43 research outputs found
Controle quĂmico e biolĂłgico de Mahanarva fimbriolata StĂ„l, 1854 (Hemiptera: Cercopidae) para regiĂ”es produtoras de cana-de-açĂșcar de Mato Grosso do SulChemical and biological control of Mahanarva fimbriolata StĂ„l, 1854 (Hemiptera: Cercopidae)
Mahanarva fimbriolata (StĂ„l, 1854) (Hemiptera: Cercopidae) pode causar prejuĂzos expressivos em cultivos de cana-de-açĂșcar sendo necessĂĄrio empregar inseticidas para o controle das ninfas e adultos da cigarrinha. No entanto, nĂŁo existem informaçÔes sobre a eficiĂȘncia dos mĂ©todos de controle biolĂłgico e quĂmico para regiĂ”es produtoras de cana-de-açĂșcar no estado de Mato Grosso do Sul -MS. Por isso, o objetivo da pesquisa foi avaliar a eficiĂȘncia de inseticidas quĂmico e biolĂłgico no controle cigarrinha-da-raiz, em um canavial, situado no municĂpio de AngĂ©lica - MS. O delineamento experimental foi composto por blocos casualizados, com trĂȘs tratamentos e oito repetiçÔes. Os tratamentos testados foram: 1) Testemunha (nĂŁo tratada), 2) Thiamethoxam (Actara 250 WGÂź) â 1 Kg ha-1, 3) Metarhizium anisopliae â 10 Kg ha-1 (Biometha GÂź). As avaliaçÔes de eficiĂȘncia dos tratamentos foram obtidas aos 15, 30, 45, 60, 75 e 90 dias apĂłs a aplicação (DAA). No tratamento com o inseticida quĂmico, aos 15 e 30 DAA, foi registrada baixa infestação de ninfas e adultos de M. fimbriolata. Aos 45, 60, 75 e 90 DAA foram observadas menores infestaçÔes da cigarrinha-da-raiz onde foi utilizado o fungo M. anisopliae. Assim, sugere-se optar pela utilização dos fungos entomopatogĂȘnicos para o controle da cigarrinha-da-raiz em cana-de-açĂșcar.Abstract Mahanarva fimbriolata (StĂ„l, 1854) (Hemiptera: Cercopidae) can cause significant losses in crops of sugarcane and insecticides are used to the control of nymphs and adults spittlebug. However, there is no information on the effectiveness of biological and chemical methods of control for producing regions of sugarcane in Mato Grosso do Sul State - MS. Therefore, the objective of this study was to evaluate the efficiency of chemical and biological insecticides in the control of leafhopper root in a sugarcane plantation, located in the municipality of Angelica - MS. The experimental design consisted of randomized blocks with three treatments and eight replications. The treatments tested were: 1) control (untreated), 2) Thiamethoxam (Actara 250 WGÂź) â 1 Kg ha-1, 3) Metarhizium anisopliae â 10 Kg ha-1 (Biometha GÂź). The efficiency ratings of treatments obtained at 15, 30, 45, 60, 75 and 90 days after application (DAA) were: in treatment with the chemical insecticide, at 15 and 30 DAA, low infestation of nymphs and adults of M. fimbriolata was recorded; at 45, 60, 75 and 90 DAA, it was observed smaller infestations of leafhopper root where the fungus M. anisopliae was used. Thus, it is suggested to opt for the use of entomopathogenic fungi for the control of the leafhopper root on sugarcane
Primero relato de Costalimaita ferruginea (Fabricius, 1801) (Coleoptera: Chrysomelidae) em eucalipto no estado do Mato Grosso do Sul
The occurrence of the eucalyptus yellow beetle Costalimaita ferruginea (Fabricius, 1801) (Coleoptera: Chrysomelidae) was repoted in November 2009 in clonal plantations of Eucalyptus grandis x Eucalyptus urophylla in TrĂȘs Lagoas, Mato Grosso do Sul state. This is the first record of this species of eucalyptus seedlings in this state. In Brazil, Costalimaita ferruginea is considered a major pest of eucalyptus because of its ability to cause injuries such as the apical defoliation in parts of the plant, promoting significant losses in the development and inhibiting the marketing of wood and its derivatives.Relatou-se a ocorrĂȘncia do besouro amarelo do eucalipto, Costalimaita ferruginea (Fabricius, 1801) (Coleoptera: Chrysomelidae), em novembro de 2009, em plantios clonais de Eucalyptus grandis x Eucalyptus urophylla, no municĂpio de TrĂȘs Lagoas, Mato Grosso do Sul. Este Ă© o primeiro registro dessa espĂ©cie em mudas clonais de eucalipto no Estado. No Brasil, Costalimaita ferruginea Ă© considerada uma das principais pragas do eucalipto, devido a sua capacidade de causar injĂșrias, como o desfolhamento nas partes apicais da planta, promovendo perdas significativas no desenvolvimento e inviabilizando a comercialização da madeira e seus derivados
Biological parameters of the non-target pest Aphis gossypii Glover (Hemiptera: Aphididae) on genetically modified (GM) Bt cotton
