During a two years study (1993-1994) in southwestern Quebec, Artogeia rapae and Plutella xylostella were found to be the most important lepidopterous pests of cruciferous crops, followed by Trichoplusia ni and four minor species. The relationship between plant sampling and the use of degree-days, pheromone traps (P. xylostella) or butterflies counts (A. rapae) was assessed for A. rapae and P. xylostella. Three generations of A. rapae were observed annually, with a duration of 319.7 degree-days above $ rm 10 sp circ C (DD sb{10}),$ while P. xylostella had three to four generations with a duration of 277.7 $ rm DD sb{10}.$ Captures of P. xylostella were not linked to the level of infestations. By the end of summer, A. rapae was the most abundant species, especially on broccoli, while P. xylostella was often abundant early in the season. The complex of lepidopterous pests' natural enemies was identified, and the data were analyzed using an illustrated parasitoid web. Fourteen parasitoid and three hyperparasitoid species (12 Hymenoptera, 2 Diptera) were identified. The most important parasitoid, Cotesia rubecula, is a larval parasitoid of A. rapae that is newly established in Quebec. Overall, parasitism of lepidopterous eggs is almost not existent, whereas parasitism and infection of larvae and pupae by pathogens are important, but not significant to reduce butterfly populations. In order to evaluate the potential of oophagous parasitoids, the parasitism of up to 42 species/strains of Trichogramma was studied with different development stages of P. xylostella, A. rapae and T. ni eggs. Generally, Trichogramma females attacked preferably young eggs of a given host species. Females modified the number of offspring according to host size and host age, as fewer offspring emerged from the smallest or the oldest hosts. Host age had no impact on sex allocation. (Abstract shortened by UMI.)

A biomassa lignocelulósica pode ser considerada como uma fonte inesgotável de matériaprima de baixo custo para a produção de biocombustíveis, que são alternativos aos combustíveis fósseis. Entretanto, a disponibilidade de enzimas eficientes e econômicas é um dos gargalos para se chegar a xaropes de glicose, etapa anterior à fermentação no desenvolvimento da tecnologia do etanol celulósico. O nabo forrageiro (Raphanus sativus L.) é uma planta com grande potencial para a produção de biodiesel, pois apresenta elevado teor de óleo em suas sementes, comparativamente a outras oleaginosas. A obtenção de óleo do nabo forrageiro gera uma torta, considerada como resíduo (RNF), com elevada concentração de proteínas (em torno de 40%). Neste trabalho, avaliou-se a conveniência do emprego de RNF para a formulação de meios para a produção microbiana de celulases, visando à substituição total ou parcial de componentes, como o farelo de trigo e o farelo de soja. Como microrganismo para secreção das enzimas, utilizou-se o mutante S1M29 de Penicillium echinulatum, considerado um bom produtor de celulases. A produção de celulases e xilanases foi estudada tanto em cultivo em estado sólido (CES) como em cultivo submerso (CS). Foi constatado o crescimento do fungo tanto em CES como em CS, contendo apenas RNF como principal fonte de carbono e nitrogênio ou nos meios com variações nas concentrações de RNF, em substituição aos farelos de trigo e de soja. Quando os meios foram constituídos somente com RNF, as atividades enzimáticas não foram satisfatórias, provavelmente devido às baixas concentrações de substratos indutores (celulose e xilose), à elevada concentração de proteínas ou ao óleo residual. No cultivo em estado sólido, verificou-se que é possível substituir parcialmente o farelo de trigo (FT) por RNF, permitindo a produção de - glicosidases com títulos enzimáticos de 22,62 UI/g, endoglicanases com 210,5 UI/g e xilanases com 1.137,59 UI/g. Em cultivo submerso, a substituição parcial ou total de farelos de trigo e de soja