Southeastern Bahia Research Articles

Ascomycota in the litter of Inga edulis and Lafoensia pacari in an Atlantic Forest remnant in southeastern Bahia state, Brazil

Abstract The Ascomycota population in the litter of Inga edulis and Lafoensia pacari trees was identified and its richness was evaluated. The collections were carried out from October 2018 to July 2019. Twenty fallen leaves were collected in different stages of decomposition. The leaf samples were carefully washed in running water and incubated in humid chambers. The fungal structures were mounted in PVLG resin and observed under a light microscope. The identification was done by consulting the specific literature. Distribution studies included richness, frequency, constancy, and similarity of the fungal populations. The total richness was 48 species and 36 genera corresponding to 58.33% in I. edulis and 60.41% in L. pacari. Most taxa had sporadic frequency and accidental constancy. There was low similarity between plant species. Ascomycota populations are well represented in Inga edulis and Lafoensia pacari litter. Richness, frequency, constancy, and similarity of these populations varied little in function of the collection date, climate and host plant. Lower richness observed in the second collection may reflect the effect of reduced humidity observed in that time of the year.

New records of threatened cotingas (Aves, Cotingidae) in fragments of Atlantic Forest in southeastern Bahia, Brazil

We provide new records of three globally threatened species of bird belonging to the family Cotingidae: Procnias nudicollis (Vieillot, 1817), Xipholena atropurpurea (Wied, 1820), and Cotinga maculata (Statius Müller, 1776). These findings in non-protected areas of the Brazilian Atlantic Forest and, for C. maculata, at higher altitudes than previously reported, improve our understanding of the distribution of these threatened species and can aid in conservation efforts to protect them.

EXERCÍCIOS FUNCIONAIS NA 'AUTOGESTÃO’ E ‘AUTONOMIA’ DE PESSOAS IDOSAS COM OSTEOARTROSE

This paper reports the project developed by the Interdisciplinary Center of Studies and Extension in Health Care to Families Living with Chronic Diseases – NIEFAM at the State University of Southeastern Bahia. The project aimed to perform and intervention, using physical activity, on the musculoskeletal system of elderly people in Osteoarthrosis treatment, and verify whether post-intervention patients presented improvement in their daily life functional capability, self-management and health autonomy. A mixed and interventionist method was implemented in the Urban Social Center of Jequie, BA, during the period March-June/2019, through a kinesiotherapy protocol, supported by instruments such as the Lawton Scale, Analog Visual Scale; semi-structured interview and clinical record and medical record for the treatment of five elderly women. The results showed positive impacts on the process of healthier longevity in the patients’ daily activities, in prevention/control of non-communicable chronic diseases, pain relief, and the significance of the interventionist method which provided the patients with the first proximal care actions.

Ant Community Evolution According to Aging in Brazilian Cocoa Tree Plantations

Agriculture is frequently held accountable for the depletion of biotic diversity, although a few agroforestry systems support the conservation of a number of organisms. Cocoa farming is noteworthy as an example of an agricultural activity that benefits or maintains species richness. However, the mechanism by which the biodiversity persists throughout the entire process of plant development remains obscure. In Southeastern Bahia, Brazil, cacao tree plantations support the conservation of a large amount of organisms native to the Atlantic Forest, between them the ants. This study aims at recording the relationship between cocoa tree development and ant community structure. The experiment was carried out in a series of six cocoa tree plantations aged one, three, four, eight, fifteen and 33 years, distributed across the experimental grounds of the Cocoa Research Center at Ilhéus. 1,500 ant samples were collected using the sampling techniques: hand collection, honey and sardine baits, entomological blanket and “pitfall”. Highest values for diversity and richness were reported in the 15-years-old cocoa plantation. No significant correlations between diversity, richness or plant age were reported. Considering the faunistic composition, a statistical similarity was observed between the plantations close in age to one another. Plant aging did not exert any influence on the diversity gradient and richness in the succession process of the ant community. In young plantations, there are low differences between the ants found on the ground and the ones found on the young cocoa trees. In older plantations, the ant community divides in two distinct assemblages on the ground and on the trees. The variations observed in the ant community along the plant development were likely caused by the structural organization of the dominant species mosaic.

