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1.
Biology (Basel) ; 10(3)2021 Mar 17.
Article in English | MEDLINE | ID: mdl-33802973

ABSTRACT

Herein, CuO-NPs were fabricated by harnessing metabolites of Aspergillus niger strain (G3-1) and characterized using UV-vis spectroscopy, XRD, TEM, SEM-EDX, FT-IR, and XPS. Spherical, crystallographic CuO-NPs were synthesized in sizes ranging from 14.0 to 47.4 nm, as indicated by TEM and XRD. EDX and XPS confirmed the presence of Cu and O with weight percentages of 62.96% and 22.93%, respectively, at varied bending energies. FT-IR spectra identified functional groups of metabolites that could act as reducing, capping, and stabilizing agents to the CuO-NPs. The insecticidal activity of CuO-NPs against wheat grain insects Sitophilus granarius and Rhyzopertha dominica was dose- and time-dependent. The mortality percentages due to NP treatment were 55-94.4% (S. granarius) and 70-90% (R. dominica). A botanical experiment was done in a randomized block design. Low CuO-NP concentration (50 ppm) caused significant increases in growth characteristics (shoot and root length, fresh and dry weight of shoot and root, and leaves number), photosynthetic pigments (total chlorophylls and carotenoids), and antioxidant enzymes of wheat plants. There was no significant change in carbohydrate or protein content. The use of CuO-NPs is a promising tool to control grain insects and enhance wheat growth performance.

2.
Insects ; 12(4)2021 Mar 26.
Article in English | MEDLINE | ID: mdl-33810271

ABSTRACT

In Pakistan, the control of stored-product insect pests mainly relies on the use of phosphine gas along with other control tactics. The aim of this study was to determine the level of phosphine resistance among ten differently located populations of the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), the granary weevil, Sitophilus granarius (L.) (Coleoptera: Curculionidae), the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and the khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae). Laboratory-susceptible populations of all insect species were also considered in the experiments. Concentration-response bioassays were conducted for each species. All of the tested populations (10 out of 10) of each species were found to be resistant to phosphine, but varied in their level of resistance. Probit analysis estimated LC50 at 2.85, 1.90, 2.54 and 2.01 ppm for laboratory-susceptible populations of R. dominica, S. granarius, T. castaneum and T. granarium, respectively. Against R. dominica, the highest and lowest resistance levels were observed in the Rahim Yar Khan (LC50 at 360.90 ppm) and Rawalpindi (LC50 at 210.98 ppm) populations, respectively. These resistant populations were 126.67- and 74.02-fold more resistant than the laboratory population. The Multan and Lahore populations of S. granarius exhibited the maximum (LC50 at 122.81 ppm) and minimum (LC50 at 45.96 ppm) resistance levels, respectively, i.e., they were 64.63- and 24.18-fold more resistant than the laboratory population. The Layyah population of T. castaneum showed the maximum resistance level (LC50 at 305.89 ppm) while the lowest was observed in the Lahore population (LC50 at 186.52 ppm), corresponding to 120.42- and 73.43-fold more resistant than the laboratory population, respectively. Regarding T. granarium, the Layyah population showed the maximum resistance level (LC50 at 169.99 ppm) while the Lahore population showed the minimum resistance (LC50 at 74.50 ppm), i.e., they were 84.57- and 37.06-fold more resistant than the laboratory population, respectively. Overall, R. dominica presented the highest resistance level, followed by T. castaneum, T. granarium and S. granarius. The current study suggests that the application of phosphine may not be an adequate control strategy for the management of the above tested insect pests in Pakistan.