por RNF ermitiu títulos enzimáticos de -glicosidases de 0,18 UI/ mL, endoglicanases de 8,3 UI/mL e xilanases de 14,3 UI/mL, que foram semelhantes ao meio controle que utiliza suplementação de farelo de trigo e farelo de soja. Os complexos enzimáticos produzidos nas duas condições, CES e CS, mostraram-se mais eficientes do que o complexo enzimático utilizado como controle quanto à capacidade de hidrólise em celulose, Avicel ®, bagaço de cana-de-açúcar e capim elefante in natura e pré-tratados. / Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2015-02-23T12:20:18Z No. of bitstreams: 1 Dissertacao Loiva Sukovski.pdf: 1633156 bytes, checksum: d7fc9e0fd31b362da50561f20d114766 (MD5) / Made available in DSpace on 2015-02-23T12:20:18Z (GMT). No. of bitstreams: 1 Dissertacao Loiva Sukovski.pdf: 1633156 bytes, checksum: d7fc9e0fd31b362da50561f20d114766 (MD5) / The lignocellulosic biomass can be considered as an inexhaustible source of raw material of low cost for the production of biofuels, which are alternatives to fossil fuels. However, the availability of efficient and low cost enzymes is one of the bottlenecks to obtain glucose syrups step prior to fermentation in the development of the technology for cellulosic ethanol. The fodder radish (Raphanus sativus L.) is a plant with great potential for the production of biodiesel, because it presents, high oil content in their seed, compared toother crops. The obtaining of oil of fodder radish seed generates a cake, considered as residue (FRC), with a high concentration of protein (around 40 %). In this study, was evaluated the convenience of use of FRC for the formulation of cellulases production medium, or even the total or partial replacement of components, such as the wheat bran and soybean meal. As microorganism for secretion of enzymes it was used the mutant S1M29 of Penicillium echinulatum, considered a good producer of cellulases. The production of cellulases and xylanases was studied both in solid-state cultivation (SSC) and submerged cultivation (SC). It was noted the growth of the fungus in both SSC as in SC, containing only FRC as the main source of carbon and nitrogen, or in the medium with different concentrations of FRC, in replacement of the wheat bran and soybean meal. When the medium were formed only with FRC, enzyme activities were not satisfactory, probably due to the low concentrations of substrates inductors (cellulose and xylose), the high concentration of proteins or of residual oil. In SSC, it was found that it is possible to replace partially the wheat bran by FRC, enabling the production of β-glucosidases with titles enzymatic of 22.62 IU/g, endoglucanases with 210.5 IU/g and xylanases with 1,137.59 IU/g. In SC, total or partial replacement of soybean meal and wheat bran by FRC allowed -glucosidases titles of 0.18 IU/mL, endoglucanases of 8.3 IU/mL and xylanases of 14.3 IU/mL, which were simila to control, which uses supplementation of wheat bran and soybean meal. The enzymatic complexes produced in two conditions, SSC and SC, shown to be more efficient than the enzymatic complex used as a control for the ability of hydrolysis of cellulose, Avicel ®, sugar cane bagasse and elephant grass in natura or pre-treated.

O nabo forrageiro apresenta extensa aplicação na agricultura, enquanto que o óleo de sua semente é uma importante matéria prima para a produção de biodiesel. No entanto, o processo de extração do óleo da semente via prensagem gera um resíduo (bagaço de semente de nabo forrageiro - BSNF). No presente trabalho, este resíduo foi submetido a um processo de pirólise em um reator rotativo, a diferentes velocidades de rotação (0, 3 e 6 rpm) do reator e vazões de gás inerte (0,25; 0,75 e 1,25 L/min). Ensaios de pirólise do farelo do BSNF (isento de óleo) também foram conduzidos para a investigação do efeito do óleo residual presente no BSNF sobre os produtos do processo de pirólise. Os experimentos demonstraram