilla, chlorfenapyr, abamectin, and spinosad caused the highest thrips mortality in both application types. Among horticultural oils, mineral oil and sesame oil increased mortality in prophylactic applications only. In gardenia, neither curative nor prophylactic applications of these products led to significant thrips mortality, and the possible reasons and recommendations for best thrips management are presented.

Thrips parvispinus (Karny) (Thysanoptera: Thripidae), an invasive thrips species, poses a significant threat to global agriculture due to its polyphagous nature and rapid spread. Its recent arrival in the continental United States raises concerns about potential impacts on ornamental and vegetable crops. Dip treatments might serve as a phytosanitary practice for growers to start with plants free of visible pests. This study aimed to assess the efficacy of dip treatments using 4 biorational and microbial insecticides (mineral oil and Beauveria bassiana-based) in controlling T. parvispinus on bean seedlings. Following gentle agitation of cuttings, artificially infested with 10 second-instar (L2) larvae, for 15 s in each solution, thrips infestation was evaluated at 1, and 24 h postdipping, scoring the numbers of dislodged and dead larvae. Additionally, we tested whether dipping could cause phytotoxicity on bean (Phaseolus vulgaris L.), gardenia (Gardenia jasminoides Ellis), and mandevilla (Mandevilla splendens (Hook.f.) Woodson) cuttings during a 7-day period. Our results demonstrated that dip treatments effectively dislodged and killed T. parvispinus L2 larvae from infested cuttings, with BotaniGard-ES and Suffoil-X exhibiting the highest efficacy and a dislodgment rate of 80%–100%. BotaniGard-ES was the only product causing phytotoxicity on bean seedlings, but not on mandevilla and gardenia. Overall, we demonstrated that dip treatment using biorational insecticides is an additional tool that can be incorporated in the integrated pest management of T. parvispinus. These results hold implications for the broader application in the management of thrips across various plants propagated from cuttings.