3.
JAMA Netw Open ; 4(3): e210307, 2021 Mar 01.
Article in English | MEDLINE | ID: mdl-33646313

ABSTRACT

Importance: Rates of breast and ovarian cancer are high in the Caribbean; however, to date, few published data quantify the prevalence of inherited cancer in the Caribbean population. Objective: To determine whether deleterious variants in genes that characterize the hereditary breast and ovarian cancer syndrome are associated with the development of breast and ovarian cancer in the English- and Creole-speaking Caribbean populations. Design, Setting, and Participants: This multisite genetic association study used data from germline genetic test results between June 2010 and June 2018 in the Bahamas, Cayman Islands, Barbados, Dominica, Jamaica, Haiti, and Trinidad and Tobago. Next-generation sequencing on a panel of 30 genes and multiplex ligation-dependent probe amplification (BRCA1 and BRCA2) were performed. Medical records were reviewed at time of study enrollment. Women and men diagnosed with breast and ovarian cancer with at least 1 grandparent born in the participating study sites were included; 1018 individuals were eligible and consented to participate in this study. Data were analyzed from November 4, 2019, to May 6, 2020. Exposures: Breast and/or ovarian cancer diagnosis. Main Outcomes and Measures: Rate of inherited breast and ovarian cancer syndrome and spectrum and types of variants. Results: Of 1018 participants, 999 (98.1%) had breast cancer (mean [SD] age, 46.6 [10.8] years) and 21 (2.1%) had ovarian cancer (mean [SD] age, 47.6 [13.5] years). Three individuals declined to have their results reported. A total of 144 of 1015 (14.2%) had a pathogenic or likely pathogenic (P/LP) variant in a hereditary breast and ovarian cancer syndrome gene. A total of 64% of variant carriers had P/LP variant in BRCA1, 23% in BRCA2, 9% in PALB2 and 4% in RAD51C, CHEK2, ATM, STK11 and NBN. The mean (SD) age of variant carriers was 40.7 (9.2) compared with 47.5 (10.7) years in noncarriers. Individuals in the Bahamas had the highest proportion of hereditary breast and ovarian cancer (23%), followed by Barbados (17.9%), Trinidad (12%), Dominica (8.8%), Haiti (6.7%), Cayman Islands (6.3%), and Jamaica (4.9%). In Caribbean-born women and men with breast cancer, having a first- or second-degree family member with breast cancer was associated with having any BRCA1 or BRCA2 germline variant (odds ratio, 1.58; 95% CI, 1.24-2.01; P < .001). A BRCA1 vs BRCA2 variant was more strongly associated with triple negative breast cancer (odds ratio, 6.33; 95% CI, 2.05-19.54; P = .001). Conclusions and Relevance: In this study, among Caribbean-born individuals with breast and ovarian cancer, 1 in 7 had hereditary breast and ovarian cancer. The proportion of hereditary breast and ovarian cancer varied by island and ranged from 23% in the Bahamas to 4.9% in Jamaica. Each island had a distinctive set of variants.

4.
Glob Health Promot ; : 1757975921995716, 2021 Mar 22.
Article in English | MEDLINE | ID: mdl-33752535

ABSTRACT

Internship programmes have the potential to provide learning and professional experiences, build students' competency and strengthen partnerships between community and training institutions. In this paper, we examine the extent to which a structured internship at The University of the West Indies contributed to experience and competency-building, provided focus and met learners' expectations and satisfaction among a cohort of unpaid health promotion interns. The contribution of placements to the strengthening of health education and promotion competencies and interns' feelings about their experiences are included. Twenty-four (24) internship reports were reviewed using a mix of quantitative and qualitative methods. The majority of interns were Jamaicans (70.8%), 12.5% were from Dominica and the remaining 16.7% represented other nationalities. Health professionals comprised the highest percentage of cohorts (79.2%) and governmental agencies comprised the largest proportion (63%) of internship sites. Activities undertaken were in the areas of planning, implementing and evaluating programmes (71%) and conducting needs assessments (63%). Communication-related activities were reported by 43% of interns. Twenty-one per cent were engaged in lobbying and collaboration with other partners, while 23% established committees to oversee the sustainability of initiatives. While some interns reported negative experiences with supervision at their placement agencies, all valued internship seminars, which they found as a supportive environment in which they were able to share their progress with peers and academics. The opportunity for applying theory to practice and acting as resource persons were reflected as positives. The structured internship approach seems to have merits for building competence and engendering individual satisfaction.

