ABSTRACT
Colpolopha minuta sp. nov. (Orthoptera: Romaleidae) is described from Floresta Nacional do Aripe near Crato in Ceará State, Brazil from 17 specimens collected by Moacyr Alvarenga deposited at the Insect Collection of the University of Michigan Museum of Zoology. This new species is characterized by its small size and brachypterous tegmina compared to other known Colpolopha species. A comparison with other short-winged Colpolopha species is provided. A discussion about some iNaturalist records is provided in order to help us identify possible new records or species in the region.
Subject(s)
Grasshoppers , Orthoptera , Animals , Brazil , Animal Distribution , Animal Structures , Body Size , Organ SizeABSTRACT
Diponthus Stl, one of the most diversified and widely distributed Romaleinae genera, is endemic to southern South America. This colorful grasshopper genus is placed within Romaleini and currently includes 16 valid species from a total of 22 nominal ones, most of them only known from their original descriptions. The aims of this study were to propose a morphology-based phylogenetic hypothesis of relationships among the species of Diponthus, and to conduct a taxonomic revision, including the description of four previously unknown species. Parsimony analysis of 79 morphological characters strongly recovered the monophyly of genus Diponthus, and Gurneyacris as its sister group. Internal clades within Diponthus were supported by external morphology and coloration patterns, while characters from male genitalia were shown to be more useful for species differentiation. Based on the results of the taxonomic review, Diponthus is constituted by 16 valid species, with the following nomenclatural changes proposed: Diponthus nigroconspersus (Stl) is considered a valid name; D. invidus Carl and D. bilineatus Rehn are synonymized under D. virgatus (Gerstaecker); Diponthus clarazianus Pictet & Saussure is synonymized under D. cribratus (Serville); D. paulista Rehn is synonymized under D. porphyreus (Gerstaecker); D. maculiferus (Walker) is synonymized under D. electus (Serville). New names are proposed for four undescribed species from Bolivia (D. colorbellus sp. nov. and D. dilatatus sp. nov.), Argentina (D. paranaensis sp. nov.) and Brazil (D. salvadorii sp. nov.).
Subject(s)
Grasshoppers , Orthoptera , Male , Animals , Phylogeny , Animal DistributionABSTRACT
Four new species of Reyesacris Fontana, Buzzetti Mario-Prez, 2011 are described from Southern Mexico (Guerrero and Oaxaca States). Reyesacris zihua sp. nov., R. atoyacensis sp. nov., R. mephaa sp. nov. and R. tika sp. nov. A dichotomous key to species of Reyesacris and distribution map are provided together with an analysis of external and internal male genitalia to place this genus in the subtribe Vilernina within the tribe Ommatolampidini.
Subject(s)
Grasshoppers , Orthoptera , Animal Distribution , Animals , Male , MexicoABSTRACT
Spatial patterns of species richness have been found to be positively associated, a phenom called cross-taxon congruence. This may be explained by a common response to environment or by ecological interactions between taxa. Spatial changes in species richness are related to energy and environmental heterogeneity but their roles in cross-taxon congruence remain poorly explored. Elevational gradients provide a great opportunity to shed light on the underlying drivers of species richness patterns. We study the joint influence of environment and biotic interactions in shaping the cross-taxon congruence of plants and orthopterans species richness, along three elevational gradients in Sierras Grandes, central Argentina. Elevational patterns of species richness of orthopterans and plants were congruent, being temperature the best single predictor of both patterns supporting the energy-related hypotheses. Using a structural equation model, we found that temperature explained plant richness directly and orthopteran richness indirectly via orthopteran abundance. Cross-taxon congruence is likely due to a common response of both taxa to temperature although via different theoretical mechanisms, possibly, range limitations for plants and foraging activity for orthopterans. We disentangled the role of temperature in determining the cross-taxon congruence of plants and orthopterans by showing that a common response to the environment may mask different mechanisms driving the diversity of different taxonomic groups.
