The temporal occurrence of the invasive and economically important pest fruit fly, Bactrocera invadens was studied in three agro-ecological areas of Morogoro Region, central Tanzania, during 2004Tanzania, during -2005. Weekly and monthly trappings were carried out with methyl eugenol, protein bait and synthetic food attractant. Bactrocera invadens was permanently present at low and mid-altitudes (380-520 m a.s.l.) with peak periods coinciding with the fruiting season of mango (Mangifera indica) and guava (Psidium guajava). At high altitude (1650 m a.s.l.) its incidence was only temporal and apparently the result of dispersal from lower altitudes after the mango fruiting season. Rearing results showed mango, loquat (Eriobotrya japonica), guava and grapefruit (Citrus · paradisi) to be the favoured commercial host fruits. Other Citrus species, cucurbits, papaya (Carica papaya) and avocado (Persea americana) were less favoured.

The host range of major fruit fly pests in Central Tanzania was evaluated from October 2004 to October 2006. Samples of 48 potential hosts were collected and incubated for fruit fly emergence. Bactrocera invadens was the dominant species in incidence expressed as the ratio of infested to total number samples collected, as well as infestation rate, expressed as number of flies emerging per unit weight. Eight new host fruits are reported. Infestation by native pests, such as Ceratitis capitata and C. cosyra, was minor compared to B. invadens. Ceratitis rosa was the dominant species in temperate fruits, and Cucurbitaceae were mainly infested by Bactrocera cucurbitae, a specialized cucurbit feeder. Among commercial fruits, high infestation incidences were observed in mango and guava, but they decreased throughout the fruiting season. Low infestation rates were observed in all Citrus species and in avocado, indicating these fruits as poor hosts for the studied fruit fly pests in this region. Widespread availability and abundance of fruit species studied here ensures year-round breeding of B. invadens. Seasonal infestation differs, with mango being the most important host in October to January, while guava being important from February to August. Tropical almond showed very high incidence and infestation rate for B. invadens and might act as an important reservoir host, bridging the fruiting seasons of mango and guava. Soursop acts as an important host for C. cosyra after the mango season. Ceratitis capitata is a pest of minor importance of the commercial fruits studied in this region.

Biodiversity of fruit flies (Diptera, Tephritidae) in orchards in different agroecological zones of the Morogoro region, Tanzania.Abstract --Introduction. Fruit flies (Diptera, Tephritidae) are among the major constraints in commercial horticulture in many African developing countries. Knowledge of the tephritid spectrum in any given area is a prerequisite for the development of an IPM program to alleviate the pest problem. We studied the fruit fly diversity in four main agro-ecological zones which are significant fruit-producing areas in the Morogoro Region, Tanzania. Materials and methods. Fruit fly diversity was investigated for one year (October 2004 -October 2005. Parapheromones, synthetic food attractant and protein-bait traps were used to trap the flies at the different locations in Morogoro region, Tanzania. One mixed orchard was selected at each of four locations representing the different agro-ecological zones of the region. Results. The recently introduced alien species, Bactrocera invadens, and three indigenous pest species, Ceratitis rosa, Dacus bivittatus and D. punctatifrons, were found at all the four sites, while Bactrocera cucurbitae, Ceratitis cosyra, Dacus chiwira and D. humeralis were found in three out of the four sites. The Sokoine University of Agriculture (SUA) Horticulture Unit and Mikese sites had the highest species diversity while the Mkindo and Nyandira sites had the lowest diversity. The between-habitats diversity (Beta diversity) was similar among the SUA, Mkindo and Mikese sites. Only the Nyandira site had a higher dissimilarity in comparison with the other three sites. Discussion. The most abundant species at low-and mid-elevation sites was Bactrocera invadens while, at high elevation, Ceratitis rosa was the dominant species. Protein-baited traps attracted the highest diversity of fruit flies in comparison with the more specific parapheromones. The synthetic food attractant (three-component lure) was less efficient compared with the protein bait. The large dissimilarity at the Nyandira site is probably due to the different types of host fruits found and grown in high altitude areas (mainly temperate fruits). Fruit fly species associated with these types of fruits, e.g., Ceratitis rubivora and Trirhithrum coffeae, were found only at this site.Tanzania / fruit trees / Tephritidae / fruit flies / biodiversity / Ceratitis / Bactrocera / Dacus / surveys / traps / identification Biodiversité des mouches des fruits (Diptera, Tephritidae) en vergers, dans différentes zones agro-écologiques de la région de Morogoro, Tanzanie.Résumé --Introduction. Les mouches des fruits (Diptera, Tephritidae) font partie des principales contraintes de l'horticulture commerciale dans de nombreux pays africains en voie de développement. La connaissance du spectre des tephritides dans un secteur donné est un préalable au développement d'un programme d'IPM permettant d'atténuer le problème parasitaire. Nous avons étudié la diversité des mouches des fruits dans quatre principales zones agro-écologiques qui s...

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Pot and field experiments were conducted to compare the effects of dairy cow, goat and poultry manures on soil available levels of N and P and amaranths yield and root growth. The three amendments were applied on Oxisols at 100, 150 and 170 kg N/ha in a split plot design and replicated three times. Pot experiment lasted for one month whereas field experiment was conducted over three monthly crop cycles. Results of both experiments indicated that applications of the three manures significantly (P < 0.01) increased soil available levels of N and P shoot dry matter yield, taproot length and root dry weight. Comparison of the responses from the three manures revealed that for all the parameters evaluated the trend was; Poultry manure > goat manure > dairy cow manure. This was largely attributed to differences in total N, total P, C/N and C/P ratios of the amendments. Field experiment results revealed that responses were highest after the third crop harvest suggesting that mineralization of organic N and P increased with time. Based on fertilizer recommendations of N and P for Southern highlands of Tanzania and the highest rate used in this study (170 kg N/ha), applications of 5.8 tons/ha, 9.8 tons/ha and 13.4 tons/ha of poultry, goat and dairy cow manure will suffice the requirement of 40 kg N/ha and 20 kg P/ha recommended for most field crops.