43 research outputs found

    The use of different stingless bee species to pollinate cherry tomatoes under protected cultivation

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    Under standard greenhouse conditions, the tomato fruits of spontaneous self-pollination are expected to be of lower quality than those of bee pollination, as well as that simultaneously use different bee species which can complement pollination services. To test these hypotheses, we evaluated the complementarity of pollination services from the use of three native stingless bee species that have distinct foraging behaviors, Melipona bicolor Lepeletier 1836, Nannotrigona testaceicornis (Lepeletier 1836) and Partamona helleri (Friese 1900) during flowering of cherry tomatoes in greenhouses. Fruit quality parameters resulted from pollination experiments were measured and the acclimatization of the analyzed bee species was evaluated. Visits of M. bicolor and N. testaceicornis to the tomato flowers contributed significantly to the increase in the average weight, seed number, and thickness of the pericarp (only for N. testaceicornis) of the fruits, compared to the spontaneous self-pollination treatment. Partamona helleri, however, did not show any pollen collection behavior in the experimental conditions. Although N. testaceicornis do not perform the buzzing behavior, fruits from its pollination were equivalent to those fruits from pollination by M. bicolor. The simultaneous use of bee species with different flower-visiting behaviors can optimize tomato pollination in greenhouses, contributing significantly to the quality of the fruits and the increase of productivity and consequently the commercial value

    Karyotypic description of the stingless bee Melipona quinquefasciata Lepeletier, 1836 (Hymenoptera, Meliponini) with emphasis on the presence of B chromosomes

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    Stingless bees are distributed widely in the tropics, where they are major pollinators of several plant spe- cies. In this study, the karyotype of Melipona quinquefasciata Lepeletier, 1836 was analysed, with emphasis on the presence of B chromosomes. Post-defecating larvae were analysed using Giemsa staining, the C- banding technique, sequential staining with fluorochromes, and FISH. The chromosome number ranged from 2n = 18 to 22 (females) and from n = 9 to 13 (males) due to the presence of 0–4 B chromosomes. This result demonstrates that M. quinquefasciata has the same chromosomal number as other Melipona Illiger, 1806 species. Considering the A complement, heterochromatin was located only in the pericentro- meric region of pair 1. Staining with chromomycin A 3 (CMA 3 ) and labelling with rDNA probe, indicated that this region corresponded to the nucleolus organising region. The B chromosomes of M. quinquefas- ciata could be found in individuals from different localities, they were completely heterochromatic (C- banding) and uniformly stained by 4’,6-diamidino-2-phenylindole (DAPI). Variations in the number of B chromosomes were detected between cells of the same individual, between individuals of the same colony, and between colonies from different localities

    Post-embryonic Development of the Seminal Vesicle in the Stingless Bee Melipona quadrifasciata Lepeletier, 1836 (Apidae: Meliponini)

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    The male accessory glands of stingless bees (Apidae: Meliponini) are absent and the morphology of their seminal vesicle indicate probable secretory function by this organ. This study investigated the post-embryonic development of the seminal vesicles in males of the stingless bee Melipona quadrifasciata by histology and histochemistry. White-eyed pupae, pink-eyed pupae, brown-eyed pupae, black-eyed pupae, newly emerged and sexually mature males were studied. Seminal vesicle has a wall with a single layered epithelium onto a thin basement membrane, followed by a well-developed muscle layer. The epithelium is polarized in the pupal stage with basal cell region strongly positive for glucoconjugates and carbohydrates. The seminal vesicle has an enlarged lumen from the young pupal stages with luminal content increasing gradually with glucoconjugates along the pupal development. In the newly emerged and mature males, the histochemical tests to carbohydrates were negative. In the sexually mature males, spermatozoa clusters are embedded by the glucoconjugates content of the seminal vesicle lumen. In conclusion, the seminal vesicle of M. quadrifasciata has a secretory function during the pupal stage and in newly emerged males, whereas in adult males this organ stores the spermatozoa.

    Prediction of social structure and genetic relatedness in colonies of the facultative polygynous stingless bee Melipona bicolor (Hymenoptera, Apidae)

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    Stingless bee colonies typically consist of one single-mated mother queen and her worker offspring. The stingless bee Melipona bicolor (Hymenoptera: Apidae) shows facultative polygyny, which makes this species particularly suitable for testing theoretical expectations concerning social behavior. In this study, we investigated the social structure and genetic relatedness among workers from eight natural and six manipulated colonies of M. bicolor over a period of one year. The populations of M. bicolor contained monogynous and polygynous colonies. The estimated genetic relatedness among workers from monogynous and polygynous colonies was 0.75 ± 0.12 and 0.53 ± 0.16 (mean ± SEM), respectively. Although the parental genotypes had significant effects on genetic relatedness in monogynous and polygynous colonies, polygyny markedly decreased the relatedness among nestmate workers. Our findings also demonstrate that polygyny in M. bicolor may arise from the adoption of related or unrelated queens

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    Testis length distinguishes haploid from diploid drones in Melipona quadrifasciata (Hymenoptera: Meliponinae)

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    Testes length in diploid and haploid larvae drones of Melipona quadrifasciata were investigated to ascertain whether it is a good character to distinguish haploid from diploid drones. Two groups of haploid and two groups of diploid drones were compared. The results show that diploid males have shorter testes than haploid males. Another interesting observation was that whereas diploid males from different groups had testes of similar sizes, haploid males produced by different queens had testes which differed significantly in size. It is suggested that measurements of the testes length could be used to determine ploidy and contribute to the understanding of the population biology of this and other related Hymenoptera species

    Isoenzyme variation in Melipona rufiventris (Hymenoptera: Apidae, Meliponina) in Minas Gerais State, Brazil

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    The stingless bee Melipona rufiventris is an important pollinator in several Brazilian ecosystems. Originally widely distributed in Minas Gerais (MG) state, this species is becoming very rare. Therefore this species was included in the endangered species list of MG. We used isoenzyme data for a better understanding of the genetic structure of several M. rufiventris colonies. Samples of 35 colonies were collected from 12 localities and evaluated by nine enzymatic systems, which yielded 17 loci. M. rufiventris genetic variation was found to be low, typical of an endangered species. The proportion of polymorphic loci was 5.88% in both ecosystems. Only Est-4 was polymorphic in colonies from the Forest and Mdh-1 in colonies from the Cerrado. The expected heterozygosity ranged from 0.0068 in the Cerrado to 0.0078 in the Forest. Despite this, enzyme electrophoretic analyses provided a good idea of the diversity between samples from Cerrado and Forest which reinforce the existence of two different “forms” of M. rufiventris in MG, one present in the Cerrado and the other in Forest. This information is of great importance for the conservation of, M. rufiventris in MG
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