Susceptibility of Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) to imidacloprid, thiamethoxam, dinotefuran and flupyradifurone in south Florida

Authors: SMITH, HUGH - University Of Florida; NAGLE, CURTIS - University Of Florida; MACVEAN, CHARLES - St Francis University; McKenzie, Cindy

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/18/2016
Publication Date: 10/20/2016
Citation: Smith, H.A., Nagle, C.A., MacVean, C.A., McKenzie, C.L. 2016. Susceptibility of Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) to imidacloprid, thiamethoxam, dinotefuran and flupyradifurone in south Florida. Insects. 7(57). doi:10.3390/I.2016-7040057.

Interpretive Summary: The sweetpotato whitefly, Bemisia tabaci (Gennadius) Middle East Asia Minor 1 (MEAM 1), formerly known as B. tabaci biotype B, is a globally important pest of agronomic, horticultural and ornamental crops and is the primary pest of tomato in Florida transmitting devastating viruses and inducing plant disorders such as irregular ripening. Florida is the foremost producer of fresh market tomatoes in the United States, with over 33,000 acres harvested in 2014 at a value of $437 million. In addition to determining the relative susceptibility of nineteen field populations of B. tabaci to three insecticides that have been in common use for several years (imidacloprid, thiamethoxam, and dinotefuran), our objective was to gather baseline information on the susceptibility of B. tabaci to flupyradifurone, which was not commercially available at the time the populations were collected. Several populations were either generally tolerant of all materials or generally susceptible. Based on overlapping fiducial limits, there were no statistical differences in relative mean potency estimates for flupyradifurone and dinotefuran in relation to imidacloprid and thiamethoxam. On the whole, populations tended to respond to imidacloprid and thiamethoxam in a similar fashion, and to dinotefuran and flupyradifurone in a similar fashion.

Technical Abstract: Populations of Bemisa tabaci Middle East Asia Minor 1 (MEAM 1) were established from nineteen locations in south Florida, primarily from commercial tomato fields, and were tested using a cotton leaf petiole systemic uptake method for susceptibility to the nicotinic acetylcholine agonist insecticides imidacloprid, thiamethoxam, dinotefuran and flupyradifurone. Several populations were either generally tolerant of all materials or generally susceptible. Eleven populations produced LC50s for one or more chemicals that were not statistically different from the susceptible laboratory colony based on overlapping fiducial limits, indicating some degree of susceptibility. LC50s more than a 100-fold the laboratory colony were measured in at least one population for each material tested, indicating tolerance. LC50s (ppm) from field populations ranged from 0.901 - 24.95 for imidacloprid, 0.97-24.43 for thiamethoxam, 0.043 – 3.35 for dinotefuran and 0.011 – 1.47 for flupyradifurone. Overall LC50s (and 95% fiducial limits) calculated from pooled field populations were 4.169 (3.449-5.020) for imidacloprid, 4.038 (3.347-4.854) for thiamethoxam, 0.422 (0.329- 0.535) for dinotefuran and 0.252 (0.193-0.324) for flupyradifurone. Based on overlapping fiducial limits, LC50s for imidacloprid and thiamethoxam were not statistically different. LC50s for dinotefuran and flupyradifurone did not overlap, however the difference between the upper bound for flupyradifurone and the lower bound for dinotefuran was 0.006. Based on overlapping fiducial limits, there were no statistical differences in relative mean potency estimates for flupyradifurone and dinotefuran in relation to imidacloprid and thiamethoxam. On the whole, populations tended to respond to imidacloprid and thiamethoxam in a similar fashion, and to dinotefuran and flupyradifurone in a similar fashion.