Geographic Distribution, Host Fruit, and Parasitoids of African Fruit Fly Pests <I>Ceratitis anonae</I>, <I>Ceratitis cosyra</I>, <I>Ceratitis fasciventris</I>, and <I>Ceratitis rosa</I> (Diptera: Tephritidae) in Kenya

Abstract

The fruit of indigenous, cultivated, and naturalized exotic plants was sampled in Kenya to determine the geographical and host plant distributions of the fruit fly pests Ceratitis anonae (Graham), Ceratitis cosyra (Walker), Ceratitis fasciventris (Bezzi), and Ceratitis rosa Karsch. In 1997, cultivated and wild fruit were sampled on the Kenya coast to determine seasonal patterns of host use by C. cosyra and C. rosa. From 1999 to 2004, the sampling effort was expanded to forested areas of the central and western highlands and to all fruit-infesting tephritids. Together, the four pest tephritid species were reared from 5.1% of 3,794 fruit collections, the latter making up 116 families and 882 species of host plants. C. anonae, C. cosyra, C. fasciventris, and C. rosa were reared throughout Kenya, from 14, 9, 30, and 28 plant species, respectively. Fifty-two of these plants represented previously unknown hosts for one or more of the tephritids. C. anonae was restricted to habitats west of the Gregory Rift Valley. C. fasciventris was found in western and central Kenya, but it was not reared from coastal fruit collections. C. rosa occurred at the coast and in central highland fruit. We provide evidence for the recent introduction of C. rosa into the central highlands. Only C. cosyra was found in habitats located in all three of the major regions sampled. Although distributed over a wider geographic area than the other species, C. cosyra had a markedly restricted host range. On the coast, C. cosyra used wild fruit, primarily Sclerocarya birrea (A. Rich.) Hochst. (Anacardiaceae), as hosts when mango was not fruiting. C. rosa was absent from our mango samples but attacked common guava and wild fruit species. Overall, C. anonae, C. fasciventris, and C. rosa had similar host profiles, but each also had unique hosts in which infestations were usually heavy. Members of the Sapotaceae and Annonaceae were the most important wild hosts of these three species. Within these families, host fruit were partitioned among these tephritid species and the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). The availability of wild host fruit, sometimes supplemented by naturalized invasive plants or cultivated fruit, provided for year-round breeding of C. anonae and C. fasciventris, whereas indigenous fruit were sufficient for breeding of C. rosa and C. cosyra during most of the year. Opiine braconids were reared from all four species of Ceratitis.