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1.
J Insect Sci ; 20(1)2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31925424

RESUMO

Urbanization has a significant impact on abiotic and biotic factors in nature. We examined the morphometric characters of four carabid species (Abax parallelepipedus, Carabus scheidleri, Carabus violaceus, and Pterostichus oblongopunctatus) along urbanization gradients in and around the cities of Vienna (Austria) and Debrecen (Hungary). We found significant differences among urban, suburban, and rural areas in the parameters of antennomers, the maxillary palpus, the labial palpus, and the length of the tibia and the elytra of the carabids studied. We also found significant differences between males and females based on the parameters of antennomers, the maxillary palpus, the labial palpus, the femur, and the elytra. An interaction between urbanization and sex was found in the case of antennomers, the maxillary palpus, the labial palpus, the femur, and the elytra. Our findings suggested that in the cases of species from Carabini tribus the parameters of antennomers, the maxillary palpus, and the elytra could be useful for assessing the effects of urbanization because these morphometric characters responded sensitively to the environmental stress, whereas the most useful parameters are those of antennomers and the tibia for the species of Pterostichini tribus. Our findings also revealed that females are more sensitive to environmental stress than males.


Assuntos
Besouros/anatomia & histologia , Urbanização , Animais , Áustria , Cidades , Feminino , Hungria , Masculino , Especificidade da Espécie
2.
Ecol Lett ; 23(3): 467-475, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31912600

RESUMO

Although interspecific competition has long been recognised as a major driver of trait divergence and adaptive evolution, relatively little effort has focused on how it influences the evolution of intraspecific cooperation. Here we identify the mechanism by which the perceived pressure of interspecific competition influences the transition from intraspecific conflict to cooperation in a facultative cooperatively breeding species, the Asian burying beetle Nicrophorus nepalensis. We not only found that beetles are more cooperative at carcasses when blowfly maggots have begun to digest the tissue, but that this social cooperation appears to be triggered by a single chemical cue - dimethyl disulfide (DMDS) - emitted from carcasses consumed by blowflies, but not from control carcasses lacking blowflies. Our results provide experimental evidence that interspecific competition promotes the transition from intraspecific conflict to cooperation in N. nepalensis via a surprisingly simple social chemical cue that is a reliable indicator of resource competition between species.


Assuntos
Besouros , Animais , Cruzamento , Larva , Comportamento Social
3.
Insect Sci ; 27(2): 375-388, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30260074

RESUMO

Carabids (Coleoptera: Carabidae) seem to be suitable bioindicators of the environmental impacts of novel agrotechnologies, including deployment of the genetically engineered (GE) crops. In this article, we describe our effort to employ carabids in the environmental risk assessment (ERA). GE maize MON88017, its near-isogenic hybrid nontreated or treated with the soil insecticide chlorpyrifos, and two reference hybrids were used to compare three different ways how to utilize carabids in ERA. The analysis of abundance of all captured carabids or of the most abundant carabid species did not disclose any differences between the treatments. The analysis based on the categories of functional traits revealed distinct features of some treatments and proved suitable for ERA because it permitted field data transportability in spite of different species compositions. Our results indicate that GE maize has no detrimental environmental effect. On the other hand, we found significant trends toward lower abundance and lower species number (including analysis of all carabid species together) in plots treated with the insecticide, and some tendencies to higher abundance and higher species number in plots sown with the reference hybrid PR38N86. Using functional group indicators allows identification of unintended changes in ecological functions of agroecosystem and comparability across geographies. We recommend data evaluation at the level of the categories of functional traits in ERA of GE crops and other agricultural practices.


Assuntos
Biodiversidade , Besouros , Biomarcadores Ambientais , Animais , Clorpirifos , Inseticidas , Plantas Geneticamente Modificadas , Medição de Risco/métodos , Zea mays
4.
Bull Entomol Res ; 110(1): 106-114, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31190655

