Threatened Neotropical seasonally dry tropical forest: evidence of biodiversity loss in sap-sucking herbivores over 75 years.

Tropical forests cover 7% of the earth's surface and hold 50% of known terrestrial arthropod species. Alarming insect declines resulting from human activities have recently been documented in temperate and tropical ecosystems worldwide, but reliable data from tropical forests remain sparse. The sap-sucking tribe Athysanini is one herbivore group sensitive to anthropogenic perturbation and the largest within the diverse insect family Cicadellidae distributed in America's tropical forests. To measure the possible effects of deforestation and related activities on leafhopper biodiversity, a survey of 143 historic collecting localities was conducted to determine whether species documented in the Mexican dry tropical forests during the 1920s to 1940s were still present. Biostatistical diversity analysis was performed to compare historical to recent data on species occurrences. A data matrix of 577 geographical records was analysed. In total, 374 Athysanini data records were included representing 115 species of 41 genera. Historically, species richness and diversity were higher than found in the recent survey, despite greater collecting effort in the latter. A strong trend in species decline was observed (-53%) over 75 years in this endangered seasonally dry ecosystem. Species completeness was dissimilar between historic and present data. Endemic taxa were significantly less important and represented in the 1920s-1940s species records. All localities surveyed in the dry tropical forest are disturbed and reduced by modern anthropogenic processes. Mexico harbours highly endemic leafhopper taxa with a large proportion of these inhabiting the dry forest. These findings provide important data for conservation decision making and modelling of distribution patterns of this threatened seasonally dry tropical ecosystem.

Nomenclatural changes in the grass-feeding Mexican leafhopper genus Cocrassana Blocker & Larsen (Hemiptera: Cicadellidae: Deltocephalinae: Athysanini)

ABSTRACT Two nomenclatural changes are proposed in the tribe Athysanini (Cicadellidae: Deltocephalinae). Chlorotettix sexvarus DeLong, 1959, is newly placed in the genus Cocrassana Blocker & Larsen and is a senior synonym of the type species of Cocrassana, C. riepmai Blocker & Larsen, 1991, syn. nov. A revised diagnosis and illustration of the species are provided.

A new species of the genus Ceratagallia (Cicadellidae: Megophthalminae) from Central Mexico.

Ceratagallia (Ceratagallia) brailovskyi sp. nov., is here described and illustrated from Central Mexico. The new species appears to be closely related to the C. bigeloviae species group, which includes previously described Mexican species. A key, species list, and distributional map for Ceratagallia in Mexico are provided.

Duocrassana longula, new genus and species of leafhopper (Hemiptera: Cicadellidae: Deltocephalinae) from southern Mexico and its relationship to other genera in Athysanini.

The new leafhopper genus, Duocrassana Pinedo-Escatel, Zahniser & Dietrich, gen. nov., and its type species, Duocrassana longula Pinedo-Escatel, Zahniser & Dietrich sp. nov., are described and illustrated based on material from Oaxaca, Mexico. The relationship with other genera in the tribe Athysanini is discussed, highlighting the importance of male genitalia for its identification.

A New Genus of Macropsinae (Hemiptera: Cicadellidae) From Madagascar.

Paragalboa acuta GEN & SP N: is described and illustrated from Madagascar. The new genus shows morphological affinities to the Macropsini genus Galboa Distant recorded from Seychelles. A checklist of all known genera of Macropsinae is provided.

Illustrated checklist of mileewine leafhoppers (Hemiptera: Cicadellidae: Mileewinae) of China, with descriptions of four new species.

Four new species of Mileewini, Mileewa houhensis Yang, Meng & He, sp. nov., M. xiaofeiae Yang, Meng & He, sp. nov., M. yangi Yang, Meng & He, sp. nov. and Ujna liangae Yang, Meng & He, sp. nov. are described and illustrated. Mileewa nigricauda Yang & Li, 1999 is placed as a junior synonym of M. dorsimaculata (Melichar, 1902); three of the previously described Chinese Mileewa are transferred to the genus Ujna. These are Ujna harpa (Yang & Li, 2004) comb. nov., U. nigrimaculata (Yang & Li, 2004) comb. nov., and U. puerana (Yang & Meng, 2010) comb. nov. M. lynchi (Distant, 1918) is recorded as new for China. A checklist of Mileewini leafhoppers of China along with photograph of their dorsal habitus is provided.

Tungurahualini, a new tribe of Neotropical leafhoppers, with notes on the subfamily Mileewinae (Hemiptera, Cicadellidae).

A new cicadellid tribe, Tungurahualini, is recognized to include Tungurahuala Kramer, and a related new genus, Ilyapagen. n., based on six new species. The tribe is included in subfamily Mileewinae, the concept of which is further expanded to include tribes Makilingiini Baker, and Tinteromini Godoy and Webb, taxa previously treated as separate subfamilies. Keys to tribes of Mileewinae (sensu lato) and genera of Tungurahualini are provided. A new species of Tungurahuala, Tungurahuala acuminatasp. n., is also described and keys to species of Tungurahuala and Ilyapa are provided. The new tribe is presently recorded only from cloud forests in the northern Andes Mountains of South America.

Phylogeny of the major lineages of Membracoidea (Insecta: Hemiptera: Cicadomorpha) based on 28S rDNA sequences.