que a velocidade de rotação ótima para a produção de bio-óleo é de 3 rpm, com rendimento em bio-óleo de 60,99 % (m/m). Os experimentos conduzidos a diferentes vazões de gás inerte indicaram um aumento do rendimento de bio-óleo para a vazão de 1,25 L/min. A presença do óleo residual na biomassa aumenta o rendimento em bio-óleo, sendo que a pirólise do farelo do BSNF (isento de óleo) apresentou rendimento em bio-óleo de 49,34% (m/m). O biochar obtido nas três condições de velocidade de rotação investigadas apresentou composição físico-química semelhante, com potencial para ser aplicado no solo a fim de melhorar a sua fertilidade. Os gases não condensáveis apresentaram elevada concentração de CO2, e consequentemente possuem baixo conteúdo energético, não sendo de interesse industrial. Os bio-óleos obtidos da pirólise do BSNF, bem como do seu farelo, apresentaram composição química distinta. O bio-óleo proveniente do BSNF apresentou, além de aromáticos, aminas, amidas e nitrilas (funções nitrogenadas). O bio-óleo obtido a partir da pirólise do farelo de BSNF apresentou teor de aromáticos maior que o bio-óleo proveniente do bagaço, apresentando menores teores de amidas e aminas e ausência de nitrilas na composição. O bio-óleo obtido a partir da pirólise do BSNF a 3 rpm foi o que apresentou as propriedades físico-químicas mais adequadas para utilização na indústria e produção de energia. Devido à composição, os bio-óleos podem ser utilizados como combustível, na obtenção de produtos químicos e como matéria-prima para gaseificação. / Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2017-01-30T13:31:39Z No. of bitstreams: 1 Dissertacao Wendel Paulo Silvestre.pdf: 3100406 bytes, checksum: e1e612a57e43982953f084252b6f0672 (MD5) / Made available in DSpace on 2017-01-30T13:31:39Z (GMT). No. of bitstreams: 1 Dissertacao Wendel Paulo Silvestre.pdf: 3100406 bytes, checksum: e1e612a57e43982953f084252b6f0672 (MD5) Previous issue date: 2017-01-30 / The fodder radish has extensive use in agriculture and the oil from its seed is an important feedstock in biodiesel production. However, the extraction of the oil from the seed by pressing generates a residue (fodder radish seed cake - FRSC) that does not has any application. In this work, this residue was pyrolysed in a rotary kiln reactor in different rotation speeds (0, 3 and 6 rpm) and inert gas flow rates (0.25; 0.75 and 1.25 L/min). Pyrolysis of the FRSC bran (oil free) was also carried to investigate the effect of the residual oil present in the FRSC on the products of the pyrolysis. The experiments show that the optimal rotation speed for bio-oil production is 3 rpm, with bio-oil yield of 60.99 wt.%. The experiments carried at different inert flow rates indicated an increase of the bio-oil yield at inert flow rate of 1.25 L/min. The presence of the residual oil in the biomass increases bio-oil yield; the pyrolysis of the bran (oil free) presented bio-oil yield of 49.34 wt.%. The biochar obtained in the three rotation conditions have similar physical-chemical composition, with potential to be applied in the soil to improve its fertility. The non-condensable gases, presented high CO2 content, and, consequently, have poor energy content, being not interesting for industrial uses. The bio-oil obtained from the pyrolysis of the FRSC and its bran showed distinct chemical composition. The bio-oil obtained from the FRSC presented, beyond aromatics, amines, amides and nitriles (nitrogen containing functions). The bio-oil obtained from the FRSC bran presented higher aromatics content than the FRSC bio-oil and presenting lesser contents of amides and amines and absence of nitriles. The bio-oil obtained from the FRSC at 3 rpm presented the more adequate physical-chemical properties for use in industry and for energy production. Due to the composition, the bio-oils can be used as fuels, to obtain chemicals and as a feedstock in gasification process.

