Immature stages of three species of Blissidae from Mexico (Heteroptera: Lygaeoideae)

Chinch bugs are associated with several species of monocots, and species of Gramineae are the principal plants utilized. In Mexico, 24 species of Blissidae have been recorded. The immature stages of Ischnodemus sallei (Signoret), Toonglasa munda (Slater & Wilcox), and T. tumorosis (Slater & Wilcox) are described and illustrated. These species have been recorded from several species of bamboo. Distributional records in Mexico and the host plants of these chinch bugs are also included.     

Secondary invasion: When invasion success is contingent on other invaders altering the properties of recipient ecosystems

Positive interactions between exotic species may increase ecosystem‐level impacts and potentially facilitate the entry and spread of other exotic species. Invader‐facilitated invasion success—”secondary invasion”—is a key conceptual aspect of the well‐known invasional meltdown hypothesis, but remains poorly defined and empirically underexplored. Drawing from heuristic models and published empirical studies, we explore this form of “secondary invasion” and discuss the phenomenon within the recognized conceptual framework of the determinants of invasion success. The term “secondary invasion” has been used haphazardly in the literature to refer to multiple invasion phenomena, most of which have other more accepted titles. Our usage of the term secondary invasion is akin to “invader‐facilitated invasion,” which we define as the phenomenon in which the invasion success of one exotic species is contingent on the presence, influence, and impacts of one or more other exotic species. We present case studies of secondary invasion whereby primary invaders facilitate the entry or establishment of exotic species into communities where they were previously excluded from becoming invasive. Our synthesis, discussion, and conceptual framework of this type of secondary invasion provides a useful reference to better explain how invasive species can alter key properties of recipient ecosystems that can ultimately determine the invasion success of other species. This study increases our appreciation for complex interactions following invasion and highlights the impacts of invasive species themselves as possible determinants of invasion success. We anticipate that highlighting “secondary invasion” in this way will enable studies reporting similar phenomena to be identified and linked through consistent terminology.     

Sampling Rhodnius neglectus in Mauritia flexuosa palm trees: a field study in the Brazilian savanna

Two sampling methods (manual capture and live-baited adhesive traps) were compared for collecting the bug Rhodnius neglectus Lent (Hemiptera: Reduviidae: Triatominae) from palm trees, Mauritia flexuosa L. (Arecaceae), in the savanna of Brasília DF. R. neglectus was found in 19/50 (38%) of palm trees sampled. The detection rate was much higher by visual inspection and manual capture (18/50=36%) than by our trapping method (5/50=10%), although one tree was found to be positive by trapping but not by manual capture. Bugs collected manually were mostly (146/154=95%) found among the dead organic material in palm crowns. In combination, these sampling techniques are useful for quick detection of triatomine bug infestation in palm trees, especially in areas of high ecological value where the palms should not be cut and dissected, but arboreal Rhodnius are suspected to transmit enzootic Trypanosoma cruzi that might represent a risk of causing human cases of Chagas disease.     

On the accuracy of efficiency of estimating equation approach

Liang and Zeger (1986, Biometrika 73, 13-22) introduced a generalized estimating equation (GEE) approach based on a working correlation matrix to obtain efficient estimators of regression parameters in the class of generalized linear models for repeated measures data. As demonstrated by Crowder (1995, Biometrika 82, 407-410), because of uncertainty of the definition of the working correlation matrix, the Liang-Zeger approach may, in some cases, lead to a complete breakdown of the estimation of the regression parameters. After taking this comment of Crowder into account, recently Sutradhar and Das (1999, Biometrika 86, 459-465) examined the loss of efficiency of the regression estimators due to misspecification of the correlation structures. But their study was confined to the regression estimation with cluster-level covariates, as in the original paper of Liang and Zeger. In this paper, we study this efficiency loss problem for the generalized regression models with within-cluster covariates by utilizing the approach of Sutradhar and Das (1999).     

Revised and annotated checklist of aquatic and semi-aquatic Heteroptera of Hungary with comments on biodiversity patterns

A basic knowledge of regional faunas is necessary to follow the changes in macroinvertebrate communities caused by environmental influences and climatic trends in the future. We collected all the available data on water bugs in Hungary using an inventory method, a UTM grid based database was built, and Jackknife richness estimates and species accumulation curves were calculated. Fauna compositions were compared among Central-European states. As a result, an updated and annotated checklist for Hungary is provided, containing 58 species in 21 genera and 12 families. A total 66.8% of the total UTM 10 × 10 km squares in Hungary possess faunistic data for water bugs. The species number in grid cells numbered from 0 to 42, and their diversity patterns showed heterogeneity. The estimated species number of 58 is equal to the actual number of species known from the country. The asymptotic shape of the accumulative species curve predicts that additional sampling efforts will not increase the number of species currently known from Hungary. These results suggest that the number of species in the country was estimated correctly and that the species accumulation curve levels off at an asymptotic value. Thus a considerable increase in species richness is not expected in the future. Even with the species composition changing the chance of species turn-over does exist. Overall, 36.7% of the European water bug species were found in Hungary. The differences in faunal composition between Hungary and its surrounding countries were caused by the rare or unique species, whereas 33 species are common in the faunas of the eight countries. Species richness does show a correlation with latitude, and similar species compositions were observed in the countries along the same latitude. The species list and the UTM-based database are now up-to-date for Hungary, and it will provide a basis for future studies of distributional and biodiversity patterns, biogeography, relative abundance and frequency of occurrences important in community ecology, or the determination of conservation status.     