Babesia spp. and Ehrlichia chaffeensis infection in Dogs from Southeastern Bahia, Brazil

Background: Tickborne diseases are frequent in tropical countries such as Brazil. Protozoa of the Babesia genus and bacteria of the Ehrlichia genus spread throughout the country with high prevalences in urban and rural areas, causing clinical or subclinical diseases in dogs. This study aimed to investigate the prevalence of infection from Babesia spp. and Ehrlichia chaffeensis in the dog population in the municipality of Ituberá, Bahia, Brazil, and to verify the risk factors associated with the infections.Materials, Methods & Results: A cross-sectional study was conducted, consisting of the following procedures: clinical examination and blood samples collection from 380 dogs and application of a structure questionnaire to dog owners to collect epidemiological data. All dogs were evaluated for the presence of ticks and clinical signs associated with the infections. Blood samples were collected and tested for Babesia spp. through capillary blood smears, indirect immunofluorescence assays (IFAT), and polymerase chain reaction (PCR); all the samples were also tested for E. chaffeensis through nested PCR. Intra-erythrocyte piroplasms were visualized in the blood smears of two animals (2/380; 0.5%) in the cytology exams. Anti-B. canis antibodies were detected in 140/380 (36.8%) dogs, at 1:40 dilution. By PCR, 147/380 (38.7%) dogs tested positive for infection by Babesia sp., but no animal was infected by E. chaffeensis. Only 115/380 dogs (30.3%) were infested by ticks. In total, 223/380 dogs (58.7%) were found infected by Babesia spp. No clinical signs were it found to be significant for the infection. The infected (Ht = 40%) and uninfected dogs’ (Ht = 39%) hematocrit averages were not found to significantly differ (P = 0.47). No hematological changes were found to be significant for the disease. The evaluated variables sex, habitat (urban or rural), exposure to other dogs, age, and infestation by ticks were not found to be risk factors. The condition of semirestriction of 175/223 (78.4%) dogs was found as a risk factor for the infection (P = 0.01; OR = 1.75; IC 95% = 1.10-2.78).Discussion: The low detection from blood smears was inferior to the lowest prevalences found in Brazil. On the other hand, the high seroprevalence rate by IFAT observed in this study was found in other Brazilian states. The low infection prevalence in the cytologic analysis associated with high seroprevalence are characteristics of chronic or subclinical infections. The high seroprevalence rates may also indicate chronicity and/or subclinical disease when associated with low parasitemia and may also be indicated by the low title variation observed. In this study, some dogs that tested positive for Babesia by serology tested negative in the PCR, which suggests a previously exposure to this pathogen and maintenance of detectable levels of antibodies, or that they were subclinical or chronic carriers of the infection. The equal hematocrit averages of dogs either carrying or not the disease suggests that the infected animals, especially the seemingly healthy dogs, are subclinical or chronic carriers, either asymptomatic or otherwise, that are adapted to the disease, which may contribute to the agent remaining in this population. The fact that no clinical sign of hematological change was significant for the infection may demonstrate the low pathogenicity of this agent in the evaluated population. The semi-restricted condition of the dogs as a risk factor is probably due to the increased exposure of these animals to canine babesiosis vectors during their movement through different neighborhood areas and villages in the municipality. The combination of diagnostic methods is important to identify the infection and determine its prevalence in epidemiological studies. Also, PCR was fundamental in this study, to identify the infection in asymptomatic dogs.

