In the agricultural muck soil area of southwestern Quebec, two native parasitoids, Peristenus pallipes and P. pseudopallipes (Hymenoptera: Braconidae) were found to parasitize nymphs of the tarnished plant bug Lygus lineolaris (Hemiptera: Miridae), on various flowering plants and on cultivated lettuce. Parasitism levels (ranging from 1.3% to 92.3%) varied with host plant species sampled, and with methods used for the calculation of percentage parasitism. The percentage parasitism of tarnished plant bug populations was expressed as pooled values from all samples in the season (method 1), and by the Southwood and Jepson's graphical method (method 2). Phenology of parasitism, defined as the time during which female parasitoids are active in the field, was evaluated for both native parasitoid species. The cold-hardiness of P. digoneutis, a European nymph parasitoid introduced in northern United States, was evaluated in the laboratory by measuring the supercooling point and cumulative cold damage at sub-zero temperatures. When compared to the native P. pallipes and P. pseudopallipes the exotic parasitoid showed the same capacity to withstand cold temperatures. Prior to introduction, the evaluation of the impact of P. digoneutis on indigenous species will require a rapid identification to species level. The development of immature stages of P. digoneutis was studied to find taxonomic and developmental differences between the three species. At $21 pm1 sp circ$C, the egg matures in five days, and there are three larval instars, the first two molting inside the host while the third emerges from the host, three to four weeks after egg deposition. Adult characters of the pre-imaginal stage can be used to distinguish the exotic P. digoneutis from the two native species since mouth sclerites of the final instar larvae of P. digoneutis, P. pallipes and P. pseudopallipes do not possess reliable distinguishing characters. (Abstract shortened by UMI.)

Baculoviruses are arthropod-specific DNA viruses that are highly virulent to most lepidopteran insects. Their host specificity and compatibility with IPM programmes has enabled their usage as safe microbial insecticides (biopesticides). Two baculovirus-based biopesticides, Cryptogran and Cryptex, which have been formulated with Cryptophlebia leucotreta granulovirus (CrleGV) have been registered for the control of false codling moth (FCM), Thaumatotibia (=Cryptophlebia) leucotreta (Meyrick) (Lepidoptera: Tortricidae) in South Africa and have been successfully incorporated into IPM programmes. However, several studies have indicated that insects can develop resistance to baculovirus-based biopesticide as was shown with field populations of codling moth (CM), Cydia pomonella (L.), which developed resistance to the biopesticide Cydia pomonella granulovirus (CpGV-M) in Europe. Other studies have shown that, under laboratory conditions, FCM populations differ in their susceptibility to Cryptogran and Cryptex. In order to investigate difference in susceptibility as well as protect against any future resistance by FCM to Cryptogran and Cryptex, a search for novel CrleGV-SA isolates from diseased insects from different geographic regions in South Africa was performed. Six geographic populations (Addo, Citrusdal, Marble Hall, Nelspruit, Baths and Mixed colonies) of FCM were established and maintained in the laboratory. Studies on the comparative biological performance based on pupal mass, female fecundity, egg hatch, pupal survival, adult eclosion and duration of life cycle of the Addo, Citrusdal, Marble Hall, Nelspruit and Mixed colonies revealed a low biological performance for the Citrusdal colony. This was attributed to the fact that FCM populations found in the Citrusdal area are not indigenous and may have been introduced from a very limited gene pool from another region. When insects from five colonies, excluding the Baths colony, were subjected to stress by overcrowding , a latent baculovirus resident in the Addo, Nelspruit, Citrusdal, Marble Hall and Mixed colonies was brought into an overt lethal state. Transmission electron micrographs revealed the presence of GV occlusion bodies (OBs) in diseased insects. DNA profiles obtained by single restriction endonuclease analysis of viral genomic DNA using BamH 1, Sa/1, Xba1 , Pst1, Xh01 , Kpn1, Hindlll and EcoR1 revealed five CrleGV-SA isolates latent within the insect populations. The new isolates were named CrleGV-SA Ado, CrleGV-SA Cit, CrleGV-SA Mbl, CrleGVSA Nels and CrleGV-SA Mix isolates. The novelty of the five CrleGV-SA isolates was confirmed by the presence of unique submolar bands, indicating that each isolate was genetically different. PCR amplification and sequencing of the granulin and egt genes from the five isolates revealed several single nucleotide polymorph isms (SNPs) which, in some cases, resulted in amino acid substitutions. DNA profiles from RFLPs, as well as phylogenetic analysis based on granulin and egt sequencing showed the presence of two CrleGV-SA genome types for the CrleGV-SA isolate. Cryptex and CrleGV-SA Ado, CrleGV-SA Cit, CrleGV-SA Mbl and CrleGV-SA Mix were placed as members of Group one CrleGV-SA, and Cryptogran and CrleGV-SA Nels isolate were placed into Group two CrleGV-SA. In droplet feeding bioassays, the median survival time (STso) for neonate larvae inoculated with Group one and two CrleGV-SA were determined to range from 80 - 88 hours (3.33 - 3.67 days), for all five colonies. LDso values for Group one and two CrleGV-SA against neonates from the Addo, Citrusdal, Marble Hall, Nelspruit and Mixed colonies varied between some populations and ranged from 0.80 - 3.12 OBs per larva, indicating some level of variation in host susceptibility. This is the first study reporting the existence of genetically distinct CrleGV baculovirus isolates infecting FCM in different geographical areas of South Africa. The results of this study have broad-ranging implications for our understanding of baculovirus-host interactions and for the application of baculovirus basedbiopesticides.

