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1.
J Asthma ; 60(9): 1677-1686, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36755521

RESUMO

OBJECTIVE: Caregiver depressive symptoms are prevalent among children with asthma and associated with greater asthma morbidity. Identifying caregivers with depression and connecting them to appropriate treatment may reduce child asthma morbidity. The goal of this project was to implement a workflow for caregiver depression screening and treatment referral in an urban, community-based, asthma clinic serving under-resourced children. METHODS: The Model for Improvement with weekly Plan-Do-Study-Act cycles was utilized. A two-item depression screening tool (Patient Health Questionnaire-2; PHQ-2) and an acceptability question using a 5-point Likert scale were added to an existing social needs screening checklist administered to all caregivers during the child's clinic visit. Caregivers with a positive PHQ-2 score (≥3) received the PHQ-9. Positive screens on the PHQ-9 (≥5) received information and referrals by level of risk. PHQ-9 positive caregivers received a follow-up phone call two weeks post-visit to assess connection to support, improvement in depressive symptoms, and satisfaction with resources provided. RESULTS: The PHQ-2 was completed by 84.4% of caregivers (233/276). Caregivers had a mean age of 33.8 years (SD = 8.3; Range: 18-68) and were predominately female (86.4%), Black (80.4%), and non-Hispanic (78.4%). The majority (72.3%) found the screening acceptable (agree/strongly agree). Nearly one in six caregivers (37/233, 15.9%) reported depressive symptoms (PHQ-2 ≥ 3); 11.6% (27/233) had clinically significant symptoms (PHQ-9 score ≥ 10); and 2.1% (5/233) reported suicidal thoughts. Of those with depressive symptoms, 70.3% (26/37) participated in the follow-up phone call. While 50% (13/26) reported the resources given in clinic were "extremely helpful," no caregivers contacted or used them. CONCLUSIONS: Caregiver depression screening was successfully integrated into a pediatric asthma clinic serving under-resourced children. While caregivers found screening to be acceptable, it did not facilitate short-term connection to treatment among those with depressive symptoms.


Assuntos
Asma , Humanos , Criança , Feminino , Adulto , Asma/diagnóstico , Asma/terapia , Depressão/diagnóstico , Depressão/epidemiologia , Melhoria de Qualidade , Cuidadores , Instituições de Assistência Ambulatorial
2.
Plant Dis ; 107(6): 1769-1776, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36399004

RESUMO

'Candidatus Liberibacter asiaticus' is the bacterium associated with the citrus disease known as huanglongbing (HLB). This study evaluated the influence of 'Ca. L. asiaticus' infection on a number of key plant physiological variables concerning photosynthesis, cell integrity, reactive oxygen species scavengers' activity, and osmoregulation of two different species of citrus-the pomelo Citrus maxima and the mandarin C. reticulata 'Tankan'-relative to their measured 'Ca. L. asiaticus' infection load. Results indicated that all measured physiological variables except soluble sugar were affected by increased 'Ca. L. asiaticus' infection titers, wherein the variety C. maxima proved overall more resistant than C. reticulata. 'Ca. L. asiaticus' infection was linked in both plants to decrease in chlorophyll concentration, cell membrane permeability, and malondialdehyde, as well as increased free proline and starch contents. Chlorophyll fluorescence measurements taken 9 months after grafting the mandarin C. reticulata with 'Ca. L. asiaticus' scions revealed a significant decrease in the photosynthesis variables maximum photochemical quantum yield of photosystem II (PSII), effective photochemical quantum yield of PSII, and coefficient of photochemical fluorescence quenching assuming interconnected PSII antennae, whereas nonphotochemical fluorescence quenching increased significantly; C. maxima plants, on the other hand, did not show significant differences until the 12th month from infection exposure. The variables superoxide dismutase, catalase, peroxidase, and soluble protein initially increased and later decreased. In addition, progression of 'Ca. L. asiaticus' replication in both citrus species was accompanied by rapid changes in three reactive oxygen species scavenging enzymes in C. maxima, while the pattern was different in C. reticulata. We hypothesize that the observed interspecific differences in physiological change are related to their relative resistance against 'Ca. L. asiaticus' infection. These results provide a scaffold for better describing the pathogenesis, selecting the most resistant breeds, or even validating pertaining omics research; ultimately, these detailed observations can facilitate the diagnosis of 'Ca. L. asiaticus' infection.


