Title: Preliminary evaluation of Delphastus catalinae (Coleoptera:Coccinellidae)as a predator of the ficus whitefly, Singhiella simplex (Singh) (Hemiptera:Aleyrodidae) Authors
|Mannion, Catharine -|
|Amalin, Divina -|
Submitted to: Subtropical Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 4, 2013
Publication Date: June 18, 2013
Citation: Legaspi, J.C., Mannion, C., Amalin, D. 2013. Preliminary evaluation of Delphastus catalinae (Coleoptera:Coccinellidae)as a predator of the ficus whitefly, Singhiella simplex (Singh) (Hemiptera:Aleyrodidae). Subtropical Plant Science. 64:34-36. Interpretive Summary: The ficus whitefly is an economic pest of ficus plants in India, Burma and China. The pest was first reported in the United States in Miami, Florida in August 2007. Since then, the whitefly has increased its geographic range to include most of southern Florida, as well as along both coasts up to central Florida. Very little is known about the biology or control of this pest.Scientist at the USDA-Agriculture Research Service Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida, tested the possibility of controlling the pest using Delphastus, a type of lady beetle being sold commercially for the control of other whitefly pests. Female adult beetles were starved for 24 hours, and then allowed to feed on leaves containing either 200 eggs, 100 small whitefly nymphs, or 10 large whitefly nymphs. After the feeding period, we counted the numbers of whitefly that remained. We also tested larvae of the beetles which we starved for 1 hour before allowing them to feed on the whiteflies. Each beetle larva ate about 76 eggs, 36 small whitefly nymphs and 4 large nymphs of the ficus whitefly. The adult beetles each ate about 148 eggs, 40 small nymphs and 1 large nymph of the whitefly. These feeding rates were compared against those of Delphastus on the silverleaf whitefly, against which it is sold as a biological control agent. Adult beetles ate about the same numbers of silverleaf whitefly eggs and small nymphs, but fewer large nymphs. These results suggest that Delphastus is a promising biological control agent against the ficus whitefly.
Technical Abstract: The predatory lady beetle Delphastus catalinae (Horn) (Coleoptera: Coccinellidae) was evaluated as a potential biological control agent against the ficus whitefly, Singhiella simplex (Singh) (Hemiptera: Aleyrodidae), a newly-invasive pest of ficus plants. Adult D. catalinae females were starved for 24 h, then introduced into leaf enclosures containing 200 eggs, 100 second to third instars, or 10 fourth instars as treatments, and allowed to feed for 24 h. After the predation period, the numbers of remaining immature whiteflies were recorded. Similar tests were conducted using third instar immature D. catalinae, which had been starved for 1 h. All feeding treatments were replicated 10 times. The immature predators consumed 76.2 ± 5.0 eggs (mean ± SE), 35.5 ± 7.2 second and third instars and 3.7 ± 0.8 fourth instars of the ficus whitefly. Adult predators consumed 147.3 ± 9.8 eggs, 39.4 ± 6.7 second and third instars and 1.2 ± 0.6 fourth instar whiteflies. When compared to predation on another species of whitefly Bemisia argentifolii Bellows & Perring, adult D. catalinae consumed approximately equal numbers of eggs and small nymphs. However, significantly more large nymphs of B. argentifolii were eaten compared to the ficus whitefly. These results suggest that D. catalinae is a promising biological control agent against the ficus whitefly.