Research Article

Efficacy of Plant Extracts and Selective Insecticides Against Wheat Aphid in Faisalabad, Pakistan

Usama Saleem1, Muhammad Asrar1*, Dilbar Hussain2, Saddam Hussain1, Abdul Ghaffar2, Hassan Usman1, Muhammad Imran1, Mubshar Saleem3 and Maryam Hamid1

1Department of Zoology, Government College University Faisalabad, Faisalabad, Pakistan; 2Entomological Research Institute, Ayub Agricultural Research Institute, Faisalabad, Pakistan; 3Department of Plant Pathology, PMAS Arid Agriculture University Rawalpindi, Rawalpindi, Pakistan.

Received | January 18, 2023; Accepted | March 07, 2023; Published | April 03, 2023

*Correspondence | Muhammad Asrar, Department of Zoology, Government College University Faisalabad, Faisalabad, Pakistan; Email: [email protected]

Citation | Saleem, U., M. Asrar, D. Hussain, S. Hussain, A. Ghaffar, H. Usman, M. Imran, M. Saleem and M. Hamid. 2023. Efficacy of plant extracts and selective insecticides against wheat Aphid in Faisalabad, Pakistan. Journal of Innovative Sciences, 9(1): 65-71.

DOI | https://dx.doi.org/10.17582/journal.jis/2023/9.1.65.71

Keywords | Eucalyptus leaf extract, Neem leaf extract, Synthetic insecticides, Wheat aphid

Copyright: 2023 by the authors. Licensee ResearchersLinks Ltd, England, UK.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

1. Introduction

Agriculture is an important sector of the economy in several developed and undeveloped countries like Pakistan that are considered to be among the world least developed. Agriculture is the cornerstone of Pakistan’s economy and is regarded as the backbone of the economy, which relies heavily on its main crops. Wheat, cotton, rice, sugarcane, fruits, and vegetables are Pakistan’s primary agricultural crops. Agriculture represents 26% of the gross domestic product. Pakistan’s irrigation system is among the largest agricultural support systems in the world (Azam and Shafique, 2017; Rehman et al., 2015).

The first cereal crop to be planted was wheat (Triticum aestivum), a member of the Poaceae family. Wheat is an annual monocotyledon plant that is cultivated in numerous regions of the world. It is the most significant crop for food production (Kole, 2011). Pakistan is the eighth largest producer of wheat in the world (FAOSTAT, 2015). The average wheat production in Pakistan is 24.946 million tons and its contribution is 1.7 percent to the GDP of Pakistan (Pakistan Bureau of Statistics, 2020). It is estimated that 64% of the world’s T. aestivum is used for human consumption, 21% for animal feed, 8% as seed, and 6% in industry sectors (Ullah et al., 2020). Many EFSA health experts have approved that wheat fibers have a positive response on intestinal functions, glucose response, or cholesterol control (Giraldo et al., 2019). T. aestivum chaff is useful for protection against heart disease, constipation, obesity and diabetes (Kumar et al., 2011). Wheat hay is mainly used as animal feed, particularly during the dry season and when food becomes short (Shrivastava et al., 2011).

Insects are an important part of the agricultural system because they affect crop yield in different ways. Insects can decrease crop yield by direct damage or by spreading different diseases. Wheat is contrived by different kinds of insect pests like Aphids, Grasshopper, Termites, Flea beetles, Armyworms, Helicoverpa armigera, Stinkbugs, Wheat midges, Wheat weevil, and Hessian flies (Hussain et al., 2021; Khanal et al., 2020). Among the different insect pests, aphids are the most destructive pest of wheat crops and cause high yield losses (John et al., 2017; Khan et al., 2011; Akhtar et al., 2010). Aphids, often known as phloem feeders, are the closest relatives of Adelgidae and Phylloxeridae. They are members of the Hemiptera order and suborder Sternorryhncha, a large superfamily Aphidoidea and family Aphididae (Maryam et al., 2019). There are approximately 5,000 known species of aphids across the world; 24 of these species have been found in Punjab, Pakistan, and four of these species have been reported on wheat (Favret, 2018; Bodlah et al., 2011). English grain aphid (Sitobion avenae), Corn leaf aphid (Rhopalosiphum maidis), and Green-bug (Schizaphis graminum) and Bird cherry-oat aphid (R. padi) are the four aphid species that feed on the wheat crop in Pakistan (Shahzad et al., 2013; Aziz et al., 2013; Shahid et al., 2012). Among the aphid species that have been observed on wheat crop S. graminum is the most destroying because it attacks the spikes which directly bears the grain and R. maidis is mostly seen on stem and leaves of wheat (Wains et al., 2014). R. padi causes a loss of wheat yield up to 600 kg/ha (Ali et al., 2015). Barley yellow dwarf is a disease caused by a virus that is usually spread by R. padi or S. graminum (Bockus et al., 2016). Direct yield loss by aphids that are sucking insect pests is 35-40% and indirect loss is 20-80% by spreading fungal and viral diseases (Faheem et al., 2019; Zeb et al., 2016; Sabbir et al., 2014; Aslam et al., 2005). The yield loss is greater than 30% with 15 aphids per plant.

