Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 153
Filtrar
1.
Plants (Basel) ; 13(11)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38891312

RESUMO

Macrophytes and cladocerans represent the main antagonistic groups that regulate phytoplankton biomass; however, the mechanism behind this interaction is unclear. In laboratory conditions, we separately evaluated the effects of three submerged macrophytes (Ceratophyllum demersum, Myriophyllum aquaticum, and Stuckenia pectinata), as well as their exudates, and plant-associated microbiota (POM < 25 µm) + exudates on the population growth of Daphnia cf. pulex and Simocephalus cf. mixtus. Living Ceratophyllum, exudates, and POM < 25 µm + exudates exhibited the most robust positive effects on Simocephalus density and the rate of population increase (r). Subsequently, we examined the effects of Ceratophyllum on the filtration and feeding rates of Simocephalus and Daphnia, revealing significant (p < 0.001) promotion of filtration and feeding in Simocephalus but not in Daphnia. To elucidate the specific effects of this macrophyte on Simocephalus demography, we assessed selected life table variables across the same treatments. The treatments involving exudates and living Ceratophyllum resulted in approximately 40% longer survivorship and significantly (p < 0.01) enhanced fecundity. Our findings indicate that exudates from submerged macrophytes positively influence Simocephalus demography by increasing filtration rates, survivorship, and fecundity. This synergy suggests a substantial impact on phytoplankton abundance.

2.
Insects ; 15(5)2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38786886

RESUMO

Green lacewings are valuable predators, utilized in augmentative biological control against various agricultural pests. However, further studies are required to comprehend the performance of these predators when consuming natural prey. We investigated the capacity of Chrysoperla externa (Hagen) to utilize the following three distinct prey types: the pupae of the coffee leaf miner Leucoptera coffeella (Guérin-Mèneville & Perrottet), the eggs of the sugarcane borer Diatraea saccharalis (F.), and the eggs of the Mediterranean flour moth Ephestia kuehniella (Zeller). The first two of these species are naturally occurring prey found in field crops, while the last serves as a factitious prey species for the mass rearing of natural enemies. We hypothesized that the type of prey would differentially affect the life history and population-level parameters of C. externa. Laboratory experiments were conducted to compare the pre-imaginal survival and developmental times, adult longevity and reproduction, and population growth of C. externa when larvae were provided with each of the three prey items. Results indicated that C. externa utilized the two natural prey items, L. coffeella pupae and D. saccharalis eggs, for its development, reproduction, and population growth. However, larvae developed significantly faster and females exhibited higher reproductive parameters, including fecundity and daily oviposition, when consuming the factitious prey, E. kuehniella eggs. This resulted in a higher intrinsic rate of population increase, as well as shorter times for the population to double in size. Understanding the population dynamics of C. externa when consuming different prey items is crucial for optimizing their utilization in augmentative biological control programs.

3.
Neotrop Entomol ; 53(3): 531-540, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38329712

RESUMO

Anthocoris minki Dohrn (Hemiptera: Anthocoridae) is used as a biological control agent of various agricultural pests. This study determined the effect of different egg laying materials, i.e., faba bean, common bean, and pea on population parameters of A. minki using age-stage, two-sex life table. The longest (34.45 d) and the shortest (21.32 d) adult longevity was noted on common bean and pea, respectively. Likewise, the highest (92%) and the lowest (69%) preadult survival rate was recorded on faba bean and pea, respectively. The highest fecundity (93.74 eggs/female) was noted on faba bean followed by common bean (43.95 eggs/female) and pea (48.69 eggs/female). Oviposition period remained unaffected, while higher oviposition days (22 d) were noted on faba bean compared with common bean (10 d) and pea (14 d). The shortest and the longest adult pre-oviposition period and total pre-ovipositional period were calculated for common bean and pea, respectively. The highest intrinsic rate of increase (r) (0.1159 d-1) and finite rate of increase (λ) (1.1229 d-1) were noted on common bean, while the lowest (r = 0.0939 d-1; λ = 1.0985 d-1) were noted on pea. Paired bootstrap analyses indicated that the highest net reproductive rate (R0) (43.12 offspring) was recorded on faba bean. Egg hatching rate significantly differed among plants (P < 0.01) and it was 80.50%, 71.10%, and 38.90% on common bean, faba bean and pea, respectively. It is concluded that faba bean would be the most suitable host for mass rearing of A. minki, while pea proved unsuitable.