RESUMO

We investigated the effects of the antiparasitic drug ivermectin on the dung beetles Copris acutidens Motschulsky, Onthophagus bivertex Heyden, O. lenzii Harold and Phelotrupes auratus auratus Motschulsky in Japan. Ivermectin was detected in cattle dung from 1 to 3 or 7 days post-treatment, with a peak at 3 days post-treatment in two pour-on administrations (500 µg kg-1). In C. acutidens, adult survivals and numbers of brood balls were significantly reduced in dung collected at 3 and 7 days post-treatment, and adult emergence rates were significantly decreased in dung collected at 7 and 14 days post-treatment. Feeding activity of C. acutidens was inhibited in dung collected at 3 days post-treatment, but was not significantly different from that seen in control dung at 7 and 14 days post-treatment. In O. bivertex and O. lenzii, there were no effects of ivermectin on adult survival or feeding activities, but the numbers of brood balls of O. bivertex constructed in dung collected at 3 and 7 days post-treatment were significantly lower than observed with control dung. The adult emergence rates of O. bivertex and O. lenzii were significantly reduced in dung collected at 1 to 3 and 1 to 7 days post-treatment, respectively. In P. auratus, there were no effects of ivermectin on adult survival, oviposition, feeding activity, or larval survival (until the third instar) in dung at 3 days post-treatment. The environmental risks affecting the populations of dung beetles in Japan are discussed.


Assuntos
Antiparasitários/toxicidade , Besouros/efeitos dos fármacos , Ivermectina/toxicidade , Animais , Antiparasitários/análise , Fezes/química , Comportamento Alimentar/efeitos dos fármacos , Feminino , Ivermectina/análise , Masculino , Reprodução/efeitos dos fármacos , Testes de Toxicidade Subcrônica
5.
J Chem Ecol ; 46(1): 30-39, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31808075

RESUMO

Cerambycid beetles of the subfamily Lamiinae use male-produced aggregation-sex pheromones that are attractive to both sexes. Terpenoid pheromones have been identified from species in the tribes Acanthoderini and Acanthocinini native to North and South America, comprised of (E)-6,10-dimethyl-5,9-undecadien-2-one (geranylacetone), the structurally related 6-methylhept-5-en-2-one (sulcatone), and/or specific enantiomers or nonracemic ratios of enantiomers of the related compounds (E)-6,10-dimethyl-5,9-undecadien-2-ol (fuscumol), its acetate ester, (E)-6,10-dimethyl-5,9-undecadien-2-yl acetate (fuscumol acetate), and 6-methylhept-5-en-2-ol (sulcatol). Here, we present new information about the chemical ecology of six acanthoderine and acanthocinine species native to the eastern USA. The pheromone of Astyleiopus variegatus (Haldeman) previously was identified as a blend of (S)-fuscumol and (S)-fuscumol acetate, and we report here that geranylacetone is a synergistic component. Males of Aegomorphus modestus (Gyllenhal), Lepturges angulatus (LeConte), and Lepturges confluens (Haldeman) were found to produce similar blends composed of the enantiomers of fuscumol acetate and geranylacetone, whereas males of Astylidius parvus (LeConte) and Sternidius alpha (Say) produced both enantiomers of fuscumol together with (R)-fuscumol acetate and geranylacetone. Field experiments with synthesized chemicals revealed that species with similar pheromone composition nevertheless differed in their responses to individual components, and to various blends of components, and in how attraction was influenced by chemicals that were pheromone components of other species. Sulcatone and/or sulcatol antagonized attraction of some species to pheromones of the geranylacetone class, suggesting that there is an adaptive advantage in an ability to detect these heterospecific compounds, such as in avoiding cross attraction to other cerambycid species, as yet unknown, that use pheromones composed of both chemical classes.


Assuntos
Besouros/química , Feromônios/química , Animais , Besouros/metabolismo , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Feromônios/isolamento & purificação , Feromônios/farmacologia , Comportamento Sexual Animal/efeitos dos fármacos , Especificidade da Espécie , Estereoisomerismo , Terpenos/química , Terpenos/isolamento & purificação , Terpenos/farmacologia , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/isolamento & purificação , Compostos Orgânicos Voláteis/farmacologia
6.
J Forensic Sci ; 65(1): 283-287, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31436852

RESUMO

Species identification of necrophagous insects found on a dead body is an essential key in applying medicolegal entomology to the estimation of postmortem interval (PMI). Due to limited morphological identification of insect evidence, several studies have identified species using molecular information such as DNA markers. While considerable cytochrome c oxidase subunit I (COI) gene sequence data of necrophagous fly species have been collected and annotated, those of necrophagous beetle species have not. Since necrophagous beetles such as Dermestes species have a larval period longer than that of flies, beetles are useful in even the late decomposition phase in estimating minimum PMI. To obtain the full-length COI gene sequences of six Dermestes species collected from South Korea, we designed primers for polymerase chain reaction amplification and sequencing. The obtained full COI nucleotide sequences were used for performing phylogenic analysis and comparison with previously reported sequences. The results demonstrated that the COI gene sequences could be used to identify forensically important Dermestes species in South Korea.