5.
Zootaxa ; 4938(1): zootaxa.4938.1.4, 2021 Feb 25.
Article in English | MEDLINE | ID: mdl-33756985

ABSTRACT

The Neotropical species of the genus Manota Williston are studied, based on material of 146 specimens from French Guiana, Ecuador, Nicaragua, Dominica and the Dominican Republic. Four new species are described, viz. M. corniculata sp. n. (French Guiana), M. pseudocavata sp. n. (French Guiana), M. truuverki sp. n. (French Guiana) and M. vladi sp. n. (Dominican Republic). Manota defecta Williston, 1896, the type species of the genus, is listed from Dominica, representing the first record since its description more than a century ago from a Southern Caribbean Island, St. Vincent. New records of 13 additional species are provided: M. acutistylus Jaschhof Hippa, 2005 (Dominica), M. aligera Hippa, Kurina Sääksjärvi, 2017 (French Guiana), M. digitata Hippa, Kurina Sääksjärvi, 2017 (French Guiana), M. iota Hippa Kurina, 2013 (French Guiana), M. micula Hippa Kurina, 2013 (French Guiana), M. nordestina Kurina, Hippa Amorim, 2018 (French Guiana), M. parva Jaschhof Hippa, 2005 (Nicaragua), M. pauloides Hippa, Kurina Sääksjärvi, 2017 (Ecuador), M. perplexa Kurina, Hippa Amorim, 2017 (Nicaragua), M. rotundistylus Jaschhof Hippa, 2005 (Ecuador), M. serrulata Hippa, Kurina Sääksjärvi, 2017 (French Guiana), M. spinosa Jaschhof Hippa, 2005 (French Guiana), M. subaristata Kurina, Hippa Amorim, 2017 (Ecuador). The number of Neotropical Manota species has risen to 96.


Subject(s)
Diptera , Animal Structures , Animals
6.
Sci Rep ; 11(1): 3933, 2021 Feb 16.
Article in English | MEDLINE | ID: mdl-33594183

ABSTRACT

Phosphine is the most commonly used gas for fumigation for durable commodities globally, but there is still inadequate information regarding its efficacy in conjunction with proper concentration monitoring. In a series of bioassays, insect mortality after specific exposure intervals to phosphine in selected species was examined, as well as the appearance of the so called "sweet spot". The species that were tested were: Oryzaephilus surinamensis (L.), Tribolium castaneum (Herbst), Sitophilus oryzae (L.) and Rhyzopertha dominica (F.) with populations that had different levels of phosphine resistance. Evaluation was conducted by using the Phosphine Tolerance Test (PTT), with exposure of the adult stage for 15, 30, 60, 90, 150 and 300 min at 3000 ppm. At the end of these intervals (separate bioassays for each time interval), the insects were transferred to Petri dishes, in which recovery was recorded at different time intervals (2 h, 1, 2 and 7 days). The majority of susceptible populations of all species were instantly immobilized even in the shortest exposure period (15 min), in contrast with resistant populations that were active even after 300 min. After exposure to phosphine, populations and exposure time affected mortality of susceptible populations, whereas resistant populations recovered regardless of species and exposure time. Additional bioassays at the concentrations of 500, 1000, 2000 and 3000 ppm for 1, 3, 5, 20, 30 and 40 h showed the presence of the "sweet spot", i.e., decrease of mortality with the increase of concentration. In fact, for most of the tested species, the "sweet spot" appeared in 1000 and 2000 ppm at a 5-h exposure time, regardless of the level of resistance to phosphine. This observation is particularly important both in terms of the assessment of resistance and in the context of non-linear recovery at elevated concentrations, indicating the occurrence of strong hormetic reversals in phosphine efficacy.

7.
BMC Genomics ; 22(1): 65, 2021 Jan 20.
Article in English | MEDLINE | ID: mdl-33472593

ABSTRACT

BACKGROUND: The lesser grain borer, Rhyzopertha dominica is a serious pest of stored grains. Fumigation and contact insecticides play a major role in managing this pest globally. While insects are developing genetic resistance to chemicals, hormonal analogues such as s-methoprene play a key role in reducing general pest pressure as well as managing pest populations that are resistant to fumigants and neurotoxic contact insecticides. However, resistance to s-methoprene has been reported in R. dominica with some reports showing a remarkable high resistance, questioning the use of this compound and other related analogues in grain protection. The current study attempts to identify possible molecular mechanisms that contribute in resistance to s-methoprene in R. dominica. RESULTS: Transcriptome analysis of resistant and susceptible strains of this pest species identified a set of differentially expressed genes related to cytochrome P450s, indicating their potential role in resistance to s-methoprene. Laboratory bioassays were performed with s-methoprene treated wheat grains in presence and absence of piperonyl butoxide (PBO), a cytochrome P450 inhibitor. The results indicate that PBO, when applied alone, at least at the concentration tested here, had no effect on R. dominica adult emergence, but has a clear synergistic effect to s-methoprene. The number of produced progeny decreased in presence of the inhibitor, especially in the resistant strain. In addition, we also identified CYP complement (CYPome) of R. dominica, annotated and analysed phylogenetically, to understand the evolutionary relationships with other species. CONCLUSIONS: The information generated in current study suggest that PBO can effectively be used to break resistance to s-methoprene in R. dominica.

