_____________________________________________________________________________________________________ *Corresponding author: Email: edward.missanjo@magu.ac.mw; Original Research Article Journal of Global Ecology and Environment 13(2): 27-34, 2021 ISSN: 2454-2644 EFFECTIVENESS OF Pauesia juniperorum IN CONTROLLING POPULATION OF CYPRESS APHIDS IN MALAWI GIFT KAMANGA-THOLE 1 , WESTON MWASE 1 , JUDITH KAMOTO 1 , CLEMENT CHILIMA 2 AND EDWARD MISSANJO 3* 1 Department of Forestry, Faculty of Natural Resources, Lilongwe University of Agriculture and Natural Resources, Lilongwe, Malawi. 2 Department of Forestry Headquarters, Nkhalango House, Lilongwe, Malawi. 3 Department of Research, Malawi Assemblies of God University, Lilongwe, Malawi. AUTHORS’ CONTRIBUTIONS This work was carried out in collaboration among all authors. All authors read and approved the final manuscript. Received: 03 August 2021 Accepted: 12 October 2021 Published: 18 October 2021 __________________________________________________________________________________ ABSTRACT The cypress aphid, Cinara cupressivora is a significant pest of Cupressaceae species and has caused serious damage to naturally regenerating and planted forests in Africa, Europe, Latin America and the Caribbean and the Near East. This study was conducted to determine the effectiveness of biological control of Cypress Aphids (Cinara cupressivora) using Pauesia juniperorum in Cupressus lusitanica clonal seed orchard in Dedza, Malawi. The data was extracted from monthly reports (1994 to 2002) of the Forestry Research Institute of Malawi. A statistically significant (X 2 =57.62, P<0.001) association was found between the presence of P. juniperorum and presence of C. Cupressivora. The reduction on the percentage presence of C. cupressivora was 23 times (Odds ratio = 22.9) more likely to occur in the presence of P. juniperorum than in its absence. The study further revealed that there was a statistically significant (X 2 =3573.06, P<0.001) association between the presence of P. juniperorum and damage of C. lusitanica. The damage on the C. lusitanica was 65 times (odds ratio 65.3) more likely to get reduced in the presence of P. juniperorum than in their absence. There was also a significant (P<0.001) difference in the mean number of cypress aphids per tree branch per month before (5.56±0.75) and after (2.69±0.51) the release of P. juniperorum. The study therefore confirms effectiveness of P. juniperorum as a sustainable biological control agent for Cypress Aphids. Keywords: Biological control; association; odds ratio; Cinara cupressivora; Pauesia juniperorum. 1. INTRODUCTION Cypress aphids (Cinara cupressivora) Watson & Voegtlin (Hemiptera: Aphididea) are perceived to be a significant pest of cypress trees. The pest has been accidentally introduced into Africa where cypress trees are planted and are not native. The pest was first reported in 1986 in Malawi and later in other African countries namely; Burundi (1988), Democratic Republic of Congo, Ethiopia (2004), Kenya (1990), Mauritius (1999), Morocco, Rwanda (1989), South Africa (1993), Uganda (1989), United Republic of Tanzania (1988), Zambia (1985), and Zimbabwe (1989) [1,2]. Cypress trees are among the tree species planted in softwood plantations in Malawi. Softwood plantations were first established in 1930s in Malawi [3]. Exotic softwood species including Widdringtonia cupressoides, and the Mexican cypress