Numerous botanicals have been examined as potential synthetic pesticide alternatives. The usage of botanical extracts can result in mortality, infertility, slowed growth, and decreased egg viability. Botanical pesticides have a limited impact on the environment, and their low cost and use as food ingredients indicate minimal toxicity to humans (Bedini et al., 2020; Silva et al., 2017). Inherently biodegradable and less persistent than synthetic pesticides, botanical aphidicides are naturally biodegradable. Plant-derived aphicidal agents and various biologically active chemicals with high toxicity to insect pests are being developed (Nong et al., 2015). At present, insecticides, such as foliar sprays and seed treatments, are one of the primary control methods for limiting the damage caused by wheat aphids and the plant infection they transmit (Armstrong et al., 1993). By using insecticides, up to 98% of the aphid population can be eliminated (Royer et al., 2005). After pesticide spraying, a 2.06% increase in yield was found (Iqbal et al., 2008). Controlling aphid populations using insecticides is not advantageous for wheat because to numerous negative side effects, including chemical residues, environmental contamination, and ecological instability (Aktar et al., 2009; Yano, 2006; Fishel, 2005).

2. Materials and Methods

During the Rabi season of 2020-21, the research trials were done at the Entomological Research Institute, Ayub Agricultural Research Institute (AARI), in Faisalabad, Pakistan.

2.1 Cultivation of crop

Wheat variety Akbar-2019 was cultivated by the traditional method, also known as the Drill sowing method. The experiment was designed with three repetitions using Randomized Complete Block Design. Following treatments were sowing; Neem leaf extract (50g/l), Eucalyptus leaf extract (50g/l), Carbosulfan (500ml/acre), Imidacloprid (200ml/acre) and Control. In addition, proper evaluation and identification were performed at the Entomological Research Institute, AARI Faisalabad.

2.2 Preparation of botanical extracts

Two botanical extracts, Neem leaf extract, and Eucalyptus leaf extract were used. For this purpose, Neem and Eucalyptus leaves were collected from Ayub Agricultural Research Institute Faisalabad, Pakistan, and transported to the laboratory where these leaves were thoroughly washed with distilled water. After drying in the shade, the fine powder was made by grinding the leaves through the electric grinder and mixing 200gm of powder of each plant leaves with 1000ml of water, keeping it overnight, and sieving it through muslin cloth to make a stock solution. When the aphid population reached the Economic Threshold Level (ETL), the solution was mixed with 20 L of water and sprayed on the wheat crop to overcome the aphid infestation. Calculation of percentage mortality of aphids was taken as.

2.3 Insecticides tested

When the population of wheat aphids reached Economic Threshold Level (ETL), insecticides (Carbosulfan @ 500ml/acre and Imidacloprid @ 200ml/acre) were sprayed using a knapsack hand sprayer. Each insecticide was dissolved in 1L water in a measuring jug to make a solution. Before application, of insecticide add 200 ml spray material to the spray machine tank and mix it thoroughly. The formula for calculating percent mortality was:

2.4 Data collection

After applying botanical extracts and insecticides for 24, 48, 72, and 168 hours, data regarding the wheat aphid population was recorded by randomly selecting 10 tillers on each plot. Aphid density was calculated by counting the number of aphids on each plant’s tiller.

2.5 Statistical analysis

Using Statistics 8.1, an Analysis of Variance (ANOVA) and mean comparison were calculated. Tukey’s HSD test was applied at 0.05 for comparing means.