Assuntos
Citrus , Rhizobiaceae , Citrus/microbiologia , Liberibacter , Rhizobiaceae/fisiologia , Espécies Reativas de Oxigênio , Doenças das Plantas/microbiologia , Melhoramento Vegetal , Clorofila
3.
J Insect Sci ; 23(2)2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36916278

RESUMO

Fusarium concentricum Nirenberg & O' Donnell (Ascomycota: Hypocreales) is a fungal species known to infect plants, but never reported as entomopathogenic. Polychrosis cunninhamiacola Liu et Pei (Lepidoptera: Tortricidae: Olethreutinae) is a major and widespread insect pest causing economic losses to cultivated Chinese fir Cunninghamia lanceolata (Lamb.) Hook. It is routinely controlled by extensive use of chemical insecticides, which is perceived as environmentally unsustainable. During March and April of 2019-2020, muscardine cadavers of larvae and pupae of P. cunninhamiacola infected with growing fungus were collected in a fir forest in northern Guangdong Province, China. Conidia were isolated and cultured on PDA medium, from which the fungal strain was identified as F. concentricum FCPC-L01 by morphology and by sequence alignment match with Tef-1α gene. Pathogenicity bioassays at the conidial concentration 1 × 107 revealed P. cunninhamiacola adults and Danaus chrysippus (L.) (Lepidoptera: Nymphalidae) larvae are sensitive to the fungal infection, but not the fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae). We believe results indicate this fungal strain might be applicable against specific target insect pests. As this is the first record of a natural infection caused by F. concentricum in insects, we propose host specificity tests should be done to evaluate its potential as a biocontrol agent.


Assuntos
Formigas , Fusarium , Hypocreales , Mariposas , Animais , Controle Biológico de Vetores/métodos , Insetos , Larva , Esporos Fúngicos
4.
Annu Rev Entomol ; 67: 367-385, 2022 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-34678043

RESUMO

Ants have outstanding capacity to mediate inter- and intraspecific interactions by producing structurally diverse metabolites from numerous secretory glands. Since Murray Blum's pioneering studies dating from the 1950s, there has been a growing interest in arthropod toxins as natural products. Over a dozen different alkaloid classes have been reported from approximately 40 ant genera in five subfamilies, with peak diversity within the Myrmicinae tribe Solenopsidini. Most ant alkaloids function as venom, but some derive from other glands with alternative functions. They are used in defense (e.g., alarm, repellants) or offense (e.g., toxins) but also serve as antimicrobials and pheromones. We provide an overview of ant alkaloid diversity and function with an evolutionary perspective. We conclude that more directed integrative research is needed. We suggest that comparative phylogenetics will illuminate compound diversification, while molecular approaches will elucidate genetic origins. Biological context, informed by natural history, remains critical not only for research about focal species, but also to guide applied research.


Assuntos
Alcaloides , Formigas , Animais , Biodiversidade , Evolução Biológica , Feromônios
5.
J Insect Sci ; 20(4)2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32725158

RESUMO

The removal of corpses (aka 'necrophoric behavior') is critical to sanitation in ant colonies. However, little is known about differences in the necrophoric responses of Solenopsis invicta workers towards corpses of nestmates and non-nestmates. We introduced corpses of S. invicta workers from either intracolony (i.e., nestmate) or intercolony (i.e., non-nestmate) origin at the entrance of artificial nests, and recorded workers' aggressive responses and necrophoric behaviors for analysis. Solenopsis invicta workers displayed distinct responses towards corpses of different origins. Specifically, resident workers were more likely to remove fresh non-nestmate corpses than nestmate corpses, but there was no difference regarding corpses that had been dead for 15 min or longer. Resident workers reacted more aggressively to, and removed more quickly, fresh non-nestmate corpses than corpses of their nestmates. On the other hand, there was no significant difference in the removal time between nestmate and non-nestmate corpses that had been dead for 15 min or longer. Resident workers always displayed stronger aggressiveness towards non-nestmate corpses than nestmate corpses, excepting to corpses that had been dead for 6 h, which elicited a response. No significant correlation between the removal times and aggressiveness levels were detected in any treatments. It remains to be tested whether this differential response is adaptive in how it influences colony fitness and competition.


