Status of antestia bug (Antestiopsis spp.) (Hemiptera: Pentatomidae) in Arabica Coffee under smallholder farming inTanzania
| dc.contributor.author | Edmond, Andrew Zani | |
| dc.date.accessioned | 2026-01-17T16:35:33Z | |
| dc.date.available | 2026-01-17T16:35:33Z | |
| dc.date.issued | 2024 | |
| dc.description | Dissertation | |
| dc.description.abstract | Coffee is an imperative cash crop grown in Tanzania for beverage and household income generating activity. The crop is grown in the vast and varying landscape of Tanzania. Around 17 out of 26 Regions in Tanzania mainland grow coffee. Both Arabica and Robusta coffee are grown in Tanzania. Tanzania is the third largest producer of coffee in Africa after Ethiopia and Uganda, contributing about one percent of the world`s coffee and ranking the 15th largest coffee producing country in the world. Close to 90 percent of Tanzanian coffee is produced by some 450 000 small families operations on 265 000 hectares of land of which 120 000 are in the Robusta growing areas of Kagera. The remaining ten percent of coffee is grown by larger producers (Estates). The production and trade in coffee contributes indirectly to the incomes of roughly seven percent of Tanzania`s 60 million population. Arabica coffee production in Tanzania accounts for 70% of the total coffee produced in the country. The giant Arabica coffee producing Regions in Tanzania are Kilimanjaro, Ruvuma and Songwe. Coffee is Tanzania`s second largest export cash crop, accounting for 24% of the country's total foreign exchange earnings after Tobacco. Coffee export has generated about USD 100 million per year over the past 15 years. In the 2018/2019 coffee season, Tanzania exported a total of 68,147 MT of green coffee beans, with Japan accounting for 34% of this volume, Italy 18%, Germany 11%, Belgium 10% and the USA 10%. Despite these admirable facts coffee production is constrained by abiotic and biotic factors. Recently smallholder Arabica coffee farmers reported the presence of pentatomid, variegated bugs which destructs all the vegetative and fruiting part of coffee tree, likewise, Tanzania Coffee Board reported about stagnated coffee production. These problems were allied with the presence of the Antestia bug in coffee fields. The Antestia bug (Antestiopsis spp.) has been mentioned among the major pests of coffee in Tanzania. The pest has not been extensively studied creating a huge knowledge gap about status. Knowledge on the Antestia bugs abundance and their species is lacking. This study aimed at bridging that gap by establishing the Antestia bug status to enable farmers, extension officers and decision makers to have appropriate knowledge for developing suitable management strategies and options for managing the pest. The studies were carried out in three major Arabica coffee producing regions namely; Kilimanjaro, Ruvuma and Songwe. Diagnostic surveys were conducted through a multistage sampling method used to select Districts and farms to be studied. In each Region; two Districts were selected in which three villages were selected. Twenty smallholder coffee farms were subsequently randomly selected in each Village for the study. In each farm numbers of coffee trees were selected according to specific objectives. A total of 360 farms (120 from each region) were selected each with 64 coffee trees that were visited for data collection in 12 months. Thus, a total of 23,040 coffee trees were used for the study. To determine the Antestia bug species and abundance in the three Regions visual physical counts were adopted coupled with sampling of Antestia bug specimens every month. Using the available identification key, the collected Antestia bugs (Antestiopsis spp.) were identified in the field based on morphological features. Specimens (nymphs) that were difficult to identify up to species level were collected in perforated bottles and reared at Tanzania Coffee Research Institute (TaCRI) to allow full development of their colors and strips on the pronotum and scutellum. Aided by literature, the identification of reared Antestia bug was made possible coupled with confirmation of the species expert at SUA and TPHPA in Arusha. Obtained results established the existence of only one species of Antestiopsis orbitalis Westwood with two subspecies namely Antestiopsis orbitalis bechuana Kirkaldy and Antestiopsis orbitalis ghesquiere Carayon exist. Of the 748.96 total number of specimens collected 637.39 (85.10%) were A. orbitalis bechuana and 111.57 (14.90%) were A. orbitalis ghesquiere. The region-wise discretion of pest abundance suggested contribution of 62.44%, 26.90% and 10.65% by Kilimanjaro, Ruvuma and Songwe Regions respectively. The canopy shade intensity played a significant role on the abundance of Antestia bugs. A statistically highly significant (P<0.001) difference was established on the Antestia bugs, with the dense shade canopy having higher pest population than the sparsely shaded ones. Pearson's linear correlation analysis of Antestia bug damage indices suggested a positive relationship between dense shade canopy and Antestia bug damage on foliage, flowers and fruits incidences and severities. Likewise, the coffee fruiting phenology had a significant (p<0.001) effect on bug density. The finding provided insights into the species, abundance and distribution of Antestia bugs on Arabica coffee in Tanzania. Furthermore, the incidence and severity of Antestia bug (Antestiopsis spp.) was determined. Manifestation of Antestia bug damage through symptoms and signs were used to gauge the pest incidences and severity based on the established scales. Results suggested that all Regions were infested by Antestia bugs albeit at varied intensities with the highest incidence and severity being in Kilimanjaro both in dense and sparse shade locations, where the average bugs number per tree was 4.29, 3.25, average incidence of foliage (39.95%, 31.3%), flowers (45.03%, 33.15%), and fruits (56.78%, 43.08%) and average severity was foliage (1.99, 1.55), flower (2.26, 1.66) and fruits severity (2.96, 2.06) respectively. In Kilimanjaro, the maximum number of Antestia bugs, incidence and severity recorded was 12.4, 100%, and 5 respectively. The two other regions; Ruvuma and Songwe had relatively low numbers, incidence and severity of Antestia bug. The lowest counts were established in Songwe Region at Ileje District with abundance, incidence and severity of 0.01, 0, 0 score respectively. Dense shade had the highest Antestia bug damage incidence than sparse shade canopy (p<0.05). Conclusively, the current study shaded insights into the species, incidence and severity of Antestia bugs on Arabica coffee fields as well as the influence of canopy shades and fruiting phenology on the pest in Tanzania. The study possibly escalates the necessity to understand the effects of shade, and fruit phenology in the buildup of Antestia bug population in the coffee field for development of effective management options. Furthermore, the study provides a clear picture of critical time for controlling Antestia bugs through intervention on the fruit phenology during which increase of the Antestia bugs to damage the crop is stimulated. Although the pest is omnipresent in all surveyed regions, Kilimanjaro was the worst affected while Songwe was the least affected. Concerted efforts to manage the pests are highly advised to minimize the losses caused by the alarming population density of the pest on coffee crops. Education to smallholder coffee farmers on pest monitoring, canopy shade management, use of pest resistant improved varieties and rational spray of insecticides in the IPM- based approach is advised. Further studies on naturally existing natural enemies that may be used for biological control may be over- emphasized. | |
| dc.description.sponsorship | Tanzania Coffee Board | |
| dc.identifier.uri | https://www.suaire.sua.ac.tz/handle/20.500.14820/7220 | |
| dc.language.iso | en | |
| dc.publisher | Sokoine University of Agriculture | |
| dc.subject | Antestia bug (Antestiopsis spp.) | |
| dc.subject | Hemiptera: Pentatomidae | |
| dc.subject | Arabica Coffee | |
| dc.subject | Smallholder farming | |
| dc.subject | Tanzania | |
| dc.title | Status of antestia bug (Antestiopsis spp.) (Hemiptera: Pentatomidae) in Arabica Coffee under smallholder farming inTanzania | |
| dc.type | Thesis |