Tospoviruses belong to the sole phytovirus genus, Tospovirus, in the family Bunyaviridae. Tospoviruses are known to be exclusively transmitted by thrips belonging to the family Thripidae and subfamily Thripinae. Of the known 1,710 species of Thripidae only 14 thrips species are currently reported to transmit tospoviruses. Thrips-transmitted tospoviruses cause severe yield losses to several economically important crops in the United States and worldwide. For instance, a single Tospovirus (Tomato spotted wilt virus) alone caused an estimated $1.4 billion in losses in the U.S. over 10 years. Global trade and associated movement of plant materials across borders have introduced tospoviruses and their vectors into newer areas. Advances in serological and molecular techniques have also led to identification of new tospoviruses. This scenario has also initiated new vector-pathogen interactions between introduced and native thrips species and tospoviruses. The goal of this manuscript is to provide a comprehensive and updated list of thrips species that serve as vectors of tospoviruses along with information pertaining to common names, key diagnostic characters, distribution, important crops economically affected, and thrips and Tospovirus-induced symptoms. The manuscript is prepared with special emphasis to the U.S., but information pertaining to other countries is also included.
Using artificial intelligence (AI) and the IoT (Internet of Things) is a primary focus of applied engineering research to improve agricultural efficiency. This review paper summarizes the engagement of artificial intelligence models and IoT techniques in detecting, classifying, and counting cotton insect pests and corresponding beneficial insects. The effectiveness and limitations of AI and IoT techniques in various cotton agricultural settings were comprehensively reviewed. This review indicates that insects can be detected with an accuracy of between 70 and 98% using camera/microphone sensors and enhanced deep learning algorithms. However, despite the numerous pests and beneficial insects, only a few species were targeted for detection and classification by AI and IoT systems. Not surprisingly, due to the challenges of identifying immature and predatory insects, few studies have designed systems to detect and characterize them. The location of the insects, sufficient data size, concentrated insects on the image, and similarity in species appearance are major obstacles when implementing AI. Similarly, IoT is constrained by a lack of effective field distance between sensors when targeting insects according to their estimated population size. Based on this study, the number of pest species monitored by AI and IoT technologies should be increased while improving the system’s detection accuracy.
28 April 2022 in Annals of the Entomological Society of America
The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is one of the most damaging, polyphagous insect pests of agricultural cropping systems around the world. Insecticide control is one of the main tactics used to mitigate damage and crop injury caused by the species. Similarly, plant chemical defenses are primary natural mechanisms that reduce attacks from whiteflies. Like all Sternorrhyncha insects, whiteflies have piercing/sucking mouthparts and feed on phloem sap from vascular plants through a stylet. Therefore, if this insect can overcome the physical barriers of the plant and pierce the vascular bundle, the main remaining barriers to nutrition uptake and utilization are phytochemicals that might exhibit some degree of toxicity toward the insect. Bemisia tabaci has been reported to feed on over 1,000 plant species representing an enormous range of phytochemicals to which whiteflies are potentially exposed. Recently, whiteflies were shown to have acquired a gene from plants to detoxify the plant’s phenolic glycosides that are usually toxic. Additionally, host plants have been shown to alter the response of a single whitefly population to insecticides. Herein, we review possible interactions between the highly polyphagous B. tabaci, the potential phytochemicals associated with its extensive plant host range, and the main chemical insecticides used to control this pest. This review aims to provide a conceptual framework for studying possible biological interactions between the insect, host plant, and insecticidal toxins used to control this pest at the mechanistic and population selection levels.
We conducted maximum dose bioassays of insecticide for the control of diamondback moth (DBM), Plutella xylostella (Linnaeus), in cole crops, from 2016 to 2019 at several commercial locations in Georgia and Florida. The nominal maximum dose was defined as the highest labeled rate of an insecticide at the beginning of the survey in the equivalent of 935 liters/ha dilution. The results indicated low insecticide efficacy for high labeled rates of the following insecticides by common name (Insecticide Resistance Action Committee group number in parentheses). Our 4-yr survey identified very low levels of DBM larval control (74%) listed in decreasing average levels of efficacy were naled (1B), cyclaniliprole (28), tolfenpyrad (21A), emamectin benzoate (6), and cyantraniliprole (28). Intermediate levels of control (61–71%) were obtained with Bacillus thuringiensis subspecies aizawai (11A), Bacillus thuringiensis, subsp. kurstaki, strain ABTS-351 (11A), and spinetoram (5). This rapid bioassay provided the grower with a ranking of insecticide efficacy for the control the DBM population for that farm site. These data allowed growers to make an informed decision on control quickly and plan for resistance management rotations for DBM that season.
Cucurbit chlorotic yellows virus (CCYV) belongs to the genus Crinivirus and is part of a complex of whitefly-transmitted viruses that cause yellowing disease in cucurbits. In the southeastern USA, heavy incidences of CCYV have been observed on all cucurbits grown in the fall. CCYV was detected from wild radish (Raphanus raphanistrum L.), a common weed that grows in the southeastern USA by high-throughput sequencing as well as RT-PCR. CCYV sequence from wild radish was 99.90% and 99.95%, identical to RNA 1 and RNA 2 of cucurbit isolates of CCYV from the region. Transmission assays using whiteflies demonstrated that wild radish is a good host for CCYV. Whiteflies were also able to acquire CCYV from wild radish and transmit the virus to cucurbit hosts, which developed typical symptoms associated with CCYV. Using quantitative PCR, the titer of CCYV in wild radish was also estimated to be on par with that of cucurbit hosts of the virus. Whitefly bioassays revealed that wild radish is an acceptable feeding and reproductive host plant. These results indicate that wild radish could serve as a reservoir host for CCYV in the USA and other parts of the world where similar conditions exist.
Two Bemisia tabaci populations from Georgia and Florida, USA, were tested for their response to insecticides across different toxicological bioassay methods. Five insecticides in four Insecticide Resistance Action Committee (IRAC) groups (imidacloprid (4A), dinotefuran (4A), flupyradifurone (4D), pyriproxyfen (7C) and cyantraniliprole (28)), were evaluated against a water check. The routes of application to the plant used were either leaf drench or (systemic) root drench. The four different whitefly bioassay methodologies tested were two published IRAC methods, a clip cage method, and a new tube method. A split–split experimental design was used to assess any interactions between application route, bioassay method and insecticide treatment. Application route had no significant effect on efficacy. However, bioassay method affected overall whitefly mortality, with the dish method having reduced mortality compared to other methods, except for the clip cage method. High rates of cyantraniliprole, dinotefuran and flupyradifurone insecticides resulted in the highest incidence of adult whitefly mortality. Significant interactions relative to percent adult mortality were found between the insecticide and bioassay method for both populations assayed. The clip cage method was more sensitive in terms of dose mortality response followed by the cup and tube methods. The dish method was the least responsive to insecticide dose. Other interactions are discussed.