8.
Fungal Genet Biol ; 148: 103528, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33515682

ABSTRACT

Among the emerging fungal diseases threatening food security, the Pseudocercospora fijiensis fungus causing black leaf streak disease of banana is one of the most marked examples of a recent worldwide pandemic on a major crop. We assessed how this pathogen spread throughout the latest invaded region, i.e. Central America and the Caribbean. We retraced its population history combining detailed monitoring information on disease outbreaks and population genetic analyses based on large-scale sampling of P. fijiensis isolates from 121 locations throughout the region. The results first suggested that sexual reproduction was not lost during the P. fijiensis expansion, even in the insular Caribbean context, and a high level of genotypic diversity was maintained in all the populations studied. The population genetic structure of P. fijiensis and historical data showed that two disease waves swept northward and southward in all banana-producing countries in the study area from an initial entry point in Honduras, probably mainly through gradual stepwise spore dispersal. Serial founder events accompanying the northern and southern waves led to the establishment of two different genetic groups. A different population structure was detected on the latest invaded islands (Martinique, Dominica and Guadeloupe), revealing multiple introductions and admixture events that may have been partly due to human activities. The results of this study highlight the need to step up surveillance to limit the spread of other known emerging diseases of banana spread mainly by humans, but also to curb gene flow between established pathogen populations which could increase their evolutionary potential.

9.
Article in English | MEDLINE | ID: mdl-33449320

ABSTRACT

The residual efficacy of the enhanced diatomaceous earth (DE) formulation DEBBM alone and in combination with Beauveria bassiana (Hypocreales: Cordycipitaceae) or with the neonicotinoid insecticide imidacloprid against Tribolium castaneum (Coleoptera: Tenebrionidae), Rhyzopertha dominica (Coleoptera: Bostrychidae), Cryptolestes ferrugineus (Coleoptera: Laemophloeidae), and Liposcelis paeta (Psocoptera: Liposcelididae) was investigated in the laboratory. The combination treatments were more effective compared to the single treatments against all examined species. The combinations of DEBBM and imidacloprid and imidacloprid with the highest dose rate of B. bassiana provided the highest mortality values against all tested species for 90 days of storage period. The combination of DEBBM plus B. bassiana resulted to the highest mortalities and to the lowest offspring production of all combinations tested after 180 days of storage. Mortality of adults for each test insect species was decreased over the storage period of 6 months, and the progeny production was increased with the extended storage period. Among the tested insect species, L. paeta was the most susceptible to all three grain protectants followed by C. ferrugineus, R. domina, and T. castaneum. The findings of the current study suggest that the use of DEBBM, imidacloprid, and B. bassiana as grain protectants may provide elevated control of major stored-grain insect species during a prolonged period of storage.

10.
Pest Manag Sci ; 77(4): 1990-2006, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33340233

ABSTRACT

BACKGROUND: There has been a push to diversify integrated pest management (IPM) programs away from exclusive fumigant use in food facilities. Residual insecticides increasingly have been included among plans. In stored products, sublethal toxicity has been neglected in favor of evaluating direct mortality. Here, we evaluated the movement of Tribolium castaneum, Rhyzopertha dominica, Sitophilus oryzae and Sitophilus zeamais in response to aged residues of an existing (Diacon IGR+® with 11.4% methoprene + 4.75% deltamethrin) and novel (Gravista® with 2.85% methoprene + 1.2% deltamethrin + 33.3% piperonyl butoxide synergist) residual insecticide. RESULTS: Using the maximum labeled rate and two exposure times for each species, we assessed distance moved and velocity on wheat, rice and corn. Assessments were made from commodity residues aged between 0 and 12 months (at 3-month intervals). We found that after exposure, movement was reduced by 50-88% and equally by adults exposed to each insecticide formulation compared to untreated controls. After initial application, predicted distance moved increased from 4 to 14 m then 28 m in a 24 h period at 3 and 12 months post-application, respectively. Effectiveness of each insecticide at suppressing movement generally declined by 9-12 month post-application. CONCLUSIONS: Given the quick and dramatic increases in sublethal movement after initial application, our results suggest that sanitation programs in post-harvest environments are extremely important and it may be beneficial to pair chemical control with monitoring to prevent dispersal of affected insects to new areas of a facility. Published 2020. This article is a U.S. Government work and is in the public domain in the USA.


