Oviposition by the banded fruit weevil, Phlyctinus callosus (Schoenherr) (Coleoptera: Curculionidae), in deciduous fruit orchards in South Africa

1989 ◽  
Vol 79 (1) ◽  
pp. 31-40 ◽  
Author(s):  
B. N. Barnes ◽  
K. L. Pringle
Keyword(s):  
South Africa ◽  
Cover Crop ◽  
Plant Material ◽  
Soil Surface ◽  
Fruit Trees ◽  
Dispersion Pattern ◽  
Western Cape ◽  
Deciduous Fruit ◽  
Fruit Orchards ◽  
Oviposition Sites

AbstractOviposition sites of Phlyctinus callosus (Schoenherr) in an apple and a nectarine orchard in the South Western Cape, South Africa, were investigated. No eggs were found on the fruit trees, only in different fractions of the orchard floor, viz. in orchard weeds, leaf litter and soil. Significantly more oviposition took place in plant material on the orchard floor than in the top 20 mm of the soil. Microscopic dissection of samples of such plant material revealed that females prefer to oviposit in confined or hollow spaces in moist, live or decaying plant tissue on the soil surface or in weeds comprising the cover-crop. P. callosus females favoured certain weeds above others for oviposition. The dispersion pattern of eggs in the cover-crop was contagious. The implications of the observed ovipostion behaviour in terms of control strategy, and for exploitation in a monitoring system for this species, are discussed.

scholarly journals A krimpsiekte-like syndrome in small stock poisoned by Ornithogalum toxicarium Archer & Archer

2000 ◽  
Vol 71 (1) ◽  
Author(s):  
C.J. Botha ◽  
R.A. Schultz ◽  
J.J. Van der Lugt ◽  
C. Archer
Keyword(s):  
South Africa ◽  
Cardiac Glycoside ◽  
Plant Material ◽  
Western Cape ◽  
Western Cape Province ◽  
Fresh Plant Material ◽  
Small Stock ◽  
First Time ◽  
Glycoside Poisoning ◽  
Fluorescence Polarisation

Krimpsiekte (the syndrome associated with chronic cardiac glycoside poisoning) was purportedly induced by Ornithogalum toxicarium in the Karas mountains area of Keetmanshoop, Namibia. This chinkerinchee species was previously linked to a condition known as 'kwylbek' krimpsiekte in small stock in the Beaufort West district of the Western Cape Province, South Africa. In a dosing trial, respiratory distress, tachycardia and sternal recumbency were observed in 2 sheep drenched with fresh plant material. A fluorescence polarisation immunoassay (FPIA) detected the presence of a substance that cross-reacted with digoxin antibodies in some of the plant material collected at Keetmanshoop and Beaufort West. This is the first time that apparent cardiac glycoside poisoning was induced by a southern African chinkerinchee species. The presence of the cardiac glycoside-like substance in O. toxicarium requires further chemical verification.

scholarly journals Comparative demography of Bactrocera dorsalis (Hendel) and Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) on deciduous fruit

2019 ◽  
Vol 110 (2) ◽  
pp. 185-194
Author(s):  
Welma Pieterse ◽  
Aruna Manrakhan ◽  
John S. Terblanche ◽  
Pia Addison
Keyword(s):  
South Africa ◽  
Ceratitis Capitata ◽  
Prunus Persica ◽  
Reproductive Rate ◽  
Bactrocera Dorsalis ◽  
Population Increase ◽  
Western Cape ◽  
Net Reproductive Rate ◽  
Fruit Growing ◽  
Deciduous Fruit

AbstractBactrocera dorsalis (Hendel) and Ceratitis capitata (Wiedemann) are highly polyphagous fruit fly species and important pests of commercial fruit in regions of the world where they are present. In South Africa, B. dorsalis is now established in the north and northeastern parts of the country. B. dorsalis is currently absent in other parts of the country including the Western Cape Province which is an important area for the production of deciduous fruit. C. capitata is widespread in South Africa and is the dominant pest of deciduous fruit. The demographic parameters of B. dorsalis and C. capitata on four deciduous fruit types Prunus persica (L.) Batsch, Prunus domestica L., Malus domestica Borkh. and Pyrus communis L. were studied to aid in predicting the potential population establishment and growth of B. dorsalis in a deciduous fruit growing environment. All deciduous fruit types tested were suitable for population persistence of both B. dorsalis and C. capitata. Development was fastest and survival highest on nectarine for both species. B. dorsalis adults generally lived longer than those of C. capitata, irrespective of the fruit types that they developed from. B. dorsalis had a higher net reproductive rate (Ro) on all deciduous fruit tested compared to C. capitata. However, the intrinsic rate of population increase was estimated to be higher for C. capitata than for B. dorsalis on all fruit types tested primarily due to C. capitata's faster generation time. Provided abiotic conditions are optimal, B. dorsalis would be able to establish and grow in deciduous fruit growing areas.

scholarly journals Effects of Ground Cover Management on Biotic Communities, Ecosystem Services and Disservices in Organic Deciduous Fruit Orchards in South Africa

2019 ◽  
Vol 3 ◽  
Author(s):  
Klaus Birkhofer ◽  
Matthew F. Addison ◽  
Fredrik Arvidsson ◽  
Corinna Bazelet ◽  
Janne Bengtsson ◽  
...  
Keyword(s):  
South Africa ◽  
Ecosystem Services ◽  
Ground Cover ◽  
Deciduous Fruit ◽  
Fruit Orchards

Occurrence of Canker and Wood Rot Pathogens on Stone Fruit Propagation Material and Nursery Trees in the Western Cape of South Africa