Assuntos
Oviposição , Phaseolus , Pisum sativum , Vicia faba , Animais , Feminino , Masculino , Fertilidade , Longevidade , Heterópteros/fisiologia , Controle Biológico de Vetores , Hemípteros/fisiologia
4.
Insects ; 15(2)2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38392505

RESUMO

The palm leafhopper, Haplaxius crudus, is a possible vector of the pathogen that causes the Lethal Wilt of oil palms in Colombia. This disease represents the biggest phytosanitary problem in the eastern palm zone. From 2010 to 2021, more than 7700 ha have been eradicated, with economic losses exceeding 154 million USD. Therefore, knowing the biology of this insect and its population parameters is necessary for developing population control tools. To evaluate these parameters, a cohort of 100 eggs obtained from H. crudus adults from the breeding unit established in the Campo Experimental Palmar de las Corocoras de Cenipalma in Paratebueno, Cundinamarca, was monitored to record the life cycle and the population parameters using a life table under semi-controlled conditions in an oil palm plantation. The life cycle from egg to adult was 62.7 ± 15.5 days (26.1 ± 2.9 °C; HR: 89.8 ± 14.0%). The egg stage lasted 14.6 ± 0.6 days, the nymphal stage 48.1 ± 2.8 days through five instars, and the adult longevity was 14.8 ± 8.4 days. The specific mortality rate (qx) calculated in the life table was 0.14 (for the egg stage), 0.05 (for I instar), 0.05 (for II instar), 0.03 (for III instar), 0.04 (for IV instar), and 0.07 (for V instar). The population parameters' values were as follows: net reproductive rate Ro = 10.96; generation time T = 62.3 days, intrinsic natural growth rate rm = 0.03, and finite growth rate λ = 1.03. These results help us to understand the population dynamics of this insect in the field and for the development of population control studies.

5.
Neotrop Entomol ; 53(2): 424-438, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38356097

RESUMO

Arbuscular mycorrhizal fungi (AMF) are one of the environment-friendly organisms that enhance plant performance. AMF affect the herbivorous insect community by indirectly modifying host plant nutrient uptake, growth, and defense, also known as priming. In the current study, under greenhouse conditions, the effects of inoculating tomato seedlings with four species of AMF, i.e., Funneliformis mosseae, Rhizophagus intraradices, Rhizophagus irregularis, and Glomus iranicus, were studied in relation to tomato plant growth parameters, plant defense enzymes, and total phenol content, and additionally, the life table of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) feeding on these plants was determined. The results demonstrated that the growth parameters of tomato plants, including plant height, stem diameter, number of leaves, root volume, leaf surface area, weight of the root, and aerial organs (containing the leaves and stem), were greater and larger in the AMF-inoculated plants compared to the non-inoculated plants. Furthermore, there were higher defense enzyme activities, including peroxidase, phenylalanine ammonia lyase and polyphenol oxidase, and also higher total phenol contents in the AMF-inoculated plants. The whitefly life table characteristics were decreased in the group feeding on the AMF-inoculated plants. All together, the AMF colonization made the tomato plants more resistant against B. tabaci by improving plant growth and increasing defense enzymes. The degree of priming observed here suggests the potential of AMF to have expansive applications, including their implementation in sustainable agriculture.


Assuntos
Glomeromycota , Hemípteros , Micorrizas , Solanum lycopersicum , Animais , Fenóis
6.
Med Vet Entomol ; 38(1): 73-82, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37877753

RESUMO

The hematophagous insect Mepraia spinolai (Hemiptera: Reduviidae: Triatominae) is naturally infected with the protozoan parasite Trypanosoma cruzi, the agent of Chagas disease in humans. In this study, we compared the demographic parameters of M. spinolai with and without T. cruzi infection. We collected the immature life table data of 479 M. spinolai individuals of control cohort (reared on mice without T. cruzi infection) and 563 M. spinolai individuals of treatment cohort (reared on mice with T. cruzi infection). Nymphs were maintained in individual compartments inside a growth chamber (26°C; 65-75%) until adult emergence; moulting and survival were recorded daily. For the adult life table study of the control, we used 24 pairs of adults from the control cohort. For the adult life table study of T. cruzi-infected cohort, 25 infected females were paired with 25 males from the control cohort. Life table data were analysed using bootstrap-match technique based on the age-stage, two-sex life table. The preadult survival rate (0.5282) of the control cohort was significantly higher than that of the infected cohort (0.2913). However, the mean fecundity of reproductive females (Fr = 22.29 eggs/♀) and net reproductive rate of population (R0 = 5.07 offspring/individual) of the 0.5th percentile bootstrap-match control cohort were not significantly different from those of the infected cohort (Fr = 23.35 eggs/♀, R0 = 3.77 offspring/individual). Due to the shorter total preoviposition period and higher proportion of reproductive female, the intrinsic rate of increase (r = 0.0053 d-1 ) and finite rate of increase (λ = 1.0053 d-1 ) of control cohort of M. spinolai were significantly higher than those of the T. cruzi-infected cohort (r = 0.0035 d-1 , λ = 1.0035 d-1 ). These results suggest that T. cruzi infection reduces the population fitness of the Chagas disease vector M. spinolai.


