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Colonização e dispersão nos sítios de ocorrência, a genética das populações e história natural de Partamona ailyae Camargo, 1980 (Hymenoptera: Apidae: Meliponini)
(Universidade Federal de São Carlos, 2016-06-03) Cardoso, Pedro Filipe Menezes; Del Lama, Marco Antonio; https://lattes.cnpq.br/7198095288825585; https://lattes.cnpq.br/3023009653193208
Particular biological features of different bee groups can affect how a certain area will be occupied by them and this can affect directly the genetics of their populations over the long term. In Brazil, there are few studies about gene variation and genetic structure of bee natural populations, as well as on the genetic differentiation levels between eusocial bee populations. The Partamona genus comprises 33 species, distributed from Southern Mexico to Southern Brazil. Partamona ailyae, the model species of this study, occurs in rainforests of Southwestern Amazonia, Central Brazil and xeric regions of Piauí. Its wide distribution, as well as the ability to occupy such heterogeneous environments, piqued our interest to take P. ailyae as a study model. This work aimed to analyze the occupation process at the P. ailyae occurrence sites, population genetics and interpopulational gene flow, and the natural history of this species. Eight expeditions were carried out, and 41 localities of 10 states of Brazil were visited. Among them, active colonies of P. ailyae were found only in 17 localities, being collected specimens of 75 nests. To identify the mitochondrial lineages present in the sampled colonies, five gene regions were used (COI, CytB, 12S, 16S and COI-COII). Estimates of polymorphism levels showed COI and CytB as the most variable regions (11 and seven haplotypes, respectively). For the ribosomal genes, only a few samples were analyzed, because few differences were identified among the sequences. All the 31 samples analyzed for the 12S showed a five bases insertion starting from the position 25 of the sequence, a result not observed in other Partamona species. The most informative genes (COI and CytB) had their sequences concatenated (1114pb). For these regions, 13 haplotypes were observed, two of them were shared and 11 characterized as exclusive of localities. The AMOVA showed that 94.3% of the gene variation is due to interpopulacional differences, revealing a high differentiation among the populations (ΦST = 0.9426; P = 0.000). In addition, one individual from each colony was analyzed for eight heterologous microsatellite loci designed from Melipona bicolor and Partamona helleri. A moderate and statistically significant XIV interpopulational genetic differentiation (ΦST = 0.1491; P = 0.000) was found. The cluster analysis identified four groups by ΔK as the ideal model, and STRUCTURE software showed that all individuals could belong to more than one group, corroborating the “Assignment test”, which indicated that only 50% of the samples were correctly assigned to their original population. Phenotypic segregation analysis was realized in some offsprings, revealing a monoginic/monandric familial structure. From the mitochondrial data, the Mantel test showed a significant correlation between genetic distance and geographic distance (r = 0.2589; P = 0.0231), whereas on basis of the nuclear data, the Mantel test did not indicate significant correlation between genetic distance and geographic distance (r = 0.2090; P = 0.0610). Fu’s Fs and R2 tests did not show significant values. The Bayesian Skyline Plot analysis (BSP) did not show significant fluctuations in the effective size populations of P. ailyae, indicating population stability over time. The values of ΦST estimated for mitochondrial genes and microsatellites were compared, being detected evidence of sex-asymmetric dispersal, in which females are responsible for the areas occupation, and males constitute the disperser sex. In addition, some relevant aspects of the natural history of P. ailyae are shown.
Uso da serologia na avaliação da preferência alimentar de predadores pelas principais pragas da cultura do milho (Zea mays L.)
(Universidade Federal de São Carlos, 2016-06-03) Redoan, Ana Carolina Maciel; Sousa e Silva, Carlos Roberto; https://lattes.cnpq.br/4890369735136839; https://lattes.cnpq.br/8227680889423834
This study objective to identify the diversity of predators through the use of serology producing specific antiserums for the main pests found in maize, Spodoptera frugiperda, Helicoverpa armigera and H. zea, Rhopalosiphum maidis and uses it to determine their predators. Pest samples were macerated in 0.85% saline solution. The macerated were centrifuged and the supernatants used as immunizing antigens for obtaining antiserum. For this purpose, a rabbit was immunized with 3.0 ml of the immunizing antigen on the lymph node region. Homologous serological tests were performed in double diffusion in agar. Homologous serological reactions were positive after seven days of antigen inoculation. The technique has sensitivity to detect predation of the four pests studied in this paper. The tests were positive for a prey in the digestive tract of the predator to 96 hours of ingestion. Regarding the number of preys, there was no difference in the lines, they only grew stronger and sharper. In laboratory, D. luteipes, O. vnigrum and C. externa presented preference for R. maidis and E. annulipes for S. frugiperda. In tests where predators were collected in the field, serological tests showed that there was a certain food preference of D. luteipes and O. v-nigrum by S. frugiperda. E. annulipes, H. axyridis, E. connexa and C. externa, by the aphid. After a single injection of antigen in rabbit’s lymph node region, it was possible to get an antiserum specific for pests of corn.