Assuntos
Formigas/fisiologia , Comportamento Animal , Agressão , Animais , Comportamento Social
7.
Pest Manag Sci ; 80(10): 5277-5285, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38946320

RESUMO

BACKGROUND: The Red Imported Fire Ant (RIFA), scientifically known as Solenopsis invicta, is a destructive invasive species causing considerable harm to ecosystems and generating substantial economic costs globally. Traditional methods for RIFA nests detection are labor-intensive and may not be scalable to larger field areas. This study aimed to develop an innovative surveillance system that leverages artificial intelligence (AI) and robotic dogs to automate the detection and geolocation of RIFA nests, thereby improving monitoring and control strategies. RESULTS: The designed surveillance system, through integrating the CyberDog robotic platform with a YOLOX AI model, demonstrated RIFA nest detection precision rates of >90%. The YOLOX model was trained on a dataset containing 1118 images and achieved a final precision rate of 0.95, with an inference time of 20.16 ms per image, indicating real-time operational suitability. Field tests revealed that the CyberDog system identified three times more nests than trained human inspectors, with significantly lower rates of missed detections and false positives. CONCLUSION: The findings underscore the potential of AI-driven robotic systems in advancing pest management. The CyberDog/YOLOX system not only matched human inspectors in speed, but also exceeded them in accuracy and efficiency. This study's results are significant as they highlight how technology can be harnessed to address biological invasions, offering a more effective, ecologically friendly, and scalable solution for RIFA detection. The successful implementation of this system could pave the way for broader applications in environmental monitoring and pest control, ultimately contributing to the preservation of biodiversity and economic stability. © 2024 Society of Chemical Industry.


Assuntos
Formigas , Espécies Introduzidas , Robótica , Animais , Inteligência Artificial , Comportamento de Nidação , Controle de Insetos/métodos , Controle de Insetos/instrumentação , Formigas Lava-Pés
8.
Pest Manag Sci ; 80(6): 2892-2904, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38411441

RESUMO

BACKGROUND: Given the chemical diversity within stink bugs scent glands, they can be convenient models for bioprospecting novel pest control products. Preliminary behaviour observations indicated that adult Mictis fuscipes stink bugs secrete liquid droplets when defending against Solenopsis invicta fire ants, killing them within minutes. Hence, this study aimed to analyse the chemical composition of the metathoracic scent gland secretions of M. fuscipes adults, as well as assess their biological activities against fire ants. RESULTS: Bioassaying fire ants against secretions of several local stink bugs confirmed that the defensive secretions of two Mictis species are significantly more lethal, where M. fuscipes was the most lethal. Volatiles chromatography analysis indicated the secretions of female and male M. fuscipes stink bugs contains 20 and 26 components, respectively, chiefly hexanoic acid and hexyl hexanoate. Five compounds were consistently present in the secretion of female adults: hexyl hexanoate, hexanoic acid, hexyl acetate, hexyl butyrate, and eugenol. These yielded a strong electrophysiological antennal (EAD) response from S. invicta workers, female alates and males, where hexyl acetate showed the strongest response. The combination of these five compounds proved strongly repellent to S. invicta. When tested singly, hexanoic acid, hexyl butyrate, hexyl hexanoate, and eugenol were repellent to S. invicta, but hexyl acetate seemed slightly attractive. Additionally, the same mixture of five components exhibited strong contact and fumigant toxicity towards S. invicta workers, eugenol being the strongest. CONCLUSION: Defensive chemicals of M. fuscipes exhibit robust biological activity against S. invicta and could inspire the development of biopesticides. © 2024 Society of Chemical Industry.