O nabo forrageiro apresenta extensa aplicação na agricultura, enquanto que o óleo de sua semente é uma importante matéria prima para a produção de biodiesel. No entanto, o processo de extração do óleo da semente via prensagem gera um resíduo (bagaço de semente de nabo forrageiro - BSNF). No presente trabalho, este resíduo foi submetido a um processo de pirólise em um reator rotativo, a diferentes velocidades de rotação (0, 3 e 6 rpm) do reator e vazões de gás inerte (0,25; 0,75 e 1,25 L/min). Ensaios de pirólise do farelo do BSNF (isento de óleo) também foram conduzidos para a investigação do efeito do óleo residual presente no BSNF sobre os produtos do processo de pirólise. Os experimentos demonstraram que a velocidade de rotação ótima para a produção de bio-óleo é de 3 rpm, com rendimento em bio-óleo de 60,99 % (m/m). Os experimentos conduzidos a diferentes vazões de gás inerte indicaram um aumento do rendimento de bio-óleo para a vazão de 1,25 L/min. A presença do óleo residual na biomassa aumenta o rendimento em bio-óleo, sendo que a pirólise do farelo do BSNF (isento de óleo) apresentou rendimento em bio-óleo de 49,34% (m/m). O biochar obtido nas três condições de velocidade de rotação investigadas apresentou composição físico-química semelhante, com potencial para ser aplicado no solo a fim de melhorar a sua fertilidade. Os gases não condensáveis apresentaram elevada concentração de CO2, e consequentemente possuem baixo conteúdo energético, não sendo de interesse industrial. Os bio-óleos obtidos da pirólise do BSNF, bem como do seu farelo, apresentaram composição química distinta. O bio-óleo proveniente do BSNF apresentou, além de aromáticos, aminas, amidas e nitrilas (funções nitrogenadas). O bio-óleo obtido a partir da pirólise do farelo de BSNF apresentou teor de aromáticos maior que o bio-óleo proveniente do bagaço, apresentando menores teores de amidas e aminas e ausência de nitrilas na composição. O bio-óleo obtido a partir da pirólise do BSNF a 3 rpm foi o que apresentou as propriedades físico-químicas mais adequadas para utilização na indústria e produção de energia. Devido à composição, os bio-óleos podem ser utilizados como combustível, na obtenção de produtos químicos e como matéria-prima para gaseificação. / The fodder radish has extensive use in agriculture and the oil from its seed is an important feedstock in biodiesel production. However, the extraction of the oil from the seed by pressing generates a residue (fodder radish seed cake - FRSC) that does not has any application. In this work, this residue was pyrolysed in a rotary kiln reactor in different rotation speeds (0, 3 and 6 rpm) and inert gas flow rates (0.25; 0.75 and 1.25 L/min). Pyrolysis of the FRSC bran (oil free) was also carried to investigate the effect of the residual oil present in the FRSC on the products of the pyrolysis. The experiments show that the optimal rotation speed for bio-oil production is 3 rpm, with bio-oil yield of 60.99 wt.%. The experiments carried at different inert flow rates indicated an increase of the bio-oil yield at inert flow rate of 1.25 L/min. The presence of the residual oil in the biomass increases bio-oil yield; the pyrolysis of the bran (oil free) presented bio-oil yield of 49.34 wt.%. The biochar obtained in the three rotation conditions have similar physical-chemical composition, with potential to be applied in the soil to improve its fertility. The non-condensable gases, presented high CO2 content, and, consequently, have poor energy content, being not interesting for industrial uses. The bio-oil obtained from the pyrolysis of the FRSC and its bran showed distinct chemical composition. The bio-oil obtained from the FRSC presented, beyond aromatics, amines, amides and nitriles (nitrogen containing functions). The bio-oil obtained from the FRSC bran presented higher aromatics content than the FRSC bio-oil and presenting lesser contents of amides and amines and absence of nitriles. The bio-oil obtained from the FRSC at 3 rpm presented the more adequate physical-chemical properties for use in industry and for energy production. Due to the composition, the bio-oils can be used as fuels, to obtain chemicals and as a feedstock in gasification process.

