Assessment of Oecophylla longinoda (Hymenoptera: Formicidae) in the Control of Mango Seed Weevil (Sternochetus mangiferae) in Mkuranga District Tanzania

Mango seed weevil S. mangiferae (Fabricius) (Coleoptera:Curculionidae), is one of the most important quarantined pest in commercial mango crop grown by small and medium growers in Tanzania. Though the damaged caused by mango seed weevil is pulp damage and mango seed which is used for propagation materials. The heavy use of broad spectrum insecticides in mango production has resulted in increased production costs, environmental pollution, disputes among neighbors and the reduction in natural enemies of insect pests and pollinators. Random fruit collection of 300 fruits during the mango season was carried out from weaver ant orchard and non weaver ant orchard to assess the effect of weaver ant on the management of mango seed weevil. Fruits were sampled at an interval of 30 days 60days and 90 days near to ripening stage. Foraged fruits with weaver ants were the only fruits collected for the assessment of the effect of weaver ant on the management of mango seed weevil. The African weaver ant colonization of mango trees ranged from 60% to 80%. An overall mean percentage infested mango fruits sampled at different stages of development to maturity stage were significantly different (p = 0.0001). The results from this study conclude that African weaver ant were able to control mango seed weevil and should be considered as a suitable component of Integrated Pest Management (IPM) for mango seed weevil in mango growing areas in Tanzania. Keywords: mango seed weevil, African Weaver Ant (AWA) Integrated Pest Management (IPM

Survey of Potato aphid (Myzus persicae) from Selected on-farm Potato growing Areas in Mbeya and Njombe regions of Tanzania

Potato aphid green peach (Myzus persicae Sulzer) is one of the serious pests in potato (Solanum tuberosum) production areas in the world. A survey was carried out during 2014 potato growing season to assess aphid and Coccinellid population abundance in potato production areas in Mbeya and Njombe regions situated in southern highlands of Tanzania. Aphid and Coccinellid abundance were sampled from 30 leaves selected randomly from ten plants. Estimates of aphid abundance from potato fields were carried out from transectline replicated three times. A total of 1,370 aphid populations were sampled during the survey period. Abundance from young leaves was 898, followed by medium leaves 270 and the least was old leaves represented by 202 individuals. The relative abundance of aphid population resulted from 15 minutes sampling effort per transect ranked from 8 individuals from Swaya village to 171 individuals from Atwelo village and the rest were in between. The differences between selected plant parts showed significant differences (p = 0.001). The results from this survey provides database on aphid population and Coccinellid natural enemies of potato aphid in potato growing areas which can be used for future research in the selected regions. Key words: Myzus persicae, potato aphid, Coccinelli

ANT SPECIES DIVERSITY AND COMPOSITION AT MLINGANO MANGO ORCHARD IN TANZANIA

ABSTRACT: Ants are major decomposers and they are sensitive to any human influence in our environment. Presence or absence of ants in cropland habitat is resulted from alteration of forest habitat into cropland. Ant's species diversity in mango orchard was considered as an important biodiversity indicator due to alteration of the primary forest into cropland habitat. Ants were sampled from mango trees searching species of ants from tree bases to 2M high. Dental rolls with 10% sugar as attractant bait were also used to attract ground preference of ant species. Attractant bait was placed on a tree base for 30 minutes and thereafter inspected for data collection. This study has revealed that ant species composition in mango orchard varies according to cropping system. Dominance of species was Crematogaster followed by Pheidole megacephala and the least was Oecopyhlla longinoda ants. Comparison of species composition revealed that there were significant differences. Species with low representative individuals were considered as extinct or rare species. The intended study was carried out at Mlingano mango orchard with the aim to determine the ant's species diversity and composition. The results from this work will help in developing sustainable biodiversity conservation programmes as well as for future research