Assuntos
Formigas , Glândulas Odoríferas , Animais , Feminino , Masculino , Formigas/efeitos dos fármacos , Glândulas Odoríferas/química , Heterópteros/efeitos dos fármacos , Heterópteros/fisiologia , Hemípteros/efeitos dos fármacos , Hemípteros/fisiologia , Formigas Lava-Pés
9.
Virulence ; 15(1): 2413329, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39370781

RESUMO

The urgency surrounding Candida auris as a public health threat is highlighted by both the Center for Disease Control (CDC) and World Health Organization (WHO) that categorized this species as a priority fungal pathogen. Given the current limitations of antifungal therapy for C. auris, particularly due to its multiple resistance to the current antifungals, the identification of new drugs is of paramount importance. Some alkaloids abundant in the venom of the red invasive fire ant (Solenopsis invicta), known as solenopsins, have garnered attention as potent inhibitors of bacterial biofilms, and there are no studies demonstrating such effects against fungal pathogens. Thus, we herein investigated the antibiotic efficacy of solenopsin alkaloids against C. auris biofilms and planktonic cells. Both natural and synthetic solenopsins inhibited the growth of C. auris strains from different clades, including fluconazole and amphotericin B-resistant isolates. Such alkaloids also inhibited matrix deposition and altered cellular metabolic activity of C. auris in biofilm conditions. Mechanistically, the alkaloids compromised membrane integrity as measured by propidium iodide uptake in exposed planktonic cells. Additionally, combining the alkaloids with AMB yielded an additive antifungal effect, even against AMB-resistant strains. Finally, both extracted solenopsins and the synthetic analogues demonstrated protective effect in vivo against C. auris infection in the invertebrate model Galleria mellonella. These findings underscore the potent antifungal activities of solenopsins against C. auris and suggest their inclusion in future drug development. Furthermore, exploring derivatives of solenopsins could reveal novel compounds with therapeutic promise.


Assuntos
Alcaloides , Antifúngicos , Formigas , Biofilmes , Candida auris , Testes de Sensibilidade Microbiana , Animais , Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida auris/efeitos dos fármacos , Candida auris/genética , Alcaloides/farmacologia , Alcaloides/química , Formigas/microbiologia , Candidíase/microbiologia , Candidíase/tratamento farmacológico , Venenos de Formiga/farmacologia , Venenos de Formiga/química , Formigas Lava-Pés
10.
J Insect Sci ; 13: 70, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24224520

RESUMO

The digestive system of adults and mature larvae of two ant species of Monomorium Mayr (Hymoneptera: Formicidae) were described with the aid of light and scanning electron microscopy, as there is a lack of studies in this area. These two ant species are recurrently found in urban habitats and are known as 'tramp species,' as they cause problems in households, businesses, and hospitals. The most interesting finds of the present study include the existence of spinules in the crop of adults, and the number of Malpighian tubules and rectal pads was constant among different castes, ages, and species.


Assuntos
Formigas/anatomia & histologia , Animais , Formigas/crescimento & desenvolvimento , Formigas/ultraestrutura , Sistema Digestório/anatomia & histologia , Sistema Digestório/crescimento & desenvolvimento , Sistema Digestório/ultraestrutura , Larva/anatomia & histologia , Larva/crescimento & desenvolvimento , Larva/ultraestrutura , Microscopia Eletrônica de Varredura , Especificidade da Espécie
11.
Neotrop Entomol ; 52(4): 584-595, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37310662

RESUMO

Ants of the genus Solenopsis are globally distributed, presenting high diversity and many generalist species. In South America, the dominant species is Solenopsis saevissima (Smith, 1855), commonly found nesting in grassy fields surrounding humanized areas. In spite of being so common, there has been no research evaluating the effect of human disturbances on the mitochondrial DNA (mtDNA) haplotype diversity in this species. In this context, we here characterized the mtDNA haplotype diversity in S. saevissima nests by highway roadsides, dust roads, and forest borders of Atlantic Forest, based on partial sequences of cytochrome c oxidase subunit I (COI). Based on the facts that the species is a rapid colonizer of disturbed habitats, we specifically probed how the genetic diversity of native S. saevissima is impacted by highways and roads infrastructure expanding around the rainforest. Species diagnosis was established both by morphological characters and obtained mtDNA COI sequences. Overall, the species exhibited high haplotypes and nucleotide diversity, particularly around forest borders; though all haplotypes seemed closely related across the different habitats. We identified seven mitochondrial haplotypes (H1 to H7), where haplotype H1 was exclusively found in highway roadside nests, and H7 on dust roads; the remaining haplotypes were recorded from all habitats. Haplotype H1 was geographically isolated to the south of the Atlantic Forest, supporting previous suggestions that it acts as a biogeographical barrier. The pattern is suggestive of a recent species expansion, probably resulting from extensive habitat fragmentation. Taken together, our data demonstrates fire ant haplotypes prevailing in some anthropized habitats, characterizing how a native species lining the remnants of the Brazilian Atlantic Forest might be a concern for environmental conservation.