3. Results and Discussion

3.1 Impact of botanical extracts on wheat aphid population

The comparison of means of aphid population is described in Table 1 by Neem and Eucalyptus leaf extract. On 24 hours, Neem leaf extract caused 48.91% mortality followed by Eucalyptus leaf extract 48.68%. Percentage mortality after 48, 72, and 168 hours by Neem leaf extract was 63.35%, 72.29%, 85.06% followed by Eucalyptus leaf extract 62.45%, 71.69%, and 79.29%, respectively as shown in Figure 1. The wheat aphid population was maximum in the control plot while Neem and Eucalyptus leaf extracts significantly reduced the wheat aphid population.

 

Table 1: Mean comparisons of wheat aphid population by treating botanicals.

Sr. #	Treatments	Pre-treatment	After 24 h	After 48 h	After 72 h	After 168 h
1	Neem leaf extract	7.83 B	4.00 B	2.87 B	2.17 B	1.17 B
2	Eucalyptus leaf extract	8.83 B	4.30 B	3.17 B	2.50 B	1.33 B
3	Control	11.30 A	14.13 A	13.30 A	12.53 A	11.87 A
	HSD	1.12	1.92	1.87	2.45	5.14

 

Table 2: Means comparisons of wheat aphid population by treating insecticides.

Sr. #	Treatments	Pre-treatment	After 24 h	After 48 h	After 72 h	After 168 h
1	Carbosulfan	12.37 AB	2.87 B	1.93 B	1.07 B	0.57 B
2	Imidacloprid	13.00 A	3.17 B	2.07 B	1.23 B	0.80 B
3	Control	11.30 B	14.13 A	13.30 A	12.53 A	11.87 A
	HSD	1.67	1.75	1.46	2.42	4.94

 

3.2 Impact of insecticides on wheat aphid population

The results described in Table 2 Carbosulfan and Imidacloprid significantly minimized the wheat aphid population after 24, 48, 72, and 168 hours while the population in the control plot was highest.

 

Figure 1 revealed the mortality of Carbosulfan and Imidacloprid against the wheat aphid population. Carbosulfan and Imidacloprid caused 76.80% and 75.62% followed by 84.40% and 84.08%, 91.35% and 90.53% and 95.39% and 93.85% after 48, 72 and 168 hours, respectively.

During the Rabi season, this research was carried out at the Entomological Research Institute in Faisalabad, Pakistan. This study aimed to assess the effectiveness of plant extracts and selective synthetic pesticides. Results revealed that botanical extracts and synthetic insecticides caused high mortality against the wheat aphid in comparison to control treatment within 24, 48, 72, and 168 hours. Ali et al. (2018) conducted an experiment to determine the effectiveness of entomopathogenic fungi and botanical extracts against wheat aphids. Their finding showed that Neem leaf extract was more effective to control the wheat aphid as compared to Eucalyptus leaf extract. This study’s findings were in agreement with those of Ali et al. (2018), who investigated the effectiveness of botanical extracts to control the wheat aphid. As a result, it may be concluded that botanicals showed economical and environmentally safe product alternatives against wheat aphids, and it must be implemented into an integrated management program. The results of the study also paralleled those of Ahmad et al. (2016), who evaluated the effect of botanical extracts. Neem leaf extract was more effective to control the wheat aphid population as compared to the Eucalyptus leaf extract.

Ali et al. (2015) conducts an experiment to evaluate the efficacy of plant extracts against the wheat aphid population, and our findings were comparable. Their findings indicated that Neem leaf extract was effective to cause the mortality of wheat aphids as compared to other extracts. Neem leaf extract in our study caused maximum mortality (85.06%) after 168 hours of application, which showed significant mortality in comparison to the control treatment.

In this study, two synthetic insecticides (Carbosulfan and Imidacloprid) were used to manage the wheat aphid population. Results revealed that Carbosulfan@500 ml/acre was more effective in comparison to Imidacloprid@200 ml/acre. After 24, 48, 72, and 168 hours, the mortality rate of Carbosulfan was 76.80%, 84.40%, 91.35%, and 95.39%, respectively. Imidacloprid caused 75.62%, 84.08%, 90.53 and 93.85% mortality after 24, 48, 72 and 168 hours, respectively. Our findings were also consistent with those of Faheem et al. (2016), who conducted an experiment to assess the efficacy of the insecticide against a population of wheat aphids. Carbosulfan and Imidacloprid were found effective to manage the wheat aphid population. The significant difference between the Carbosulfan and Imidacloprid treated plot was recorded in comparison to the control plot. It may be concluded that synthetic insecticides can be integrated to manage wheat aphids.

