New Stage and Species Description on Brazilian Thraulodes Ulmer, 1920 (Ephemeroptera, Leptophlebiidae).

We examined material from two poorly documented areas in Brazil concerning the mayfly genus Thraulodes: Minas Gerais, the largest state in Southeastern Brazil, but also the least studied regarding mayflies; and Tocantins, located in the North-Central area of the country. As a consequence of these efforts, we describe a new species from Minas Gerais based on imagos and nymphs, as well as the nymphs of Thraulodes solstitium Orlando, Salles, Boldrini & Krolow, 2021. Thraulodes viola sp. nov. is characterized by the femora translucid with brown maculae and blackish stripe in distal half, and a light brown maculae in proximal half; abdominal terga II-VI translucent white with transversal reddish mark on posterior margins, one antero-lateral reddish dot, one antero-sublateral blackish spot, and one postero-submedian brown spot; penis lobes sinuous sideways, with lateral pouch present and very developed, and apico-lateral area with an ear-like projection; nymph with galea-lacinia dark brown, 14-16 medium-sized pectinate setae in subapical-ventral row. The nymph of T. solstitium nymph is characterized by the galea-lacinia dark brown, 11 medium-sized pectinate setae in a subapical-ventral row.

Seasonal and Simultaneous Cleistogamy in Rostrate Violets (Viola, subsect. Rostratae, Violaceae).

The special mixed reproductive system, i.e., the ability of an individual plant to develop both open, chasmogamous (CH) flowers adapted to cross-pollination and closed, cleistogamous (CL) flowers with obligate self-pollinating, is a common phenomenon in Viola L. In most sections of Northern Hemisphere violets, cleistogamy is seasonal, and CH and CL flowers develop sequentially in the season. Non-seasonal cleistogamy (simultaneous) is a rare phenomenon in rostrate violets. In the current study, we focused on modification of the CH/CL mating system in V. caspia by environmental conditions, resulting in a gradual switch from temporal cleistogamy, occurring in nature, to simultaneous cleistogamy under greenhouse conditions. V. reichenbachiana with seasonal cleistogamy was the control for V. caspia with the labile seasonal/simultaneous cleistogamy system. In simultaneous cleistogamy, the CH and CL flowers, fruits and seeds developed on an individual plant at the same time on the same branch. The typical difference between CH and CL flowers' pistils is a straight style ending with a head-like stigma in CH and a curved style in CL adapted to self-pollination. This trait persists in the fruit and seed stages, allowing for easy recognition of fruit of CL and CH flowers in simultaneous cleistogamy. Floral meristems of CH flowers of V. reichenbachiana developed on the rhizome at the end of the growing season under short-day conditions and remained dormant until the following season. The CL floral meristems formed under long-day conditions on elongating lateral branches in the upper leaf axils. The daily temperature influenced the variable CH/CL ratio of V. caspia in nature and greenhouse conditions. Regulation of the CL/CH flower ratio by modifying environmental factors is important for basic research on genetic/epigenetic regulation of cleistogamy and for practical use to produce genetically stable lines of economically important species via CL seeds.