Assuntos
Formigas , Humanos , Animais , Formigas/genética , Haplótipos , Ecossistema , Florestas , DNA Mitocondrial/genética , Brasil
12.
J Proteome Res ; 11(9): 4643-53, 2012 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-22881118

RESUMO

Fire ants are well-known by their aggressive stinging behavior, causing many stinging incidents of medical importance. The limited availability of fire ant venom for scientific and clinical uses has restricted, up to now, the knowledge about the biochemistry, immunology, and pharmacology of these venoms. For this study, S. invicta venom was obtained commercially and used for proteomic characterization. For this purpose, the combination of gel-based and gel-free proteomic strategies was used to assign the proteomic profile of the venom from the fire ant S. invicta. This experimental approach permitted the identification of 46 proteins, which were organized into four different groups according to their potential role in fire ant venom: true venom components, housekeeping proteins, body muscle proteins, and proteins involved in chemical communication. The active venom components that may not present toxic roles were classified into three subgroups according to their potential functions: self-venom protection, colony asepsis, and chemical communication. Meanwhile, the proteins classified as true toxins, based on their functions after being injected into the victims' bodies by the fire ants, were classified in five other subgroups: proteins influencing the homeostasis of the victims, neurotoxins, proteins that promote venom diffusion, proteins that cause tissue damage/inflammation, and allergens.


Assuntos
Venenos de Formiga/química , Formigas/química , Proteínas de Insetos/análise , Proteoma/análise , Sequência de Aminoácidos , Animais , Formigas/metabolismo , Eletroforese em Gel Bidimensional , Proteínas de Insetos/química , Espectrometria de Massas , Dados de Sequência Molecular , Mapeamento de Peptídeos , Proteoma/química , Proteômica
13.
J Insect Sci ; 12: 59, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22934715

RESUMO

The immatures of males of two species of Camponotus ants (Hymenoptera: Formicidae) are described and compared by light and electron microscopy. The numbers of larval instars were determined: Camponotus rufipes Fabricius (Hymenoptera: Formicidae) have four instars; and Camponotus vittatus Forel have three. Male larvae of the two species are similar to previously described Camponotus larvae, sharing the following traits: basic shape of body and mandible, presence of 'chiloscleres', 'praesaepium' (some specimens), labial pseudopalps, and ten pairs of spiracles. However, larvae of the two species can be separated by bodily dimensions and based on their hair number and types. Worker larvae of C. vittatus previously described are extensively similar to male larvae, with only a few inconspicuous differences that may result from intraspecific variation or sexual differences.


Assuntos
Formigas/ultraestrutura , Animais , Formigas/classificação , Formigas/crescimento & desenvolvimento , Larva/classificação , Larva/ultraestrutura , Masculino , Óvulo/citologia , Pupa/anatomia & histologia , Caracteres Sexuais
14.
Clin Child Psychol Psychiatry ; 27(1): 244-258, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34923834

RESUMO

Delivery of mental health treatment in the home can close gaps in care. Telehealth also provides access to healthcare that has been disrupted due to the COVID-19 pandemic. In 2016, a home direct-to-consumer telehealth program was initiated. Mental health encounters made up a significant portion of all telehealth encounters and COVID-19 had a significant impact on accelerating the utilization of telehealth. Telemental health has been more successful at meeting targeted volumes than the overall health system. Of all the mental health diagnoses before and during COVID-19, attention deficit hyperactivity disorder, Autism Spectrum Disorder, and Anxiety Disorder were most common. The direct-to-consumer telehealth program saved patients a significant amount of travel miles and associated time, based on data from the period before COVID-19. Payment reimbursement for direct-to-consumer telehealth professional services was similar to reimbursement for in-person visits. This program demonstrates direct-to-consumer telehealth is a feasible and acceptable care modality for a variety of youth mental health disorders.