Assuntos
Doença de Chagas , Doenças dos Roedores , Triatominae , Trypanosoma cruzi , Humanos , Masculino , Feminino , Animais , Camundongos , Aptidão Genética , Insetos Vetores/parasitologia , Doença de Chagas/veterinária , Triatominae/parasitologia
7.
Exp Appl Acarol ; 92(1): 27-39, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37985607

RESUMO

Multiple arthropod pests can affect the same crop in agricultural systems, requiring the integration of control methods. In the present study, the effects of residual exposure to four broad-spectrum insecticides/acaricides (azadiractin, abamectin, chlorfenapyr, and fenpyroximate) on immature (development and survival time) and adult females (longevity, fecundity, and fertility life table parameters) of the predatory mite Neoseiulus barkeri were evaluated. Additionally, the insecticides/acaricides were categorized according to their selectivity based on the classification proposed by the International Organization for Biological Control (IOBC) for assessing the susceptibility of arthropods in laboratory experiments. Method 004, proposed by the Insecticide Resistance Action Committee (IRAC), was adopted for the bioassays with predators exposed to insecticide-acaricide residues. Among the insecticides/acaricides studied, azadirachtin had minimal effects on immature and adult N. barkeri (all non-significant) and was considered harmless based on the classification of toxicity according to the standards/categories proposed by the IOBC. All other insecticides/acaricides affected immature and adult N. barkeri and were considered slightly harmful in terms of toxicity, according to the IOBC.


Assuntos
Acaricidas , Inseticidas , Ácaros , Praguicidas , Feminino , Animais , Acaricidas/toxicidade , Praguicidas/farmacologia , Inseticidas/farmacologia , Fertilidade , Comportamento Predatório
8.
Braz. j. biol ; 84: e254479, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1355910

RESUMO

Abstract Earias vittellaFabricius, 1794 (Noctuidae: Lepidoptera) is deliberated to be one of the most destructive pests of cotton and okra vegetation in the world including Asia. The pest has established resistance to various synthetic insecticides. The use of bio-pesticide is one of the unconventional approaches to develop a vigorous ecosystem without harming non- target pests and beneficial natural insect fauna. In the present study, the toxicity levels of Citrullus colocynthis seed extract have been evaluated against the populations of E. vittellaunder standardized laboratory conditions. The toxic effects of C. colocynthis on development periods, protein contents and esterase activity of the life stages of E. vittella were also evaluated. The toxicity levels of methanol, ethanol, hexane, water and profenofos were evaluated on the 1st instar larvae of E. vittella. LC30 and LC80 concentrations exhibited the effectiveness of methanol-based C. colocynthis seed extract against 1st instar larvae of E. vitella. The enhanced larval and pupal periods were revealed in treated samples during the comparison with untreated samples. The intrinsic rate of increase, net reproductive rate in the LC30 and LC80 concentrations exposed larvae remained less than the control treatment. Fecundity, the esterase activity and protein contents were declined in LC30 and LC80 treated samples as compared to the control. The present findings suggest that C. colosynthis extracts based botanical insecticides are beneficial, ecosystem sustainable and can be integrated with insect management programs from environment safety perspective.


Resumo Earias vittella Fabricius, 1794 (Noctuidae: Lepidoptera) é considerada uma das pragas mais destrutivas de algodão e quiabo no mundo, incluindo a Ásia. Essa praga estabeleceu resistência a vários inseticidas sintéticos. O uso de biopesticidas é uma das abordagens não convencionais para desenvolver um ecossistema saudável sem prejudicar as pragas não alvo e a fauna natural benéfica de insetos. No presente estudo, os níveis de toxicidade do extrato de semente de Citrullus colocynthis foram avaliados nas populações de E. vittella em condições de laboratório padronizadas. Os efeitos tóxicos de C. colocynthis nos períodos de desenvolvimento, conteúdo de proteína e atividade esterase das fases de vida de E. vittella também foram avaliados. Os níveis de toxicidade de metanol, etanol, hexano, água e profenofós foram avaliados em larvas de 1º instar de E. vittella. As concentrações de LC30 e LC80 apresentaram eficácia do extrato de sementes de C. colocynthis à base de metanol contra larvas de 1º instar de E. vittella. Os períodos larval e pupal aumentados foram revelados nas amostras tratadas durante a comparação com as amostras não tratadas. A taxa intrínseca de aumento e a taxa reprodutiva líquida nas concentrações de larvas expostas LC30 e LC80 permaneceram menores do que o tratamento controle. A fecundidade, a atividade da esterase e o conteúdo de proteína diminuíram nas amostras tratadas com LC30 e LC80 em comparação com o controle. As presentes descobertas sugerem que os extratos de C. colocynthis à base de inseticidas botânicos são benéficos, sustentáveis ​​para o ecossistema e podem ser integrados com programas de manejo de insetos do ponto de vista da segurança ambiental.


Assuntos
Animais , Citrullus colocynthis , Inseticidas , Mariposas , Extratos Vegetais/farmacologia , Ecossistema , Larva
9.
Braz. j. biol ; 842024.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1469311