ABSTRACT
En masse inoculations with Paranosema locustae, an intracellular parasite of adipose tissue of grasshoppers and locusts and the only microsporidium registered as a biocontrol agent, were conducted against crowded fourth-instar nymphs of the South American locust Schistocerca cancellata and the grasshoppers Dichroplus schulzi and Ronderosia bergii. Infection did not develop in the locust, but was highly prevalent in the two grasshopper species. We hypothesize that absolute absence of infection in S. cancellata may constitute a case of density-dependent prophylactic resistance, an elevation of the baseline immunity of an organism in order to cope with disease that is prevalent in species exhibiting phase polyphenism.
Subject(s)
Biological Control Agents/pharmacology , Grasshoppers/microbiology , Microsporidia/physiology , Pest Control, Biological , Animals , Grasshoppers/growth & development , Insect Control , Nymph/growth & development , Nymph/microbiologyABSTRACT
The species Melanotettix dibelonius Bruner, 1904 was previously recorded from Michoacán and Guerrero states in Mexico. This species is characterized by its tegmina, which are always shorter than head and pronotum together and sometimes shorter than the pronotum. After recent field expeditions (2015-2019) and an extensive review of museum specimens from the most important Orthoptera collections in Mexico and USA (291 specimens), we discovered a long-winged form of this species south of its previous known range, which effectively expanded its distribution range into Oaxaca state. We discuss some aspects regarding the patterns of geographic distribution and morphological variation among the long-winged and short-winged morphs. We conduct statistical analyses and observed that on average, the tegmina of long-winged individuals (both females and males) are slightly longer than twice the length of pronotum; whereas in short-winged individuals the tegmina are nearly as long or slightly longer than the length of the pronotum. Moreover, on average, females appear to have longer tegmina than males in both morphotypes. We provide photographic records of both forms live and mounted, the most comprehensive distribution map to date and a discussion of evolutionarily interesting patterns found in this species.
Subject(s)
Grasshoppers , Animals , Environment , Female , Male , Mexico , Polymorphism, GeneticABSTRACT
Three independent but complementary lines of research have provided evidence for the recognition of refugia: paleontology, phylogeography and species distributional modelling (SDM). SDM assesses the ecological requirements of a species based on its known occurrences and enables its distribution to be projected on past climatological reconstructions. One advantage over the other two approaches is that it provides an explicit link to environment and geography, thereby enabling the analysis of a large number of taxa in the search for more general refugia patterns. We propose a methodology for using SDM to recognize biogeographical patterns of endemic insects from Southern South America. We built species distributional models for 59 insect species using Maxent. The species analyzed in the study have narrow niche breadth and were classified into four assemblages according to the ecoregion they inhabit. Models were built for the Late Pleistocene, Mid-Holocene and Present. Through the procedure developed for this study we used the models to recognize: Late Pleistocene refugia; areas with high species richness during all three periods; climatically constant areas (in situ refugia); consistent patterns among in situ refugia, Pleistocene refugia and current distribution of endemic species. We recognized two adjacent Pleistocene refugia with distinct climates; four in situ refugia, some of which are undergoing a process of fragmentation and retraction or enlargement. Interestingly, we found a congruent pattern among in situ refugia, Pleistocene refugia and endemic species. Our results seem to be consistent with the idea that long-term climate stability is known to have a key role in promoting persistence of biodiversity in an area. Our Pleistocene and in situ refugia are consistent with refugia identified in studies focusing on different taxa and applying other methodologies, showing that the method developed can be used to identify such areas and prove their importance for conservation.
Subject(s)
Global Warming , Insecta , Models, Statistical , Animals , South AmericaABSTRACT
As in other regions of the world, bumble bees (Bombus spp.) are important pollinators in the neotropics. Despite its relevance, knowledge on their health is still limited in the region. While external acari are known to occur in these insects, presence of the internal, tracheal mite Locustacarus buchneri is here reported for first time. After the examination of 2,508 individuals of eight Bombus species from Argentina, two workers of Bombus bellicosus and one of Bombus atratus were found parasitized by L. buchneri in localities within San Luis and Buenos Aires provinces, respectively. The rare occurrence recorded agrees with findings from elsewhere in the world.