Plant Disease ◽  
2021 ◽  
Author(s):  
Rhona van der Merwe ◽  
Francois Halleen ◽  
Meagan Van Dyk ◽  
Vernon Guy Jacobs ◽  
Lizel Mostert
Keyword(s):  
South Africa ◽  
Management Practices ◽  
Phylogenetic Analyses ◽  
Fruit Trees ◽  
Fungal Species ◽  
Stone Fruit ◽  
Western Cape ◽  
Latent Infections ◽  
Nursery Trees ◽  
Propagation Material

Dieback and canker of young stone fruit trees can cause suboptimal growth and even death under severe conditions. One source of inoculum of canker pathogens could be through nursery trees harboring latent infections that would not be visible to inspections done according to the deciduous fruit scheme. The objectives of this study were to identify the canker and wood rot fungal pathogens present in nursery stone fruit trees as well as propagation material and to evaluate their pathogenicity. Isolations were made from scion and rootstock propagation material and from certified nursery stone fruit trees. The plant material sampled did not have any external symptoms. The certified nursery trees when cross-sectioned displayed brown discoloration from the pruning wound, bud union and often from the crown. Fungal species isolated were identified by sequencing of the relevant barcoding genes and phylogenetic analyses thereof. Canker and wood rot associated fungi were identified. Buds used for budding had low levels of infection, with 1.2% of dormant buds infected and 0.4% of green buds infected. The dormant rootstock shoots had canker pathogen incidence of 6.2% before it was planted in the nursery fields and increased as the ungrafted, rooted rootstock plants had 11.1% infection with canker and wood rot pathogens. Out of 1080 nursery trees, the canker and wood rot associated fungi infected 21.8% of trees. The canker causing pathogens that were isolated the most were Cadophora luteo-olivacea and Diplodia seriata. A low incidence of wood rot fungi was found with only 1.5% of nursery trees infected. In total 26 new reports of fungal species on stone fruit in South Africa were made. Of these, 22 have not been found on stone fruit world-wide. The pathogenicity trials’ results confirmed the pathogenic status of these newly reported species. All of the isolates tested formed lesions significantly longer than the control, 4 months after wound inoculation of 2-year-old shoots of two plum orchards. Lasiodiplodia theobromae was the most virulent species on both plum cultivars. The results of this research showed that nursery stone fruit trees and propagation material can harbor latent infections. Different management practices need to be evaluated to prevent these infections to ensure healthier stone fruit nursery trees.

scholarly journals Identification of Pseudomonas Isolates Associated With Bacterial Canker of Stone Fruit Trees in the Western Cape, South Africa

Plant Disease ◽  
2020 ◽  
Vol 104 (3) ◽  
pp. 882-892 ◽  
Author(s):  
Khumbuzile N. Bophela ◽  
Yolanda Petersen ◽  
Carolee. T. Bull ◽  
Teresa. A. Coutinho
Keyword(s):  
South Africa ◽  
Pseudomonas Syringae ◽  
Bacterial Species ◽  
Fruit Trees ◽  
Stone Fruit ◽  
Bacterial Disease ◽  
Bacterial Canker ◽  
Western Cape ◽  
Vegetable Crops ◽  
Phylogenetic Groups

Bacterial canker is a common bacterial disease of stone fruit trees. The causal agents responsible for the disease include several pathovars in Pseudomonas syringae sensu lato and newly described Pseudomonas species. Pseudomonad strains were isolated from symptomatic stone fruit trees, namely apricot, peach, and plum trees cultivated in spatially separated orchards in the Western Cape. A polyphasic approach was used to identify and characterize these strains. Using a multilocus sequence typing approach of four housekeeping loci, namely cts, gapA, gyrB, and rpoD, the pseudomonad strains were delineated into two phylogenetic groups within P. syringae sensu lato: P. syringae sensu stricto and Pseudomonas viridiflava. These results were further supported by LOPAT diagnostic assays and analysis of clades in the rep-PCR dendrogram. The pseudomonad strains were pathogenic on both apricot and plum seedlings, indicative of a lack of host specificity between Pseudomonas strains infecting Prunus spp. This is a first report of P. viridiflava isolated from plum trees showing symptoms of bacterial canker. P. viridiflava is considered to be an opportunistic pathogen that causes foliar diseases of vegetable crops, fruit trees, and aromatic herbs, and thus the isolation of pathogenic P. viridiflava from twigs of plum trees showing symptoms of bacterial canker suggests that this bacterial species is a potentially emerging stem canker pathogen of stone fruit trees in South Africa.

Investigating the validity of the species status of the false codling moth in South African deciduous fruit orchards using mating studies and mtDNA

2016 ◽  
Vol 106 (5) ◽  
pp. 598-605 ◽  
Author(s):  
N. Mgocheki ◽  
P. Addison
Keyword(s):  
South Africa ◽  
Host Range ◽  
Host Species ◽  
Codling Moth ◽  
Western Cape ◽  
Management Options ◽  
Thaumatotibia Leucotreta ◽  
False Codling Moth ◽  
Fruit Orchards ◽  
Mating Tests

AbstractThe false codling moth is a polyphagous pest of various kinds or fruit, and it has expanded its geographical distribution and host range. The expanding host range could result in subspecies requiring varied pest management options. Laboratory no-choice cross-mating tests were conducted to establish whether Thaumatotibia leucotreta individuals from six areas and three host species, in South Africa, share mating characteristics and belong to the same subspecies or strain. The no-choice cross-mating tests indicated that all individuals in self- and out-crosses readily mated within 24 h with those derived from different hosts and areas. The mtDNA results confirmed that all individuals formed one group or clade. Overall, the results indicate that T. leucotreta individuals from the six areas and three host species in the Western Cape Province and two other provinces in South Africa represent a single genetical species. The results imply that similar control options can be effective across host ranges and distribution areas.

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