FECUNDITY, SIZE AND DISPERSAL OF THE WHITE WAX SCALE, CEROPLASTES DESTRUCTOR NEWSTEAD (HEMIPTERA: COCCIDAE), IN THE WESTERN CAPE PROVINCE OF SOUTH AFRICA

Abstract

FECUNDITY, SIZE AND DISPERSAL OF THE WHITE WAX SCALE, CEROPLASTES DESTRUCTOR NEWSTEAD (HEMIPTERA: COCCIDAE) IN THE WESTERN CAPE PROVINCE OF SOUTH AFRICA.

Ceroplastes destructor Newstead has recently attained pest status in areas of South Africa where citrus is grown, particularly on Citrus reticulata in the Western Cape Province. The fecundity, fertility and dispersal of C. destructor were studied as part of a comprehensive overview of its morphology, biology and population dynamics, with the aim of providing a more informed basis for control programs. Fecundity varied significantly both between orchards (P<0.01) and between individual females from the same orchard (P<0.001). Female body-size also differed between orchards (P<0.05) and was positively correlated with fecundity (r2=0.84). The oviposition period was longer for large individuals. No differences in fertility were found between orchards (P>0.05). Dispersal was by 1st-instar nymphs, mainly on air-currents, and the numbers caught on a series of sticky traps up to 4m from the source were very similar, suggesting that wind dispersal was very efficient. The numbers caught appeared to be positively correlated to the initial population. The population of 2nd-instar nymphs on the seedlings after 6 weeks was smaller after an initially heavy infestation than on those initially more lightly infested.

Key words: hosts, incubation period, Psidium quajava, Ponocirus trifoliata, Eugenia malaccensis, Gardenia thunbergia.