Anredera cordifolia (Basellaceae), Madeira vine, is a perennial, semi- succulent climber native from Paraguay to southern Brazil and northern Argentina. It has a history of weediness and difficulty of control once established. In South Africa Madeira vine has a wide range and distribution with altitudes ranging from 10-1800m above sea level. Described as a transformer species, its sheer weight is capable of breaking branches off trees, causing the potential collapse of forest canopies. Chemical and mechanical control methods are expensive, labour intensive and may provide only temporary relief. A biological control programme was therefore initiated in 2003. Cf Phenrica sp. 2 (Coleoptera: Chrysomelidae: Alticinae), was field collected from A. cordifolia in Brazil, SSW of Cascavel in the Paraná Province during a survey in November 2003. Eggs are laid in groups of 16 with the average fertility rate being 89%. After going though three larval instars, the larvae pupate in the soil with the adults eclosing after a period of 17 days. The total developmental time for a generation from egg to egg ranges between 7-8 weeks. Biological traits that favour the flea beetle as a possible biological control agent include long-lived adults (up to 5 months) and multiple generations during the summer period. Both adults and larvae feed extensively on leaves and stems and although developmental rates will slow down during the winter period, no indication of a definite diapause was found under the prevailing laboratory conditions. After completing the larval no-choice trials with twenty-six plant species from 14 plant families Phenrica sp. 2 proved to be adequately host specific, as larval development was only supported by 3 Basellaceae species (including the control A. cordifolia) and one Portulacaceae species. All of these are introduced species in South Africa. The only indigenous Basella species could not be tested as it has a very marginal distribution, and because it’s inconspicuous nature, it is seldom seen or collected. Adult multi-choice trials were restricted to species that could sustain larval development to give some indication of the acceptability of these species for adult feeding and oviposition. Although adult feeding was initially concentrated on B. alba, the oviposition preference was clear-cut as females only oviposited on A. cordifolia. In order to quantify the impact of Phenrica sp. 2 on plant biomass and to assess the incidence and intensity of foliar damage, a pair of adults was confined to the host plant, for 2 generations, with different levels of larval densities. The results indicated that the host plant, due to both larval and adult feeding, suffered leaf losses of up to 55%. Anredera cordifolia was however still capable of enlarging the root mass despite suffering huge leaf losses. This would imply that A. cordifolia has an effective re-growth capacity and it will only be vulnerable to attack of the storage organs that enable re-growth, or to repeated attack of other plant parts through which reserves are exhausted. Unfortunately the period of exposure (24 days) was too short to prove that Phenrica sp. 2 impacts on the below ground dry mass, but should the plant be completely defoliated, as was observed in the field, the host plant would be forced to deplete stored resources. Phenrica sp.2 has shown to be very host specific and although A.cordifoia loses its leaves during the winter period in most provinces in South Africa, the adults are long-lived and should be able to survive the leafless periods. Further more the relatively short life cycle, high fecundity and 3 generations per year should theoretically insure a strong population build-up that would improve the chances of establishment in the field. All indications are that Phenrica sp. 2 is an agent well worth considering for the biological control of A. cordifolia.

No description available.

