Search results for "Whitefly"

Viral diseases causing the greatest economic losses to the tomato crop. II. The Tomato yellow leaf curl virus — a review

1996

Abstract Tomato yellow leaf curl geminivirus (TYLCV), transmitted by the whitefly Bemisia tabaci (Gennadius) is one of the most devastating diseases of cultivated tomato (Lycopersicon esculentum Mill.). TYLCV causes economic losses up to 100% in tomato crop in many tropical and subtropical regions, and is spreading towards new areas. The increasing economic importance of TYLCV has resulted in the need for accurate detection and identification procedures, stimulating intensive research efforts focused on virus biology, diversity, and epidemiology to develop successful control strategies. Breeding for resistance appears to be the best approach to control this disease, but to date only partial…

Variation in mortality among populations is higher for pymetrozine than for imidacloprid and spiromesifen inTrialeurodes vaporariorumin greenhouses i…

2014

BACKGROUND Insecticide resistance in Trialeurodes vaporariorum W. is unknown in the species' northern distribution range where it inhabits mainly commercial greenhouses. Resistance development in whiteflies feeding on year-round crops in greenhouses is possible owing to the use of chemical treatments to back up biocontrol. The authors tested the response levels to spiromesifen, pymetrozine and imidacloprid in whiteflies collected from seven greenhouses within a 35 km radius in western Finland. RESULTS All except one (PR) population had LC50 values below the recommended concentrations for the tested compounds. However, some populations showed reduced susceptibility to pymetrozine in comparis…

To B or Not to B: Comparative Genomics Suggests

2018

Insect lineages feeding on nutritionally restricted diets such as phloem sap, xylem sap, or blood, were able to diversify by acquiring bacterial species that complement lacking nutrients. These bacteria, considered obligate/primary endosymbionts, share a long evolutionary history with their hosts. In some cases, however, these endosymbionts are not able to fulfill all of their host's nutritional requirements, driving the acquisition of additional symbiotic species. Phloem-feeding members of the insect family Aleyrodidae (whiteflies) established an obligate relationship with Candidatus Portiera aleyrodidarum, which provides its hots with essential amino acids and carotenoids. In addition, ma…

The role of agroecosystems for invasion of a generalist herbivore

2014

Preconditioning of the generalist herbivore Trialeurodes vaporariorum to greenhouse monocultures and its subsequent performance on wild polycultures

2016

Generalist herbivores can face many challenges when choosing their host plant. This can be particularly difficult if their choice and performance are affected by host experience. Greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), is an invasive generalist herbivore, which has established in year-round greenhouses at northern latitudes where it cannot overwinter outdoors. It mainly uses crops such as cucumber (Cucumis sativus L.), tomato (Solanum lycopersicum L.), and ornamentals as host plants. However, every summer the insect escapes greenhouses and is exposed to natural vegetation. We evaluated the performance of T. vaporariorum on diverse vegetation outside…