Assuntos
Besouros/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Análise de Sequência de DNA , Animais , Primers do DNA , Larva , Filogenia , Reação em Cadeia da Polimerase , República da Coreia , Especificidade da Espécie
7.
J Chem Ecol ; 46(1): 63-75, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31832894

RESUMO

Plants experience seasonal fluctuations in abiotic and biotic factors such as herbivore attack rates. If and how root defense expression co-varies with seasonal fluctuations in abiotic factors and root herbivore attack rates is not well understood. Here, we evaluated seasonal changes in defensive root latex chemistry of Taraxacum officinale plants in the field and correlated the changes with seasonal fluctuations in abiotic factors and damage potential by Melolontha melolontha, a major natural enemy of T. officinale. We then explored the causality and consequences of these relationships under controlled conditions. The concentration of the defensive sesquiterpene lactone taraxinic acid ß-D glucopyranosyl ester (TA-G) varied substantially over the year and was most strongly correlated to mean monthly temperature. Both temperature and TA-G levels were correlated with annual fluctuations in potential M. melolontha damage. Under controlled conditions, plants grown under high temperature produced more TA-G and were less attractive for M. melolontha. However, temperature-dependent M. melolontha feeding preferences were not significantly altered in TA-G deficient transgenic lines. Our results suggest that fluctuations in temperature leads to variation in the production of a root defensive metabolites that co-varies with expected attack of a major root herbivore. Temperature-dependent herbivore preference, however, is likely to be modulated by other phenotypic alterations.


Assuntos
Besouros/fisiologia , Glucosídeos/metabolismo , Lactonas/metabolismo , Sesquiterpenos/metabolismo , Taraxacum/química , Animais , Biomassa , Besouros/crescimento & desenvolvimento , Glucosídeos/química , Glucosídeos/farmacologia , Herbivoria/efeitos dos fármacos , Lactonas/química , Lactonas/farmacologia , Larva/efeitos dos fármacos , Larva/fisiologia , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Raízes de Plantas/parasitologia , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/parasitologia , Estações do Ano , Sesquiterpenos/química , Sesquiterpenos/farmacologia , Taraxacum/metabolismo , Taraxacum/parasitologia , Temperatura Ambiente
8.
Bull Entomol Res ; 110(1): 115-122, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31138336

RESUMO

The Chinese white pine beetle Dendroctonus armandi (Coleoptera: Scolytinae) typically displays bivoltinism at altitudes below 1700 m in the Qinling Mountains, China. The periods of host colonization and larval overwintering are two important phases in the life cycle of bark beetles, as it is during these periods that they have to contend with host plant defences and periods of intense cold, respectively. Although during different seasons, the females and males of Chinese white pine beetles show varying tolerances to host plant terpenoids, the sex ratio and survival physiology condition of the two beetle generations are unknown. We investigated the sex ratio of individuals, and also examined the body mass, energy stores, and detoxication enzymes of males and females in each of the two generations in order to determine the overall population stability of each generation. We identified a female-biased sex ratio among adults in both generations. Furthermore, patterns of body mass, energy stores, and detoxication enzymes were found to differ between the two sexes and two seasons. Compared with the males, the females have a larger body mass and higher amounts of stored lipids, which are assumed to be adaptations designed to overcome host resistance and facilitate subsequent oviposition.


Assuntos
Besouros/fisiologia , Estações do Ano , Razão de Masculinidade , Animais , Sistema Enzimático do Citocromo P-450/metabolismo , Metabolismo Energético , Feminino , Masculino
9.
Insect Sci ; 27(2): 361-374, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30298557