Call number: LD2668 .T4 1979 C54 / Master of Science

Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Alien invasive species are a global concern not only threating biodiversity, but also negatively impacting regional economies. Consequently research aimed at understanding the invasion process is crucial for management of invasive alien species to reduce these impacts. Identifying accurate natal ranges is the key first step for efficient alien plant management, especially biological control. Such knowledge may assist in selecting host-specific biological control agents and help prevent non-target impact on native species. A case in point is the genus Cardiospermum of which species have been extensively moved around the globe with two species now being possible widespread invaders (C. grandiflorum and C. halicacabum), and a third species (C. corindum) having significant invasion potential. However, in some regions the native statuses of these species are not clear, hampering management. In order to minimize potential non-target impacts it is prudent to determine the relationships between Cardiospermum taxa in unknown native ranges prior to the release of biological control agents. With this thesis I aim to review available literature on the genus Cardiospermum, determine potential spread to suitable habitats globally for selected taxa, resolve unknown native ranges in southern Africa, and investigate rapid speciation of an endemic Namib Desert species of balloon vine. Through exhaustive searches for available literature on the genus Cardiospermum I report on the biology and ecology of selected species within the genus, with special focus on the most widespread species. Specifically, using species distribution modelling I investigate the potential spread of C. halicacabum, C. corindum and C. grandiflorum globally and assess the accuracy with which this can be determined using known native ranges to predict current alien ranges. Results indicate that these species have significant potential to spread, though highlighting that species distribution modelling over-fit predicted suitable ranges when using native range data alone. To resolve uncertain native ranges of selected species within the genus I reconstructed a dated multi-gene phylogeny and chloroplast haplotype network to investigate relationships within and among Cardiospermum species. I conclude that C. halicacabum is non-native in southern Africa due to polyphyletic relationships among accessions, while C. corindum is native due to natural long distance dispersal as indicated by a single monophyletic southern African clade. The close relationship observed between C. corindum and the African species, C. pechuelii, lead to a population-level genetic investigation of these two taxa. For this, I constructed a multi-gene phylogeny, chloroplast haplotype network and conducted population genetic diversity analyses which all indicated that the African arid adapted taxa, C. pechuelii, endemic to the Namib Desert of Namibia, evolved from C. corindum following long distance dispersal from South America. This study firstly provides insights into the ecology and biology of Cardiospermum, warning against further introduction due to potential spread. Secondly I resolved the unknown native statutes of Cardiospermum species in southern Africa and, lastly, illustrated the origin of African C. pechuelii. My research findings have major implications for on-going biological research against C. grandiflorum in South Africa and cautions strongly against the release of already-identified biological control agents due to their potential non-target impacts. / AFRIKAANSE OPSOMMING: Indringerspesies is 'n wêreldwye probleem as gevolg van hul direkte bedreiging van biodiversiteit asook hul negatiewe impakte op streeksekonomieë. Gevolglik is navorsing aangaande die indringingsproses van uiterste belang om doeltreffende beheer van indringerspesies te verseker. Die bepaling van die inheemse herkoms van indringerpopulasies is die eerste belangrike stap tot doeltreffende beheer, veral biologiese beheer. Hierdie informasie kan help met die identifisering van gasheer-spesifieke biologiese agente en om potensiële nie-teiken impakte op inheemse plant spesies verhoed. ‘n Voorbeeld is ballon rankplante in die genus Cardiospermum, waarvan verskeie spesies wêreldwyd verspreid is, met die gevolg dat minstens twee spesies (C. halicacabum en C. grandiflorum) nou moontlike wydverspreide indringers is en ‘n derde spesie (C. corindum) ook potensiaal toon as ‘n indringerspesie. In sommige