Population structure and migration of the witches’ broom pathogen Moniliophthora perniciosa from cacao and cultivated and wild solanaceous hosts in southeastern Brazil

Moniliophthora perniciosa, causal agent of witches’ broom disease in cacao plantations in South America and the Caribbean Islands, has co‐evolved with its host cacao, but the pathogen has also emerged in many solanaceous hosts in Brazil, including economically important food crops and wild species. This study was carried out to: (i) determine the existence of host subpopulations of M. perniciosa in Brazil; (ii) estimate gene and genotypic diversity of M. perniciosa host subpopulations infecting solanaceous hosts in southeastern Bahia and Minas Gerais states, Brazil; and (iii) estimate the amount and directionality of historical migration of M. perniciosa subpopulations. Up to 203 M. perniciosa isolates collected from solanaceous hosts with symptoms from Bahia and Minas Gerais states in Brazil and from Theobroma spp. (cacao) and Herrania spp. were characterized with 11 microsatellite markers. Factorial correspondence analyses, minimum‐spanning network and Bayesian clustering revealed genetic clusters associated with their host of origin. Significant subpopulation differentiation was evident (ΦST = 0.30, P ≤ 0.05) among M. perniciosa host subpopulations. Most of the multilocus microsatellite genotypes (MLMGs) were host‐specific, with few MLMGs shared among subpopulations. Pairwise comparisons among M. perniciosa host subpopulations were significant, except between jurubeba (Solanum paniculatum) and cultivated solanaceous subpopulations. The combined analyses rejected the null hypothesis that M. perniciosa in Brazil is a single genetic population not structured by host. These findings support a scenario of introduction and subsequent adaptation to solanaceous hosts that should be taken into consideration to improve mitigation and management of M. perniciosa.

Contrasting effects of habitat management on different feeding guilds of herbivorous insects in cacao agroforestry systems

Human pressure on natural habitats increases the importance of agroforests for biodiversity conservation. The objective of this study was to evaluate the role of cacao traditional cultivation system (CTCS) on the conservation of the herbivorous insect community when compared with a monodominant rubber agroforest, a type of agricultural system for cacao cultivation. The insects were sampled in three habitats in Southeastern Bahia, Brazil: native forests, CTCS and rubber agroforests. In each habitat, 18 plots of 10 m2 were established, and the structural measures were collected and herbivorous insects were sampled with a Malaise/window trap. The diversity of folivorous decreased with the simplification of vegetation structure, but species composition was similar among habitats. In addition to a decrease in the availability of resources in monodominant rubber agroforests, the latex present in these systems have limited the occurrence of species that cannot circumvent latex toxicity. The diversity of sap-sucking insects was similar among habitats, but species composition was similar only in the CTCS and native forest, and it was different in the rubber agroforest. We observed turnover and a higher frequency of individuals of the family Psyllidae in the rubber agroforest. The biology and behavior of Psyllids and absence of natural enemies enable their diversity to increase when they are adapted to a new host. We observed a shift in the composition of xylophagous insects in the rubber agroforest compared to that in other habitats. Moreover, this agroforest has low species richness, but high individual abundance. Latex extraction is likely an important additional source of volatile compounds discharged into the environment, and it increases the attraction and recruitment of coleoborers to these sites. We concluded that CTCS has an herbivorous insect community with a structure similar to the community found in native forests of the region, and they present a more interesting conservation strategy when compared to rubber agroforests. We also emphasized the potential risk of local pest outbreaks in rubber agroforests for both the rubber and associated cacao trees.

Predatory beetles in cacao agroforestry systems in Brazilian Atlantic forest: a test of the natural enemy hypothesis

