Location: Biological Control of Pests ResearchTitle: Juvenile coloration as a predictor of health in Nezara viridula (Heteroptera: pentatomidae) Author
Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/10/2014
Publication Date: 4/1/2014
Publication URL: http://handle.nal.usda.gov/10113/62314
Citation: Rojas, M.G., Morales Ramos, J.A. 2014. Juvenile coloration as a predictor of health in Nezara viridula (Heteroptera: pentatomidae). Journal of Entomological Science. 49:166-175. Interpretive Summary: The southern stink bug is a major pest of more than 150 species of plants, including cotton, beans, peanuts, strawberries, etc. For this reason, these insects have been reared in the laboratories around the world to facilitate research for their control. In field conditions, these insects show changes in coloration on the latest stage of development being green the normal pattern. Under laboratory conditions, other patterns such as faded green, green-black, and black were also observed. The fitness of nymphs with coloration pattern groups was measured by recording survival to the adult stage, adult weight, fecundity, and egg viability. Survival from fifth instar to adult was significantly lower in nymphs displaying abnormal coloration patterns showing 21 and 12.5% survival in the black and faded groups, respectively, as compared to 76.2% in the normal green coloration group. Adults originating from nymphs of black coloration did not produce progeny, while adults originating from the faded coloration produced significantly fewer eggs with lower viability than adults originating from nymphs with normal coloration. Abnormal nymphal coloration can be used as an indicator of health and can aid on the selection of healthy individuals for culture.
Technical Abstract: A new stackable modular system was developed for continuous in-vivo production of phytoseiid mites. The system consists of cage units that are filled with lima bean, Phaseolus lunatus, or red beans, P. vulgaris, leaves infested with high levels of the two-spotted spider mites, Tetranychus urticae. The cage units connect with each other through a connection cup, which also serves for monitoring and collection. Predatory mites migrate upwards to new cage units as prey is depleted. The system was evaluated for production of Phytoseiulus persimilis. During a 6-month experimental period 20,894.9 ± 10,482.5 (mean ± standard deviation) predators were produced per week. The production consisted of 4.1 ± 4.6 % nymphs and 95.9 ± 4.6 % adults. A mean of 554.5 ± 59.8 predatory mites were collected per cage harvested and the mean interval length between harvests was 6.57 ± 6.76 days. The potential for commercial and experimental applications is discussed.