Knowledge of the natural history of the order Megaloptera is incomplete. Immatures are long-lived and widely known for their role as aquatic predators (Contreras-Ramos 1998; Azevêdo & Hamada 2007), yet information on habits of the winged terrestrial adults is limited. Previously, it was thought that adults do not feed (Table 1), perhaps because of the relatively short life span of about one week to a month (Contreras-Ramos 1998, 1999; Hayashi 1993), as well as the inability of males of Corydalus Latreille, 1802 to feed due to their large mandibles. Tierno de Figueroa & Palomino (2002) analyzed the digestive tract of Sialis nigripes Pictet, 1865 in Spain, and found debris and a spermatophore in a female. Also, Contreras-Ramos (1999) recorded the acceptance of sugar water by adults of Platyneuromus soror (Hagen, 1861). However, consumption of solid organic matter in adult Megaloptera has not previously been recorded.

A new species of Pergalumna from soil and litter was reared in laboratory and a description of adult and juveniles is provided. Adults are characterized by having bands of striae in the posterior part of notogaster, the interlamellar seta are longer than all other prodorsal setae and the lenticular area covers most of the prodorsum. It differs from Pergalumna boliviana by having long interlamellar seta, bigger ellipsoidal porose area Aa and the presence of A2; it differs from Pergalumna paraboliviana by the shape of porose areas; i.e. Aa being ellipsoidal and big, A1 is the smallest, Ap is absent and there are longitudinal striate bands on the prodorsum and ventral plate.

This paper analyzes the community structure of edaphic oribatid mites from the tropical forest at Los Tuxtlas, Veracruz, showing its monthly variation during only one year, considering two contrasting tree species and their relation with abiotic edaphic parameters. Randomly, five Astrocaryum mexicanum and Guarea glabra plants were chosen and near the stem of each one, a sample of soil was taken and processed in the same biological station with Berlese-Tullgren funnels. The most abundant families were Scheloribatidae, Oppiidae, Xylobatidae, Arceremaeidae, and Galumnidae. The Kruskall-Wallis test showed that structure of oribatid mite community is not significative related to tree identity, which they are associated. Pearson's multiple correlation showed that the edaphic temperature is one of the most important abiotic factors in the structuring of oribatid mites communities. The abiotic variables explained 58% of oribatid community variance in its first two axes, with temporality and CO2 being the factors with most influence over the community. It is concluded that tree identity is not a factor that affects the structuring of oribatid mite communities in this tropical forest, while temporality, soil temperature and CO2 are the factors that most influence its establishment, this last factor as an indirect indicator of system productivity.

The genus Galumnopsis (Galumnellidae) is recorded for the first time from Mexico with a new species described here, and Notogalumna (Galumnidae), represents a second record for the country, also with a new species; both from the tropical rainforest in Veracruz state. Notogalumna rickiglesiasi sp. nov. lives in the canopy, while Galumnopsis andydoreyae sp. nov. inhabits soil and litter of Guarea glabra and Astrocaryum mexicanum; most likely they are not only restricted to these plants but are distributed in this forest on a continuous stratum across canopy (Notogalumna) or soil (Galumnopsis). A key for the species of each genus is included.

The female of Eremobittacus spinulatus Byers, 1997 is described for the first time. A key to the two species known of this genus endemic to Mexico is provided, and species distribution is illustrated. A case is made for adults of Eremobittacus to be sexually dimorphic, which appears to be an exceptional occurrence in Bittacidae. It is claimed that Eremobittacus spinulatus habitus has a wasp-like appearance, which may potentially depict a case of mimicry.