The natural enemy hypothesis predicts a positive correlation between plant species diversity and natural enemy control. This study aimed to evaluate the role of traditional cacao agroforests, known as “cabrucas,” on the conservation of the predatory beetle community compared to that of monodominant rubber agroforests. Predatory beetles were sampled in three habitats in Southeastern Bahia, Brazil: cabrucas and rubber agroforests and native Atlantic forests. In each habitat, 18 10 m2 plots were established, in which canopy cover was measured and beetles were sampled with a modified Malaise/window trap. Land use intensification did not affect the composition of predatory beetles, with the presence of widely distributed species that are also capable of colonizing simpler environments such as the rubber agroforest. Canopy cover had a positive effect on generalist predator diversity and we observed a reduction in the abundance and species richness of generalist predators with increasing habitat homogenization. Despite the simplified structure of the habitat, the remaining tree diversity and canopy cover in cabrucas supported a community of generalist predators similar to the one found in the native forest. Species diversity of bark beetle predators was higher in cabrucas, which may be due to the high diversity of bark beetles and the favorable abiotic conditions, whereas the low abundance of prey in the native forest and severe abiotic conditions in the rubber agroforest probably determined the lower diversity of generalist predators in these habitats. Cabrucas play an important role in the conservation, supporting a community of predatory beetles more similar to the one found in native forest and that is more effective at controlling populations of herbivores than in homogeneous rubber agroforests.

Diagnosis and epidemiology of canine leishmaniasis in southeastern Bahia, Brazil.

Leishmaniasis is a disease caused by protozoa of the genus Leishmania. Two distinct forms are recognized: visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL). In the Americas, the causative agent of VL is L. infantum chagasi, whereas L. braziliensis is principally responsible for CL. Domestic dogs constitute the main source of VL in urban environments, and have also been implicated in CL epidemiology. We carried out molecular and serological surveys to detect Leishmania infection in dogs from the municipality of Ituberá in Bahia, Brazil. Furthermore, we identified risk factors associated with illness in dogs from this locality. Blood samples were collected from 399 dogs and tested using an indirect immunofluorescence assay (IFA) and polymerase chain reaction (PCR) to detect Leishmania spp antibodies and L. infantum chagasi and L. braziliensis DNA, respectively. Dogs were clinically evaluated and tissue samples from those exhibiting skin lesions were examined for parasites. In addition, the dog owners completed an epidemiological questionnaire to identify factors associated with infection. Skin lesions consistent with CL were found on 37 (9.3%) of the evaluated animals, but parasitological examination was negative for all samples. The IFA returned positive results for 60 (15%) dogs. PCR identified DNA from L. braziliensis in 86 (21.6%) animals, where as all samples proved negative for L. infantum chagasi. The 134 dogs (33.6%) testing positive using IFA and/ or PCR were considered infected, and of these, only 13 demonstrated skin lesions. Animals from rural areas were 3.39-times more likely to be infected compared to those in urban environments.

Canine hepatozoonosis in southeastern Bahia, Brazil.

In Brazil, canine hepatozoonosis is a tick-borne subclinical hemoparasitosis caused by a protozoa Hepatozoon canis and is highly prevalent in dogs in rural areas. An epizootiological study was conducted to investigate the prevalence of H. canis in the canine population of Ituberá, Bahia, and to analyze any associated risk factors. Blood samples were collected from 380 dogs and determined the presence of the protozoan by performing capillary blood smear and polymerase chain reaction (PCR). Epizootiological data were collected by asking dog owners to answer a structured questionnaire. H. canis gamonts were not detected in the blood smears. However, PCR detected H. canis in 163/380 (42.9%) dogs examined. Physical examination and anamnesis indicated 105 (64.4%) positive asymptomatic dogs. Hematological alterations were observed in 115 (70.5%) infected dogs. No clinical, hematological, or epizootiological variable was found to be significantly associated to the infection. In conclusion, the high prevalence of H. canis infection in local dogs may be because of the peri-urban features of this municipality. Moreover, to the best of our knowledge, this study the first study to report H. canis infection in the State of Bahia.