Subject(s)
Coleoptera , Insecticides , Tribolium , Weevils , Animals , Insecta , Insecticides/pharmacology
11.
Zootaxa ; 4878(2): zootaxa.4878.2.12, 2020 Nov 13.
Article in English | MEDLINE | ID: mdl-33311163

ABSTRACT

Brescovit (1993), in the revision of the genus Hibana, described H. talmina, based on males from Venezuela, Colombia, Guyana and northern Brazil. Subsequently, Brescovit Lise (1993) described its female, in an attempt to associate with the male, based on specimens collected in Dominica and Trinidad. Unfortunately, there was no justification for this mating. Recently Galvis et al. (2019) collected several couples of Hibana talmina in mangrove forests in some surrounding areas of Cartagena (Bolívar, Colombia), during a study of predation of crabs on these spiders. The detailed study of these couples showed that there was a wrong mating by Brescovit Lise (1993) and this is corrected here. The original distribution is updated, with the exclusion of Dominica. The females previously assigned to H. talmina are treated here as Hibana labonita sp. nov., which is diagnosed in relation to the other species of Hibana.


Subject(s)
Spiders , Animal Distribution , Animals , Female , Male
12.
Washington, D.C.; PAHO; 2020-11-09.
in English, Spanish | PAHO-IRIS | ID: phr-53109

ABSTRACT

All 54 countries and territories in the Region of the Americas have reported COVID-19 cases and deaths. Since the 15 October 2020 PAHO/WHO Epidemiological Update on COVID-19 and as of 5 November 2020, 592,561 additional confirmed cases of COVID-19, including 54,832 deaths, have been reported in the Region of the Americas, representing a 14.3% increase in cases and a 8.5% increase in deaths. In the last 7 weeks (between 16 September and 4 November), a relative increase was observed, both in the number of cases and number of deaths across all subregions. The highest increase was observed in Central America subregion, with a 30.7% increase in cases and a 24.9% increase in deaths, followed by the North America subregion, with a 29.8% increase in cases and a 17.6% increase in deaths, the Caribbean and the Atlantic Ocean Islands subregion, with a 29.7% increase in cases and an 24.4% increase in deaths, and the South America subregion, with a 26.1% increase in cases and a 22.3% increase in deaths. In the last 7 weeks, a relative increase in confirmed cases greater than 50% (range 52.0% to 80.8%) is observed in the Bahamas, Belize, Bonaire, Sint Eustatius and Saba, Curacao, Dominica, Guadeloupe, Guyana, Jamaica, Martinique, Paraguay, Saint Barthelemy, and Saint Lucia. With respect to deaths, a relative increase of ≥ 50% (range 50.0% to 80.5%) is observed in Argentina, the Bahamas, Belize, Bonaire, Sint Eustatius, and Saba, Costa Rica, Guadeloupe, Guyana, Jamaica, Paraguay, and Saint Martin. [...]


Los 54 países y territorios de la Región de las Américas han notificado casos y defunciones de COVID-19. Desde la última actualización epidemiológica publicada por la OPS/OMS el 15 de octubre de 2020 hasta el 4 de noviembre de 2020, fueron notificados 592.561 casos confirmados de COVID-19, incluidas 54.832 defunciones adicionales en la región de las Américas, lo que representa un aumento de 14,3% de casos y de 8,5% de defunciones. En las últimas 7 semanas (entre el 16 de septiembre y el 4 de noviembre) en todas las subregiones se observó un incremento relativo, tanto en el número de casos como en el número de defunciones. En América Central se observó el mayor incremento, con 30,7 % de aumento en casos y 24,9% de aumento en defunciones. El resto de las subregiones, incrementaron de la siguiente manera, en orden decreciente: América del Norte con 29,8 % de incremento en casos y 17,6% de incremento en defunciones, las Islas del Caribe y del Océano Atlántico con 29,7% de aumento en casos y 24,4% de aumento en defunciones y América del Sur con 26,1% de aumento en casos y 22,3% aumento en defunciones. En este mismo período de 7 semanas, Bahamas, Belice, Bonaire, San Eustaquio y Saba, Curazao, Dominica, Guadalupe, Guyana, Jamaica, Martinica, Paraguay, San Bartolomé y Santa Lucía presentaron un incremento relativo de casos confirmados mayor a 50% (rango 52,0% a 80,8%). Respecto de las defunciones, Argentina, Bahamas, Belice, Bonaire, San Eustaquio y Saba, Costa Rica, Guadalupe, Guyana, Jamaica, Paraguay y San Martín presentaron un incremento relativo ≥ 50,0% (rango 50,0%% a 80,5%). [...]


