Some new cases of ectoparasitoid wasps from the Polysphincta genus-group manipulating the behaviour of host spiders have been described in recent years, indicating that the modification of normal web structure is the rule rather than an exception as the outcome of these interactions. In most cases, orb web diameter and the number of adhesive spirals are reduced, which decreases the probability of web damage from the interception of insects on the viscid threads during the development of the parasitoid within the cocoon. In this study, we describe a new interaction between the host spider Leucauge volupis and the recently described parasitoid Hymenoepimecis jordanensis. Web modifications induced by larvae in their last instar, in this case, are different to those described for two other Leucauge species attacked by Hymenoepimecis spp., L. argyra and L. roseosignatha. The cocoon webs constructed by the parasitized L. volupis are similar to those webs constructed by immature individuals, presenting a lower tangle, which may increase the stability of the web or offer additional physical protection for the cocoon. As in other previously described cases, sticky spirals are absent from cocoon webs. However, the photographs of webs constructed by spiders carrying second instar larvae indicated that the reduction in spirals begins before the construction of the cocoon web. These webs remain functional, being substantially modified only when the larvae reach the third instar. Variation among cocoon web designs of congeneric hosts attacked by distinct Hymenoepimecis species indicate that the substance used for host manipulation may vary in concentration and/or composition. Alternatively, distinct host responses may occur to the same substances.

View related articles View Crossmark data Citing articles: 2 View citing articles A reassessment of the vocalization and distribution of Scinax exiguus (Duellman, 1986) (Anura: Hylidae) in the Amazonian savanna of Roraima, northern Brazil, with the description of its aggressive call

Scinax rostratus is a large species of the S. rostratus group and has an extensive distribution throughout northern South America. We provide the first record of S. rostratus from the state of Roraima (municipality of Cantá), which fills a previously assumed gap in this species’ distribution. We also describe the species’ advertisement call from this locality, providing further notes on the call emission pattern and fine scale temporal and spectral structure.

Scinax comprises more than 120 species which are split in two clades, the S. ruber and the S. catharinae clades. A few species within the S. catharinae clade occur in gallery forests of the Brazilian Cerrado. We here extend the distribution of S. centralis southwards based on new populations sampled in the banks of the Rio Paranaíba, in the borders of Minas Gerais (MG) and Goiás (GO) states, southeastern Brazil. We also provide further data on the species vocalization. Variation was seen among our population and topotypes regarding SVL and call dominant frequency, both likely representing a clinal variation. Our new population of S. centralis represents the first record of the species for the state of Minas Gerais.

Reassessment of the advertisement call of topotypic Scinax squalirostris (Anura: Hylidae), with an acoustic evaluation of its occurrence in the Serra da Mantiqueira, southeastern Brazil. Scinax squalirostris (Lutz, 1925) is thought to occur along a broad range in South America. The values reported for calls of topotypes differ substantially among studies. Because vocalizations often play a key role in uncovering cryptic diversity, the call of S. squalirostris is herein redescribed based on a new sample of topotypes. The call of a population from Poços de Caldas, Minas Gerais state, is also described. Topotypic advertisement calls have a dominant frequency between 3970 and 4125 Hz; 13–15 notes emitted at a rate of 24–27/s; call rate of 67/min and duration of 0.52–0.61 s; mid-call notes having 6 or 7 well-defined pulses, and an intra-note pulse rate of 223–266/s. Calls of the Poços de Caldas population have dominant frequency between 4083 and 4358 Hz; 15–18 notes emitted at a rate of 32–34/s; call rate of 64/min and duration of 0.46–0.56 s; mid-call notes having 6 or 8 well-defined pulses, and an intra-note pulse rate of 252–312/s. The advertisement calls of these populations have some differences with each other, and are promptly distinguished from calls of morphologically similar species. Our data to topotypes are inconsistent with some previously reported. A more detailed study of the population from Poços de Caldas is required, and more marked differences may be found in populations more distant from type locality of S. squalirostris.

The vocalizations of Ololygon hiemalis, O. ranki, and O. canastrensis are redescribed to provide further details on their complex vocal repertoires. The acoustic diagnosis of O. hiemalis is updated in relation to congeners, especially with respect to the morphologically similar O. ranki, for which we also evaluate the morphological diagnosis of both species. Three distinct types of notes are recognized in the vocalization of the three species (short squawk-like, long squawk-like and click-like), which are emitted in distinct acoustic organizations. The main organization of the three species is herein referred as the call Type “A”, each of which has a multi-note structure composed of a series of short squawk-like notes with note-by-note increase in amplitude along call duration. The call Type A of O. hiemalis was not described in the species original description. That of topotypes of O. ranki structurally resembles the call described in the original species description. Likewise, The call Type A of O. canastrensis matches that described in the original species description. Although O. hiemalis and O. ranki are phenotypically indistinguishable, there are quantitative differences in some call traits. Many species of Ololygon have complex vocalizations consisting of, at least, two types of notes, which can be emitted in different combinations. Despite the complexity of acoustic emissions, the call Type A of many species seems to be phylogenetically conserved. Because calls sometimes are only briefly described, we emphasize the need for, and importance of, comprehensive characterizations of anuran vocalizations to support future acoustic comparisons

The dwarf swamp frogs, genus Pseudopaludicola, include 21 species, which occur throughout South America (Frost 2016). Pseudopaludicola is recognized as monophyletic, supported by a set of osteological, morphological, and molecular characters (Veiga-Menoncello et al. 2014, and cites therein). Veiga-Menoncello et al. (2014) recognized a clade (“clade II” there), which included two species that share karyotypes with 2n = 20: P. ameghini (Cope, 1887) and P. ternetzi Miranda-Ribeiro, 1937. However, historically these two sister species have undergone many taxonomic changes and so far they do not have a clear taxonomic diagnosis one from the other (Haddad & Cardoso 1987; Lobo 1996; Fávero et al. 2011; Pansonato et al. 2013; Cardozo & Toledo 2013, and cites therein).

Acoustics suggests hidden diversity in Scinax garbei (Anura: Hylidae). Scinax garbei is a treefrog species thought to be widely distributed across forest habitats of the Amazon Basin, occurring in Venezuela, Colombia, Ecuador, Peru, Bolivia, and Brazil. However, the morphological, acoustic and molecular characters of this species vary across its distribution. In view of this variation, the present study re-analyzes published advertisement calls and analyses new call data of nine populations of S. garbei from five countries, aiming to assess acoustic divergence. In addition, the territorial call of the species is described for the first time. Based on multivariate analyses of advertisement call data, there are three groups of populations with distinct calls, referred to herein as S. garbei Brazil, Northwestern, and Southwestern. Scinax garbei Northwestern is distinguished from S. garbei Southwestern by temporal call traits, whereas S. garbei Brazil differs from the other two groups based on both temporal and spectral traits. These results indicate that S. garbei may represent a complex of up to three species, thereby highlighting the need for a thorough taxonomic revision of this species.