RESUMO

Diet quality influences organismal fitness within and across generations. For herbivorous insects, the transgenerational effects of diet remain relatively underexplored. Using a 3 × 3 × 2 factorial experiment, we evaluated how N enrichment in parental diets of Neolema abbreviata (Larcordaire) (Coleoptera: Chrysomelidae), a biological control agent for Tradescantia fluminensis Vell. (Commelinaceae), may influence life history and performance of F1 and F2 offspring under reciprocal experiments. We found limited transgenerational effects of foliar nitrogen variability among life-history traits in both larvae and adults. Larval weight gain and mortality were responsive to parental diet contrary to feeding damage, pupal weight and duration taken to pupate. There were significant parental diet × test interactions in larval feeding damage, weight gain, pupal weight and time to pupation. Generally, offspring from parents under high N plants performed better even under low N test plants. Adult traits including oviposition selection, feeding weight and longevity did not respond to the effects of parental diet nor its interaction with test diet as was the case in the larval stage. However, the main effects of test diet were more important in determining adult performance in both generations suggesting limited sensitivity to parental diet in the adult stage. Our results show conflicting responses to parental diet between larvae and adults of the same generation among an insect species with both actively feeding larval and adult life stages. These transgenerational effects, or lack thereof, may have implications on the field performance of N. abbrevita under heterogeneous nutritional landscapes.


Assuntos
Besouros , Dieta , Herbivoria , Traços de História de Vida , Animais , Feminino , Larva/crescimento & desenvolvimento , Masculino , Nitrogênio , Oviposição
10.
Chemosphere ; 240: 124857, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726599

RESUMO

Colorado potato beetle, Leptinotarsa decemlineata Say (coleoptera: chrysomelidae), is the important pest of potato all over the world. This insect pest is resistant to more than 50 active compounds belonging to various chemical groups. Potential of RNA interference (RNAi) was explored to knock down transcript levels of imidacloprid resistant genes in Colorado potato beetle (CPB) under laboratory conditions. Three important genes belonging to cuticular protein (CP), cytochrome P450 monoxygenases (P450) and glutathione synthetase (GSS) families encoding imidacloprid resistance were targeted. Feeding bio-assays were conducted on various stages of imidacloprid resistant CPB lab population by applying HT115 expressing dsRNA on potato leaflets. Survival rate of insects exposed to CP-dsRNA decreased to 4.23%, 15.32% and 47.35% in 2nd, 3rd and 4th instar larvae respectively. Larval weight and pre-adult duration were also affected due to dsRNAs feeding. Synergism of RNAi with imidacloprid conducted on the 2nd instar larvae, exhibited 100% mortality of larvae when subjected to reduced doses of GSS and CP dsRNAs along with imidacloprid. Utilization of three different dsRNAs against imidacloprid resistant CPB population reveal that dsRNAs targeting CP, P450 and GSS enzymes could be useful tool in management of imidacloprid resistant CPB populations.


Assuntos
Besouros/genética , Resistência a Medicamentos/genética , Genes de Insetos , Inseticidas/farmacologia , Larva/metabolismo , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia , Animais , Besouros/efeitos dos fármacos , Besouros/crescimento & desenvolvimento , Sistema Enzimático do Citocromo P-450/genética , Regulação para Baixo , Resistência a Medicamentos/efeitos dos fármacos , Glutationa Sintase/genética , Larva/efeitos dos fármacos , Larva/genética , Interferência de RNA/efeitos dos fármacos , Solanum tuberosum/crescimento & desenvolvimento
11.
J Environ Manage ; 254: 109792, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31731030

RESUMO

Windfelled Norway spruce (Picea abies) trees play a crucial role in triggering large-scale outbreaks of the European spruce bark beetle Ips typographus. Outbreak management therefore strives to remove windfelled trees to reduce the risk of outbreaks, a measure referred to as sanitation logging (SL). Although this practice has been traditionally applied, its efficiency in preventing outbreaks remains poorly understood. We used the landscape simulation model iLand to investigate the effects of different spatial configurations and intensities of SL of windfelled trees on the subsequent disturbance by bark beetles. We studied differences between SL applied evenly across the landscape, focused on the vicinity of roads (scenario of limited logging resources) and concentrated in a contiguous block (scenario of spatially diversified management objectives). We focused on a 16 050 ha forest landscape in Central Europe. The removal of >80% of all windfelled trees is required to substantially reduce bark beetle disturbances. Focusing SL on the vicinity of roads created a "fire break effect" on bark beetle spread, and was moderately efficient in reducing landscape-scale bark beetle disturbance. Block treatments substantially reduced outbreaks in treated areas. Leaving parts of the landscape untreated (e.g., conservation areas) had no significant amplifying effect on outbreaks in managed areas. Climate change increased bark beetle disturbances and reduced the effect of SL. Our results suggest that past outbreak management methods will not be sufficient to counteract climate-mediated increases in bark beetle disturbance.


