Natural biological control of green scale (Hemiptera: Coccidae): a field life-table study

• Published in: Biocontrol science and technology Vol. 24; no. 2; pp. 190 - 202
• Main Authors: Rosado, J.F., Bacci, L., Martins, J.C., Silva, G.A., Gontijo, L.M., Picanço, M.C.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 01.02.2014
• Subjects: Abscission; biological control; Coccidae; Coccinellidae; Coccus viridis; coffee; green scale; life table
• ISSN: 0958-3157; 1360-0478
• DOI: 10.1080/09583157.2013.855165

Understanding how the biotic and abiotic factors influence pest-population dynamics is important to implement sound pest management strategies in biological control and integrated pest management (IPM) programmes. Coccus viridis (Green) is an important indirect pest of coffee plants, but very little has been done to understand the factors that contribute most for its biological control in the field. In the present study, we examined the critical life stage and the key factors associated with the mortality of C. viridis in coffee plantations in Brazil by conducting field-based life table studies. Predators, parasitoids, fungi, infested leaf abscission and rainfall were collectively responsible for a total C. viridis mortality of 96.08%. Predation by coccinellids was the key factor governing the mortality of C. viridis. The parasitism of early instars by parasitoids was the second most important factor contributing to C. viridis mortality. Unlike the parasitoids, the fungus Lecanicillium lecanii caused mortality of scales in more advanced life stages. The abscission of infested leaves from the trees, and rainfall also contributed to the mortality of C. viridis. The nymph stage was considered the critical stage for mortality of C. viridis in the field. The results suggest that predators (Coccinellidae) are the most important factors controlling C. viridis, and thus should be the target of conservation measures in coffee plantations infested with this pest.