A biomassa lignocelulósica pode ser considerada como uma fonte inesgotável de matériaprima de baixo custo para a produção de biocombustíveis, que são alternativos aos combustíveis fósseis. Entretanto, a disponibilidade de enzimas eficientes e econômicas é um dos gargalos para se chegar a xaropes de glicose, etapa anterior à fermentação no desenvolvimento da tecnologia do etanol celulósico. O nabo forrageiro (Raphanus sativus L.) é uma planta com grande potencial para a produção de biodiesel, pois apresenta elevado teor de óleo em suas sementes, comparativamente a outras oleaginosas. A obtenção de óleo do nabo forrageiro gera uma torta, considerada como resíduo (RNF), com elevada concentração de proteínas (em torno de 40%). Neste trabalho, avaliou-se a conveniência do emprego de RNF para a formulação de meios para a produção microbiana de celulases, visando à substituição total ou parcial de componentes, como o farelo de trigo e o farelo de soja. Como microrganismo para secreção das enzimas, utilizou-se o mutante S1M29 de Penicillium echinulatum, considerado um bom produtor de celulases. A produção de celulases e xilanases foi estudada tanto em cultivo em estado sólido (CES) como em cultivo submerso (CS). Foi constatado o crescimento do fungo tanto em CES como em CS, contendo apenas RNF como principal fonte de carbono e nitrogênio ou nos meios com variações nas concentrações de RNF, em substituição aos farelos de trigo e de soja. Quando os meios foram constituídos somente com RNF, as atividades enzimáticas não foram satisfatórias, provavelmente devido às baixas concentrações de substratos indutores (celulose e xilose), à elevada concentração de proteínas ou ao óleo residual. No cultivo em estado sólido, verificou-se que é possível substituir parcialmente o farelo de trigo (FT) por RNF, permitindo a produção de - glicosidases com títulos enzimáticos de 22,62 UI/g, endoglicanases com 210,5 UI/g e xilanases com 1.137,59 UI/g. Em cultivo submerso, a substituição parcial ou total de farelos de trigo e de soja por RNF ermitiu títulos enzimáticos de -glicosidases de 0,18 UI/ mL, endoglicanases de 8,3 UI/mL e xilanases de 14,3 UI/mL, que foram semelhantes ao meio controle que utiliza suplementação de farelo de trigo e farelo de soja. Os complexos enzimáticos produzidos nas duas condições, CES e CS, mostraram-se mais eficientes do que o complexo enzimático utilizado como controle quanto à capacidade de hidrólise em celulose, Avicel ®, bagaço de cana-de-açúcar e capim elefante in natura e pré-tratados. / The lignocellulosic biomass can be considered as an inexhaustible source of raw material of low cost for the production of biofuels, which are alternatives to fossil fuels. However, the availability of efficient and low cost enzymes is one of the bottlenecks to obtain glucose syrups step prior to fermentation in the development of the technology for cellulosic ethanol. The fodder radish (Raphanus sativus L.) is a plant with great potential for the production of biodiesel, because it presents, high oil content in their seed, compared toother crops. The obtaining of oil of fodder radish seed generates a cake, considered as residue (FRC), with a high concentration of protein (around 40 %). In this study, was evaluated the convenience of use of FRC for the formulation of cellulases production medium, or even the total or partial replacement of components, such as the wheat bran and soybean meal. As microorganism for secretion of enzymes it was used the mutant S1M29 of Penicillium echinulatum, considered a good producer of cellulases. The production of cellulases and xylanases was studied both in solid-state cultivation (SSC) and submerged cultivation (SC). It was noted the growth of the fungus in both SSC as in SC, containing only FRC as the main source of carbon and nitrogen, or in the medium with different concentrations of FRC, in replacement of the wheat bran and soybean meal. When the medium were formed only with FRC, enzyme activities were not satisfactory, probably due to the low concentrations of substrates inductors (cellulose and xylose), the high concentration of proteins or of residual oil. In SSC, it was found that it is possible to replace partially the wheat bran by FRC, enabling the production of β-glucosidases with titles enzymatic of 22.62 IU/g, endoglucanases with 210.5 IU/g and xylanases with 1,137.59 IU/g. In SC, total or partial replacement of soybean meal and wheat bran by FRC allowed -glucosidases titles of 0.18 IU/mL, endoglucanases of 8.3 IU/mL and xylanases of 14.3 IU/mL, which were simila to control, which uses supplementation of wheat bran and soybean meal. The enzymatic complexes produced in two conditions, SSC and SC, shown to be more efficient than the enzymatic complex used as a control for the ability of hydrolysis of cellulose, Avicel ®, sugar cane bagasse and elephant grass in natura or pre-treated.

