Feeding and development of Nephaspis Oculata (Coleoptera: Coccinellidae) on rugose spiraling whitefly

Authors: TARAVATI, SIAVASH - University Of California - Cooperative Extension Service; MANNION, CATHARINE - University Of Florida; OSBORNE, LANCE - University Of Florida; McKenzie, Cindy

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/19/2016
Publication Date: 9/16/2016
Citation: Taravati, S., Mannion, C., Osborne, L., McKenzie, C.L. 2016. Feeding and development of Nephaspis oculata (Coleoptera: Coccinellidae) on rugose spiraling whitefly. Florida Entomologist. 99(3):516-521.

Interpretive Summary: Rugose spiraling whitefly (RSW), Aleurodicus rugioperculatus Martin 2004, recently invaded the United States in 2009 and has become an escalating problem for homeowners, landscapers, businesses, and governmental officials throughout the southern coastal counties of Florida. Identifying effective biological control agents is key to long-term sustainable control of this new exotic whitefly pest. Nephaspis oculata (Blatchley, 1917) is a whitefly predatory lady beetle often found on plants infested with RSW. We studied the feeding rate and development of this beetle on RSW to determine its feasibility for use in a biological control strategy. Nephaspis oculata is able to complete its development from egg to adult solely on RSW and its appetite is quite ferocious consuming 246 eggs prior to larval pupation with adults consuming 51 eggs per day. Life cycle from egg to adult at 26.7 degree Celsius(°C) took 21 days. Female beetles produced more adult progeny when fed eggs compared to whitefly nymphs and would be the more suitable prey when rearing beetles for biological control efforts.

Technical Abstract: Nephaspis oculata (Blatchley, 1917) is a whitefly predatory lady beetle which has been studied for its biological control effect on different whiteflies. Here, we studied the feeding rate and development of this beetle on rugose spiraling whitefly (RSW), Aleurodicus rugioperculatus Martin 2004, an invasive whitefly species which was first found in the United States in 2009. Our results showed that Nephaspis oculata is able to complete its development from egg to adult solely on RSW. At 26.7 degree Celsius (°C), immature (1st-4th instars combined) beetles consumed an average of 245.7 ± 14.4 RSW eggs prior to pupation. Adult beetles consumed 50.6 ± 1.8 eggs per day. There was no difference between the feeding rate of adult males and females or between immature males and females. Larvae searched for prey by sweeping the leaf surface in an arc-shaped area around them. Extra-oral digestion was observed during feeding which involved withdrawing and regurgitating of fluids from and into the egg shell. It took 21.3 ± 0.7 days for the beetles to develop from egg to the adult stage. The feeding rate of Nephaspis oculata on rugose spiraling whitefly was compared to that of on Bemisia tabaci based on the data from literature. Adult Nephaspis oculata consumed significantly lower number eggs when fed on RSW compared to when feeding on Bemisia tabaci which can be explained by a 3.7 times larger egg size of RSW compared to Bemisia tabaci eggs. Nevertheless, in our study, adult beetles consumed a significantly higher volume of eggs per day. Female Nephaspis oculata produced significantly more adult progeny when fed on RSW eggs compared to when fed on RSW nymphs. Therefore, RSW egg is considered as a more suitable choice than RSW nymphs for rearing Nephaspis oculata.