13 research outputs found

    Estimating the effect of tracking tag weight on insect movement using video analysis: A case study with a flightless orthopteran

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    In this study, we describe an inexpensive and rapid method of using video analysis and identity tracking to measure the effects of tag weight on insect movement. In a laboratory experiment, we assessed the tag weight and associated context-dependent effects on movement, choosing temperature as a factor known to affect insect movement and behavior. We recorded the movements of groups of flightless adult crickets Gryllus locorojo (Orthoptera:Gryllidae) as affected by no tag (control); by light, medium, or heavy tags (198.7, 549.2, and 758.6 mg, respectively); and by low, intermediate, or high temperatures (19.5, 24.0, and 28.3 degrees C, respectively). Each individual in each group was weighed before recording and was recorded for 3 consecutive days. The mean (+/- SD) tag mass expressed as a percentage of body mass before the first recording was 26.8 +/- 3.7% with light tags, 72 +/- 11.2% with medium tags, and 101.9 +/- 13.5% with heavy tags. We found that the influence of tag weight strongly depended on temperature, and that the negative effects on movement generally increased with tag weight. At the low temperature, nearly all movement properties were negatively influenced. At the intermediate and high temperatures, the light and medium tags did not affect any of the movement properties. The continuous 3-day tag load reduced the average movement speed only for crickets with heavy tags. Based on our results, we recommend that researchers consider or investigate the possible effects of tags before conducting any experiment with tags in order to avoid obtaining biased results.Web of Science167art. no. e025511

    Decomposition and Coleoptera succession on exposed carrion of small mammals

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    Abstract In 1997 and 1998, field studies on exposed rat carcasses were conducted in Opava, the Czech Republic, to describe the decomposition process and Coleoptera succession patterns. Coleoptera assemblages were monitored during three 40-d succession series conducted in spring, summer and autumn in two different habitats: meadow and deciduous forest. The rate of decomposition was studied in carcasses open to insects and isolated from them. The stages of decomposition recognised in this study follow Reed's classification: fresh, bloated, decay and dry stage. Carcass in summer decayed much faster than in spring and autumn and the decomposition of insect-free carcasses was less rapid than that of carcasses exposed to insects. A total of 145 Coleoptera species belonging to 22 families was recorded on the carcasses. The number of species in the succession series increased from the fresh stage, reached a maximum in the decay stage and gradually declined in the dry stage. The greatest diversity of Coleoptera was found in spring, followed by summer and autumn. More species were collected in forest site than in meadow. Four ecological groups, each characterised by a specific type of carrion association and varying in food specialisation and species biology, have been distinguished

    Cryptic diversity in Zoraptera: Latinozoros barberi (Gurney, 1938) is a complex of at least three species (Zoraptera: Spiralizoridae).

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    The order Zoraptera contains relatively few species, but current molecular phylogenetic studies suggest an unexpectedly high level of cryptic diversity in the order with many overlooked species based on morphology alone. Latinozoros Kukalova-Peck & Peck, 1993 represents the only genus of monotypic Latinozorinae (Zoraptera: Spiralizoridae) with only one species described, L. barberi (Gurney, 1938), until now. Although this species has been repeatedly reported from a number of locations in South and Central America, it is likely a complex of unrecognized species. Here, we present a molecular phylogenetic reconstruction revealing three genetically distinct lineages in Latinozoros, and we also present detailed morphological comparisons that prove the species status of Latinozoros cacaoensis sp. nov. from French Guiana and L. gimmeli sp. nov. from the Dominican Republic, Trinidad and Panama. The results indicate that the species previously referred to L. barberi is actually a species complex that includes L. barberi, the new species described here, and perhaps other species

    Estimation of the Recent Expansion Rate of Ruspolia nitidula (Orthoptera) on a Regional and Landscape Scale

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    Recent changes in insect distribution are consistent with the expected interacting effects of climate and habitat change. The orthopteran Ruspolia nitidula has expanded its area of distribution in Western and Central Europe in recent decades. Because males emit a sound that is easily detected at a distance of up to 40 m, it is possible to detect spreading individuals and to therefore document routes and rates of spread. Using occurrence data at the landscape scale and three methods, including least-cost path analysis with habitat suitability, we estimated the R. nitidula expansion rate from 2006 to 2020 in the Czech Republic; this involved estimating distances between two origin occurrences in 2006 and two occurrences on the area margin in 2020. For comparison, we directly monitored expansion based on detection of singing males at the regional scale at the areal margin in the Odra River basin (2016–2020). The estimated maximum expansion rate ranged from 13.8 to 16.2 km/year based on occurrence data at the landscape scale and from 11.1 to 11.7 km/year based on the monitoring of males in the Odra River basin. To our knowledge, this is the first report of the direct monitoring of individual spreading males to detect changes in the distribution of an orthopteran