Assuntos
Transtorno do Espectro Autista , COVID-19 , Telemedicina , Adolescente , Criança , Humanos , Saúde Mental , Pandemias , SARS-CoV-2
15.
J Insect Sci ; 11: 24, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21529152

RESUMO

The Neotropical ant genus Myrmelachista Roger comprises 69 described species and subspecies, and still is a poorly studied group. Larvae play a paramount role in colony nutrition in social hymenopterans and bear considerable value in the reconstruction of group phylogenies, however, they are generally neglected. Larvae of different instars of Myrmelachista catharinae Mayr (Hymenoptera: Formicidae) are herein described in detail by light and scanning electron microscopy. The number of larval instars was estimated as three based on the frequency distribution of maximum head capsule widths. The described larvae confirmed some traits typical of the genus: general shape of body and mandibles, general aspect and distribution of body hairs, and the number of sensilla on the palps and galea. Differently from other Myrmelachista larvae previously described, M. catharinae presented two distinct kinds of second instars, some additional types of body hairs, different number of antennal sensilla, and a distinct labrum shape. M. catharinae presented ten pairs of spiracles, which is the first record for this genus.


Assuntos
Formigas/crescimento & desenvolvimento , Formigas/ultraestrutura , Animais , Brasil , Larva/crescimento & desenvolvimento , Larva/ultraestrutura , Microscopia Eletrônica de Varredura
16.
Insects ; 12(8)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34442301

RESUMO

Citrus tristeza virus (CTV) is one of the most important citrus tree viruses: a graft-transmissible virus that can be vectored by several aphid species. Diaphorina citri is the insect vector of "Candidatus Liberibacter spp.", a bacterium associated with citrus Huanglongbing (HLB). However, no detailed description of the relationship between CTV and D. citri has been reported. In this study, D. citri adults collected from CTV-infected "Shatangju" mandarin, "Newhall" sweet orange, and "fingered citron" trees in different orchards yielded CTV-positive rates of 40%, 65%, and 95%, respectively, upon detection by conventional PCR. Illumina HiSeq sequencing followed by de novo assembly recovered the primary full CTV genome from the RNA of 30 D. citri adults sampled from CTV-positive citrus plants. Molting and adult emergence did not affect the presence or titers of CTV within the D. citri; however, the persistence of CTV in psyllids varied among different host plant species. Groups of 10 D. citri (from a population 85% CTV-positive) were shown to potentially transmit CTV to two citrus species, "Shatangju" mandarin and "Eureka" lemon, yielding 58.33% and 83.33% CTV-positive plants, respectively. No transmission of CTV to orange jasmine plants occurred. Thus, this study reports on the ability of D. citri to acquire and transmit CTV, making D. citri as a vector of two important citrus pathogens, warranting further attention and investigation.

17.
Environ Entomol ; 50(1): 160-166, 2021 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-33381806

RESUMO

Seven entomopathogenic fungi strains (M1-7) were isolated from field-obtained dead coconut hispine beetles Brontispa longissima (Gestro), identified to species, and bioassayed for their pathogenicity. According to ITS sequences, all isolates belong in the genus Metarhizium, mainly M. flavoviride and M. anisopliae. Measured median lethal times (LT50) of 1×107 conidia/ml of M1-7 against fourth-instar B. longissima larvae within 15 d following exposure were, respectively: 5.43, 10.64, 11.26, 10.93, 6.62, 4.73, and 5.95 d. The isolate M6 yielded the highest mortality to fourth-instar larvae, and was thus selected to be tested against other larval instars and adults of B. longissima, after Time-Dose-Mortality (TDM) models. M6 proved more pathogenic against larvae than adults. The obtained bioassays data produced a good fit to the TDM models, yielding estimated LC50 and LT50 for each of the tested developmental stages of B. longissima. Both the obtained dose (ß) and time effect (ri) parameters from TDM models suggest that first-instar larvae are the most susceptible life stage of the pest insect, while adults are more resistant to M6 infection. Calculated LC50 values were, respectively, 1.23×103 and 1.15×106 conidia/ml for first-instar larvae and adults, on the 15th day following M6 inoculation. Estimated LT50 were 3.3 and 5.9 d for first-instar larvae and adults, respectively, at 1×108 conidia/ml. Taken together, these results would suggest Metarhizium M6 as an option for the biological control of B. longissima in the field.