Subject(s)
Coronavirus Infections , Coronavirus Infections , Coronavirus , Infection Control , Betacoronavirus , Emergencies , International Health Regulations , Coronavirus Infections , Infection Control , Emergencies , International Health Regulations
13.
3 Biotech ; 10(11): 481, 2020 Nov.
Article in English | MEDLINE | ID: mdl-33101827

ABSTRACT

The present study aimed to highlight the insecticidal activity of the Algerian desert truffle Terfezia claveryi Chatin against two post-harvest pests of rice and other cereal products, the rice weevil Sitophilus oryzae (L.), and the lesser grain borer Rhyzopertha dominica (F.), using direct contact application method with the filter paper impregnation technique. Soxhlet apparatus was used for extraction with chloroform as solvent. The major compounds in chloroform extract of T. claveryi were identified using gas chromatography-mass spectrometry (GC-MS). The two-way ANOVA was used for statistical analysis to determine the exposure time and doses with the greatest insecticidal activity. Findings of this study revealed that the major compounds were fatty acids: linoleic acid, methyl ester (14.84%), 11,14-eicosadienoic acid, methyl ester (11.55%), oleic acid, methyl ester (7.1%), and palmitic acid (6.96%). However, chamazulene (0.88%) was found to be minor compound. Our results describe for the first time the presence of chamazulene in desert truffle. The result showed also that the most potent insecticidal activity of chloroform extract of T. claveryi was found towards S. oryzea with LD50 value of 162.11 µg/mL. For concentrations of 250 and 300 µg/mL, this extract was able to eradicate 96.65 ± 1.15% and 100.0 ± 0.0% of S. oryzea after 24 h of exposure. However, it caused only 47.24 ± 1.15% and 50.66 ± 1.15% of mortality of R. dominica, respectively, after 6 days. This work offers promising prospects for the use of desert truffles extracts as a potential insecticidal agent for improving quality and safety of stored foods against damage caused by stored-product pests.

14.
Pest Manag Sci ; 2020 Oct 13.
Article in English | MEDLINE | ID: mdl-33051965

ABSTRACT

BACKGROUND: Phosphine-susceptible or resistant populations of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae) adults were exposed to 0 (control), 1000 and 3000 ppm of phosphine for 15 or 90 min, to estimate behavioral and mobility responses after exposure to phosphine. Knockdown of the exposed individuals after exposure was recorded visually. The total distance moved and velocity of movement were assessed immediately after exposure to phosphine, 2 or 24 h later using a camera coupled with automated video tracking software (i.e. Ethovision®). RESULTS: For both species tested, the highest percentage of dead adults was noted at the highest concentration (3000 ppm) for both exposure times. For T. castaneum, total distance moved and velocity decreased as the concentration increased for the susceptible population, whereas there was significant variation among individuals in the resistant population. For R. dominica, the distance moved was reduced at the highest concentrations. Individuals of R. dominica moved less than those of T. castaneum and there were significant differences in mobility between susceptible and resistant populations for both species tested. Recovery was much faster in the case of the resistant populations. CONCLUSIONS: Changes in movement parameters can be further exploited in assessing the efficacy of different management tactics, such as trapping and sampling. Automated video tracking systems such as Ethovision® can be used to track and record insect behavioral response, providing a more objective measure of insecticide efficacy than visual categorizations. These data shed light on insect mobility and behavioral responses to fumigation treatments in relation to resistance.