RESUMO

Abstract Earias vittellaFabricius, 1794 (Noctuidae: Lepidoptera) is deliberated to be one of the most destructive pests of cotton and okra vegetation in the world including Asia. The pest has established resistance to various synthetic insecticides. The use of bio-pesticide is one of the unconventional approaches to develop a vigorous ecosystem without harming non- target pests and beneficial natural insect fauna. In the present study, the toxicity levels of Citrullus colocynthis seed extract have been evaluated against the populations of E. vittellaunder standardized laboratory conditions. The toxic effects of C. colocynthis on development periods, protein contents and esterase activity of the life stages of E. vittella were also evaluated. The toxicity levels of methanol, ethanol, hexane, water and profenofos were evaluated on the 1st instar larvae of E. vittella. LC30 and LC80 concentrations exhibited the effectiveness of methanol-based C. colocynthis seed extract against 1st instar larvae of E. vitella. The enhanced larval and pupal periods were revealed in treated samples during the comparison with untreated samples. The intrinsic rate of increase, net reproductive rate in the LC30 and LC80 concentrations exposed larvae remained less than the control treatment. Fecundity, the esterase activity and protein contents were declined in LC30 and LC80 treated samples as compared to the control. The present findings suggest that C. colosynthis extracts based botanical insecticides are beneficial, ecosystem sustainable and can be integrated with insect management programs from environment safety perspective.


Resumo Earias vittella Fabricius, 1794 (Noctuidae: Lepidoptera) é considerada uma das pragas mais destrutivas de algodão e quiabo no mundo, incluindo a Ásia. Essa praga estabeleceu resistência a vários inseticidas sintéticos. O uso de biopesticidas é uma das abordagens não convencionais para desenvolver um ecossistema saudável sem prejudicar as pragas não alvo e a fauna natural benéfica de insetos. No presente estudo, os níveis de toxicidade do extrato de semente de Citrullus colocynthis foram avaliados nas populações de E. vittella em condições de laboratório padronizadas. Os efeitos tóxicos de C. colocynthis nos períodos de desenvolvimento, conteúdo de proteína e atividade esterase das fases de vida de E. vittella também foram avaliados. Os níveis de toxicidade de metanol, etanol, hexano, água e profenofós foram avaliados em larvas de 1º instar de E. vittella. As concentrações de LC30 e LC80 apresentaram eficácia do extrato de sementes de C. colocynthis à base de metanol contra larvas de 1º instar de E. vittella. Os períodos larval e pupal aumentados foram revelados nas amostras tratadas durante a comparação com as amostras não tratadas. A taxa intrínseca de aumento e a taxa reprodutiva líquida nas concentrações de larvas expostas LC30 e LC80 permaneceram menores do que o tratamento controle. A fecundidade, a atividade da esterase e o conteúdo de proteína diminuíram nas amostras tratadas com LC30 e LC80 em comparação com o controle. As presentes descobertas sugerem que os extratos de C. colocynthis à base de inseticidas botânicos são benéficos, sustentáveis para o ecossistema e podem ser integrados com programas de manejo de insetos do ponto de vista da segurança ambiental.

10.
Neotrop Entomol ; 52(5): 921-931, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37584879

RESUMO

Tetrastichus howardi (Olliff) (Hymenoptera: Eulophidae) parasitizes the diamond back moth Plutella xylostella (L.) (Lepidoptera: Plutellidae), but not much is known about its potential as a biocontrol agent. A rearing protocol has been established for this parasitoid on pupae of the factitious host Tenebrio molitor (L.) (Coleoptera: Tenebrionidae), with the aim of releasing it in the field to manage several lepidopteran species. The potential population growth of a parasitoid can be measured through fertility life tables and provide supporting information for using T. howardi in the management of P. xylostella. Also, the fitness and behavior of T. howardi reared on a factitious host can be indicators of its potential to control P. xylostella. Thus, in this study, the fertility life table parameters of T. howardi parasitizing P. xylostella were determined, as well as the effects of the natal host on the behavior of T. howardi towards host volatiles and parasitism rate. The results showed that net reproduction rate (Ro) and the intrinsic rate of population growth (rm) of T. howardi parasitizing P. xylostella were 13.6 (♀/♀) and 0.124 (♀/♀*day), respectively, whereas the mean generation time was 20.9 days. Moreover, the natal host (T. molitor or P. xylostella) did not affect the fitness, parasitism rate, or olfactory response of T. howardi. In general, regardless of the natal host, parasitoid females responded to volatiles of both host species and exhibited the same rate of parasitism on P. xylostella. Therefore, T. howardi reared on the factitious host maintains its attraction and potential to parasitize P. xylostella, and can contribute to the biological control of this pest.


Assuntos
Besouros , Himenópteros , Mariposas , Tenebrio , Feminino , Animais , Himenópteros/fisiologia , Tábuas de Vida , Olfato , Fertilidade , Larva
11.
Environ Entomol ; 52(5): 832-846, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37487591

