New Neotropical Haplothripini (Thysanoptera: Phlaeothripidae) with a key to Central and South American genera

The tribe Haplothripini includes a large diversity of Thysanoptera–Phlaeothripinae, comprising more than 550 species in about 35 genera. They are characterised by having a maxillary bridge in the head, prosternal basantra well developed and fore wings with a median constriction. Members of this group are present in all geographical regions, but are particularly poorly studied in Central and South America. In this study, we describe a new genus and species, Myrciathrips variabilis gen. et. sp. nov., and a new Haplothrips species; and propose two new combinations: Karnyothrips grassoi (De Santis), and Mirothrips vespicola (De Santis). A key to the nine Haplothripini genera now recognised from Central and South America is provided, together with an updated key to Haplothrips and Mirothrips species. A total of 45 species of Haplothripini are now recognised from Central and South America, and a list of these and their distributions is given. The genera Karnyothrips, Haplothrips and Leptothrips are the most commonly encountered, and some exotic species such as Androthrips ramachandrai and Dolichothrips indicus are now widespread in the Americas.     

Population dynamics of the bark-dwelling spider Eustala perfida Mello-Leitão, 1947 (Araneidae)

Population dynamics of spiders may vary according to biotic and abiotic factors. We studied the phenology of the bark-dwelling spider Eustala perfida over a two-year period and investigated how temperature, precipitation, and prey availability were associated with the population of this species. The population of E. perfida presented a well-defined fluctuation, with one reproductive cycle per year. The recruitment of spiders occurred in summer, followed by successive phenological peaks at all stages of development. The species is protogynic, and the population of adult males peaks in the cold/dry season, indicating a winter mature phenological pattern. The diet of E. perfida is composed mainly of medium-sized homopterans, complemented by small dipterans and hymenopterans. We found that the higher abundance of spiders occurred two months after the highest values of precipitation and temperature, and three months after the higher abundance of potential prey items. These results indicate that spiders require time to respond to changes in environmental conditions. The species’ natural history and the structure of the trunks in which it lives may also affect the number of individuals in a particular area and over time.     

Wnt and lithium: a common destiny in the therapy of nervous system pathologies?

Wnt signaling is required for neurogenesis, the fate of neural progenitors, the formation of neuronal circuits during development, neuron positioning and polarization, axon and dendrite development and finally for synaptogenesis. This signaling pathway is also implicated in the generation and differentiation of glial cells. In this review, we describe the mechanisms of action of Wnt signaling pathways and their implication in the development and correct functioning of the nervous system. We also illustrate how a dysregulated Wnt pathway could lead to psychiatric, neurodegenerative and demyelinating pathologies. Lithium, used for the treatment of bipolar disease, inhibits GSK3β, a central enzyme of the Wnt/β-catenin pathway. Thus, lithium could, to some extent, mimic Wnt pathway. We highlight the possible dialogue between lithium therapy and modulation of Wnt pathway in the treatment of the diseases of the nervous system.     

Identification and characterization of new functional truncated variants of somatostatin receptor subtype 5 in rodents

Somatostatin and cortistatin exert multiple biological actions through five receptors (sst1-5); however, not all their effects can be explained by activation of sst1-5. Indeed, we recently identified novel truncated but functional human sst5-variants, present in normal and tumoral tissues. In this study, we identified and characterized three novel truncated sst5 variants in mice and one in rats displaying different numbers of transmembrane-domains [TMD; sst5TMD4, sst5TMD2, sst5TMD1 (mouse-variants) and sst5TMD1 (rat-variant)]. These sst5 variants: (1) are functional to mediate ligand-selective-induced variations in [Ca²⁺]_i and cAMP despite being truncated; (2) display preferential intracellular distribution; (3) mostly share full-length sst5 tissue distribution, but exhibit unique differences; (4) are differentially regulated by changes in hormonal/metabolic environment in a tissue- (e.g., central vs. systemic) and ligand-dependent manner. Altogether, our results demonstrate the existence of new truncated sst5-variants with unique ligand-selective signaling properties, which could contribute to further understanding the complex, distinct pathophysiological roles of somatostatin and cortistatin.     

Neotropical Lispe (Diptera: Muscidae): notes,redescriptions and key to species

The following species of the fly genus Lispe are redescribed: L. albitarsis (Stein, 1898), L. latana Snyder, 1949, L. levis (Stein, 1911), L. lisarba Snyder, 1949, L. nasoni (Stein, 1898), L. serotina Wulp, 1896, L. setuligera (Stein, 1911) and L. vilis (Stein, 1911). Additionally, a new diagnosis is proposed for L. rufitibialis Macquart, 1843, and in order to fix the identity of the name the lectotype is designated. To facilitate species identification, a pictorial key for the species of Lispe in the Neotropical region and distribution maps are presented, together with the first published illustrations of the male terminalia of L. latana, L. levis and L. lisarba, and the female of L. lisarba.     

Life history of Subulina octona (Brugüière) (Gastropoda: Pulmonata: Subulinidae) based on four-year laboratory observations and a comparative histological analysis of egg-retaining and ovoviviparous subulinids

In the present study, we aimed to characterize the life history of the land snail Subulina octona integrating information on life-history traits and morphology. We also compared the histology of the free-oviduct and spermoviduct of ovoviviparous and egg-retaining species of subulinids. We considered as ovoviviparous the species in which the complete embryonic development as well as egg hatching occurs inside the parent’s body and, at the end of this process, the parent releases juveniles instead of eggs. We considered as egg-retaining the species in which a great part of the embryonic development takes place inside the parent’s body and the eggs laid contain well-developed embryos. The results showed that the free-oviduct of both ovoviviparous and egg-retaining species shows a histological arrangement that confers greater strength to its walls and is probably related to egg retention. The wall of the spermoviduct is formed by pseudostratified columnar epithelium, with cell apical processes (probably cilia), and by underlying secretory cells. In gravid egg-retaining snails, the eggshells appear in close contact with the secretory cells of the spermoviduct. This fact suggests that these cells play a role in eggshell formation. The present study is the first account for histological features of S. octona, Allopeas gracile and Allopeas micra. The life history of S. octona is a combination of long lifespan, early sexual maturity, indeterminate growth and egg retention. Egg retention limits the number of young that can be produced in one reproductive event. However, the reproductive strategy adopted by S. octona, associating egg retention and K-strategism, compensates this cost of retaining eggs, because the reproductive success may be enhanced as a result of the higher survival of juveniles and the possibility of performing several reproductive events during the year.