Browsing by Author "Giliomee, Jan H."
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- ItemEntomology in South Africa : where do we come from, where are we now and where are we going?(Academy of Science of South Africa, 2013) Giliomee, Jan H.Entomology in South Africa can be traced back to the mid-18th century when Ryk Tulbagh was governor at the Cape from 1751 to 1771. Tulbagh was interested in nature and instructed his gardener, J.A. Auge, to collect plants, insects and other animals for scientists at European universities. He also sent specimens to Linnaeus in Sweden, with whom he as a Dutchman corresponded in Latin, their only common language. To thank and honour him, Linnaeus named for him the plant genus Tulbaghia as well as the beautiful Mountain Pride butterfly Aeropetes tulbaghia L. (Lepidoptera: Satyridae) that occurs along the slopes of Table Mountain.
- ItemGuiding classical biological control of an invasive mealybug using integrative taxonomy(Public Library of Science, 2015) Beltra, Aleixandre; Addison, Pia; Avalos, Juan Antonio; Crochard, Didier; Garcia-Mari, Ferran; Guerrieri, Emilio; Giliomee, Jan H.; Malausa, Thibaut; Navarro-Campos, Cristina; Palero, Ferran; Soto, AntoniaDelottococcus aberiae De Lotto (Hemiptera: Pseudococcidae) is a mealybug of Southern African origin that has recently been introduced into Eastern Spain. It causes severe distortions on young citrus fruits and represents a growing threat to Mediterranean citrus production. So far, biological control has proven unsatisfactory due to the absence of efficient natural enemies in Spain. Hence, the management of this pest currently relies only on chemical control. The introduction of natural enemies of D. aberiae from the native area of the pest represents a sustainable and economically viable alternative to reduce the risks linked to pesticide applications. Since biological control of mealybugs has been traditionally challenged by taxonomic misidentification, an intensive survey of Delottococcus spp. and their associated parasitoids in South Africa was required as a first step towards a classical biological control programme. Combining morphological and molecular characterization (integrative taxonomy) a total of nine mealybug species were identified in this study, including three species of Delottococcus. Different populations of D. aberiae were found on wild olive trees, in citrus orchards and on plants of Chrysanthemoides monilifera, showing intraspecific divergences according to their host plants. Interestingly, the invasive mealybug populations from Spanish orchards clustered together with the population on citrus from Limpopo Province (South Africa), sharing COI haplotypes. This result pointed to an optimum location to collect natural enemies against the invasive mealybug. A total of 14 parasitoid species were recovered from Delottococcus spp. and identified to genus and species level, by integrating morphological and molecular data. A parasitoid belonging to the genus Anagyrus, collected from D. aberiae in citrus orchards in Limpopo, is proposed here as a good biological control agent to be introduced into Spain.
- ItemMutualism between armoured scale insects and ants : new species and observations on a unique trophobiosis (Hemiptera: Diaspididae; Hymenoptera: Formicidae: Melissotarsus Emery)(Wiley Online Library, 2013) Schneider, Scott A.; Giliomee, Jan H.; Dooley, John W.; Normark, Benjamin B.The association between African armoured scale insects (Hemiptera: Coccoidea: Diaspididae) and ants belonging to Melissotarsus Emery (Hymenoptera: Formicidae: Myrmicinae) is the only trophobiosis known in which ants do not receive honeydew or nectar in exchange for protection and other services. Food reward for the ants in this mutualism remains unknown, despite repeated suggestions that diaspidids are consumed by the associated ants, thus serving as ‘domestic cattle’. We describe new observations on interactions between Melissotarsus emeryi Santschi and the diaspidid Morganella conspicua (Brain) from South Africa. Worker ants exhibited previously undescribed tending behaviours, most notably a ‘squeezing and licking’ performed on an adult female diaspidid and ‘culling’, in which a worker removed an adult female armoured scale from the host plant. These could represent the gathering of secretory products and the cultivation of an individual for consumption, respectively. An ant exclusion study over 12 days of isolation showed that adult female diaspidids and second‐instar nymphs secreted no wax or exudates that attending ants would ordinarily collect. Workers of M. emeryi did not defend their nest against invading colonies of Crematogaster and other unidentified ants: we hypothesize that the primary mode of defence is maintenance of isolation within galleries. We describe three new ant‐associated diaspidid species: Affirmaspis cederbergensis Schneider sp.n. from South Africa, Diaspis doumtsopi Schneider sp.n. from Cameroon, and Melissoaspis incola Schneider sp.n. from Madagascar. Melissoaspis formicaria (Ben‐Dov) comb.n. is transferred from Morganella (Brain). Diagnostic characteristics for Melissoaspis Ben‐Dov are revised, and additional taxonomic information defining this genus allows ease of identification. An updated identification key to the species of ant‐associated diaspidids is provided.