RESUMO

The sweetpotato whitefly, Bemisia tabaci (Gennadius) Middle East-Asia Minor 1 (MEAM1), is widespread across tropical and subtropical regions, affecting hundreds of cultivated and wild plant species. Because the species transmits a variety of viruses, the whitefly has become one of the most economically significant insect pests in the world. Determining a pest's population growth potential as a function of temperature is critical for understanding a species population dynamics, predicting the potential range of the species and its associated diseases, and designing adaptive pest management strategies. The life history of B. tabaci MEAM1 was studied in life-table experiments at 7 constant temperatures ranging from 12 to 35 °C. Nonlinear equations were fitted to development, mortality, and reproduction data and compiled into an overall phenology rate-summation model using Insect Life Cycle Modeling (ILCYM) software, to simulate life-table parameters based on temperature. Life tables of B. tabaci MEAM1 observed at naturally variable temperature in La Molina, Lima, during different seasons, covering the entire temperature range of the species' predicted performance curve, were used to validate the model. Simulations predicted population growth within temperature between 13.9 and 33.4 °C, revealing a maximum finite rate of population increase (λ = 1.163), with a generation time of 33.3 days at 26.4 °C. Predicted species performance agreed well when compared against observed life tables and published data. The process-based physiological model presented here for B. tabaci MEAM1 should prove useful to predict the potential spatial distribution of the species based on temperature and to adjust pest control measures taking different population growth potentials due to prevailing temperature regimes into account.

12.
Insects ; 14(5)2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37233076

RESUMO

The brown stink bug, Euschistus heros (Fabricius, 1798) (Hemiptera: Pentatomidae), is one of the most abundant soybean stink bug pests in Brazil. Temperature is a key factor that affects its development and reproduction, and fluctuating temperatures may impact the development and reproduction of E. heros differently from those under constant temperatures. The objective of this study was to evaluate the influence of constant and fluctuating temperature on the biological characteristics of E. heros in three successive generations. Treatments consisted of six constant temperatures (19 °C, 22 °C, 25 °C, 28 °C, 31 °C and 34 °C) and four fluctuating temperatures (25:21 °C, 28:24 °C, 31:27 °C, and 34:30 °C) evaluated for three successive generations. Second-stage nymphs were evaluated daily, and after they reached the adult stage, they were separated by sex, and the individual weight (mg) and pronotum size (mm) were recorded. After pair formation, eggs were collected to evaluate the pre-oviposition period, total number of eggs, and egg viability. The duration of the nymphal stage was reduced with an increase in both constant and fluctuating temperatures; however, at constant temperatures of 19 °C, 31 °C and 34 °C and fluctuating temperatures of 28:24 °C, there was no reproduction in adults. The base temperature and total degree day requirement for nymphal development were 15.5 °C and 197.4 dd, respectively. Pre-oviposition period (d), number of eggs per female, and viability of eggs (%) were affected by temperature across the generations. The multiple decrement life table analysis revealed that mortality was highest during the molting of the second-stage nymphs. These findings have important implications for E. heros' laboratory mass-rearing programs and for its management in fields.

13.
PeerJ ; 10: e13340, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35497182

RESUMO

Background: Understanding how biotic and abiotic factors affect insect mortality is crucial for both fundamental knowledge of population ecology and for successful pest management. However, because these factors are difficult to quantify and interpret, patterns and dynamics of insect mortality remain unclear, especially comparative mortality across climate zones. Life table analysis provides robust information for quantifying population mortality and population parameters. Methods: In this study, we estimated cause-of-death probabilities and irreplaceable mortality (the portion of mortality that cannot be replaced by another cause or combination of causes) using a Multiple Decrement Life Table (MDLT) analysis of 268 insect life tables from 107 peer-reviewed journal articles. In particular, we analyzed insect mortality between temperate and tropical climate zones. Results: Surprisingly, our results suggest that non-natural enemy factors (abiotic) were the major source of insect mortality in both temperate and tropical zones. In addition, we observed that irreplaceable mortality from predators in tropical zones was 3.7-fold greater than in temperate zones. In contrast, irreplaceable mortality from parasitoids and pathogens was low and not different between temperate and tropical zones. Surprisingly, we did not observe differences in natural enemy and non-natural enemy factors based on whether the insect species was native or non-native. We suggest that characterizing predation should be a high priority in tropical conditions. Furthermore, because mortality from parasitoids was low in both tropical and temperate zones, this mortality needs to be better understood, especially as it relates to biological control and integrated pest management.


Assuntos
Ecologia , Insetos , Animais , Controle Biológico de Vetores , Clima Tropical
14.
Exp Appl Acarol ; 86(3): 327-342, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35286552

RESUMO

The intrinsic rate of natural increase of a population (rm) has been in focus as a key parameter in entomology and acarology. It is considered especially important in studies of predators that are potential biological control agents of fast-growing pests such as mites, whiteflies and thrips. Life-table experiments under controlled laboratory conditions are standard procedures to estimate rm. However, such experiments are often time consuming and may critically depend on the precise assessment of the developmental time and the fecundity rate early in the reproductive phase. Using selected studies of predatory mites with suitable life-table data, we investigated whether and how measurements of growth rates can be simplified. We propose a new method for estimating rm from partial life tables, in which the researcher can choose a level of precision based on a stand-in measure of relative error. Based on this choice, the procedure helps the researcher to decide when a life-table experiment can be terminated. Depending on the chosen precision, significant amounts of experimental time can be saved without seriously compromising the reliability of the estimated growth parameter.