Genetic composition of hybrid zones often reflects geographical and ecological gradients. Hybrid zone of Arabidopsis lyrata and A. arenosa in Central Europe can be convenient model system for testing such hypothesis. These are well circumscribed but still interfertile, and their offspring is fully fertile. Besides repeated hybridisation events, the current state is complicated by the autopolyploidisation events of one of the parents, namely A. lyrata, which is present in the area studied both as diploid and tetraploid. This hybrid zone was already described in previous publications, which showed certain gradient of introgression. Moreover, the area of the hybrid zone represents a transition between Alpine and Pannonian climate along an altitudinal gradient leading from the Prealps to the lowland Wienerwald. The current thesis is the as yet most detailed study of this hybrid zone both in respect of number of studied populations and the amount of data acquired using the methods of RAD Sequencing, multivariate morphometrics and flow cytometry. The analysis of genetic data showed a gradient of introgression, where parental populations are placed at opposite ends, whereas genetically intermediate hybrids are placed in its centre. Analysis of the genome size showed an additional gradient, where hybrids...

No description available.

Pheromone lures and trap crops are appealing pest management tools that use insect and/or plant volatiles to reduce pest populations on crops of interest. Generating pheromone-emitting trap plants may allow for a continuing and highly-specific attraction of insect pests without repeated and costly application of synthetic pheromones. These trap plants may also be used to develop area-wide pest management strategies. As a proof-of-principle study we tested the possibility of producing the pheromone of the crucifer flea beetle Phyllotreta cruciferae in transgenic plants. P. cruciferae is an important pest of Brassica crops. In the presence of a host plant, males emit an aggregation pheromone, which attracts both males and females. Himachaladiene, a sesquiterpene, has been identified as a key component of the aggregation pheromone of P. cruciferae. In a close relative, Phyllotreta striolata, the compound is synthesized by a two-step pathway with an isoprenyl diphosphate synthase (PsIDS3) making (Z,E)-farnesyl diphosphate (FPP), which is converted by a terpene synthase (PsTPS1) to himachaladiene. Transient transformation of N. benthamiana with PsIDS3-TPS1 co-localized to the plastid resulted in the emission of himachaladiene and other known PsTPS1 products. Daily emissions of himachaladiene were approximately 1 µg per plant, which is six-fold higher than emissions from individual male flea beetles. Stable transformation of Arabidopsis thaliana with the same vector construct resulted in transgenic plants that expressed PsTPS1 and PsIDS3 transcripts, but no himachaladiene or other PsTPS1 products were present in volatile collections or leaf extracts of these plants. Moreover, no PsTPS1 enzyme activity was observed, indicating that post-transcriptional/translational effects prevent proper expression or targeting of functional PsIDS3 and/or PsTPS1 proteins in A. thaliana. Overall, this study demonstrates that the key component of the P. cruciferae aggregation pheromone, himachaladiene, can be transiently produced and emitted in a plant system at rates that are biologically relevant for insect attraction. However, further work is required for the stable production of the pheromone in plants. In addition, preliminary results are presented for the development of simple two-choice arenas that may allow for assessment of the movement of beetles toward host plant leaf tissue. This work can inform future efforts in developing methods for the economic production of himachaladiene in a plant system or the establishment of transgenic plants for the production and deployment of himachaladiene in a field setting. / Master of Science / The crucifer flea beetle is an important pest of vegetable and oilseed Brassica crops such as broccoli, cabbage and canola. Feeding by beetles has its greatest impact on crop health and yield in the early spring, when adult beetles emerge from overwintering sites and feed on newly- emerging Brassica seedlings. Currently these insects are controlled using broad spectrum insecticides. A general awareness of the negative aspects of insecticides drives the search for alternative pest management strategies that could diversify our management strategies and reduce reliance on insecticides. Previous work has found that the crucifer flea beetle navigates to its host plants, in part, through plant-emitted volatiles. After locating the plant host, males emit a volatile aggregation pheromone that when blended with host plant volatiles increases attraction. Here work towards the development of a specialized trap crop is presented. Plants were engineered to emit a key component of the crucifer flea beetle aggregation pheromone. In an engineered non-host plant, Nicotiana benthamiana, transient production of the aggregation pheromone was established. However, in an engineered Brassica plant, Arabidopsis thaliana, no aggregation pheromone was detected despite evidence of the presence and expression of the required biosynthetic genes for its production. A discussion on alternative engineering strategies for A. thaliana is presented. In addition, preliminary results are presented for the development of a simple behavior assay to assess the attraction of beetles toward different smells. This work can inform future efforts aimed at developing methods for the economic production of the aggregation pheromone in a plant system or the establishment of plants for the production and deployment of the aggregation pheromone in a field setting.