Assuntos
Besouros , Árvores , Animais , Europa (Continente) , Florestas , Noruega , Casca de Planta
12.
Insect Sci ; 27(1): 159-169, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29851277

RESUMO

Agasicles hygrophila has been introduced worldwide as a control agent for the invasive weed Alternanthera philoxeroides. However, global warming has potential impact on its controlling efficacy. The aim of this research was to explore the primary factors responsible for the greatly reduced A. hygrophila population in hot summers. To imitate the temperature conditions in summers, different developmental stages of A. hygrophila were treated with high temperatures from 32.5 °C to 45 °C for 1-5 h. Based on the survival rate, the heat tolerance of each developmental stage was ranked from lowest to highest as follows: egg, 1st, 2nd, 3rd instar larva, adult and pupa. Eggs showed the lowest heat tolerance with 37.5 °C as the critical temperature affecting larval hatching. Heat treatment of the A. hygrophila eggs at 37.5 °C for 1 h decreased the hatch rate to 24%. Our results indicated that when compared with the control at 25 °C, 1 h treatment at 37.5 °C prolonged the duration of the egg stage, shortened the duration of oviposition and total longevity, and changed the reproductive pattern of A. hygrophila. The net reproductive rate, intrinsic rate and finite rate were all significantly reduced. The results suggest that low heat tolerance of the eggs was the major factor responsible for the reduction of A. hygrophila populations, and the key temperature was 37.5 °C. Therefore, appropriate measures should be taken to protect eggs in order to maintain the efficacy of A. hygrophila in the biological control of A. philoxeroides in hot summers.


Assuntos
Besouros/fisiologia , Temperatura Alta/efeitos adversos , Termotolerância , Animais , Besouros/crescimento & desenvolvimento , Feminino , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Óvulo/fisiologia , Pupa/crescimento & desenvolvimento , Pupa/fisiologia , Estações do Ano
13.
Arch Insect Biochem Physiol ; 103(1): e21642, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31667890

RESUMO

The Colorado potato beetle (Leptinotarsa decemlineata [Say]) is an insect pest that can significantly harm potato plants worldwide. Control of this insect relies heavily on chemical insecticides such as chlorantraniliprole. Nevertheless, the complete molecular signature associated with response to this compound is lacking in L. decemlineata. In this study, amplification and quantification by qRT-PCR (quantitative reverse transcription-polymerase chain reaction) of targets relevant to chlorantraniliprole were undertaken in insects exposed to this chemical. This approach showed modulation of numerous cytochrome P450s, such as CYP350D1 and CYP4Q3, as well as upregulation of microRNAs (miRNAs), including miR-1-3p and miR-305-5p, in chlorantraniliprole-exposed insects. Functional assessment of transcript targets predicted to be regulated by these miRNAs was performed and revealed their likely impact on transcriptional regulation. RNAi-based targeting of CYP350D1 notably provided preliminary evidence of its underlying implication for chlorantraniliprole response in L. decemlineata. Overall, this study strengthens the current knowledge of the molecular changes linked to chlorantraniliprole response in L. decemlineata and provides novel targets with potential relevance to chlorantraniliprole susceptibility in this insect pest of global relevance.


Assuntos
Besouros/efeitos dos fármacos , Besouros/metabolismo , Inseticidas/farmacologia , ortoaminobenzoatos/farmacologia , Animais , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Regulação da Expressão Gênica , MicroRNAs/genética , MicroRNAs/metabolismo , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa
14.
Ecotoxicol Environ Saf ; 187: 109849, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31677571

RESUMO

Harmonia axyridis is an important predator of several pest species and is part of many Integrated Pest Management (IPM) programs. To assess the risks of pesticide application to H. axyridis, we studied the effects of sulfoxaflor on H. axyridis larvae. At 72 h after treatment, the acute toxicity LR50 was 311.9476 g a. i. ha-1 by the residual contact method. This result indicated low-contact toxicity against second-instar H. axyridis larvae. The LR50 of the F1 generation decreased from 69.96 to 36.41 g a. i. ha-1 in a long-term toxicity test. The daily hazard quotient (HQ) for H. axyridis larvae lowered the safety threshold value in the first 5 d. However, the HQ values were greater than 2 during days 6-18 after sulfoxaflor treatments. We determined the No Observed Effect Application Rates of sulfoxaflor on the survival (<11.25 g a. i. ha-1), duration of larval and pupal stages (45 g a. i. ha-1), adult stage (90 g a. i. ha-1), total pre-oviposition period, adult pre-oviposition period (45 g a. i. ha-1), and reproduction (11.25 g a. i. ha-1). Pupation, adult emergence, and eggs counts of H. axyridis were reduced after sulfoxaflor treatments. The predation ability and population demography parameters were significantly impaired by higher application rates. At 90 g a. i. ha-1 or less, sulfoxaflor was slightly harmful to H. axyridis but a rate of 180 g a. i. ha-1 was moderately harmful. These results demonstrated that sulfoxaflor is harmful to H. axyridis when applied at high application rates.


