Usage of Fermental Traps for the Study of the Species Diversity of Coleoptera

Trapping liquids may bias the results of beetle diversity assessment

Several different techniques and methods are used to capture and study beetles (Coleoptera). One option is the use of window traps with various trapping liquids. However, these liquids used in comparative studies may have a biasing effect on the results. The effectiveness of the frequently used liquid baits, involving beer, wine, vinegar, and water as the reference liquid, was compared in this study. Twenty-four traps were assigned to two habitat categories (sunny and shady) and four kinds of bait: beer, wine, vinegar, and water. During the study from June to July 2021, a total of 29,944 invertebrates were captured; of these, 3,931 individuals belonged to Coleoptera. A total of 3,825 beetles were identified, belonging to 120 species and 36 families. The most abundant family was Nitidulidae, with 3,297 adults (86% of the total). The number of arthropods differed only in the trapping liquid, and the captures were similar between beer and wine and between vinegar and water. The trapping liquid had a more significant effect on beetle abundance and species richness. In contrast, exposure had a significant effect only on the number of beetle species and a higher ratio of beetles was found in the shade. Beer and wine were very attractive and collected similar beetle communities. However, the diversity (Shannon's index) was low due to the high abundance of several species. Traps with vinegar and water collected a similar composition and species richness. After removing sap beetles (Nitidulidae) from all traps, a significant difference was still recorded between trapping liquids in the number of individuals and species, and their communities were much more similar. Thus, at high abundances of sap beetles, it is possible to exclude them from analyses and obtain more accurate data when assessing environmental variables. The results showed that the type of trapping liquids used can have substantial effects on abundance and species composition captured beetles in traps especially for beer and wine. The beer and wine in traps can significantly influence the subsequent biodiversity assessment. We recommend the use of trapping liquids without the baiting effect to correctly assess the effect of environmental variables on beetle richness and abundance.

New records of non-native Coleoptera in Italy

Background

In the last decades, climate change and globalisation have been exacerbating the introduction of non-native beetles worldwide. Due toits peculiar territory, climate and geographical position in the middle of the Mediterranean Basin, Italy is one of the European countries with the highest number of intercepted, adventive and established non-native beetles, some of which are invasive. In this perspective, producing new faunistic records and continuously updating reliable and easily accessible distributional data is a fundamental step in investigating and potentially preventing further species introduction.

New information

The aim of this contribution is to report and discuss new faunistic records of non-native Coleoptera in Italy. For some species, new records enlarge the previously-known distribution (e.g. the ambrosia beetles Anisandrusmaiche (Kurentzov, 1941) and Cnestusmutilatus (Blandford, 1894) or the click beetle Monocrepidiusposticus (Eschscholtz, 1829)), while for others (e.g. the scarab beetle Archophileurusspinosus Dechambre, 2006), data confirm their establishment and highlight a possible expansion phase. The false powderpost beetles Ptilineurusmarmoratus (Reitter, 1877) and the longhorn beetle Xylotrechuschinensis (Chevrolat, 1852) are two new additions to the Italian fauna, while the establishment of the monotomid beetle Monotomaamericana Aubé 1837 is confirmed.

Usage of Fermental Traps for the Study of the Species Diversity of Coleoptera in Open Biotopes

Usage of a variety of non-trivial ways to study Coleoptera gives unexpected and original results. The studies were conducted using simple traps with fermenting baits in the central part of European Russia. There were 286 trap exposures, and 7906 Coleoptera specimens (208 species from 35 families) were collected. The largest number of species belonged to the families Cerambycidae (35 species), Curculionidae (26 species), and Elateridae (25 species). One species each was noted in 12 families. Traps were applied in five open habitats (dry meadow, shore, floodplain meadow, cuttings under power lines, and glade in woods). Only 13 species were common to all habitats: Cetonia aurata, Protaetia marmorata, Dasytes niger, Cryptarcha strigata, Glischrochilus grandis, Glischrochilus hortensis, Glischrochilus quadrisignatus, Soronia grisea, Notoxus monoceros, Aromia moschata, Leptura quadrifasciata, Rhagium mordax, Anisandrus dispar. Dry meadows were dominated by C. aurata, A. murinus, and P. cuprea volhyniensis. A shore was dominated by C. strigata, G. grandis, G. hortensis, S. grisea, and A. dispar. The dominant species in floodplain meadows were G. hortensis, S. grisea, and A. dispar. On cuttings under power lines, the most numerous were C. aurata, P. cuprea volhyniensis, and C. viridissima. In forest glades, the maximum abundance data were obtained for G. grandis, C. strigata, and A. dispar. The Shannon index was greatest in meadow habitats of varying degrees of moisture, while it was minimal on the shore. The increase in the Simpson index was also characteristic of the shore. These data indicate reduced species diversity combined with the dominance of several species in this biotope. The maximum species diversity with the highest level of species alignment was characteristic of meadow plots, while lower values were obtained under power lines and in forest glades. We recommend the usage of fermental traps with beer for ecological studies of the Coleoptera fauna in open biotopes.