15.
Insects ; 11(10)2020 Oct 19.
Article in English | MEDLINE | ID: mdl-33086529

ABSTRACT

The lesser grain borer, Rhyzopertha dominica, and the rust red flour beetle, Tribolium castaneum, are two major beetle pests commonly found infesting stored products worldwide. Both species can cause severe economic damage and their management is complicated by their potential to develop resistance to several of the limited chemical options available. However, pest management strategies can be improved by understanding the ecology of the pest insect. To determine the spatiotemporal activity of R. dominica and T. castaneum, we conducted a trapping study over two years in a temperate region of south-eastern Australia, with traps located near grain storages and fields. We captured higher numbers of R. dominica than T. castaneum, and both species were more prevalent in traps located close to grain storages. Similar and consistent seasonal patterns were displayed by both species with activity ceasing during the winter (June-August) months. We found linear correlations between maximum daily temperatures and trap catches, and minimum threshold temperatures for flight activity were 14.5 °C and 15.6 °C for R. dominica and T. castaneum, respectively. The results are discussed in relation to the ecology of these pests along with their implications for pest management.

16.
Zootaxa ; 4830(3): zootaxa.4830.3.4, 2020 Aug 14.
Article in English | MEDLINE | ID: mdl-33056145

ABSTRACT

After reviewing the systematics and distribution of the living and fossil small West Indian taxa of Tytonidae (Tyto), we reached the following conclusions: (1) Strix tuidara J. E. Gray, 1827, type locality of Brazil, is the earliest available and correct name to be used in a binomen for New World mainland barn owls; (2) the North American mainland subspecies Tyto tuidara pratincola (Bonaparte, 1838), new combination, is resident in the Bahamas ("Tyto perlatus lucayanus" Riley, 1913, is a synonym), where it probably did not colonize until after the European introduction of Rattus Fischer, in Hispaniola (Dominican Republic and Haiti) where it became established in the 20th century, and subsequently in Puerto Rico; (3) Tyto furcata (Temminck, 1827) of Cuba, Jamaica and the Cayman Islands is a different species restricted to its insular distribution, with "T. alba niveicauda" Parkes Phillips, 1978, of the Isle of Pines (now Isla de la Juventud) as a synonym; (4) the distinct species Tyto glaucops (Kaup, 1852), now endemic to Hispaniola, once occurred in Puerto Rico, as the fossil species "T. cavatica" Wetmore, 1920, is here shown to be a synonym; (5) the smallest taxon Tyto insularis (Pelzeln, 1872) of the southern Lesser Antilles is treated as a separate species, in which the nominate subspecies T. i. insularis (St. Vincent, Grenada, and the Grenadines) differs slightly but consistently in coloration from T. i. nigrescens (Lawrence, 1878) of Dominica; (6) another barn owl, Tyto maniola, new species, of this group of small tytonids from the West Indies inhabited Cuba during part of the Quaternary, and is here named and described.


Subject(s)
Strigiformes , Animals , Fossils , Rats , West Indies
17.
Article in English | MEDLINE | ID: mdl-32933140

ABSTRACT

The present study investigates the interaction between cannabidiol (CBD) oil and three biopesticides: Azatin and two baculovirus formulations (Madex and Helicovex), both separately and in combination, in order to investigate their interaction against adults of four major coleopteran stored-product pests: Sitophilus zeamais (Coleoptera: Curculionidae), Rhyzopertha dominica (Coleoptera: Bostrichidae), Prostephanus truncatus (Coleoptera: Bostrichidae) and Trogoderma granarium (Coleoptera: Dermestidae). CBD, which has been understudied for its insecticidal properties, was applied at three different doses (500, 1500 and 3000 ppm). The biopesticides were administered at 1500 ppm. Interactions in the combined treatments were mathematically estimated as not synergistic and mostly competitive except for the combined treatments of CBD (1500 and 3000 ppm) with Azatin (1500 ppm) which were marked by an additive interaction. In its individual application, CBD oil generated the highest insect mortality while its effect was clearly dose-dependent. The findings reveal a promising effect of CBD oil against these coleopterans which had not been previously tested together.