Assuntos
Besouros/efeitos dos fármacos , Larva/efeitos dos fármacos , Resíduos de Praguicidas/toxicidade , Pupa/efeitos dos fármacos , Piridinas/toxicidade , Compostos de Enxofre/toxicidade , Animais , Besouros/fisiologia , Relação Dose-Resposta a Droga , Feminino , Larva/fisiologia , Dose Letal Mediana , Controle de Pragas , Comportamento Predatório/efeitos dos fármacos , Pupa/fisiologia , Reprodução/efeitos dos fármacos , Testes de Toxicidade
15.
Environ Entomol ; 48(6): 1481-1488, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31789365

RESUMO

Ips subelongatus is a species of bark beetle experiencing population outbreaks in Korea. In this study, a predictive model and empirical prediction were used to forecast the spring flight of these beetles in Japanese larch forests. The number of beetles caught in pheromone traps was investigated in larch forests thinned in 2009, 2010, 2012, or 2013. Data from the sites thinned in 2009, 2010, or 2012 were used in the predictive model based on a degree-day model that was validated using data from the site thinned in 2013. The lower threshold temperature for flight (LTF) and a thermal sum for the spring flight of I. subelongatus were estimated. The empirical prediction that beetles initiate their flight when daily maximum temperatures reach 16 or 20°C was tested using daily maximum temperature and the beetles caught. The LTF was estimated as 5.97°C, with 42.95 degree-days required for initiation of spring flight. The median flight dates were estimated with a discrepancy from 1 to 3 d by the predictive model. Using the empirical prediction, differences between the day when daily maximum temperature reached 16 or 20°C and flight peak days ranged from 4 to 45 d. These results demonstrate that the predictive model is more suitable than the empirical prediction for predicting the spring flight of I. subelongatus. Overwintering I. subelongatus adults seem to need to gain a determined thermal sum before initiating spring flight rather than merely waiting for the daily maximum temperature to exceed a critical temperature.


Assuntos
Besouros , Larix , Pinaceae , Gorgulhos , Animais , Florestas , Japão , República da Coreia
16.
An Acad Bras Cienc ; 91(4): e20181001, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31800699

RESUMO

Laboratory trials were performed to determine the impact of three Neotropical predatory coccinellids (Cycloneda sanguinea, Eriopis connexa and Coleomegilla quadrifasciata) and a minute pirate bug (Orius insidiosus) on Chaetosiphon fragaefolii, an important strawberry aphid pest. The predation on C. fragaefolii nymphs and adults, as well as the time to the first attack of all predators were compared with predation on Aphis gossypii. Predator preferences for prey and aphid defensive behavior were also evaluated. Moreover, the effect of coccinellids on C. fragaefolii population growth was assessed in experimental greenhouse conditions. The predation rate varied among predators, being significantly lower for O. insidiosus than for the coccinellids. Consumption was higher on A. gossypii than on C. fragaefolii, regardless of the aphids developmental stage. The time to the first attack of all predators was longer in the presence of C. fragaefolii. Walking away and cornicle secretion were the most common antipredator behaviors of aphid against coccinellids and O. insidiosus, respectively. Coccinellids preferred A. gossypii over C. fragaefolii, while O. insidiosus showed indifference. Cycloneda sanguinea and E. connexa exhibited the highest suppression effect on the growth rate of C. fragaefolii. Thus, the four predators evaluated could contribute to reduce strawberry aphid populations, especially C. sanguinea and E. connexa.