In the present work, we aimed to evaluate: 1) the influence of the Cry1Ac protein expressed by the genetically modified cotton variety (Bt) NuOpal, on the biological parameters of a non-target pest, Aphis gossypii, reared under laboratory conditions; 2) the influence of plant age on aphid development. Cotton cultivars were grown following technical advice. In the laboratory, the aphids were separated into plastic containers including a cotton sheet, which was changed daily with the help of a moist cotton cloth. Observations were carried out daily, and the duration of the immature and adult stages, and offspring number, were recorded. Our results show that regardless of the differences in the duration of each instar, cultivars Bt and non-Bt and the different ages of the plant to Bt, no differences were seen in the total duration of these phases. It was only during the reproductive period that differences were observed among genotypes for 120 days. Regarding the number of offspring and longevity total, there were differences between the different ages of the Bt treatment.Keywords: Biosafety, transgenic, Gossypium hirsutum, genetically modified (GM) plantAfrican Journal of Biotechnology Vol. 12(16), pp. 1987-199
FIRST RECORD OF Costalimaita ferruginea (Fabricius, 1801) (COLEOPTERA: CHRYSOMELIDAE) IN EUCALYPTUS IN MATO GROSSO DO SUL STATE
The occurrence of the eucalyptus yellow beetle Costalimaita ferruginea
(Fabricius, 1801) (Coleoptera: Chrysomelidae) was repoted in November
2009 in clonal plantations of Eucalyptus grandis x Eucalyptus
urophylla in Tr\ueas Lagoas, Mato Grosso do Sul state. This is the
first record of this species of eucalyptus seedlings in this state. In
Brazil, Costalimaita ferruginea is considered a major pest of
eucalyptus because of its ability to cause injuries such as the apical
defoliation in parts of the plant, promoting significant losses in the
development and inhibiting the marketing of wood and its derivatives.Relatou-se a ocorr\ueancia do besouro amarelo do eucalipto,
Costalimaita ferruginea (Fabricius, 1801) (Coleoptera: Chrysomelidae),
em novembro de 2009, em plantios clonais de Eucalyptus grandis x
Eucalyptus urophylla, no munic\uedpio de Tr\ueas Lagoas, Mato
Grosso do Sul. Este \ue9 o primeiro registro dessa esp\ue9cie em
mudas clonais de eucalipto no Estado. No Brasil, Costalimaita
ferruginea \ue9 considerada uma das principais pragas do eucalipto,
devido a sua capacidade de causar inj\ufarias, como o desfolhamento
nas partes apicais da planta, promovendo perdas significativas no
desenvolvimento e inviabilizando a comercializa\ue7\ue3o da madeira
e seus derivados
Combinations of Metarhizium anisopliae with chemical insecticides and their effectiveness in Mahanarva fimbriolata (Hemiptera: Cercopidae) control on sugarcane
Some insecticides can be used jointly with entomopathogenic fungi, and therefore the combi-
nation of chemical and biological control measures can be a safe and effective method to con-
trol insect pests. The aim of this study was to evaluate the costs and efficacy of combinations of
Metarhizium anisopliae (Metschnikoff) Sorokin (Hypocreales: Clavicipitaceae) with thiameth-
oxam and imidacloprid on spittlebug (Mahanarva fimbriolata (StÄl); Hemiptera: Cercopidae)
control on sugarcane. The experiment was conducted as a randomized block design (RBD)
with 10 treatments and 4 replications. The treatments included a control (untreated), thia-
â1
â1
12
â1
methoxam (250 g ha ), imidacloprid (700 g ha ), M. anisopliae (M. a.) (3 Ă 10 conidia ha ),
A1 (3 Ă 10 12 M. a. conidia ha â1 + 65 g ha â1 of thiamethoxam), A2 (3 Ă 10 12 M. a. conidia ha â1 + 125
g ha â1 of thiamethoxam), A3 (3 Ă 10 12 M. a. conidia ha â1 + 187.5 g ha â1 of thiamethoxam), A4 (3 Ă
10 12 M. a. conidia ha â1 + 175 g ha â1 of imidacloprid), A5 (3 Ă 10 12 M. a. conidia ha â1 + 350 g ha â1 of
imidacloprid), and A6 (3 Ă 10 12 M. a. conidia ha â1 + 525g ha â1 of imidacloprid). The reductions
in the numbers of M. fimbriolata nymphs per treatment compared to the control were similar
at 15 DAT (days after treatment) in all treatments except combination A5 (M. anisopliae
and thiamethoxam). At 30 DAT, the numbers of nymphs were significantly reduced in all
treatments except A3, and their effectiveness ranged from 14.28% to 92.85%. At 45 DAT the
numbers of M. fimbriolata nymphs per treatment were significantly reduced in the following
treatments: imidacloprid alone at 700g ha -1 , A1, A2, A3, A4 and A6; and the combinations A1
and A2 caused the lowest M. fimbriolata nymph infestations and effectiveness rates of 77.41
and 87.09 %, respectively. At 75 DAT the 2 best control efficacies occurred in treatments A1 (3
Ă 10 12 M. a. conidia ha -1 of + 65g ha -1 of thiamethoxam) (82.1%) and A5 (78.6%) (3 Ă 10 12 M. a.
conidia ha â1 + 350 g ha â1 of imidacloprid). At 90 DAT the number of nymphs in the control had
increased 2.8 fold over the number at 75 DAT. Very good control efficacies at 90 DAT occurred
in all treatments with the combination of the fungus with an insecticide. At 105 DAT the
numbers of nymphs had surged in all treatments, and no treatment provided effective control.