Taxonomy of “Mouse-colored Tapaculos” (II): An endangered new species from the montane Atlantic Forest of southern Bahia, Brazil (Passeriformes: Rhinocryptidae:Scytalopus)

ABSTRACT An isolated population of tapaculos attributed to Scytalopus speluncae has been known from the mountains of southeastern Bahia state, Brazil, since the early 1990s, and a second isolated population was discovered in 1999. Morphological and bioacoustic analyses of 11 specimens and several tape recordings indicated that these populations represent a new species, in agreement with a previous molecular phylogenetic study. This species is unambiguously distinguished from its closest relatives by 4 suites of characters: (1) morphometrics–body proportions, (2) plumage color, (3) vocalizations, and (4) genetics. Using each of these character sets, separately or in combination, one can distinguish with 100% confidence the new species from its sister lineages. The new species is known from only 5 localities distributed in 2 distinct mountain ranges, 1 on the eastern slopes of the Planalto da Conquista, between the municipalities of Boa Nova and Iguai, and another in the Serra das Lontras, ∼100 km to the so...

Ant (Formicidae) Assemblages Associated with Piper spp. (Piperaceae) in the Undergrowth of an Atlantic Rainforest Remnant in Southeastern Bahia, Brazil

We studied ant assemblages associated with plants of genus Piper (Piperaceae) in the undergrowth of a fragment of Atlantic Forest in Southeastern of State of Bahia. The study was conducted in Serra Bonita Natural Reserve, in Camacan and Pau-Brazil municipalities. Hand collections of ants were made on four species of Piper during seven months; 56 ant species were collected. The genus Camponotus , Pheidole and Crematogaster were the most abundant. We highlighted the occurrence of Linepithema spp. given their scarce records in the region. Few ants were observed simultaneously (up to five) per plant during each survey. Rarefaction curves showed that collections were not exhaustive. The Shannon index showed that Piper caldense presented the largest ant diversity occurrence, perhaps due to its higher amount of resources available. The ant community in the undergrowth of the Atlantic forest appears to be diverse, although the species found in Piper constitute only a fraction of the diversity that really occurs in this stratum of the forest.

<p class="Default">A new species of Metrodorea (Rutaceae) from Brazil: morphology, molecular phylogenetics, and distribution

A new species of Metrodorea (Rutaceae), M. concinna, is described and illustrated, and morphological, molecular phylogenetic, and distributional support for the new taxon and its relationships with morphologically similar species, as well as with sympatric ones, are explored. The new species is endemic to semideciduous forests of southeastern Bahia, eastern Brazil. It is distinct from other species of the genus mainly by the combination of shrubby to treelet habit, (sub)sessile leaves, sessile leaflets without conspicuous, dark glands on the abaxial surface, and by each carpel bearing one dorsal apophysis. In addition to the diagnostic morphological features, molecular data provide further support to the new taxon.

Bacillus subtilis and Enterobacter cloacae endophytes from healthy Theobroma cacao L. trees can systemically colonize seedlings and promote growth

Clonal genotypes resistant to fungal diseases are an important component of the cocoa production system in southeastern Bahia state (Brazil), so that technologies for faster production of stronger and healthier plantlets are highly desirable. In this study, the effects of inoculated bacterial endophytes isolated from healthy adult cacao plants on seedlings, and aspects related to inoculation methods, colonization patterns, and photosynthesis were investigated. Sequencing of 16S rRNA, hsp-60, and rpo-B genes placed the wild-type isolates within the species Enterobacter cloacae (isolates 341 and 344) and Bacillus subtilis (isolate 629). Spontaneous rifampicin-resistant (rif(R)) variants for 344 were also produced and tested. Endophytic application was either by immersion of surface sterilized seeds in bacterial suspensions or direct inoculation into soil, 20days after planting non-inoculated seeds into pots. Results from in vitro recovery of inoculated isolates showed that the wild-type endophytes and rif(R) variants systemically colonized the entire cacao seedlings in 15-20days, regardless of the inoculation method. Some endophytic treatments showed significant increases in seedlings' height, number of leaves, and dry matter. Inoculation methods affected the combined application of endophytes, which maintained the growth-promotion effects, but not in the same manner as in single applications. Interestingly, the 344-3.2 rif(R) variant showed improved performance in relation to both the wild type and another related variant. Photosynthetic rates and stomatal conductance increased significantly for some endophytic treatments, being partially associated with effects on growth and affected by the inoculation method. The results suggest that E. cloacae and B. subtilis endophytes from healthy adult plants (not transmitted by seeds) were able to promote vegetative growth on cacao seedlings. The development of products for large-scale use in seedlings/plantlets production systems was discussed.