No description available.

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is an important pest of cruciferous crops worldwide. The prolonged use of synthetic chemical insecticides as a primary means of control has resulted in the development of resistance in pest populations. In addition, the pest has also evolved resistance to the bacterial insecticidal protein of Bacillus thuringiensis which is also widely used as a method of control. Baculoviruses are considered as effective alternatives to conventional methods of control when incorporated into integrated pest management (IPM) programmes. These viruses target the larval stages of insects, are generally host-specific and are safe for use in the environment. This study aimed to isolate a baculovirus from a laboratory-reared P. xylostella colony, characterise it genetically and then evaluate its virulence against neonate and fourth instar larvae. A laboratory colony of P. xylostella was established using pupae and asymptomatic larvae collected from a cabbage plantation outside Grahamstown in the Eastern Cape province of South Africa. The colony flourished in the laboratory due to prime conditions and availability of food. The duration of development from egg to adult was determined by observation and imaging of the various life stages. The mean developmental time from egg to adult was observed to be 14.59 ± 0.21 days. The population of the insects increased rapidly in number leading to overcrowding of the insect colony, and hence appearance of larvae with viral symptoms. Occlusion bodies (OBs) were extracted from symptomatic larval cadavers and purified by glycerol gradient centrifugation. Analysis of the purified OBs by transmission electron microscopy revealed the presence of a granulovirus which was named PlxyGV-SA. The virus isolate was genetically characterised by restriction endonuclease analysis of the genomic DNA, and PCR amplification and sequencing of selected viral genes. The complete genome sequence of a Japanese P. xylostella granulovirus isolate, PlxyGV-Japan, has been deposited on the GenBank database providing a reference strain for comparison with DNA profiles and selected gene sequences of PlxyGV-SA. BLAST analysis of the granulin gene confirmed the isolation of a novel South African PlxyGV isolate. Comparison of the restriction profiles of PlxyGV-SA with profiles of PlxyGV-Japan and other documented PlxyGV profiles obtained by agarose gel electrophoresis revealed that PlxyGV-SA is a genetically distinct isolate. The data obtained from the sequencing and alignment of ecdysteroid UDP-glucosyltransferase (egt), late expression factor 8 (lef-8) and late expression factor 9 (lef-9) genes with those of PlxyGV-Japan also showed that PlxyGV-SA is a genetically different isolate. In order to determine the biological activity of PlxyGV-SA against neonate and fourth instar P. xylostella larvae, surface dose bioassays were conducted. The median lethal concentration of the virus required to kill 50% (LC₅₀) and 90% (LC₉₀) of the larvae was estimated by feeding insects with a range of doses. In addition, the time to kill 50% of the larvae (LT₅₀) was determined by feeding insects with the LC₉₀ concentration. Larval mortality was monitored daily until pupation. The data obtained from the dose response assays were subjected to probit analysis using Proban statistical software. The time response was determined using GraphPad Prism software (version 6.0). The LC₅₀ and LC₉₀ values for the neonate larvae were 3.56 × 10⁵ and 1.14 × 10⁷ OBs/ml respectively. The LT₅₀ was determined to be 104 hours. The neonate larvae were found to be more susceptible to infection than the fourth instar larvae with the same virus concentration. The concentrations used for the neonate larvae assay did not have a significant effect on the fourth instar as no mortality was recorded. This is the first study to describe a novel South African PlxyGV isolate and the results suggest that PlxyGV-SA has significant potential for development as an effective biopesticide for the control of P. xylostella in the field.