Conclusions and Recommendations

It is concluded that botanical extracts were found effective and eco-friendly as compared to synthetic insecticides. Among the insecticides, carbosulfan was more effective as compared to the imidacloprid but had toxic effects on the natural enemies. Based on results it is stated that botanical extracts, which were used as part of integrated pest management, provide an alternative control to synthetic insecticides.

Acknowledgement

Authors are highly thankful to all institutes.

Novelty Statement

Wheat aphid is a crop-damaging bug. It causes significant damage by sucking cell sap, injecting a poison into the plant, eliminating photo-assimilates, and spreading plant-destroying viruses. Based on the results, it is stated that botanicals provide cost-effective and ecologically friendly alternatives to wheat aphid control and that they should be incorporated into an integrated management approach.

Author’s Contribution

All authors play equal role in this article.

Funding

The authors acknowledge Entomological Research Institute, Faisalabad for giving free field space to perform this research, despite the fact that no funding was involved in its completion.

Conflict of interest

The authors have declared no conflict of interest.

References

Ahmad, S., Ali, Q., Usman, M., Ali, M., and Binyameen, M., 2016. Evaluation of indigenous plant extract against aphid (Schizaphis graminum) under laboratory conditions. International Journal of Biology, Pharmacy and Allied Sciences, 5(12): 3189-3196. https://doi.org/10.1603/ICE.2016.104948

Akhtar, L.H., Manzoor, H., Iqbal, R.M., Marghub, A., and Tariq, A H., 2010. Losses in grain yield caused by Russian wheat aphid Diuraphis noxia (Mordvilko). Sarhad Journal of Agriculture, 26(4): 625-628.

Aktar, W., Sengupta, D., and Chowdhury, A., 2009. Impact of pesticides use in agriculture: Their benefits and hazards. Interdisciplinary Toxicology, 2(1): 1-12. https://doi.org/10.2478/v10102-009-0001-7

Ali, H., Qasim, M., Saqib, H.S.A., Arif, M., and Islam, S.U., 2015. Synergetic effects of various plant extracts as bio-pesticide against wheat aphid (Diurophous noxia L.) (Hemiptera: Aphididae). African Journal of Agricultural Research and Technology, 3(7): 310-315.

Ali, S., Farooqi, M.A., Sajjad, A., Ullah, M.I., Qureshi, A.K., Siddique, B., and Asghar, A., 2018. Compatibility of entomopathogenic fungi and botanical extracts against the wheat aphid, Sitobion avenae (Fab.) (Hemiptera: Aphididae). Egyptian Journal of Biology Pest Control, 28(1): 1-6. https://doi.org/10.1186/s41938-018-0101-9

Armstrong, J.S., Peairs, F.B., Pilcher, S.D., and Russell, C.C., 1993. The effect of planting time insecticides and liquid fertilizer on the Russian wheat aphid (Homoptera: Aphididae) and the lesion nematode (Pratylenchus thornei) on winter wheat. Journal of Kansas Entomological Society, pp. 69-74.

Aslam, M., Razaq, M., Akhter, W., Faheem, M., and Ahmad, F., 2005. Effect of sowing date of wheat on aphid (Schizaphis gramium Rondani) population. Pakistan Entomologist, 27(1): 79-82.

Azam, A., and Shafique, M., 2017. Agriculture in Pakistan and its impact on economy. A review. International Journal of Advanced Science and Technology, 103: 47-60. https://doi.org/10.14257/ijast.2017.103.05

Aziz, M.A., Ahmad, M., Nasir, M.F., and Naeem, M., 2013. Efficacy of different neem (Azadirachta indica) products in comparison with imidacloprid against English grain aphid (Sitobion avenae) on wheat. International Journal of Agriculture and Biology, 15(2): 279–284.