streke is die in- of uitheemse statusse van hierdie spesies onbekend en belemmer gevolglik hul doeltreffende beheer. Met hierdie tesis streef ek om die genus Cardiospermum te hersien en potensiële verspreiding van geselekteerde spesies na geskikte habitatte te bepaal, om onbekende inheemse streke binne Suider-Afrika op te los en laastens, om die herkoms van ‘n ware Afrika spesie (C. pechuelii) te ondersoek. Na deeglike ondersoek van beskikbare literatuur doen ek verslag omtrent die biologie en ekologie van spesies binne Cardiospermum, met spesiale fokus op die mees wydverspreidste spesies. Deur gebruik te maak van spesies verspreidings modelle bestudeer ek die potensiaal van verdere verspreiding wêreldwyd vir C. halicacabum, C. corindum en C. grandiflorum en rapporteer ook omtrent die akkuraatheid van hierdie tegniek. Resultate toon dat alle spesies aansienlike potensiaal toon om verder te versprei, maar beklemtoon ook dat hierdie metode inheemse streek data “oor-aanpas”. Om enige onsekerhede aangaande inheemse streke op te los, het ek ‘n gedateerde multi-geen filogenie en ‘n chloroplas haplotipe netwerk opgetrek om die verhoudings binne en tussen geselekteerde Cardiospermum spesies te bepaal. Ek kom tot gevolgtrekking dat C. halicacabum nie inheems in Suider-Afrika is nie, as gevolg van polifiletiese verhoudings, en dat C. corindum inheems is en moontlik ook ‘n voorbeeld van natuurlike langafstand verspreiding, soos aangedui deur ‘n enkele monofiletiese groep. Die naverwante filogetiese verhouding tussen C. corindum en C. pechuelii het daartoe gelei dat ek die herkoms van C. pechuelii in Afrika ondersoek het. ‘n Multi-geen filogenie, chloroplas haplotipe netwerk en populasie genetiese diversiteit analises het aangedui dat C. pechuelii endemies is tot die Namib Woestyn van Namibië, en die produk is van lang afstand verspreiding van C. corindum vanaf Suid-Amerika. Hierdie studie gee eerstens insig tot die ekologie en biologie van Cardiospermum en waarsku teen verdere verspreiding. Tweedens dui my studie ook die opgeloste inheemse streke in Suider-Afrika aan van sekere Cardiospermum spesies, en laastens, illustreer ek die herkoms van C. pehuelii. My navorsing het baie belangrike gevolge vir die huidige biologiese beheer program teen C. grandiflorum in Suid-Afrika en waarsku teen die vrystelling van reeds geïndentifiseerde biologiese beheer agente weens potensiële nie-teiken impakte op inheemse spesies.

Thesis (PhD)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: In surveys carried out on poultry farms in the Western Cape Province, South Africa, the larvae of the flies Musca domestica L., Fannia canicularis (L.) and Leptocera sp. were found to be numerous. The majority of M domestica larvae and the mite Proctolaelaps sp. were recovered from manure with temperatures between 20 and 26°C while the larvae of F. canicularis and Leptocera sp. were mostly found between 14 and 22°C. Predominant predatory arthropods in the manure were the histerid Carcinops pumilio (Erichson), the staphylinid Philonthus sordidus (Gravenhorst) and the mite Macrocheles muscaedomesticae (Scopoli). These had a manure temperature tolerance of between 12 and 31°C. Macrocheles muscaedomesticae and P. sordidus preferred fresh manure, whilst C pumilio preferred aged manure. Therefore these two predators could complement one another in integrated pest management programmes. From a study of the vertical cross-sectional profile of the manure cone it was clear that the larvae of the prey species M domestica and F. canicularis and predator P. sordidus distinctly occupy the crest of the manure cone. The succession of arthropods in accumulating poultry manure and the effect of manure height on their numbers was studied. The prey species M domestica and F. canicularis were the first colonizers followed by the predators P. sordidus and M muscaedomesticae. Carcinops pumilio was a late colonizer. The numbers of M domestica and F. canicularis larvae were negatively correlated with the increase in manure height whilst the numbers of the predators C pumilio and M muscaedomesticae were positively correlated with this. The total developmental time of C pumilio from egg to adult emergence at 30°C was 20.5 days. Two larval instars were recorded. The immature stages sustained about 50% mortality before adult emergence. Carcinops pumilio adults can live up to 130 days at 30°C and had a Type I survivorship curve. The intrinsic rate of natural increase (rm) was 0.064943 and net reproduction rate (Rs) was 20.191.The rate of oviposition was directly proportional