Biodiversity of Coleoptera (Insecta) in Mordovia State Nature Reserve (Russia) using fermental traps

Background

Protected areas are unique ecosystems that are minimally affected by anthropogenic activities. Therefore, in many cases, they are refugia and relevance of faunistic research is undeniable here. A simple method of catching insects, such as trapping with the help of fermental traps, was used in this area for the first time. The authors of the dataset used this method from 2018 to 2021. One thousand and fifty-one traps of our own design were installed. The dataset includes data on 367 species from 52 families (6,497 records of 44,600 specimens). Ten species were dominant in the traps (Cryptarchastrigata, Protaetiamarmorata, Glischrochilusgrandis, Glischrochilushortensis, Soroniagrisea, Rhagiummordax, Lepturathoracica, Lepturaquadrifasciata, Quediusdilatatus and Protaetiafieberi). These species accounted for 76.9% of all individuals in the total amount of captured specimens. Cryptarchastrigata was the most numerous species (28.8% of the total) and the most frequently encountered species (64.9%). The greatest species diversity was recorded in the families Cerambycidae (53 species), Elateridae and Curculionidae (39 species each), Nitidulidae and Coccinellidae (22 species each). The dataset contains information on the occurrence of 15 rare species.

New information

We have recently published a checklist of the Coleoptera of Mordovia State Nature Reserve (Egorov et al. 2020). It included 2,145 species from 88 families. However, the published list did not contain information about the occurrence of various species of beetles, especially caught in recent years. Part of this list contained information about species collected using fermental traps. However, the list of species did not provide information about specific locations.

Vertical Stratification and Seasonal Dynamics of Coleoptera in Open Biotopes of Forest Ecosystems (Centre of European Russia)

There are few studies on the vertical distribution and seasonal activity of arthropods in open habitats (in glades) in temperate forests due to methodological problems associated with the arrangement of certain structures for trapping. However, glades in forests are places of significant biodiversity of native animals, which are attracted to such areas by the possibilities of nutrition, reproduction, and wintering. The research was carried out on the territory of the Republic of Mordovia (the center of the European part of Russia). Fermental traps (bait—fermenting beer with sugar) were used to collect Coleoptera. They were installed on a special structure at heights of 2, 4, 6, 8, and 10 m. The collections were carried out from May to October 2020 in a glade with an area of 0.93 hectares in a deciduous forest. At the end of the research, 745 specimens of 80 species were registered from 30 Coleoptera families. The greatest species diversity was recorded in Nitidulidae (11 species), Cerambycidae (10 species), Scarabaeidae (7 species), Elateridae, Coccinellidae, and Curculionidae (5 species each). The greatest species diversity (53 species) and numerical abundance were obtained at a height of 2 m, and the smallest one (16 species) at a height of 10 m. The largest differences in the Jaccard similarity index were obtained between samples from a height of 2 and 10 m. The maximum values of the Shannon index and the minimum values of the Simpson index were recorded at the height of 2 m. The most significant relative number of saproxylic species was obtained at a height of 4 m. The relative number of anthophilic species was minimal at a height of 10 m. The seasonal dynamics of Coleoptera abundance were the same at different heights and the highest abundance was observed in late May and early June. However, the seasonal dynamics were different for some Coleoptera species in the glade located and inside the forest. Our data confirm the relevance of sampling in open biotopes at different heights in the study of arthropod biodiversity.

Post-fire insect fauna explored by crown fermental traps in forests of the European Russia

Wildfires considerably affect forest ecosystems. However, there is a lack of data on the post-fire status of insect communities in these ecosystems. This paper presents results of a study conducted in 2019 which considered the post-fire status of the insect fauna in a Protected Area, Mordovia State Nature Reserve (Republic of Mordovia, centre of European Russia), considered as regional hotspot of insect diversity in Mordovia. We sampled insects on intact (unburned, control) and fire-damaged (burnt in 2010) sites and compared the alpha-diversity between sites. In total, we sampled and analysed 16,861 specimens belonging to 11 insect orders, 51 families and 190 species. The largest orders represented in the samples were Coleoptera (95 species), Diptera (54 species), Hymenoptera (21 species), and Neuroptera (11 species). Other insect orders were represented by between one and four species. The largest four orders (Coleoptera, Lepidoptera, Diptera and Hymenoptera) represented 96.7% of all studied specimens. We found that in the ninth year after low intensity surface fire damage, the insect diversity had returned to a similar level to that of the control (unburned) sites. Sites damaged by crown wildfire differed considerably from other sites in terms of a negative impact on both species diversity and the number of specimens. This indicates the serious effect of the crown fires on the biodiversity and consequent long-term recovery of the damaged ecosystem.

