World Aquaculture December 2019

60 DECEMBER 2019 • WORLD AQUACULTURE • WWW.WA S.ORG throughout the experiment and did not inflict any significant injury on cucumber plants. This suggests that A. swirskii can be added once during the season and a self-sustaining population will control whiteflies and thrips (Calvo et al . 2011). If A. swirskii is introduced into the greenhouse before the populations of pest insects are enough to support it, pollen from the marigold flowers will suffice until thrip and whitefly populations are sufficient (Goleva and Zebitz 2013). Conclusion Using fish tank effluent to irrigate vegetable greenhouses is a very good use of water resources and fish feed wastes. However, the nitrogen content of aquaculture effluent, although beneficial for plant growth, renders those same plants attractive to insect pests. Accordingly, IAA systems should be coupled with an augmentative biological control strategy using beneficial insects to control harmful ones. Such an IAA scheme would help farmers increase their water productivity by producing two crops (fish and vegetables) using the same water and also limit their use of fertilizers and pesticides that are harmful to human health and the environment. Acknowledgments The project was funded by the Conservation, Food &Health Foundation, GMA Foundations, Boston, MA, USA. Notes Sara Daher, Youssef Abou Jawdeh, Mustafa Haidar, Andre Abou Haidar, Dept. of Agriculture, American University of Beirut, Beirut, Lebanon. Bruce Parker, Margaret Skinner, Department of Plant and Soil Science, University of Vermont. I. Patrick Saoud, Department of Biology, American University of Beirut, Beirut, Lebanon. Corresponding author e-mail: is08@aub. edu.lb References Ali, A.I., F. Schulthess, C.K.P.O. Ogol and C.OOmwega. 2006. Effect of nitrogen fertilizer level on infestations of Lepidopterous stemborers and yields of maize in Zanzibar. Annales de la Société Entomologique de France 42:481-486. Abdul-Rahman, S., J. Ghanawi, M.K. Owaied, H. Holail, N. Farajalla, M. Haidar and I.P. Saoud. 2011. Improving water use efficiency in semi-arid regions through integrated aquaculture/agriculture. Journal of Applied Aquaculture 23:212-230. Bensoussan, N., M.E. Santamaria, V. Zhurov, I. Diaz, M. Grbić and V. Grbić. 2016. Plant-herbivore interaction: Dissection of the cellular pattern of Tetranychus urticae feeding on the host plant.  Frontiers in Plant Science 7:1105. Calvo, F.J., K. Bolckmans and J.E. Belda. 2011. Control of Bemisia tabaci and Frankliniella occidentalis in cucumber by Amblyseius swirskii . Biological Control 56:185-192. Calvo, F.J., M. Knapp, Y.M. Houten, H. Hoogerbrugge and J. Belda. 2015. Amblyseius swirskii : what made this predatory mite such a successful biocontrol agent? Experimental and Applied Acarology 65(4):419-433. Douglas, A.E. 2006. Phloem-sap feeding by animals: problems and solutions. Journal of Experimental Botany 57(4):747-754. Draz, K., A. Darwish and R. Tabikha. 2013. Effect of different rates TABLE 1. Mean number (± SD) of aphids per leaf collected on five dates (T) on plots receiving four irrigation water source treatments (A, B, C and D). Treatment T1 T2 T3 T4 T5 A 0.8 ±1.6 2.1 ab ± 2.9 4.3 b ± 3.2 13.0 ab ±10.9 0.1 ± 0.2 B 0.2 ± 0.5 4.0 a ± 4.5 11.0 a ± 8.6 18.0 a ± 9.6 0.0 ± 0.0 C 1.2 ± 2.2 4.5 a ± 5.8 4.3 b ± 8.2 8.1b bc ± 13.7 0.0 ± 0.1 D 0.2 ± 0.6 0.4 b ± 1.2 3.3 b ± 8.3 3.3 c ± 2.2 0.1 ± 0.2 Mean values in the same column with different superscripts are significantly different at P-value<0.05. Water source: Fish tank effluent (A), Fish tank effluent + fertilizers (B), Groundwater + fertilizers (C) and Groundwater (D). TABLE 2. Mean number (± SD) of mites per leaf collected on five dates (T) on plots receiving four irrigation water source treatments (A, B, C and D). Treatment T1 T2 T3 T4 T5 A 0.6 b ± 0.9 2.2 b ± 2.4 7.4 ± 9.4 9.7 b ± 4.0 0.5 a ± 0.5 B 1.2 b ± 1.3 2.7 b ± 2.3 7.5 ± 6.4 12.8 a ± 3.8 0.0 b ± 0.0 C 3.5 a ± 2.9 6.6 a ± 3.9 6.8 ± 2.8 6.1 c ± 3.4 0.1 b ± 0.2 D 1.4 b ± 2.0 3.0 b ± 2.0 3.5 ± 4.2 5.0 c ± 5.5 0.1 b ± 0.2 Mean values in the same column with different superscripts are significantly different at P-value<0.05. Water source: Fish tank effluent (A), Fish tank effluent + fertilizers (B), Groundwater + fertilizers (C) and Groundwater (D).