Assuntos
Besouros , Metarhizium , Animais , Larva , Controle Biológico de Vetores
18.
Biol Res ; 43(1): 19-30, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21157629

RESUMO

Linepithema humile Mayr is an ant species originally native to South America that has been spread accidently throughout the globe through international trade. It is a serious urban and crop pest. Despite its economic importance, little is known about the larvae of this species apart from a brief description based on a few specimens. The present investigation is aimed at describing every immature stage of L. humile. Three larval instars were determined through the frequency distribution of the maximum width of head capsules from a sample of 525 larvae. The morphological descriptions were based on 150 eggs, 70 larvae, and 90 pupae examined by light and scanning electron microscopy. Some morphological characteristics reported to be typical of Linepithema Mayr larvae were confirmed--dolichoderoid body shape, presence of dorsal protuberance, sparse simple body hairs, presence of nine pairs of spiracles and dolichoderoid mandibles. We concluded that an earlier published description was based on queen larvae, and that the protuberance is only present in worker larvae. The information provided in this study may aid ant systematics and phylogenetics, as well provide a better understanding of the biology of this species.


Assuntos
Formigas/crescimento & desenvolvimento , Estágios do Ciclo de Vida , Animais , Formigas/ultraestrutura , Feminino , Larva/ultraestrutura , Masculino , Microscopia Eletrônica de Varredura , Óvulo/ultraestrutura , Pupa/ultraestrutura
19.
J Insect Sci ; 10: 24, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20578888

RESUMO

A group of 13 species of the genus Solenopsis is markedly difficult to assess taxonomically, although they are of considerable economical and medical importance in some countries where some of them were introduced. These ants are aggressive and their venomous stings can be very allergenic. The venom apparatus has been described in fine detail for only two of these species, and differences in this structure among the different species might prove useful as taxonomic characters. The venom apparatus of Solenopsis saevissima Smith (Hymenoptera: Formicidae) is herein described with the aid of light and electron microscopy techniques, and compared to that of S. invicta and S. richteri. The cellular organization of the different parts present differences that suggest functional specialization. In general, the different tissues were abundant in vesiculae and mitochondria, but presented little endoplasmic reticulum and few ribosomes, probably because they produce little protein. The length of the free filaments of the venom gland and the width of their internal ducts seems to vary from what was described for S. richteri, but this may be of little use to taxonomy.


Assuntos
Formigas/ultraestrutura , Animais , Venenos de Formiga/metabolismo , Glândulas Exócrinas/ultraestrutura
20.
J Insect Sci ; 10: 15, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20575746

RESUMO

Some ant species of the genus Monomorium Mayr occur worldwide and are considered important urban pests. The larvae of only a few species of this genus have been described, and these descriptions are either superficial or incomplete. This study aimed to determine the number of larval instars and describe the immature stages of the ant Monomorium floricola Jerdon (Formicidae: Myrmicinae). Specimens were analyzed and measured using light and scanning electron microscopy. Three larval instars were found, and all larvae had pheidoloid bodies with ectatommoid mandibles, consistent with other Monomorium species described previously. Five types of body hairs were described, and their distribution was instar-specific. Body and mandible dimensions of the larvae also were constant for each instar. Like other Myrmicinae, the larvae did not create a cocoon. Some of differences among the hair types and sensilla were observed by comparing the samples with larvae of other species in the genus, and these differences may have taxonomic utility.


Assuntos
Formigas/crescimento & desenvolvimento , Formigas/ultraestrutura , Animais , Larva/crescimento & desenvolvimento , Larva/ultraestrutura
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