Vertical Stratification of Beetles in Deciduous Forest Communities in the Centre of European Russia

Studies on the vertical distribution of arthropods in temperate forests have revealed the uneven vertical distribution of communities. Many factors influence these patterns simultaneously. However, there are still many questions related to the vertical distribution of Coleoptera in deciduous forests of the temperate zone. The research was carried out within the territory of the Republic of Mordovia (the center of the European part of Russia). Fermental traps with a bait made of fermenting beer with sugar were used to collect Coleoptera. The collections were carried out from May to September 2020 at five sites in a deciduous forest. We set traps at a height of 1.5, 3.5, 7.5 and 12 m above the ground) on the branches of trees. Ninety-two species were identified at the end of studies at different heights. The families Nitidulidae (15 species), Cerambycidae (14 species), Elateridae (7 species), Curculionidae (7 species) and Scarabaeidae (7 species) had the greatest species diversity. The greatest species diversity was recorded at a height of 1.5 m, while the smallest one was recorded at a height of 7.5 m. The minimum number of specimens was recorded at a height of 12 m. The largest differences in the Jaccard similarity index were obtained between samples from a height of 1.5 and 12 m. The Shannon’s diversity index was higher near the ground than in the tree crowns (at heights of 7.5 and 12 m), and the Simpson index had the opposite tendency. Glischrochilus hortensis and to a lesser extent Cychramus luteus preferred to live in the lowest layers of deciduous forest (1.5 m). Cryptarcha strigata was mainly found with relatively high numbers at heights of 3.5 m and 7.5 m. The abundance and occurrence of Protaetia marmorata and Quedius dilatatus were higher in the uppermost layers of the crowns. The number of saproxylic beetle species at heights of 3.5–12 m was almost the same, while in the surface layer it decreased. The number of anthophilic beetle species was also lower at a low altitude. Our data confirm the relevance of sampling in forest ecosystems at different altitudes while studying arthropod biodiversity.

Monitoring Exotic Beetles with Inexpensive Attractants: A Case Study

Simple Summary

Detecting and monitoring exotic and invasive beetles is a complex activity, and multiple species still manage to evade controls. Citizen science can be an important adjunct in alien species monitoring programs, but to have a greater chance of success, it must employ traps and attractants that are easy to gather and use. Bottle traps baited with food products are successfully used during long term faunistic surveys, and the same methodology can be adapted to alien species detection and monitoring. In this article, we tested the use of bottles baited with apple cider vinegar, red wine, and 80% ethyl alcohol in capturing exotic and invasive beetles in the surroundings of Malpensa Airport (Italy). The traps proved effective, and in the traps with vinegar as an attractant, they captured four out of five invasive Nitidulidae, as well as the only invasive Scarabaeidae present in the area. Popillia japonica’s response to apple cider vinegar is documented for the first time and suggests the use of this attractant in monitoring surveys for this species, especially if supported by citizen science programs. The substantial reduction in the activity time of the traps seems to have considerably reduced collateral catches of native fauna.

Abstract

Detecting and monitoring exotic and invasive Coleoptera is a complex activity to implement, and citizen science projects can provide significant contributions to such plans. Bottle traps are successfully used in wildlife surveys and can also be adapted for monitoring alien species; however, a sustainable, large scale trapping plan must take into account the collateral catches of native species and thus minimize its impact on local fauna. In the present paper, we tested the use of bottles baited with standard food products that can be purchased in every supermarket and immediately used (apple cider vinegar, red wine, and 80% ethyl alcohol) in capturing exotic and invasive beetles in the area surrounding Malpensa Airport (Italy). In particular, we reduced the exposition type of the traps in each sampling round to three days in order to minimize native species collecting. We found a significant effect of the environmental covariates (trap placement, temperature, humidity, and forest type) in affecting the efficiency in catching target beetles. Nearly all invasive Nitidulidae and Scarabaeidae known to be present in the area were captured in the traps, with apple cider vinegar usually being the most effective attractant, especially for the invasive Popillia japonica.