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United States Department of Agriculture

Agricultural Research Service

Research Project: BIOLOGICALLY BASED TECHNIQUES TO LIMIT THE DISPERSAL OF INVASIVE PESTS Title: Life table analysis for immatures and female adults of the predatory beetle,Delphastus catalinae,feeding on whiteflies under three constant temperatures

Authors
item Legaspi, Jesusa
item Legaspi,jr, Benjamin - STATE OF FLORIDA
item Simmons, Alvin

Submitted to: Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 18, 2006
Publication Date: January 28, 2008
Citation: Legaspi, J.C., Legaspi,Jr, B.C., Simmons, A.M. 2008. Life table analysis for immatures and female adults of the predatory beetle,Delphastus catalinae,feeding on whiteflies under three constant temperatures. Journal of Insect Science. 8(7). Available online:insectscience.org.

Interpretive Summary: The ladybeetle, Delphastus catalinae, is an important insect predator of the silverleaf whitefly, Bemisia argentifolii. This species is a voracious predator of whiteflies in various plants such as ornamentals, horticultural and row crops. This beetle is also mass produced by biological control companies and is popularly sold in commercial greenhouses, especially in Europe. We studied the predation, development and reproduction of this predator to optimize its use in mass rearing and augmentation in field conditions. We fed immature and adult D. catalinae with the silverleaf whitefly on tomato leaves under the following temperatures: 22, 26 and 30 ºC. Female adults weighed slightly more than males. As temperature increased from 22 to 30 ºC, immature development time from eggs to pupae declined from 24 to 15 days, and adult longevity ranged from 138 and 77 days. Thermal units required for immature development was '300 degree-days. Delphastus catalinae was found to perform better at 22 and 26 ºC; 30 ºC was detrimental to immature development and adult reproduction.

Technical Abstract: Immature development and reproductive life history of Delphastus catalinae (Horn) (Coleoptera: Coccinellidae) feeding on Bemisia argentifolii Bellows & Perring (Homoptera: Aleyrodidae) immatures was studied at three constant temperatures: 22, 26 and 30 ºC. Development rates and lower temperature threshold temperatures (T0) were estimated at 9 and 9.9 ºC, for males and females, respectively. Thermal units required for immature development was about 300 degree-days in both sexes. Female adults weighed slightly more than males (0.587 and 0.505 mg, respectively). As temperature increased from 22 to 30 ºC, immature development time from eggs to pupae declined from 24 to 15 days, and adult longevity ranged from 138 and 77 days. Thermal units required for immature development was '300 degree-days. Immature females surviving to adult emergence at a given temperature treatment were maintained at the same temperature for the duration of their adult lifetimes. Daily fecundity was measured until death. Percentage egg hatch declined at increasing temperatures, but no significant effect of time was found. The intrinsic rate of increase r, increased from 0.048 to 0.082 and doubling time DT decreased from 14.44 to 8.45 days as temperature increased from 22 to 26 ºC. Mean daily fecundity was modeled as a function of time and temperature to create a 3-dimensional surface. Delphastus catalinae was found to perform better at 22 and 26 ºC; 30 ºC was detrimental to immature development and adult reproduction.

Last Modified: 11/1/2014
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