Spatial distribution and sampling plan of the phytophagous stink bug complex in different soybean production systems

Phytophagous stink bugs are major soybean pests, and knowledge of spatial distribution models of the pest in the crop is fundamental to establishing an appropriate sequential sampling plan, and thus, allowing the correct utilization of control strategies. This work aimed to study the spatial distribution of phytophagous stink bugs in soybean grown in different cropping systems and determine a sequential sampling plan. The experiment was conducted in Maracaju, MS, Brazil, during the agricultural year of 2012/2013. Soybean cultivars BRS 284 and SYN 1163 RR were placed in an experimental area comprising six fields (two soybean cultivars × three cropping systems). Sampling was performed weekly, using a beat cloth per plot and counting the number of stink bugs found, virtually throughout the soybean reproductive period. Concerning the statistical analyses, we used the dispersion indexes (variance‐to‐mean ratio, Morisita's index, exponent k of the negative binomial and Green's coefficient) and probabilistic methods of frequency adjustment (negative binomial and Poisson). Adult and nymph phytophagous stink bugs showed aggregate disposition in the field regardless of the cropping system, and their numbers were adjusted to the negative binomial probability distribution. There was no difference in the behaviour of adult and nymphs considering the tested cultivars. We elaborated a practical sequential sampling plan for phytophagous stink bug complexes, considering crops intended for the production of grains and seeds.     

Beech versus spruce deadwood as forest microhabitat: does it make any difference to bryophytes?

The presence data of 153 bryophyte species, recorded on beech (BDW) and spruce (SDW) deadwood in the managed forests within a montane watershed, were analysed by controlling for different plot size, substrate pH and elevation. Only three pleurocarpous species, which were probably remnant epiphytes from live wood, showed relative specificity for BDW, but none to SDW. The few species displaying preference for BDW or SDW were generally true epixylic, mosses and hepatics, respectively. The chances of occurrence of epiphytic (early successional) and epixylic (mid-late successional) taxa on either deadwood species increased and respectively, decreased with the substrate pH. There was no consistent relationship between bryophyte preference to BDW/SDW and elevation. Neither total nor threatened species richness was related to deadwood species identity. However, at 100 cm² resolution and within certain extension range, the cumulative number of bryophyte species was significantly higher on BDW than on SDW, despite no significant difference in species pool size. Threatened species richness increased monotonically towards lower elevations, suggesting that valley bottoms might act as refugia with high air humidity. The number of threatened species and in particular, the presence of Lophozia ascendens, were good predictors of total bryophyte richness regardless of deadwood species identity.     

The role of maternal effects in adaptation to different diets

The environmental influences of mothers on offspring traits, or maternal effects, often arise from dietary differences experienced by mothers. However, few studies have explored if and how maternal effects facilitate adaptation to new host plants. To address this, we compared the maternal and direct effects arising from dietary differences in two populations of the large milkweed bug, Oncopeltus fasciatus that live on and feed on the seeds from different hosts. We compared a laboratory population, which has been reared for over 400 generations on sunflower seeds and is now adapted to use these as a host, to the wild population, which is adapted to the ancestral diet of toxic milkweed seeds. We first tested for changes in maternal effects, and then examined offspring performance and survivorship. We found evidence for evolution of the maternal effect facilitating the use of a novel host. However, the strongest effects were population differences and direct dietary effects for all traits. Offspring performance was more strongly influenced by diet than maternal effects. Survivorship depended on population and offspring diet, and their interaction, but was unaffected by maternal diet or other interactions. In the artificially evolved population, diet breadth was increased rather than evolving specialization. Our results suggest changes in maternal effects are likely to be weak compared to direct effects of host plants and other adaptations in adaptation to a novel host. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 114 , 202–211.     

The tribe Bryocorini (Insecta: Heteroptera: Miridae: Bryocorinae): phylogeny,description of a new genus,and adaptive radiation on ferns

A cladistic analysis of the tribe Bryocorini based on 68 morphological characters is conducted. Bryocorini are supported as a monophyletic group with Eccritotarsini as their sister taxon. Based on the phylogenetic analysis, we redefine the tribe Bryocorini to contain the following seven genera: Bryocorella Carvalho, 1956, Bryocoris Fallén, 1829, Bryophilocapsus Yasunaga, 2000, Cobalorrhynchus Reuter, 1906 gen. dist., D iplazicoris gen. nov. , Hekista Kirkaldy, 1902, and Monalocoris Dahlbom, 1851. The genus Bryocorella is transferred to Bryocorini from the tribe Eccritotarsini. The subgenus Cobalorrhynchus is treated as a separate genus. Diplazicoris is described as monotypic to accommodate D iplazicoris lombokianus sp. nov. An updated diagnosis of the tribe, a key to genera, and a diagnosis of each recognized genus are presented. Selected photomicrographs, scanning micrographs, and illustrations of the pretarsus, metepisternal scent efferent system, metafemoral trichobothria, and morphology of head, pronotum, and male and female genitalia are provided. Mapping of the host data on the revealed tree shows that Bryocorini represent one of the very few currently known examples of the adaptive radiation of a fairly large insect group on ferns. © 2015 The Linnean Society of London