Bedini, S., Guarino, S., Echeverria, M.C., Flamini, G., Ascrizzi, R., Loni, A., and Conti, B., 2020. Allium sativum, Rosmarinus officinalis, and Salvia officinalis essential oils: A spiced shield against blowflies. Insects, 11(3): 143. https://doi.org/10.3390/insects11030143

Bockus, W.W., De Wolf, E.D., and Todd, T.C., 2016. Management strategies for barley yellow dwarf on winter wheat in Kansas. Plant Health Progress, 17(2): 122-127. https://doi.org/10.1094/PHP-RS-15-0050

Bodlah, I., Naeem, M., Mohsin, A.U., 2011. Checklist, distribution, host range and ecology of Aphidoidea (Homoptera) from the rainfed region of Punjab province of Pakistan. Sarhad Journal of Agriculture, 27(1): 93-101.

Donatelli, M., Magarey, R.D., Bregaglio, S., Willocquet, L., Whish, J.P., and Savary, S., 2017. Modelling the impacts of pests and diseases on agricultural systems. Agricultural System, 155: 213-224. https://doi.org/10.1016/j.agsy.2017.01.019

Faheem, M., Saeed, S., Sajjad, A., Wang, S., and Ali, A., 2019. Spatio-temporal variations in wheat aphid populations and their natural enemies in four agro-ecological zones of Pakistan. PLoS One, 14(9). https://doi.org/10.1371/journal.pone.0222635

Faheem, M., Sajjad, A., Shafique, R.M., Rehman, A., and Aslam, M.N., 2016. Field evaluation of different insecticides against wheat aphids and their natural enemies in Pakistan. Asian Journal of Agriculture Biology, 4(4): 126-133.

FAOSTAT, 2015. Food and Agricultural commodities production/Countries by commodity.

Favret, C., 2018. Aphid species file. http://Aphid.Species File.org.

Fishel, F., 2005. Pesticide organism interactions. EDIS, 6. https://doi.org/10.32473/edis-pi080-2005

Giraldo, P., Benavente, E., Manzano-Agugliaro, F., and Gimenez, E., 2019. Worldwide research trends on wheat and barley: A bibliometric comparative analysis. Agronomy, 9(7): 352. https://doi.org/10.3390/agronomy9070352

Hussain, D., Asrar, M., Khalid, B., Hafeez, F., Saleem, M., Akhter. M., Ahmed, M., Ali, I., and Hanif, K., 2021. Insect pests of economic importance attacking wheat crop (Triticum aestivum L.) in Punjab, Pakistan. International Journal of Tropical Insect Science, 42: 9-20. https://doi.org/10.1007/s42690-021-00574-9

Hussain, M., Asgher, Z., Tahir, M., Ijaz, M., Shahid, M., Ali, H., and Sattar, A., 2016. Bacteria in combination with fertilizers improve growth, productivity and net returns of wheat (Triticum aestivum L.). Pakistan Journal of Agriculture Science, 53(3): 633-645. https://doi.org/10.21162/PAKJAS/16.4901

Iqbal, J., Ashfaq, M., and Ali, A., 2008. Screening of wheat varieties/advanced lines against aphids. Pakistan Entomologist, 30(1): 77-81.

John, F., Saeed, N.A., Nadeem, S., and Hamed, M., 2017. Integration of planting time and insecticide to manage aphid infestations in wheat for better crop productivity. Pakistan Journal of Zoology, 49(4): 1343-1351. https://doi.org/10.17582/journal.pjz/2017.49.4.1343.1351

Khan, A.A., Khan, A.M., Tahir, H.M., Afzal, M., Khaliq, A., Khan, S.Y., and Raza, I., 2011. Effect of wheat cultivars on aphids and their predator populations. African Journal of Biotechnology, 10(80): 18399-18402. https://doi.org/10.5897/AJB11.2961

Khanal, D., Maharjan, S., Lamichhane, J., Neupane, P., Sharma, S., and Pandey, P., 2020. Efficacy of biorational compounds against mustard aphid (Lipaphis erysimi Kalt.) and English Grain Aphid (Sitobion avenae Fab.) under laboratory conditions in Nepal. Advances in Agriculture, 2020: 1-7. https://doi.org/10.1155/2020/9817612

Kole, C., 2011. Wild crop relatives: Genomic and breeding resources: Temperate fruits. Springer Science and Business Media. https://doi.org/10.1007/978-3-642-16057-8

Kumar, M.V., Krishnarajan, D., Manivannan, R., and Parthiban, K.G., 2011. Formulation and evaluation of bi-layer domperidone floating tablets. International Journal of Pharmaceutical Science and Research, 2(8): 2217-2225.