to body size and weight. Increase in density had a dampening effect on fecundity and led to an increase in developmental time. Thus density will be a critical factor in any mass rearing programme for this predator of fly larvae. In addition, an increase in density stimulated the dispersal of C. pumilio. A crowding level of 50 C. pumilio adults per 200ml container resulted in the least dispersal which did not exceed 2.5% per day, compared with up to 24.0% at a crowding level of 400. The predation rate of flies by C. pumilio in the laboratory decreased with an increase in predator density, but increased with an increase in starvation. Starvation had no effect on predation rate of M muscaedomesticae. A technique exploiting Drosophila melanogaster Meig. as a source of prey was successfully developed for rearing C. pumilio, which could be of commercial value. Drosophila melanogaster appeared to be an ideal candidate as a source of prey for mass rearing C. pumilio due to its short developmental time of about ten days. It is also inexpensive and easy to breed, and has a very high biotic potential. Carcinops pumilio that were fed on artificial diet had a prolonged developmental time and increase in weight, and laid fewer eggs than those fed on natural diet. C. pumilio completed its development on the artificial diet and both the F, and F2 generations fed on an artificial diet were able to lay eggs. This could be the first step towards finding an artificial diet that would allow continuous rearing of C. pumilio and their availability at all times for utilization in the biological control of houseflies. / AFRIKAANSE OPSOMMING: In opnames wat op pluimveeplase in die Westelike Kaapprovinsie, Suid-Afrika uitgevoer is, is gevind dat die vliegsoorte Musca damestica L., Fannia canicularis (L.) en Leptacera sp. volop is. Die meeste van die M. damestica larwes en die myt Practalaelaps sp. is versamel in hoendermis met temperature tussen 20 en 26°C en die larwes van Ficanicularis en Leptacera tussen 14 en 22°C. Die volopste predatoriese arthropode in die mis was die histerid Carcinaps pumilia Erichson, die staphylinid Philanthus sardidus (Gravenhorst) en die myt Machrascheles muscaedamesticae (Scopoli). Hulle temperatuurtoleransie in die mis was tussen 12 en 31°C. Machrasceles muscaedamesticae en P. sardidus het vars mis verkies, terwyl C. pumilio voorkeur aan ouer mis gegee het. Gevolglik behoort hierdie twee predatore mekaar te komplementeer in programme van ge-integreerde plaagbestuur. In Studie van die vertikale deursnee-profiel van die miskeel het duidelik getoon dat die prooispesies M. damestica en en F canicularis en die predator P. sardidus in die kroon van die miskeel voorkom. Die opeenvolging van die arthropode in die ophopende hoendermis en die invloed van mishoogte op hulle getalle is bestudeer. Die prooispesies M damestica en F canicularis was die eerste koloniseerders, gevolg deur die predatore P. sardidus en M muscaedamesticae. Carcinaps pumilia was In laat koloniseerder. Die getalle van die larwes van M damestica en F. canicularis was negatief gekorreleer met die toename in mishoogte terwyl die getalle van die predartore C. pumilia en M. muscaedamesticae positief daarmee gekorreleer was. Die totale ontwikkelingstyd van C. pumilia van eier tot die volwassene se verskyning was 20.5 dae by 30°C. Twee larwale instars is gevind. Die onvolwasse stadia het 50% mortaliteit ondergaan voor die verskyning van die volwassenes. Die volwassenes van C. pumilia kan tot 130 dae lank by 30°C lewe en het In Tipe 1 oorlewingskurwe gehad. Die intrinsieke tempo van natuurlike toename (rm) was 0.064943 en die netto reproduksietempo (Rs) 20.191. Die tempo van eierlegging was in direkte verhouding tot die liggaamsgrootte en massa. Toename in digtheid het 'n onderdrukkende effek op vrugbaarheid gehad en tot 'n toename in ontwikkelingstyd gelei. Digtheid sal dus 'n kritieke faktor wees III emge program van massateling vir hierdie predator van vlieglarwes. Daarmee saam het 'n toename in digtheid die verspreiding van C. pumilio gestimuleer. By 'n digtheid van 50 C. pumilio volwassenes per houer het die verspreiding nie 2.5% oorskrei nie, in vergelyking met tot 24.0% by 'n dightheid van 400. Die predasietempo van vliee deur C. pumilio in die laboratorium het afgeneem met 'n toename in predatordigtheid, maar toegeneem met 'n toename in verhongering. Verhongering het nie 'n invloed gehad op die predasietempo van M. muscaedomesticae nie. 