African Plant Protection (2001) 7, 53-57
M.A. Van den Berg and J. Greenland (2001)
Pest status of two blackfly species on citrus in South Africa and Swaziland
African Plant Protection 7 (1), 53-57
Abstract: The spiny blackfly, Aleurocanthus spiniferus, and the citrus blackfly, Aleurocanthus woglumi, are introduced pests of citrus in South Africa. Leaves, fruit and branches of infested trees are usually covered with sooty mould and tree vigour and production can be impaired. Past and present outbreaks of the two blackfly species have been documented. A. woglumi is effectively controlled by the parasitoid Eretmocerus serius in parts of KwaZulu-Natal. Within two years after A. woglumi was first noticed at Nkwalini, KwaZulu-Natal, Er. serius had spread to these orchards. Nkwalini is 51 km from Gingindlovu where Er. serius had occurred in the early 1960s. Effective biological control prevailed in the orchards at Nkwalini within a year. Encarsia cf. smithi provided classical biological control of A. spiniferus in areas where it was released and also parasitised A. woglumi. However, under conditions that pervailed at Tambuti Estates, Big Bend, Swaziland, from 1996 to 1999, En.cf. smithi could not control A. woglumi or A. spiniferus. After the establishment of Er. serius at Tambuti Estates, both A. woglumi and A. spiniferus were controlled effectively by Er. serius and En.cf. smithi. A. spiniferus and A. woglumi still remain potential pests in many parts of southern Africa. En.cf. smithi and Er. serius have recently been introduced to areas where the two blackfly species became pests. The numbers of both parasitoids increased within a few months and established effective biological control.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
population dynamics/epizootiology