Analysis of sequences from a 3.5-kb region of the nuclear ribosomal 28S DNA gene spanning divergent domains D2-D10 supports the hypothesis, based on fossil, biogeographic, and behavioral evidence, that treehoppers (Aetalionidae and Membracidae) are derived from leafhoppers (Cicadellidae). Maximum-parsimony analysis indicated that treehoppers are the sister group of a lineage comprising the currently recognized cicadellid subfamilies Agalliinae, Megophthalminae, Adelungiinae, and Ulopinae. Based on this phylogenetic estimate, the derivation of treehoppers approximately coincided with shifts in physiology and behavior, including loss of brochosome production and a reversal from active, jumping nymphs to sessile, nonjumping nymphs. Myerslopiidae, traditionally placed as a tribe of the cicadellid subfamily Ulopinae, represented a basal lineage distinct from other extant membracoids. The analysis recovered a large leafhopper lineage comprising a polyphyletic Deltocephalinae (sensu stricto) and its apparent derivatives Koebeliinae, Eupelicinae (polyphyletic), Selenocephalinae, and Penthimiinae. Clades comprising Macropsinae, Neocoelidiinae, Scarinae, Iassinae, Coelidiinae, Eurymelinae + Idiocerinae, Evacanthini + Pagaroniini, Aphrodinae + Ledrinae (in part), Stenocotini + Tartessinae, and Cicadellini + Proconiini were also recovered with moderate to high branch support. Cicadellinae (sensu lato), Ledrinae, Typhlocybinae, and Xestocephalinae were consistently polyphyletic on the most-parsimonious topologies, but constraining these groups to be monophyletic did not significantly increase the length of the cladograms. Relationships among the major lineages received low branch support, suggesting that more data are needed to provide a robust phylogenetic estimate.

Phylogeny of the treehoppers (Insecta: Hemiptera: Membracidae): evidence from two nuclear genes.

We present a molecular systematic investigation of relationships among family-group taxa of Membracidae, comprising nearly 3.5 kb of nucleotide sequence data from the nuclear genes elongation factor-1alpha (EF-1alpha: 958 bp) and 28S ribosomal DNA (28S rDNA: 2363 bp); data partitions are analyzed separately and in combination for 79 taxa. Analysis of the combined sequence data provided a better-resolved and more robust hypothesis of membracid phylogeny than did separate analyses of the individual genes. Results support the monophyly of the family Membracidae and indicate the presence of two major lineages (Centrotinae + Stegaspidinae + Centrodontinae and Darninae + Membracinae + Smiliinae). Within Membracidae, molecular data support the following assertions: (1) the previously unplaced genera Antillotolania and Deiroderes form a monophyletic group with Microcentrini; (2) Centrodontini and Nessorhinini are monophyletic clades that arise independently from within the Centrotinae; (3) Centrotinae is paraphyletic with respect to Centrodontinae; (4) the subfamily Membracinae is monophyletic and possibly allied with the darnine tribe Cymbomorphini; (5) the subfamily Darninae is paraphyletic; (6) the subfamily Smiliinae is paraphyletic, with molecular evidence indicating the exclusion of Micrutalini and perhaps Acutalini and Ceresini; and (7) Membracidae arose and diversified in the New World with multiple subsequent colonizations of the Old World. Our phylogenetic results suggest that morphology-based classifications of the Membracidae need to be reevaluated in light of emerging molecular evidence.

Phylogeny of the grassland leafhopper genus Flexamia (Homoptera: Cicadellidae) based on mitochondrial DNA sequences.

Leafhoppers (Cicadellidae) are a highly diverse group of sap-sucking insects, many species of which specialize on grasses. Past attempts to examine the roles of host transfer or host plant coevolution in the diversification of leafhopper species using cladistic methods have been hindered by a paucity of discrete, phylogenetically informative morphological characters. To demonstrate the utility of DNA sequence data for species-level phylogenetic studies of Cicadellidae, we estimated phylogenetic relationships among species in the North American grassland leafhopper genus Flexamia DeLong using partial nucleotide sequences of mitochondrial 16S rDNA and NADH dehydrogenase 1, totaling 1496 base pairs and 810 potentially informative characters. Analyses of the partitioned and combined sequence data using maximum parsimony, neighbor-joining, and maximum likelihood criteria yielded similar estimates of relationships in which most nodes were well-supported by bootstrap and decay indices. These estimates largely agreed with a previously published, intuitive, morphology-based phylogeny for the genus. A parsimony reconstruction of host associations based on these results suggests that the origins of various Flexamia clades coincided with host transfers among grass subfamilies or genera. Nevertheless, associations with certain subfamilies, genera, or species of grasses appear to have been largely conserved in the evolutionary diversification of Flexamia.

Gradual and random binarization of gray-scale holograms.

A new method called gradual and random binarization to binarize gray-scale holograms, based on an iterative algorithm, is proposed. The binarization process is performed gradually, and the pixels to be binarized are chosen randomly. Errors caused by this operation are spatially diffused. A comparison with other established methods based on error diffusion, direct binary search, and iterative stepwise quantization shows that the gradual and random binarization method achieves a very good compromise between computational complexity and reconstruction quality. Optical reconstructions are presented.

Molecular taxonomy using single-strand conformation polymorphism (SSCP) analysis of mitochondrial ribosomal DNA genes.

Single-strand conformation polymorphism (SSCP) analysis detects single point mutations in DNA molecules. We demonstrate that SSCP analysis of mitochondrial ribosomal DNA (rDNA) genes is a sensitive taxonomic tool because these genes often differ at numerous sites among closely related species. Using conserved primers, portions of the 12S or 16S rDNA genes were amplified using the polymerase chain reaction (PCR) in congeneric species of ticks, leafhoppers, mosquitoes, and closely related endoparasitic wasps. SSCP was performed and products were visualized with silver staining. Species-specific patterns were observed in all taxa. Intraspecific variation at the level of single nucleotide substitutions was detected. SSCP diagnostics are less expensive and time consuming to develop than PCR with species-specific primers, and, unlike PCR with arbitrary primers, there is minimal concern with DNA contamination from non-target organisms.