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

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 (P0.01) and between individual females from the same orchard (P0.001). Female body-size also differed between orchards (P0.05) 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 (P0.05). 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

Description of adult and immature female instars of Pseudococcus viburni (Hemiptera: Pseudococcidae) found on apple in South Africa

Pseudococcus viburni (Signoret), commonly known as the obscure mealybug, was responsible for the rejection of large consignments of South African apple fruits destined for the U.S.A. market during 2002 because the immature stages could not be identified. Thus an identification guide is required as an aid to the correct identification of all developmental stages of this species before or during foreign quarantine inspections on export fruits. The first-instar, second-instar female, third-instar female and adult female were described from mealybug populations on field-collected apples (Malus domestica Korkh.). Illustrations and a diagnostic key to the different stages are provided. Morphometeric characteristics useful for separating the stages are discussed.Articl

Fecundity, fertility and phenology of white wax scale, Ceroplastes destructor Newstead (Hemiptera: Coccidae), on Citrus and Syzygium in South Africa

The population density of Ceroplastes destructor Newstead has increased steadily since 1994, particularly on Citrus reticulata (Blanco), in citrus-growing areas of the Western and Eastern Cape Provinces of South Africa. The fecundity, body size and phenology of C. destructor were studied to provide a more informed basis for control programmes. No significant differences in fecundity were found between orchards (P > 0.05). However, fecundity varied significantly between female size-classes from the same orchard (P 0.05). Ceroplastes destructor had one generation per year in the Western Cape Province, South Africa. Oviposition commences in mid November and continues until the end of December, with a few females ovipositing until mid January. The decline in population density of the second instar in February was followed by a steady increase in that of the third instar. The third instar stage extended to the end of July followed by a peak population of adults in August.Articl

Description of the stages of the white wax-scale, Ceroplastes destructor Newstead (Homoptera: Coccidae)

The white wax-scale, Ceroplastes destructor Newstead, has recently increased in numbers and distribution in some Easy-peel (Citrus reticulata (Blanco)) orchards in the Western Cape Province of South Africa. A study was conducted to investigate its morphology and biology. Characteristics of the immature and adult females are described and illustrated from field-collected and slide-mounted specimens. A key to the different stages is provided. The biology of C. destructor is briefly described. Morphometric characteristics useful for separating the stages are discussed.Articl

The biology of three mealybug species (Hemiptera: Pseudococcidae) found on citrus in the Western Cape Province, South Africa

The biology of Planococcus citri (Risso), Pseudococcus calceolarias (Maskell) and Pseudococcus longispinus (Targioni Tozzetti) on Citrus limon (L.) and Citrus reticulata (Blanco) in the Western Cape Province of South Africa was studied through intensive field-sampling and rearing in the laboratory. P. citri was most common on C. limon while P. longispinus was most abundant on C. reticulata. Fruits of butternut (Cucurbita moshata Duch) and lemon (C. limon) were used as substrates for rearing the three mealybug species in the laboratory. The fecundity of females of all species reared on butternuts was significantly higher than females reared on lemons. Egg viability for the three species was not affected by the rearing substrates. The population density of mealybugs in the field varied significantly between orchards and mealybug species (P < 0.001). No distinct phenological pattern was seen in the field for any of the species. This was due to asynchronous progeny production, resulting in overlap of generations. The implications of these findings for biological control of these mealybugs in citrus orchards in South Africa are discussed.Articl

Description of adult and immature females of six mealybug species (Hemiptera: Pseudococcidae) found on citrus in South Africa

Mealybugs are one of the major constraining factors in South African citrus fruit exports to foreign markets. An identification guide is required as an aid to field and laboratory identification of the species and to help reduce the rejection rate of exported fruits during foreign quarantine inspections. Adult and immature females of the striped mealybug Ferrisia virgata (Cockerell), the spherical mealybug Nipaecoccus viridis (Newstead), the oleander mealybug Paracoccus burnerae (Brain), the citrus mealybug Planococcus citri (Risso), the citrophilous mealybug Pseudococcus calceolariae (Maskell) and the longtailed mealybug Pseudococcus longispinus (Targioni-Tozzetti) are described and illustrated from field-collected and slide-mounted specimens. A diagnostic key to the different stages and species is provided. Morphometric characteristics useful for separating the different developmental stages of each species and the six species are discussed.Articl