INTRODUCTION Wheat (Triticum aestivum L.) is the most important cereal crop with the vast area under cultivation in Pakistan (Anwar et al., 2009). To feed increasing population, increase in productivity is necessary (Khakwani et al., 2012). Various abiotic and biotic stresses are responsible for low yield, like unfavorable weather conditions, traditional style of cultivation, lack of high yielding varieties, drought, improper use of fertilizers, soil fertility levels and occurrence of diseases and insect pests (Akhtar et al., 2010). Among insect pests, aphids are the serious pest possessing an extensive range of 60 plant species including barley, sorghum, vegetables and maize (Bowling et al., 1998). In Pakistan, Schizaphis graminum (Green-bug), Rhopalosiphum padi (Bird cherry-oat aphid), Diuraphis noxia (Russian wheat aphid) and Sitobion avenae (English grain aphid) are commonly known species reported on wheat (Shahid et al., 2012; John et al., 2017). But, the specie S. graminum is found the most abundant and dangerous for wheat crop in our country (Wains et al., 2014). Yield losses are positively correlated with aphid populations (Riazuddin et al., 2004). Aphids suck the sap of plants which results in leaf curling, discoloring and distortion, shorten growth and molds are develop on their honey dews (Akhtar and Khaliq, 2003). It also injects toxin into the plant that interrupts grain formation, reduce photosynthetic rate, decrease carbon assimilation, transpiration and total chlorophyll (Ryan et al., 1987; Burd and Elliott, 1996; Kannan, 1999). In addition, these are the vectors which transmit many fungal and viral diseases in plants (Bukvayova et al., 2006). So, yield losses may reach up to 7.9 to 34.2% with aphid damage in wheat (Akhtar et al., 2010). It has been reported that combination of feeding infestation and honeydew secretion can result in yield losses of 72% (Rabbinge et al., 1981). Reduction in shoot biomass, number of grains per spike, thousand grain weight and yield has also been recorded (Shahzad et al., 2013). To manage aphids, various integrated pest management (IPM) strategies have been employed i.e. cultural, physical, mechanical, biological and chemical, the host plant resistance has been proved the best tool to inhibit losses by aphids worldwide (Junaid et al., 2016). In IPM, plant resistance to insects recommends the utilization of resistant varieties to restrict insect pest damage. Lowe (1987) reported that host plant resistance can check aphid population below the economic threshold level (ETL). Leszczynski et al. (1995) revealed that allelochemicals released by resistant varieties restrict aphid abundance, reduce fecundity and their development. Also, the aphid incidence has been recorded significantly variable in different wheat cultivars (Parvez and Ali, 1999; Ahmad and Nasir, 2001). Aphids pre-reproductive, reproductive and post-reproductive growth, development and fecundity is significantly influenced by crop varieties (Saikia et al., 1998). Plant resistance could be used in conjunction with other direct control tactics (Akhtar et al., 1991). J. Glob. Innov. Agric. Soc. Sci., 2019,7(3):105-109. ISSN (Online): 2311-3839; ISSN (Print): 2312-5225 DOI: https://doi.org/10.22194/JGIASS/7.869 http://www.jgiass.com PERFORMANCE OF SOME WHEAT CULTIVARS AGAINST APHID AND ITS DAMAGE ON YIELD AND PHOTOSYNTHESIS Muhammad Waseem Shahzad 1,* , Haroon Ghani 1 , Muhammad Ayyub 1 , Qurban Ali 2 , Hafiz Muneeb Ahmad 1 , Muhammad Faisal 1 , Asim Ali 1 and Muhammad Umar Qasim 2 1 Pest Warning and Quality Control of Pesticides, Punjab, Lahore, Pakistan; 2 Entomological Research Institute, Ayub Agricultural Research Institute, Faisalabad, Pakistan * Corresponding author’s e-mail: wshahzad105@gmail.com The aim of the study was to check the population dynamics on different wheat cultivars and to check the aphid damage on yield and photosynthetic activities on wheat crop. Aphid (Shizaphis graminum R.) herbivory results in significant loss yield in many crops. Planting resistant cultivars is a simple and effective method to reduce its damage. The experiment was conducted in agricultural farm of Multan, Pakistan. Four wheat varieties i.e. Galaxy 2013, Faisalabad 2008, Punjab 2011and AARI 2011 were sown on November 14, 2015. The study was conducted in Randomized Complete Block Design with three replications. The results revealed that aphids’ population was increased during last week of February to the 3 rd week of March. Peak populations were recorded in 3 rd week of March in all cultivars. But Galaxy 2013 showed significant difference in aphid abundance as compared to other cultivars. Also, Galaxy 2013 was significantly different for thousands grain weight, yield, photosynthetic rate and chlorophyll contents as compared to other cultivars. It was proved that Galaxy 2013 can withstand/tolerate aphid damage and give higher yield. Keywords: Wheat cultivars, aphid, yield, photosynthesis.