'n Tegniek met Drosophila melanogaster Meig. as bron van prooi in die teling van C pumilio is suksesvol ontwikkel en dit kan van kommersiele waarde wees. Dit blyk dat D. melanogaster ideaal kan wees as 'n bron van prooi in die massateling van Cpumilio vanwee sy kort ontwikkkelingstyd van ongeveer tien dae. Die spesies is ook goedkoop en maklik om te teel, en het 'n baie hoe biotiese potensiaal.Care inops pumilio wat op 'n kunsmatige dieet gevoed het, het 'n verlengde ontwikkelingstyd en gewigstoename gehad, en het minder eiers gele as die wat op 'n natuurlike dieet gevoed het. C. pumilio het sy lewensloop op die kunsmatige dieet voltooi en beide die FJ en F2 generasies wat op die kunsmatige dieet gevoed het, was in staat om eiers te Ie. Dit kan die eerste stap wees in 'n poging om 'n kunsmatige dieet te vind wat dit sal moontlik maak om C. pumilio aaneenlopend te teel sodat dit deurlopend beskikbaar kan wees vir gebruik in die biologiese beheer van huisvliee,

Thesis (MSc)--Stellenbosch University, 1992. / One copy microfiche. / ENGLISH ABSTRACT: The effects of synthetic pyrethroids on the spider mite, Tetranychus urticae Koch, and its natural enemies was investigated. The pyrethroid cyfluthrin, sprayed for the control of fruit weevil Phlyctinus callosus, did not cause mite outbreaks and was not harmful to the predators when sprayed before they appeared on the apple trees. This spray also gave good control of thrips, bollworm (Heliothis armigera) and fruit weevil (P. callosus). A late season spray of deltamethrin against codling moth, caused an increase in the phytophagous mite population. This was assosiated with a temporary reduction in the population level of the predatory beetle, Oligota fageli. The plants found on the orchard floor were examined. The plant diversity was low and plants that acted as hosts of phytophagous mites during the winter were scarce. However, Solanum nigum carried high mite populations and infected the adjacent apple trees. The plants were too few to have an effect on the whole orchard. Eight synthetic pyrethroids were tested for repellency in a leafdisk dip and spray bioassay using T. urticae. Deltamethrin and fenvalerate caused no walk-off. Cyfluthrin and fluvalinate caused moderate walk-off and bifenthrin, cyhalothrin and lambda-cyhalothrin caused high walk-off. / AFRIKAANSE OPSOMMING: Die invloed van sintetiese piretroIedes op die rooispinmyt, Tetranychus urticae Koch en hul natuurlike vyande is ondersoek. Die piretroIed, cyfluthrin, gespuit vir die beheer van snuitkewer, P4ctinus callosus, het the mytuitbrake veroorsaak the en was ook the skadelik vir predatore nadat dit vroeg in die seisoen, voordat myte in die appelbome verskyn het, gespuit is the. Die bespuiting het ook goeie beheer van blaaspootjies, bolwurm (Heliothis amdgera) en P. callosus gegee. Deltametrien wat later in die seisoen toegedien is vir die beheer van kodlingmot, Cydia pomonella, het 'n mytuitbraak veroorsaak. Dit word geassossieer met die tydelike onderdrukking van die populasievlak van die predatoriese kewer, Oligota fageli. Die plante in die dekgewas is ondersoek. Die plant-verskeidenheid was laag en plante wat kon dien as oorwinterings gashere vir fitofage myte kon dien was skaars. Solanum nigrum het egter groot bevolkings myte gedra wat die appelbome naaste aan hulle eerste besmet het. Daar was egter te min van hierdie plante om 'n invloed op die hele boord te he. Agt piretroIedes is vir afwering van T. urticae in 'n blaarskyf doop en spuit bioessal getoets. Deltamethrin en fenvalerate het geen afwering getoon the. Cyfluthrin en fluvalinate het 'n redelike afwering, terwyl bifenthrin, cyhalothrin en lamda-cyhalothrin het 'n hod mate van afwering getoon

Dissertation (PhD Agric)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Chrysanthemoides monilifera ssp. monilifera is a shrub indigenous to South Africa, which has become a serious weed of native vegetation in Australia. Endophyllum osteospermi is a microcyclic, autoecious, rust fungus that induces witches' brooms on C. monilifera ssp. monilifera. This rust is considered as a candidate biocontrol agent for use against C. monilifera ssp. monilifera in Australia. The vegetative growth and reproductive output of healthy branches on bushes with different levels of E. osteospermi infections were measured at three sites. The growth of healthy branches on infected bushes was 26- 81% less than that of healthy branches on uninfected bushes. The number of buds, flowering capitulae, fruiting capitulae, and cypselas on healthy branches of infected bushes was 35-75%, 45-90%, 15-99%, and 15-90% less, respectively, than those on uninfected bushes. At five