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Comparou-se o número médio de adultos emergidos, número de imaturos mortos e a freqüência com que ocorre a morte de toda a prole nos parasitóides Spilochalcis morleyi (Hymenoptera, Chalcididae) e Xanthozona melanopyga no hospedeiro, Brassolis sophorae (Lepidoptera, Nymphalidae). O número de parasitóides (Spilochalcis) que completaram seu desenvolvimento e emergiram foi significativamente maior em pupas femininas do hospedeiro. O número médio de imaturos de Spilochalcis mortos por pupa não diferiu entre os sexos do hospedeiro. Entretanto, nas pupas femininas de B. sophorae ocorreu uma freqüência significativamente maior de morte de toda a prole em ambas as espécies de parasitóides.

BACKGROUND Sugarcane vinasse has a low pH and several studies report that alkalinity supplementation is essential to the stability of its dark fermentation (DF). In the context of biorefineries, the reduction, or even elimination, of alkalinizing agents could be extremely environmentally and economically advantageous. The main objective of this study was to evaluate the valorisation of vinasse DF through bioH2 and value‐added metabolite production without buffers in two similar Upflow Anaerobic Sludge Blanket (UASB) under mesophilic (U30) and thermophilic (U55) conditions. RESULTS Average organic acid yields of 376 ± 52 and 248 ± 122 mg‐CODOA.g−1CODtin, and productivities of 17 396 ± 5220 and 14 024 ± 1642 mg‐CODOA.L−1 day−1 were obtained for U30 and U55 reactors, respectively, with only vinasse as substrate (CODOA stands for organic acids chemical oxygen demand (COD) and CODin influent COD). BioH2 production was feasible with sucrose as substrate and pH below 3.0, but it ceased with substrate replacement by vinasse along with a natural pH increase. A change in microbial community was also observed: Ethanoligenens, Clostridium sensu stricto 12, and Liquorilactobacillus (using sucrose and with a pH <3.0) were replaced by Prevotella, Megasphaera, Pectinatus, Clostridium sensu stricto 11, and Lactobacillus using vinasse (with a pH > 4.0). CONCLUSION Results showed that DF of sugarcane vinasse without any buffering addition might be a promising approach for the valorization of real wastewater through the production of organic acids. Nevertheless, bioH2 production was not favored and further strategies would be needed to maintain hydrogen‐producing bacteria when sucrose is replaced by real effluent with a natural pH increase. © 2021 Society of Chemical Industry (SCI).

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