Maryam, S., Sandhu, A.A., Bodlah, I., Aziz, M.A., and Aihetasham, A., 2019. Contribution to Aphid’s Fauna of Gujranwala (Punjab), Pakistan. Punjab University Journal of Zoology, 34(1): 09-16. https://doi.org/10.17582/journal.pujz/2019.34.1.9.16

Nong, X., Chen, F.Z., Yang, Y.J., Liang, Z., Huang, B.L., Li, Y., and Yu, H., 2015. Aphicidal activity of an ageraphorone extract from Eupatorium adenophorum against Pseudoregma bambucicola (Homoptera: Aphididae, Takahashi). Journal of Insect Science, 15(1): 81. https://doi.org/10.1093/jisesa/iev060

Pakistan Bureau of Statistics. 2020. Agriculture, 18(2): 13-32.

Rehman, A., Jingdong, L., Shahzad, B., Chandio, A.A., Hussain, I., Nabi, G., and Iqbal, M.S., 2015. Economic perspectives of major field crops of Pakistan: An empirical study. Pacific Science Review B: Humanities and Social Sciences, 1(3): 145-158. https://doi.org/10.1016/j.psrb.2016.09.002

Royer, T.A., Giles, K.L., Nyamanzi, T., Hunger, R.M., Krenzer, E.G., Elliott, N.C., and Payton, M., 2005. Economic evaluation of the effects of planting date and application rate of imidacloprid for management of cereal aphids and barley yellow dwarf in winter wheat. Journal of Economic Entomology, 98(1): 95-102. https://doi.org/10.1093/jee/98.1.95

Sabbir, M.Z., Arshad, M., Hussain, B., Naveed, I., Ali, S., Abbasi, A., and Ali, Q., 2014. Genotypic response of chickpea (Cicer arietinum L.) for resistance against gram pod borer (Helicoverpa armigera (Hubner)). Advancements in Life Sciences, 2(1): 23-30.

Shahid, S., Zia, A., Naeem, M., and Naz, F., 2012. Bionomics of aphids and their parasitoid in selected wheat varieties grown under homologous ecological conditions. Pakistan Journal of Zoology, 44(5): 1423-1430.

Shahzad, M.W., Razaq, M., Hussain, A.R.J.A.D., Yaseen, M., Afzal, M., and Mehmood, M.K. 2013. Yield and yield components of wheat (Triticum aestivum L.) affected by aphid feeding and sowing time at Multan, Pakistan. Pakistan Journal of Botany, 45: 2005-2011.

Shrivastava, B., Thakur, S., Khasa, Y.P., Gupte, A., Puniya, A.K., and Kuhad, R.C., 2011. White-rot fungal conversion of wheat straw to energy rich cattle feed. Biodegradation, 22(4): 823-831. https://doi.org/10.1007/s10532-010-9408-2

Silva, E.M., Railda Roel, A., Porto, K.R., Escobar Falco, M., and Matias, R., 2017. Insecticidal effect of the ethanol extract of Baccharis dracunculifolia (Asterales: Asteraceae). Revista de Biologia. Tropical, 65(2): 517-523. https://doi.org/10.15517/rbt.v65i2.25712

Ullah, S., Adeel, M., Zain, M., Rizwan, M., Irshad, M.K., Jilani, G., and Rui, Y., 2020. Physiological and biochemical response of wheat (Triticum aestivum) to TiO2 nanoparticles in phosphorous amended soil: A full life cycle study. Environmental Management, 263: 110365. https://doi.org/10.1016/j.jenvman.2020.110365

Wains, M.S., Jamil, M.W., Ali, M.A., Hussain, M., and Anwar, J., 2014. Germplasm screening and incorporation of aphid resistance in bread wheat (Triticum aestivum L.). Journal of Animal Plant Science, 23: 919-925.

Yano, E., 2006. Ecological considerations for biological control of aphids in protected culture. Population Ecology, 48(4): 333-339. https://doi.org/10.1007/s10144-006-0008-2

Zeb, Q., Naeem, M., Khan, S.A., and Ahmad, S., 2016. Effect of insecticides on the population of aphids, natural enemies and yield components of wheat. Pakistan Journal of Zoology, 48(6): 1839-1848.