Assuntos
Afídeos , Besouros/fisiologia , Controle Biológico de Vetores/métodos , Comportamento Predatório/fisiologia , Animais , Besouros/classificação , Fragaria/parasitologia , Fatores de Tempo
17.
J Econ Entomol ; 112(6): 2751-2760, 2019 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-31815287

RESUMO

The emerald ash borer (EAB) Agrilus planipennis (Fairmaire, Coleoptera: Buprestidae) will have untold impacts on the contributions hardwood timber products provide Louisiana's economy. We modeled a scenario where ash mortality was assumed to follow a PERT-Beta distribution to kill essentially all Louisiana ash within 25 yr. Future ash mortality volumes were discounted to the present and valued using market prices to estimate a present effect on timber receipts. Assuming the dead timber would have otherwise been typical trees of average quality, stumpage was presently valued at US$1.57 million, with deliveries totaling US$3.48 million. A salvage arrangement using the double declining balance method coupled with a second PERT-Beta distribution centered upon Louisiana's current 2.84% harvest-to-inventory proportion depreciated the timber's value monthly over 1 yr. Following salvage, average stumpage revenue declined -US$1.54 million, mill deliveries fell -US$3.41 million, whereas state timber severance tax collections declined by -US$46,800. The value added and employment direct effects to Louisiana's economy averaged -US$882,400 and -41.6 jobs, respectively. The multiplier effects of these losses emanating from the timber industry resulted in additional declines averaging -US$2.56 million in value added and -45.6 jobs across the state economy on the drop in output of -US$4.51 million. The total economic effects summed to -US$3.44 million in value added and -87.1 jobs on output declines of -US$9.46 million.


Assuntos
Besouros , Fraxinus , Animais , Larva , Louisiana , Árvores
18.
Rev. Soc. Bras. Med. Trop ; 53: 1-4, dez., 2019. ilus.
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1049465

RESUMO

INTRODUCTION: Oral transmission of acute Chagas disease is an emerging public health concern. This study aimed to detect insect fragments in experimentally contaminated food, by comparing triatomines with other insects. METHODS: Food samples were experimentally contaminated with insects, processed to recover their fragments by light filth, and analyzed by microscopy and Polymerase Chain Reaction (PCR). RESULTS: Morphological differences between coleopteran and triatomine insects were observed in microscopic images. PCR was efficient in amplifying Triatominae DNA in the experimentally contaminated food. CONCLUSIONS: This methodology could be utilized by food analysts to identify possible insect contamination in food samples. (AU)


Assuntos
Besouros , Reação em Cadeia da Polimerase , Triatominae , Euterpe , Alimentos , Doenças Transmitidas por Alimentos
19.
Rev Soc Bras Med Trop ; 53: e20190119, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31859942

RESUMO

INTRODUCTION: Oral transmission of acute Chagas disease is an emerging public health concern. This study aimed to detect insect fragments in experimentally contaminated food, by comparing triatomines with other insects. METHODS: Food samples were experimentally contaminated with insects, processed to recover their fragments by light filth, and analyzed by microscopy and Polymerase Chain Reaction (PCR). RESULTS: Morphological differences between coleopteran and triatomine insects were observed in microscopic images. PCR was efficient in amplifying Triatominae DNA in the experimentally contaminated food. CONCLUSIONS: This methodology could be utilized by food analysts to identify possible insect contamination in food samples.


Assuntos
Besouros/classificação , Parasitologia de Alimentos , Sucos de Frutas e Vegetais/parasitologia , Insetos Vetores/classificação , Saccharum/parasitologia , Triatominae/classificação , Animais , Doença de Chagas/transmissão , Humanos , Reação em Cadeia da Polimerase
20.
J Insect Sci ; 19(6)2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31782963

RESUMO

Multiple mating in females is common in nature but may involve fitness costs. Adult females and males of the beetle Plagiodera versicolora Laicharting can mate multiple times. We studied the effect of mating frequency and mating pattern (time interval between matings) on female reproductive fitness by measuring fecundity, hatching probability, and female longevity. Fecundity and longevity were similar in single- and double-mated (two matings separated by a 7 d interval) females. However, two and three successive matings and three matings separated by two 7 d interval had a significant negative effect on the lifetime fecundity and longevity of females. Multiple mating had a positive effect on egg hatching, and two matings sufficed to fertilize the full egg load. These results indicate that the two matings separated by a 7 d interval are optimum for reproductive fitness in female P. versicolora. Suboptimal mating frequency (successive mating or an excessive number of matings) exacts a physiological cost that shortens the female life span and reduces fecundity.


Assuntos
Besouros/fisiologia , Longevidade , Oviparidade , Comportamento Sexual Animal , Animais , Tamanho da Ninhada , Feminino , Masculino , Oviposição , Óvulo/fisiologia
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