The treatments with the highest earnings per hectare were A1 (3 Ă 10 12 M. a. conidia ha -1 + 65
g thiamethoxam) and M. anisopliae alone at the recommended dose of 3 Ă 10 12 M. a. conidia
ha -1 . Our findings demonstrate the effectiveness of using either thiamethoxam or imidacloprid
in combination with M. anisopliae to control M. fimbriolata nymphs on sugarcane, but greater
net earnings per hectare occurred with the lowest rate of the thiamethoxam combination than
with any of the imidacloprid combinations.Algunos insecticidas se puede utilizar con hongos entomopatĂłgenos y por lo tanto, la aso-
ciaciĂłn de los controles quĂmico y biolĂłgico puede ser una estrategia segura y eficaz para
el control de insectos-plaga. El objetivo de este estudio fue evaluar los costos y eficacia de combinaciones de Metarhizium anisopliae (Metschnikoff) Sorokin (Hypocreales: Clavi-
cipitaceae) con insecticidas thiamethoxam e imidacloprid para el control de la chicharrita
(Mahanarva fimbriolata (StĂ„l); Hemiptera: Cercopidae) en caña de azĂșcar . El experimento
fue conducido en un delineamiento en bloques casualizados (DBC), con 10 tratamientos y
4 repeticiones. Los tratamientos que incluidos el control (sin tratamiento), thiamethoxam
(250 g ha â1 ), imidacloprido (700 g ha â1 ), M. anisopliae (M.a.) (3Ă10 12 conidios ha â1 ), A1 (3Ă10 12
conidios ha â1 de M. a. + 65 g ha â1 de thiamethoxam), A2 (3Ă10 12 conidios ha â1 de M. a. + 125g
ha â1 de thiamethoxam), A3 (3Ă10 12 conidios ha â1 de M. a. + 187.5 g ha â1 de thiamethoxam), A4
(3Ă10 12 conidios ha â1 de M.a + 175 g ha â1 de imidacloprido), A5 (3Ă10 12 conidios ha â1 de M. a. +
350 g ha â1 de imidacloprido) y A6 (3Ă10 12 conidios ha â1 de M. a. + 525g ha â1 de imidacloprido).
Las reducciones en el nĂșmero de ninfas M. fimbriolata por tratamiento en comparaciĂłn con
el control fueron similares a los 15 DAT (dĂas pos tratamiento) en todos los tratamientos
excepto A5 combinaciĂłn (M. anisopliae y thiamethoxam). A los 30 DAT, el nĂșmero de ninfas
se redujeron significativamente en todos los tratamientos, excepto A3, y su eficacia variĂł de
14,28% para 92,85%. A los 45 DAT, los nĂșmeros de ninfas M. fimbriolata por tratamiento se
redujeron significativamente en los siguientes tratamientos: imidacloprido solo en 700 g ha -1 ,
A1, A2, A3, A4 y A6; y las combinaciones de A1 y A2 causaron la mĂĄs bajo infestaciones de
ninfas M. fimbriolata y sus tasas de eficacia fueron de 77,41 y 87,09%, respectivamente. A los
75 DAT, los 2 mejores eficacias de control se produjeron en tratamientos A1 (3Ă10 12 conidios
ha â1 de M. a. + 65 g ha â1 de thiamethoxam) y A5 (78.6%) (3Ă10 12 conidios ha â1 de M. a.+ 350
g ha â1 de imidacloprido). A los 90 DAT, el nĂșmero de ninfas en el control habĂa aumentado
2,8 veces mĂĄs el nĂșmero a 75 DAT. Muy buenas eficacias de control en 90 DAT, se produjo
en todos los tratamientos con la combinaciĂłn del hongo con un insecticida. A los 105 DAT, el
nĂșmero de ninfas habĂan aumentado en todos los tratamientos, y ningĂșn tratamiento habĂa
proporcionado un control efectivo. Los tratamientos con los mayores rendimientos hectĂĄrea
fueron A1 (3Ă10 12 conidios ha â1 de M. a.+ 65 g de thiamethoxam) y M. anisopliae solo a la dosis
recomendada de 3Ă10 12 conidios ha â1 de M. a. Nuestros resultados demuestran la eficacia de
thiamethoxam y imidacloprido en combinaciĂłn con M. anisopliae para el control de ninfas M.
fimbriolata en caña de azĂșcar, pero mayores beneficio neto por hectĂĄrea se produjeron con la
tasa mĂĄs baja de la combinaciĂłn de thiamethoxam que con cualquiera de las combinaciones
de imidacloprid
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century