Subject(s)
Cannabidiol/toxicity , Coleoptera/drug effects , Insecticides/toxicity , Pesticides/toxicity , Weevils/drug effects , Animals , Dominica
18.
Insects ; 11(9)2020 Sep 08.
Article in English | MEDLINE | ID: mdl-32911831

ABSTRACT

Diatomaceous earth (DE) has long been known as a potential protectant for stored cereals against various stored product insects. Despite favorable effect for the environment and human health, DE has some negative side effects on the treated commodity. In order to minimize negative response and to improve its efficacy, this paper represents a study of developed natural formulation based on DE SilicoSec® enhanced with botanicals (essential oil lavender, corn oil, and bay leaves dust) and silica gel. The activity of formulation (labeled as N Form) was tested against Sitophilus oryzae (L.), Rhyzopertha dominica (F.), and Tribolium castaneum (Herbst) in seed wheat and barley under controlled conditions. As a reference comparative value, DE SilicoSec® was used. N Form showed higher efficacy than DE, especially in barley at the lowest concentration, inducing higher mortality of all three insect species. The highest average progeny inhibition was recorded in R. dominica population both in seed wheat and barley with 94.9% and 96.3% of inhibition, respectively, followed with S. oryzae and T. castaneum inhibition of 90.6% and 86.1%, respectively, in wheat and 94.9% and 89.7%, respectively, in barley. Results indicate that the developed natural formulation N Form enhanced the activity of DE SilicoSec® using lower amount of DE dust and that it could be successfully implemented for storage of cereals as alternatives to chemical pesticides for stored product insect control.

19.
Zookeys ; 966: 57-151, 2020.
Article in English | MEDLINE | ID: mdl-32982546

ABSTRACT

The long-legged flies (Dolichopodidae) of the island of Montserrat in the Lesser Antilles have been surveyed and include 63 species in 27 genera. The following eleven new species are described and illustrated: Amblypsilopus marskeae sp. nov., Medetera iviei sp. nov., Medetera montserratensis sp. nov., Systenus ladonnae sp. nov., Thrypticus mediofuscus sp. nov., Chrysotus antillensis sp. nov., Chrysotus callichromoides sp. nov., Chrysotus interfrons sp. nov., Chrysotus montserratensis sp. nov., Diaphorus robinsoni sp. nov., and Sympycnus montserratensis sp. nov. Six species have only been found on Montserrat (ca. 10% endemicity). Keys are provided to the genera and species on Montserrat, their known distribution summarized, and additional new island records provided for many species. Asyndetus wirthi Robinson is synonymized with A. interruptus (Loew) and Achradocera apicalis (Aldrich) is removed from synonymy with A. barbata (Loew). Diaphorus flavipes Aldrich is transferred to Chrysotus as a new combination. A new replacement name, Chrysotus milvadu nom. nov., is provided for the Nearctic Chrysotus parvulus Van Duzee. Lectotypes are designated for Achradocera apicalis (Aldrich) and Asyndetus fratellus Aldrich. The fauna of Montserrat is summarized and compared with that of Dominica. Collecting methods are compared and threats to the dolichopodid fauna of Montserrat discussed.

20.
Bull Entomol Res ; : 1-7, 2020 Aug 03.
Article in English | MEDLINE | ID: mdl-32744195

ABSTRACT

Primary pests such as Rhyzoperta dominica may increase the contents of dockage, dust, and frass in grain mass. Although it has been suggested that frass can affect the population growth of stored product pests and ecological interactions among primary and secondary pests in stored grain, this has not been validated experimentally. Therefore, this work experimentally tested the hypothesis that R. dominica wheat frass may support population increases in secondary pests such as Tribolium confusum, T. castaneum, and Oryzaephilus surinamensis for the first time. The effect of frass on secondary pest performance was compared with the effects of various physical qualities of wheat grain (i.e., intact grain kernels, grain fragments, flour, grain + frass) and an artificially enriched control diet (milled wheat kernels, oat flakes, and yeast). The results showed that the clean intact grain kernels did not support the population growth of any tested species, and the nutrient-rich control diet provided the best support. Frass was a significantly better food medium for O. surinamensis and T. castaneum than flour or cracked grain, while T. confusum performed equally well on flour and frass. Our results showed that in terms of food quality and suitability for the tested species, frass occupied an intermediate position between the optimized breeding diet and simple uniform cereal diets such as cracked grain or flour. The results suggest that (i) the wheat frass of primary pest R. dominica is a riskier food source for the development of the tested secondary pests than intact or cracked wheat grain or flour; (ii) frass has the potential to positively influence interspecific interactions between R. dominica and the tested secondary pests; and (iii) wheat grain should be cleaned if increases in R. dominica populations and/or accumulated frass are detected.

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