sites, the infection levels and number of witches' brooms were determined every two months. The increase in number of witches' brooms per bush ranged between o and 282 within one year, with an average increase per bush of28 (SE ± 4.8) and 39 (SE ± 9.2) during two years. The average simple interest rate (rs) increase of infection levels for all bushes was 0.015 month-I (s.e. ± 0.0041, n = 72) and 0.0098 month" (s.e. ± 0.0073, n = 43) during two years. Aecidioid teliospores germinated between 10 and 20oe, with 15°e as optimum. Light, and particularly near-uv light, stimulated germination. A period of 6 to 8 hours of light was needed to obtain optimum germination levels. The temperature requirements for basidiospore development differed from that of aecidioid teliospore germination. Optimum was at 15°e, but a rapid decrease in basidiospore production occurred at higher temperatures, few developed at 19°e. Two nuclear divisions occurred within 12 hours of germination to produce a metabasidium with three or four nuclei. A third nuclear division occurred in the basidiospores between 24 and 48 hours. Plants inoculated under controlled conditions took 5 to 24 months before witches' brooms began to develop. A Geographic Information System (GIS) approach was used to model the potential distribution of E. osteospermi in South Africa, based on monthly average climate surfaces with parameters derived from the above experiments. The same model was applied to Australia to suggest a potential distribution of the rust if released in Australia. This potential distribution was similar to one generated using the climate matching computer programme CLIMEX©, but gave greater spatial accuracy. Both approaches indicate that E. osteospermi should establish in temperate Australia. Chrysanthemoides species, as well as other South African asteraceaus plants, were monitored for E. osteospermi between 1992 and 2003. Endophyllum osteospermi was recorded on C. monilifera ssp. monilifera, C. monilifera ssp. pisifera, C. monilifera ssp. rotundata, C. monilifera ssp. canescens, C. monilifera ssp. subcanescens, C. incana, an undescribed taxon of Chrysanthemoides, Osteospermum ciliatum, 0. polygaloides and 0. potbergense. Endophyllum dimorphothecae sp. nov. is described on Dimorphotheca cuneata. Aecidium elytropappi, which was recorded on Elytropappus rhinocerostis and Stoebe plumose, is transferred to Endophyllum as E. elytropappi comb. nov. Germination of aecidioid teliospores and penetration by basidiospores were observed on the surface of excised leaves of 32 plant species at 4 days after inoculation. Germinating aecidioid teliospores aborted on 14 plant species, whilst no penetration was attempted on a further 12. Penetration only occurred on 9. Therefore only these 9 plant species need to undergo traditional host specificity testing. Pending these results, E. osteospermi could be safely released in Australia for the biological control of C. monilifera ssp. monilifera. / AFRIKAANSE OPSOMMING: Chrysanthemoides monilifera ssp. monilifera 'n meerjarige wat inheems in Suid Afrika is, het 'n belangrike onkruid in Austalië geword. Endophyllum osteospermi 'n mikrosikliese, autoecious roesswam, induseer heksebesems op C. monilifera ssp. monilifera. Hierdie roesswam word as 'n potensiële biologiese beheeragent teen C. monilifera ssp. monilifera in Austalië beskou. Die vegetatiewe groei en voortplanting van gesonde takke op struike met verskillende vlakke van E. osteospermi infeksies is by drie lokaliteite gemeet. Groei van gesonde takke op geinfekteerde bosse was 26-81 % minder as die van gesonde takke op ongeïnfekteerde bosse. Die aantalokselknoppe, blommende capitulum, vrugdraende capitulum en pitvrugte op individuele gesonde takke van geïnfekteerde bosse was onderskeidelik 35-75%, 45-90%,15-99%, en 15-90% minder, as die op ongeïnfekteerde bosse. By vyf lokaliteite is die infeksievlakke en die aantal heksebesems elke twee maande vasgestel. Die toename in heksebesems van elke plant was tussen 0 en 282 binne eenjaar, met 'n gemmidel van 28 (SE ± 4.8) en 39 (SE ± 9.2) geduurende twee jaare. Die gemiddelde eenvoudige rentekoers (rs) toename in infeksievlakke van al die struike was 0.015 maand" (s.e. ± 0.0041, n = 72) en 0.0098 maand-1 (s.e. ± 0.0073, n = 43) gedurende twee jaare. Ontkieming van aecidioidteliospore het tussen 100e en 200e met 15°e as die optimum. Lig en veral naby-uv lig het ontkieming gestimuleer, terwylontkieming relatief swak was onder donker toestande. 