Population Fluctuation and Damage Caused by Phytophagous Mites on Three Rubber Tree Clones

Our aim was to investigate the population fluctuation and the damage caused by the phytophagous mites Calacarus heveae Feres, Tenuipalpus heveae Baker, and Eutetranychus banksi (McGregor) on clones FX 2784, FX 3864, and MDF 180 in rubber tree crops from southeastern Bahia, Brazil. Moreover, we tested for the influence of climatic variables on occurrence patterns of these species throughout weekly samples performed from October to April. The infestation peaks was between mid-January and late February. The clones FX 2784 and FX 3864 had the highest infestations and more severe damage possibly caused by C. heveae, which was the most frequent and abundant species in all clones. We found that sunlight duration and rainfall were the most important factors for C. heveae while T. heveae was affected by rainfall and temperature. Eutetranychus banksi was only affected by sunlight duration. However, the best models had low goodness of fit. We concluded that the clones FX 2784 and FX 3864 had a higher susceptibility to mite attack, and the association between climatic variables and favorable physiological conditions were determinant for the population increase of the species from January to April.

Reproductive phenology of Miconia mirabilis (Melastomataceae) within three distinct physiognomies of Atlantic Forest, Bahia, Brazil

Although Miconia mirabilis is a very common species in disturbed forest areas and is known for providing food resources for the local fauna, little is known about its reproductive phenology and other ecological aspects. The present study compares intra- and inter-annual patterns in the reproductive phenophases of that species in three distinct physiognomies of Atlantic Forest in Southeastern Bahia based on semi-quantitative observations conducted over a period of three years. We searched for possiblerelationships with climatic variables, differences among sites and synchrony. Both the flowering and fruiting strategies of M. mirabilis were classified as annual extended in all three study sites. We found no significant differences among years. Despite low seasonality of the regional climate, intensities of the different phenophases were negatively correlated with day length and temperature. In general, inter- and intra-population synchrony for flowering and fruiting was high (between 0.65 and 0.78), except for inundated forest, probably due to the stress caused by flooding. Given that Miconia mirabilis has the potential to be an important food resource for the local fauna due to the large quantities of flowers and fruits produced and their almost year-round availability, and its capacity for occupying impoverished areas, the species may be considered in restoration programs as a potentially interesting species capable of attracting frugivores to disturbed areas.

The relationships between microbiological attributes and soil and litter quality in pure and mixed stands of native tree species in southeastern Bahia, Brazil

This study was conducted to link soil and litter microbial biomass and activity with soil and litter quality in the surface layer for different pure and mixed stands of native tree species in southeastern Bahia, Brazil. The purpose of the study was to see how strongly the differences among species and stands affect the microbiological attributes of the soil and to identify how microbial processes can be influenced by soil and litter quality. Soil and litter samples were collected from six pure and mixed stands of six hardwood species (Peltogyne angustifolia, Centrolobium robustum, Arapatiella psilophylla, Sclerolobium chrysophyllum, Cordia trichotoma, Macrolobium latifolium) native to the southeastern region of Bahia, Brazil. In plantations of native tree species in humid tropical regions, the immobilization efficiency of C and N by soil microbial biomass was strongly related to the chemical quality of the litter and to the organic matter quality of the soil. According to the variables analyzed, the mixed stand was similar to the natural forest and dissimilar to the pure stands. Litter microbial biomass represented a greater sink of C and N than soil microbial biomass and is an important contributor of resources to tropical soils having low C and N availability.