    An Immature Dermapteran Misidentified as an Adult Zorapteran: The Case of <i>Formosozoros newi</i> Chao & Chen, 2000

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    Zoraptera shows extreme uniformity in general body morphology, with the exception of Formosozoros (=Zorotypus) newi Chao & Chen, 2000, which stands out in terms of the shape and arrangement of its legs, the cerci, and several other morphological characters. After critical evaluation, we found that this species is not a zorapteran but is instead a nymph (1st instar) of an earwig; i.e., F. newi is a dermapteran. Because of the lack of morphological descriptions of Dermaptera nymphs that would allow species identification, and because the type material of F. newi is lost, a more detailed classification is not possible. We therefore propose that the genus name Formosozoros Chao & Chen, 2000 and the species name Formosozoros newi Chao & Chen, 2000 are nomina dubia

    Termitophily Documented in Earwigs (Dermaptera)

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    Based on behavioral observations, we report termitophily by the earwig Spirolabia kaja Ko&#269;&aacute;rek, sp. nov. (Spongiphoridae: Labiinae). The new species was found in association with the wood-boring termite Schedorhinotermes sarawakensis (Holmgren, 1913) in a dipterocarp rain forest in Borneo; in addition to being observed in the galleries, termite&ndash;earwig interactions were subsequently documented in the laboratory. We found that earwigs and termites communicate by antennation, and we observed no form of targeted mutual or unilateral aggressive behavior. The earwigs responded to the proximity of an experimentally irritated termite soldier by conflict-avoidance behavior based on thanatosis, which seems to be a defensive reaction that may reduce the chance of being attacked by an irritated termite. Based on the analysis of gastrointestinal tract contents, we conclude that S. kaja sp. nov. is an omnivorous species that feeds mainly on plant tissues and fungi but occasionally on arthropod remains. The occurrence of S. kaja sp. nov. adults together with the nymphs (2nd to 4th instars) in the galleries of S. sarawakensis strongly suggests that the earwig can reproduce inside the termite colony. Spirolabia kaja Ko&#269;&aacute;rek, sp. nov. is the first earwig species for which termitophily has been demonstrated

    Fragmented distribution of Isophya pienensis Maran, 1954 (Insecta, Orthoptera) in mountains: a result of permanent forest opening in highly forested landscape

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    Background and Purpose: Isophya pienensisMaran, 1954 (Orthoptera) is a stenotopic katydid occurring locally in Central and Eastern Europe. The purpose of the study was to document the habitat associations of I. pienensis in the Beskids in relation to historical land use and present landscape structure. Materials and Methods: Isophya pienensis was studied in the Moravian- Silesian Beskids Mountains at 15 sites representing small unforested areas surrounded by spruce forests on themassifs of the Smrk (1,276ma.s.l.) andKnehyne (1,256ma.s.l.)mountains. Thirty-minute timed counts were used. Results and Conclusions: Isophya pienensiswas found at 5 of the 15 sites but was not found at elevations below 1,000 m a.s.l. The occurrence of I.pienensis in the Beskids on small, isolated, shady sites at elevations over 1,000mis not a result of its being amountain species. Rather, it is due to the persistence of open-forest habitats and of ecotones near forest lodges where broadleaf vegetation is maintained on shady spots by occasional mowing. The permanent occurrence of I. pienensis probably depends on the presence of heterogeneous, early successional stages of forests and their ecotones, which were historically maintained by selective cutting, grazing, and charcoal production on a mosaic of grasslands

    FIGURES 17, 18 in Zorotypus asymmetricus sp. nov. from Brunei Darussalam, Borneo (Insecta: Zoraptera)

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    FIGURES 17, 18. Living status and occupied habitat of Zorotypus asymmetricus sp. nov. 17, living apterous male; 18, rotting logs in Sungai Esu stream valley where Z. asymmetricus sp. nov. was collected
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