'n Periode van 6 tot 8 uur lig was nodig vir optimale ontkiemingsvlakke. Die temperatuurvereistes vir basidiospoor ontwikkeling het verskil van die van aecidioid teliospoor ontkieming. Optimale was by 15°e, maar 'n vinnige afname in basidiospoorproduksie het by hoër temperature voorgekom, min het by 19°e voorgekom. Twee kernverdelings het binne 12 ure van die begin van ontkieming voorgekom om 'n metabasidium te produseer met drie of vier kerne. 'n Derde kern verdeling het in die basidiospore tussen 24 en 48 uur voorgekom. Plante wat onder beheeerde toestande geïnokuleer is het heksebesems 5 tot 24 maande na inokulasie ontwikkel. 'n Geografiese Inligtings Sisteem (GIS) benadering is gebruik om 'n model vir die potensiële verspreiding van E. osteospermi in Suid Afrika te ontwikkel, gebasseer op die maandelikse gemiddelde klimaatoppervlaktes met parameters wat vanaf bogenoemde eksperimente verkry is. Dieselfde model is in Austalië toegepas om 'n potensiële verspreiding van die roesswam voor te stel. Hierdie potensiële verspreiding was soortgelyk aan 'n program wat met die klimaats vergelykende rekenaarsprogram CLIMEX© ontwikel is, maar dit het groter ruimtelike akkuraatheid gemaak. Beide benaderings het aangedui dat E. osteospermi in Austalië behoort te vestig. Chrysanthemoides spesies, asook ander inheemse plante van die Asteraceae, is tussen 1992 en 2003 vir die voorkoms van E. osteospermi in Suid Afrika waargeneem. Endophyllum osteospermi is op C. monilifera ssp. monilifera, C. monilifera ssp. pisifera, C. monilifera ssp. rotundata, C. monilifera ssp. canescens, C. monilifera ssp. subcanescens, C. incana, 'n onbeskryfde taxon van Chrysanthemoides, Osteospermum ciliatum, a. polygaloides en a. potbergense waargeneem. Endophyllum dimorphothecae sp. nov. is beskryf op Dimorphotheca cuneata. Aecidium elytropappi, wat op Elytropappus rhinocerostis en Stoebe plumosa voorkom, is by Endophyllum ingesluit as E. elytropappi comb. nov. Ontkieming van aecidioidteliospore en penetrasie deur basidiospore op die oppervlak van verwyderde blare van 32 plant spesies 4 dae na inokulasie is waargeneem. Ontkiemende aecidioidteliospore het op 14 toets plant spesies ge-aborteer, terwyl geen penetrasie op 'n verdere 12 gepoog is nie. Penetrasie het slegs op 9 voorgekom. Derhalwe hoef slegs die 9 plant spesies tradisionele gasheer spesifisiteitstoetse te ondergaan. Afhangende van die resultate kan E. osteospermi dus met veiligheid in Austalië vir die biologiese beheer van C. monilifera ssp. monilifera vrygelaat word.

The ability of Nabis alternatus Parshley to reduce tobacco budworm, Heliothis virescens (F.), populations was studied in the laboratory, greenhouse and field. Tests were conducted at different temperatures and with different larval instars of tobacco budworm to determine their effects on predatory efficiency. Both immature and adult N. alternatus consumed more first-instars than of either second- or third-instars, or of the egg stage. Temperature significantly affected the predatory capability of N. alternatus. All instars and the adult exhibited a higher rate of consumption at 30°C than at temperatures of 20, 25 and 35°C; adults consumed more tobacco budworm larvae and eggs at all temperatures than did any of the nymphal instars. There were no differences in survival of the different N. alternatus stages at the different temperatures but the average number of days required to complete each instar was affected. Each increase in the predator-to-prey ratio resulted in a reduced survival of the tobacco budworm population. Release rates of 2500, 3750 and 5000 adults per acre resulted in mortalities of 55, 77, and 87%, respectively. Both adult and third-instar N. alternatus exhibited the higher searching and consumptive capacities at different ratios of first-, second-, and third-instar tobacco budworm infestations. All N. alternatus fed more at the 1:4 (predator/prey) ratio than at ratios of 1:1, 1:2, or 1:3. Longevity of adult N. alternatus varied when provided with food substances of sugar solution, green bean, no food or cotton plants at the different temperatures. Survival was greatest when provided with sugar solution over any of the other substrates, and when held at cooler temperatures. Compatibility of N. alternatus with other controls was studied under both laboratory and field conditions. Average longevity in combination with treatments of Elcarᴿ, Bacillus thuringiensis, or fenvalerate was 6.7, 5.9, and 1.3 days, respectively. Compatibility with the biological insecticides was very good and the combinations reduced first-instar tobacco budworm infestations more than did either alone.