Assuntos
Artrópodes , Ácaros , Animais , Tábuas de Vida , Controle Biológico de Vetores/métodos , Comportamento Predatório , Reprodutibilidade dos Testes
15.
Rev. bras. estud. popul ; 39: e0182, 2022. tab
Artigo em Português | LILACS | ID: biblio-1357049

RESUMO

A presente nota de pesquisa estima o impacto das mortes por Covid-19 sobre a esperança de vida no Brasil e regiões para os primeiros seis meses de 2020. Com base nos dados do Datasus e nas tábuas de vida com decremento simples, estimou-se que as mortes por Covid-19 ocorridas até 18 de agosto de 2020 tiveram impacto estatisticamente negativo na esperança de vida ao nascer, tanto masculina (-1,05 ano) quanto feminina (-0,85 ano). Em termos regionais, a maior perda em anos de vida é estimada no Norte (-1,65 ano para homens e -1,48 ano para mulheres), enquanto o Sul foi a região com menor impacto (-0,5 ano para homens e -0,36 para mulheres). Os resultados do modelo logístico para o país apontam que a mortalidade por Covid-19 tende a ser maior entre a população com mais de 65 anos, homens, pretos e de baixa instrução. As comorbidades aumentam a chance de desfecho morte, especialmente doença hepática e renal crônica. Tais análises foram ainda desagregadas por grandes regiões brasileiras.


This research note estimates the impact of deaths by Covid-19 on life expectancy in Brazil and the Regions for the first six months of 2020. Based on data from Datasus and the decreasing life tables, it was estimated that deaths by Covid-19 that occurred until August 18, 2020 had a statistically negative impact on life expectancy at birth, both male (-1.05 years) and female (-0.85 years). In regional terms, the greatest loss in years of life is estimated in the North (-1.65 years for men and -1.48 years for women), while in the South it was -0.5 year for men and -0.36 for women. The results of the logistic model for the country show that Covid-19 mortality tends to be higher among males, blacks, people with low education level and people over 65 years old. Comorbidities increase the chance of death, especially liver disease and chronic kidney disease. Such analyzes were further disaggregated by large Brazilian regions.


Esta nota de investigación estima el impacto de las muertes por Covid-19 en la esperanza de vida en Brasil y sus regiones durante los primeros seis meses de 2020. Con base en los datos de Datasus y de las tablas de vida decrecientes, se estimó que las muertes por Covid-19 que ocurrieron hasta el 18 de agosto de 2020 tuvieron un impacto estadísticamente negativo en la esperanza de vida al nacer, tanto en hombres (−1,05 años) como en mujeres (−0,85 año). En términos regionales, la mayor pérdida en años de vida se estima en el Norte (−1,65 año para los hombres y −1,48 años para las mujeres), mientras que en el Sur fue de −0,5 años para los hombres y −0,36 para las mujeres. Los resultados del modelo logístico para el país muestran que la mortalidad por Covid-19 tiende a ser mayor entre la población mayor de 65 años, hombres, afrobrasileros y de bajo nivel educativo. Las comorbilidades aumentan la probabilidad de muerte, especialmente la enfermedad hepática y la enfermedad renal crónica. Dichos análisis se desglosaron aun más por grandes regiones brasileñas.


Assuntos
Humanos , Fatores Socioeconômicos , Brasil , Mortalidade , Tábuas de Vida , COVID-19/mortalidade , Expectativa de Vida , Pandemias
16.
Rev. bras. entomol ; Rev. bras. entomol;66(2): e20210086, 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1387820

RESUMO

ABSTRACT Parasitoids of the genus Trichogramma are promising for the biological control of insect pests in several crops, including cassava, which is severely attacked by Erinnyis ello L., 1758 (Lepidoptera: Sphingidae). Evaluating the biological aspects of these parasitoids to understand their dynamics is an important step towards the implementation of this control strategy in the field. Thus, our objective was to evaluate the biology of Trichogramma manicobai Brun, Moraes & Soares, 1984, and T. marandobai Brun, Moraes & Soares, 1986 in E. ello eggs. The parasitoids were obtained by collecting E. ello eggs from a commercial production of cassava, and the host's eggs were obtained from laboratory and greenhouse rearings. The average duration of a generation (T), net reproduction rate (R0), intrinsic rate of increase (rm), and the finite rate of increase (λ) were estimated, and from these, the fertility life table was calculated. The results indicated that T. marandobai has both higher net reproduction rate and a higher intrinsic rate of increase as well as requires less time to double its population than T. manicobai. Thus, T. marandobai has potential for natural and conservative biological control of E. ello. In addition, its potential in applied biological control should be evaluated through studies on the viability of its mass rearing in alternative hosts and its dispersion behavior in the field.