Cytogenetic Studies on Workers of the Neotropical Ant Wasmannia auropunctata (Roger 1863) (Hymenoptera: Formicidae: Myrmicinae)

Wasmannia auropunctata is known as one of the worst invasive ants in the World. A cytogenetic study was conducted on two native populations from southeastern Bahia, Brazil. The analysis of the chromosomes observed in mitotic metaphases was made by a combination of methods: Giemsa conventional staining, chromomycin A3 (CMA3) and 4-6-diamidino-2-phenylindole (DAPI) fluorochrome staining, and acridine orange banding. The workers have all the karyotype 2n=32, with ten pairs of metacentric and six pairs of acrocentric chromosomes. One chromosome arm of the pair ten was positive for CMA3 and acridine orange, suggesting the occurrence of a nucleolar organizing region. This region is an interesting marker because is very conservative and seems to constitute an interesting specific taxonomic character. The pericentromeric region of many chromosomes was stained with DAPI, evidencing the occurrence of AT bases rich heterochromatin.

Disseminação de bactérias patogênicas por formigas (Hymenoptera: Formicidae) em dois hospitais do nordeste do Brasil

Nosocomial infections bring a high risk to the health of hospital patients and employees. Ants are common organisms in Brazilian hospitals, where they can act as dispersers of opportunistic microorganisms in places they forage. The occurrence of multi-resistant bacteria carried by ants was analyzed in two public hospitals (HA and HB) in southeastern Bahia, Brazil. In these two hospitals 132 workers belonging to three ant species were collected. The bacteria associated to these ants were identified and their susceptibility to antibiotics was evaluated. More than half (57.3%) of ants collected in HA were associated with some kind of bacteria, with 26.7% of them being opportunist bacteria, while 84,2% of the ants from HB presented associated bacteria growth, with 61.4% of them being opportunist bacteria. Twenty four species of bacteria were isolated. The Gram-positive bacilli of the genus Bacillus were the most frequent, followed by the Gram-positive cocci, Gram-negative bacilli (family Enterobacteriaceae) and Gram-negative non-fermenters bacilli. The profile of sensitivity of the bacterial isolates to drugs pointed out the existence of multi-resistant isolates carried by ants. For the first time, are reported cases of the same bacterial resistant isolates taken form homospecific ant workers that point out the importance of ants to bacteria dissemination and proliferation in a hospital. Our results suggest that the risk of contamination presented by these ants is similar to the one of any other mechanical vector of bacterial dissemination.

Selection of Trichoderma stromaticum isolates for efficient biological control of witches’ broom disease in cacao

Witches’ broom is the most devastating disease of cacao in Brazil, and losses to it entail serious socio-economical and environmental problems. Biological control of the causal agent Moniliophthora perniciosa ( Mp) using the antagonistic fungus Trichoderma stromaticum ( Ts) is promising, although the identification of superior isolates is necessary. Here, we report a study on the selection of more effective Ts isolates based on field experiments. Sixty-three Ts isolates from a local collection were applied on brooms and placed under typical conditions of shaded-cacao plantations in southeastern Bahia State (Brazil), during two periods of three months each. The percentages of Ts sporulation and incidence and severity of Mp were the parameters used for biocontrol assessments. The results from both experiments were very distinct, indicating a high phenotypic variation in this collection and suggesting a significant effect of the environment in the Ts– Mp interaction. Ts-sporulation rates were negatively correlated with the presence of Mp in the brooms and a number of isolates reduced Mp incidence more efficiently than the reference isolate. Contrasting isolates in their efficiency of reducing Mp incidence were selected and further tested in four subsequent field trials for validation purposes. The results partially confirmed their biocontrol phenotypes but also suggested isolate-specific responses to environmental variations. Inhibition of Mp-basidiospore germination by total protein secreted in culture supernatants of Ts isolates correlated well with field results and revealed a potentially useful procedure for pre-screening of large collections towards selection of better biological control isolates. The characteristics and efficiency of the method as a reliable protocol for identification of superior BCAs in the witches’ broom—cacao pathosystem is discussed.