Stingless bees (Hymenoptera: Meliponini) are among the most important pollinators of tropical forests. Peru is considered a hotspot of biodiversity of Meliponini, but many areas of this country (e.g., Peruvian Amazon) remain unexplored. We aimed to produce a first inventory of stingless bee species dwelling in humid and seasonally dry forests of northern Peru by combining traditional (morphologically-based) taxonomy and DNA barcoding. Specimens were collected in 2020 at five sites located in San Martin and Piura regions. We identified 12 genera of Meliponini. Among those, Trigona and Plebeia were the most abundant (45.9% and 12.8% respectively), whereas Nannotrigona and Scaura were the least represented ones (2.3%). We assigned a reliable species identification to about 30% of specimens (Trigona amazonensis, T. muzoensis, T. williana, Partamona testacea, Scaura tenuis, Tetragona goettei, and Tetragonisca angustula). Yet, more than a half of the specimens received a provisional identification (e.g., Geotrigona cf. fulvohirta, T. cf. amalthea, T. cf. fuscipennis, T. cf. hypogea, Melipona cf. cramptoni, Partamona cf. epiphytophila, Ptilotrigona cf. perenae, Scaura cf. latitarsis, Tetragona cf. clavipes, Trigonisca cf. atomaria). We also highlighted an extensive polyphyly that affected a number of currently recognized species (e.g., T. fulviventris, T. guianae, Plebeia franki, P. frontalis, M. eburnea, M. illota), whose members were split into various clades. Finally, 16% of individuals failed to be identified at the species level (Trigona sp. 1, T. sp. 2, Nannotrigona sp., Partamona sp., Scaptotrigona sp. 1, S. sp. 2, Trigonisca sp. 1, and Trigonisca sp. 2). We discuss our findings according to the current faunistic and biogeographic knowledge of Meliponini in Peru and the Neotropical region. We also remark on the importance of conducting a taxonomic revision of stingless bees and improving both their morphology-based identification keys and BOLD repository. Finally, we claim that integrative taxonomy shall be strongly implemented to truly assess the biodiversity of Neotropical stingless bees, allowing conserving these important pollinators and the associated traditional meliponiculture in an effective manner.

A new arbuscular mycorrhizal (AM) fungus, Microkamienskia peruviana, was detected in bait cultures for arbuscular mycorrhizal fungi established with rhizospheric soil substrates of the inka nut (Plukenetia volubilis). The field soil derived from three agricultural plantations in the Amazonia lowlands of the province Lamas, San Martin State, in Peru. The fungus was subsequently propagated in single species cultures on Sorghum sp., Brachiaria sp., Medicago sativa and P. volubilis as host plants. The new species differentiates hyaline spores regularly in spore clusters, up to 500–800 × 400–600 μm. The spores are 16–31(–36) × 13–29(–35) μm in diam, formed on cylindrical or slightly funnel-shaped hyphae, without a septum at or close to the spore base. Phylogenetically, the new fungus belongs to a new genus, named Microkamienskia, which has as type species M. perpusilla comb. nov. and to which also M. divaricata comb. nov. belongs. Both are transferred from Kamienskia to Microkamienskia in the present study. The new fungus can be identified by the ballooning semi-persistent to evanescent outer spore wall layer in PVLG-based mountants that is not known for the other species of these two genera, nor for any other glomeromycotan species of similar small spore sizes. Kamienskia and Microkamienskia species can be distinguished by their position in the phylogenetic tree and by hyaline spores, open pores at the spore bases and in the subtending hyphae, and by their spore sizes that are for Microkamienskia among the smallest spore sizes so far detected for AM fungi (15–35 μm).

An artificial diet to mass-rear Euschistus heros (F. 1798) (Hemiptera: Pentatomidae) was developed in the laboratory. Biological studies were conducted under controlled conditions of temperature (25 ± 2°C), RH: 60 ± 10%, and photoperiod of 14:10 (L:D) h. Out of 13 diets tested, 2 diets (D9 and D11) were the most suitable. The artificial diets selected had the same composition (green beans, peanuts, sucrose, water, Nipagin, and sorbic acid) except for different antimicrobial agents (D11 has tetracycline, and D9 doesn’t). The 68% viability for the egg–adult period of insects reared on these lyophilized artificial diets (LAD) was almost twice as high as the 38% viability obtained with the natural diet. Although adults reared on LAD weighed 17% less than those reared on the natural diet, mean fecundity was higher than on the natural diet (282 eggs/female), reaching 430 eggs/female. The net reproductive rate (Ro) increased over the generations for the diets with lyophilized material and antimicrobial agents. The opposite occurred with the diet of lyophilized material without antimicrobial agents, showing that the insects either adapted or degenerated through generations. Lyophilized diets supported the production of E. heros through at least 10 generations, with no degeneration.