17.
Ecotoxicology ; 30(10): 2071-2082, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34549369

RESUMO

Bioinsecticides based on Bacillus thuringiensis (Bt) Berliner, 1915 are widely used to control lepidopteran in several crops. However, surviving insects exposed to the sub-lethal concentration of Bt-based bioinsecticides can suffer a multitude of effects on the biological conditioning known as hormesis. Here, we aimed to provide a clearer understanding of the biological conditioning of Anticarsia gemmatalis (Hübner, 1818), exposed to different concentrations of a Bt-based bioinsecticide, by assessing life table parameters over three generations. We defined five sub-lethal concentrations (LC5, LC10, LC15, LC20, and LC25) from the response curve estimate of A. gemmatalis. Deionized water was used as a control. We assessed the parameters of eggs-viability and the duration of the stages, incubation, larval, pre-pupal, pupal, adult, pre-oviposition and total biological cycle. Data were used to construct the fertility life table using the two-sex program. The survival curves showed greater variation in the proportion of individuals at each development stage using the LC25. The sub-lethal concentrations did not influence the incubation-eggs period, pre-pupal and pupal. However, the larval and adult stages using LC25 and LC10 were the most affected. Changes in sex ratio were observed using LC20 and LC5. The toxic effect of Bt-based bioinsecticide interfered mainly in the parameters of fertility, sex ratio, net reproduction rate (R0), and gross reproduction rate (GRR).


Assuntos
Bacillus thuringiensis , Mariposas , Animais , Toxinas de Bacillus thuringiensis , Feminino , Humanos , Larva , Pupa
18.
Neotrop Entomol ; 50(6): 923-928, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34586610

RESUMO

Thrips hawaiiensis (Morgan) is a flower-inhabiting thrips with a wide range of host plants, but little is known regarding its biological and ecological characteristics on vegetable hosts. Here, we evaluated the development, survival, and oviposition of T. hawaiiensis on five vegetable species (Capsicum annuum, Solanum melongena, Cucurbita moschata, Lablab purpureus, and Brassica oleracea), and constructed its life tables on these vegetables. There were significant differences in the development of T. hawaiiensis on the five vegetables, and the developmental times from egg to adult were 12.19 days, 11.59 days, 11.12 days, 10.78 days, and 10.51 days on C. moschata, B. oleracea, L. purpureus, C. annuum, and S. melongena, respectively. There were also significant differences in T. hawaiiensis' survival rate on these plants, with S. melongena (71.00%) > C. annuum (67.33%) > L. purpureus (63.33%) > B. oleracea (57.00%) > C. moschata (49.33%). The greatest and lowest fecundity levels of T. hawaiiensis were found on S. melongena (44.28) and C. moschata (30.16), respectively. T. hawaiiensis had the greatest net reproductive rate on S. melongena (19.22), followed by C. annuum (16.11), L. purpureus (15.17), B. oleracea (11.10), and C. moschata (8.47), and the intrinsic rate of increase showed a similar trend, with values of 0.140, 0.125, 0.121, 0.112, and 0.093, respectively. Thus, S. melongena and C. moschata were the most and least suitable hosts for the population development of T. hawaiiensis among the five tested vegetable hosts. This study could provide important information for the key control of T. hawaiiensis on different crops.


Assuntos
Tisanópteros , Animais , Produtos Agrícolas , Tábuas de Vida , Oviposição , Verduras
19.
Exp Appl Acarol ; 84(4): 733-753, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34244884

RESUMO

Tetranychus urticae Koch (Acari: Tetranychidae) is a major pest species in numerous crops including hop (Humulus lupulus L.). Substantial T. urticae infestation was observed to occur in this recently introduced crop in Brazil. The adoption of less suitable cultivars to the pest species is highly desirable for integrated pest management. We used free-choice trials and two-sex life table analysis to determine the preference and population growth of T. urticae under laboratory conditions using three of hop cultivars currently expanding in Brazil (Mantiqueira, Victoria, and Yakima Gold). We also estimated the density of non-glandular trichomes and lupulin glands found on the abaxial leaf surface of these cultivars and correlated them with performance parameters of T. urticae. Mantiqueira appeared to be the least preferred by adult females for attractiveness and oviposition suggesting existence of antixenosis on this cultivar. Female immature stages developed slower on Yakima Gold and Mantiqueira, but no difference was observed between the latter and Victoria. Fecundity and longevity were significantly lower on Mantiqueira than on Victoria and Yakima Gold. No significant differences were observed among cultivars for intrinsic rate of increase (r), finite rate of increase (λ), and net rate of reproduction (R0), suggesting the absence of antibiosis. Although, lupilin gland densities were higher on Mantiqueira and Yakima Gold than on Victoria, no significant correlations were observed between these defensive traits and performance parameters of T. urticae. However, 30-day population simulations of T. urticae suggest that Yakima Gold is the least susceptible, Mantiqueira is moderately susceptible, and Victoria is highly susceptible.


Assuntos
Humulus , Tetranychidae , Animais , Feminino , Tábuas de Vida , Oviposição , Reprodução
20.
Hum Reprod ; 36(8): 2157-2169, 2021 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-34179973

RESUMO

STUDY QUESTION: What is the cumulative delivery rate (CDR) per aspiration IVF/ICSI cycle in low-prognosis patients as defined by the Patient-Oriented Strategies Encompassing IndividualizeD Oocyte Number (POSEIDON) criteria? SUMMARY ANSWER: The CDR of POSEIDON patients was on average ∼50% lower than in normal responders and varied across POSEIDON groups; differences were primarily determined by female age, number of embryos obtained, number of embryo transfer (ET) cycles per patient, number of oocytes retrieved, duration of infertility, and BMI. WHAT IS KNOWN ALREADY: The POSEIDON criteria aim to underline differences related to a poor or suboptimal treatment outcome in terms of oocyte quality and quantity among patients undergoing IVF/ICSI, and thus, create more homogenous groups for the clinical management of infertility and research. POSEIDON patients are presumed to be at a higher risk of failing to achieve a live birth after IVF/ICSI treatment than normal responders with an adequate ovarian reserve. The CDR per initiated/aspiration cycle after the transfer of all fresh and frozen-thawed/warmed embryos has been suggested to be the critical endpoint that sets these groups apart. However, no multicenter study has yet substantiated the validity of the POSEIDON classification in identifying relevant subpopulations of patients with low-prognosis in IVF/ICSI treatment using real-world data. STUDY DESIGN, SIZE, DURATION: Multicenter population-based retrospective cohort study involving 9073 patients treated in three fertility clinics in Brazil, Turkey and Vietnam between 2015 and 2017. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants were women with infertility between 22 and 42 years old in their first IVF/ICSI cycle of standard ovarian stimulation whose fresh and/or frozen embryos were transferred until delivery of a live born or until all embryos were used. Patients were retrospectively classified according to the POSEIDON criteria into four groups based on female age, antral follicle count (AFC), and the number of oocytes retrieved or into a control group of normal responders (non-POSEIDON). POSEIDON patients encompassed younger (<35 years) and older (35 years or above) women with an AFC ≥5 and an unexpected poor (<4 retrieved oocytes) or suboptimal (4-9 retrieved oocytes) response to stimulation, and respective younger and older counterparts with an impaired ovarian reserve (i.e. expected poor responders; AFC <5). Non-POSEIDON patients were those with AFC ≥5 and >9 oocytes retrieved. CDR was computed per one aspirated cycle. Logistic regression analysis was carried out to examine the association between patient classification and CDR. MAIN RESULTS AND ROLE OF CHANCE: The CDR was lower in the POSEIDON patients than in the non-POSEIDON patients (33.7% vs 50.6%; P < 0.001) and differed across POSEIDON groups (younger unexpected poor responder [Group 1a; n = 212]: 27.8%, younger unexpected suboptimal responder [Group 1b; n = 1785]: 47.8%, older unexpected poor responder [Group 2a; n = 293]: 14.0%, older unexpected suboptimal responder [Group 2b; n = 1275]: 30.5%, younger expected poor responder [Group 3; n = 245]: 29.4%, and older expected poor responder [Group 4; n = 623]: 12.5%. Among unexpected suboptimal/poor responders (POSEIDON Groups 1 and 2), the CDR was twice as high in suboptimal responders (4-9 oocytes retrieved) as in poor responders (<4 oocytes) (P = 0.0004). Logistic regression analysis revealed that the POSEIDON grouping, number of embryos obtained, number of ET cycles per patient, number of oocytes collected, female age, duration of infertility and BMI were relevant predictors for CDR (P < 0.001). LIMITATIONS, REASONS FOR CAUTION: Our study relied on the antral follicle count as the biomarker used for patient classification. Ovarian stimulation protocols varied across study centers, potentially affecting patient classification. WIDER IMPLICATIONS OF THE FINDINGS: POSEIDON patients exhibit lower CDR per aspirated IVF/ICSI cycle than normal responders; the differences are mainly determined by female age and number of oocytes retrieved, thereby reflecting the importance of oocyte quality and quantity. Our data substantiate the validity of the POSEIDON criteria in identifying relevant subpopulations of patients with low-prognosis in IVF/ICSI treatment. Efforts in terms of early diagnosis, prevention, and identification of specific interventions that might benefit POSEIDON patients are warranted. STUDY FUNDING/COMPETING INTEREST(S): Unrestricted investigator-sponsored study grant (MS200059_0013) from Merck KGaA, Darmstadt, Germany. The funder had no role in study design, data collection, analysis, decision to publish or manuscript preparation. S.C.E. declares receipt of unrestricted research grants from Merck and lecture fees from Merck and Med.E.A. H.Y. declares receipt of payment for lectures from Merck and Ferring. L.N.V. receives speaker fees and conferences from Merck, Merck Sharp and Dohme (MSD) and Ferring and research grants from MSD and Ferring. J.F.C. declares receipt of statistical services fees from ANDROFERT Clinic. T.M.H. received speaker fees and conferences from Merck, MSD and Ferring. P.H. declares receipt of unrestricted research grants from Merck, Ferring, Gedeon Richter and IBSA and lecture fees from Merck, Gedeon Richter and Med.E.A. C.A. declares receipt of unrestricted research grants from Merck and lecture fees from Merck. The remaining authors have no conflicts of interest to disclose. TRIAL REGISTRATION NUMBER: N/A.


Assuntos
Indução da Ovulação , Injeções de Esperma Intracitoplásmicas , Adulto , Coeficiente de Natalidade , Transferência Embrionária , Feminino , Fertilização in vitro , Humanos , Oócitos , Gravidez , Taxa de Gravidez , Estudos Retrospectivos , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA