Tingidae Research Articles

Key factors in the successful adaptation of the pest <i>Corythucha ciliata</i> Say in the northern subtropics of the Black Sea coast

Aim. To identify a complex of factors in the successful adaptation of the sycamore lace bug Corythucha ciliata Say for the development of methods for regulating its numbers of and effective biological control measures against this dangerous pest. Material and Methods. The research was carried out by studying scientific publications, analysing the dynamics of climate change in the Lazarevsky district of Sochi for 15 years and studying the reporting data of the Lazarevskaya Experimental Plant Protection Station, Branch of the Federal Research Center of Biological Plant Protection for the period 2008 to 2022. Results. 5 key factors of successful adaptation of Corythucha ciliata to new invasion regions have been identified: the factors of food and climatic adaptation, the factor of interaction with natural enemies, the factor of resistance to entomopathogenic organisms and the factor of adaptation to anthropogenic load. The main conditions and possible vectors of further invasion of sycamore lace in new regions have been determined. Conclusion. The development of effective methods of biological control of the invasive pest Corythucha ciliata Say should be based taking into account the totality of qualitative characteristics of the pest's living conditions. The sycamore lace bug Corythucha ciliata Say effectively builds new trophic connections, without prejudice to its population, adapts not only to new climatic conditions, but also to their changes. Natural entomophages and entomopathogens do not significantly affect the development of the Corythucha ciliata population. The pest has adapted to survival in conditions of high anthropogenic load and successfully uses it to invade new regions.

The effect of the oak powdery mildew, oak lace bug, and other foliofagous insects on the growth of young pedunculate oak trees

Pedunculate oak (Quercus robur L., 1753) is one of the widely distributed oak species in Europe. A large number of organisms develop on its leaves. To determine the extent to which the oak powdery mildew, oak lace bug, and other foliofagous insects affect the growth of young oak trees, three experimental fields were selected in a 10-year-old pedunculate oak stand. In each of them, 50 trees were randomly selected, and their height was measured at the beginning of the vegetative season. The first experimental field was treated with a systemic insecticide, the second with a systemic fungicide, and the third, a comparison area, with water, during the entire vegetative season. At the end of the vegetative season, 25 plants with one apical branch were selected in each experimental field. Their height was measured, and 20 leaves were taken from each plant to determine the extent of the damage on them at the end of the experiment. After processing the obtained data, it was determined that: 1. Both foliofagous insects and oak leaf inhabiting fungi affect the growth of the oak trees significantly; 2. The oak lace bug did not influence the growth of the young trees significantly, as its abundance was low in all of the experimental areas; 3. The greatest damage on the leaves was caused by defoliator insects, which is why they contributed the most to the decrease in growth caused by insects; 4. The influence of the foliofagous insects on the growth of the trees was not significantly different from the influence of fungi; 5. Suppression of oak powdery mildew and foliofagous insects on young trees is useful as it positively influences the vitality and growth of those trees, and contributes to economic and ecological gain.

Évolution de la colonisation par l’espèce invasive Corythucha arcuata (Say, 1832) en France métropolitaine entre 2017 et 2022, en croisant diverses sources de données (Hemiptera, Tingidae)

Evolution of the colonization by the invasive species Corythucha arcuata (Say, 1832) in mainland France between 2017 and 2022 by cross-referencing various data sources (Hemiptera, Tingidae). In recent years, studies on Corythucha arcuata (Say, 1832), an oak lace bug native to North America, have highlighted this insect’s ability to colonize European oak forests. In France, the oak lace bug was observed for the first time in 2017, in three departments of the south-west. The objective of this study is to inventory the French territories colonized by C. arcuata. A survey was carried out in the region of Occitanie to confirm the absence of the species in Hérault department, and then to assess the front of colonization of the species from west to east. French occurrence data has been collected and grouped together in order to visualize the extent of its area of distribution in 2022. At the end of the surveys, it was revealed that the Oak Lace Bug is progressing towards the east of France, having reached the Tarn at the end of 2021. Finally, C. arcuata has colonized at least 14 departments since its first occurrence in 2017.

First record of the azalea lace bug Stephanitis pyrioides (Scott, 1874) (Hemiptera: Heteroptera: Tingidae) in the European part of Russia: Molecular genetics and taxonomy of an alien pest

AbstractThe azalea lace bug Stephanitis (Stephanitis) pyrioides (Scott, 1874) (Hemiptera: Heteroptera: Tingidae) originates from the East Palaearctic. In 2020, this alien species was recorded for the first time in the European part of Russia (Krasnodar Territory, Sochi), notably attacking Rhododendron × hybridum hort. It most likely arrived there with plants for planting from Italy. The main morphological characteristics of adults and larvae are described and illustrated. The morphological differences between S. pyrioides and closely related S. pyri (Fabricius, 1775) are highlighted in the key to distinguish these two species, bearing in mind that now both of them can be found in the south of the European part of Russia. Additionally, DNA barcoding data for S. pyrioides from Sochi were analysed against other related species of Stephanitis whose DNA barcodes are available in Barcode of Life Data Systems (BOLD) and GenBank: S. takeyai Drake et Maa, 1955, S. oberti (Kolenati, 1857), S. mendica Horváth, 1912, and S. chinensis Drake, 1948. The bionomics, distribution, damage and impact of S. pyrioides are outlined.

From Field Data to Practical Knowledge: Investigating the Bioecology of the Oak Lace Bug-An Invasive Insect Species in Europe.

Corythucha arcuata, commonly known as the oak lace bug (OLB), is an insect species originally native to North America that has become an invasive species of significant concern in Europe. This invasive pest has been observed in various European countries, raising concerns about its impact on forest ecosystems. In 2015, it was first documented in Romania, further highlighting the need for research on its bioecology and life cycle. This study investigated the bioecology of the OLB in the southern region of Romania, focusing on its life cycle, development, and population dynamics. The results indicated that the OLB has three generations per year and overwinters in the adult stage in sheltered locations. Temperature significantly influenced the timing of egg hatching, nymph appearance, and adult development, with variation observed between generations. Additionally, a life table analysis provided insights into the population dynamics of the OLB in its natural environment, revealing variation in egg laying trends across generations. This research contributes to a better understanding of the OLB's bioecology and provides essential data for forest managers developing science-based management strategies to mitigate its impact. By elucidating the life cycle and development patterns of the OLB in southern Romania, this study aids in the development of predictive models and life tables tailored to the region. These findings empower forest managers with the knowledge needed to make informed decisions for effective OLB management, ultimately preserving the health of forest ecosystems.

Infestation intensity by the invasive oak lace bug, Corythucha arcuata (Say) in mixed and pure oak stands

AbstractThere has been accumulating evidence for effects of tree species composition on herbivory with many examples of lower damage by specialist feeders in tree species rich forests. In a joint study in five Central and Southeastern European countries, we studied the effect of tree species richness on infestation intensity of the oak lace bug, Corythucha arcuata (Say) (Heteroptera, Tingidae), an invasive pest on oak trees that has spread rapidly across the Balkan Peninsula and Central Europe. Intensity of infestation by C. arcuata on oaks was assessed on three or four study plots with high (pure stands) and three or four plots with low percentage of oak (mixed stands) in each country. Ordinal regression analysis showed that intensity of infestation of trees by C. arcuata differed between countries; no significant effect of stand type (mixed or pure) on infestation levels was detected. When analysing the percentage of trees in the highest infestation class, stand type had a significant effect with more intensive infestation in pure stands. We conclude that mixed stands will not prevent severe infestation but may help mitigating the impact of established C. arcuata populations.

Assessment of the Negative Impact of the Quarantine Pest Oak Lace Bug in the Western Caucasus

In 2015, an invasive oak lace bug (Corythucha arcuata) (Say, 1832), a representative of the North American fauna of lace bugs (Heteroptera: Tingidae), was discovered in the Krasnodar Territory. The main harmfulness of oak lace bug lies in it sucking the cell juices from the leaves, as a result of which their chlorosis develops, which can be especially dangerous and serve as a cause of repression and death of oaks. To assess the foraging impact of oak lace nug, we analysed the pigment composition of English oak (Quercus robur L.) leaves before and after infestation. The optical density of the extracted pigments was measured on a spectrophotometer. The functional state of the photosynthetic apparatus was assessed using a portable chlorophyll fluorometer. As a result, a significant decrease in the content of the main photosynthetic pigment, chlorophyll, as well as carotenoids was found, which indicates the suppression of the plant’s nonspecific protective mechanism. In parallel, there occurs a decrease in the photosynthetic activity coefficient and the vitality level. However, these negative processes are at least partially offset by an increase in chlorophyll b, which prevents the inhibition of CO2 assimilation. Pest damage causes a significant decrease in leaf thickness, mainly due to a decrease in the biometric parameters of spongy and columnar parenchyma.

Genetic variability of the pear lace bug Stephanitis pyri F. (Heteroptera: Tingidae) in Krasnodar Territory, Russia

Aim. Study of the genetic variability of the pear lace bug Stephanitis pyri F. depending on geographical location and trophic specialization.Material and Methods. The object of the study was insect samples (n=60) from the natural population of the pear lace bug Stephanitis pyri F. (Tingidae: Heteroptera) in the Krasnodar Territory: in Krasnodar, Kropotkin and Novorossiysk. The collection of S. pyri bugs was carried out on model trees of domestic apple (Malus domestica Borkh) and sour cherry (Prunus cerasus L.). Molecular genetic analysis was carried out in several stages: sample preparation, DNA extraction, and diagnostics based on RAPD (random amplified polymorphic DNA)‐PCR (DNA amplification).Results. With the help of molecular genetic markers, the genetic variability of the pear lace bug in the Krasnodar Territory was studied. The indicators of genetic differentiation between geographic (Gst=0.209) and trophic (Gst=0.049–0.302) intrapopulation groups of S. pyri were calculated. The levels of variability were determined within geographic (79.1 %) and trophic groups (70.0–95.1 %), as well as between them – 20.9 % and 4.9–30 %, respectively. The influence of the food factor on the genetic diversity and differentiation of insect populations is shown through the example of the Kropotkin trophic group of bugs that prefer the sour cherry P. cerasus as the main food plant.Conclusion. A small effect of isolation by distance was noted, which was characterized by a weak dependence of geographical and genetic distances between the population groups of the pear lace bug. The influence of the nutritional factor on the genetic variability of phytophages populations has been established, as is confirmed by other researchers.

Utjecaj hrastove mrežaste stjenice Corythucha arcuata na visinu biljaka hrasta lužnjaka ovisno o načinu podmlađivanja

Oak lace bug Corythucha arcuata represents a new pest of oaks in Europe, introduced from North America in year 2000. Damage is caused by adults and larvae that feed on the underside of leaves. The paper presents the results of investigation of impact of Corythucha arcuata on pedunculate oak growth. The two variant experiment was established in 2019 and included the evaluation of the effect of oak lace bug on the height of the seedlings (i) grown under the shade of the adult trees after the intermediate felling and (ii) seedlings grown unshaded after the final felling. Both variants included eight plots of which four were treated with the insecticide thiamethoxam, while other four were untreated. Assessment of the intensity of the attack was performed in June, July and August in 2019, 2020 and 2021, while the height of the plants was measured at the end of the vegetation period in 2019, 2020 and 2021.The results indicate significant decrease in the intensity of the attack on seedlings grown unshaded by the old trees. After first year, there was no difference in average height of the treated and untreated seedlings grown after the intermediate felling, while the difference was evident after second and third year. Such results indicate cumulative effect of the oak lace bug attack on the seedlings of the penduculate oak. On the other hand, during whole experiment, the differences between treated and untreated plant average height after the final felling were not evident.

Emerging Pest Problems in Exotic Olive and Grower Specific IPM Modules for Jammu and Kashmir

About 34 insect species were found infesting olive orchards in UT of J&K Among them, olive psylla, Euphyllura pakistanica; olive black scale, Saissetia olea and tinged bug, Eteoneus sp. sigilatus Drake caused serious damage. The avoidable yield losses caused by all the pest species were 33 to 53%. On the basis of various field trials conducted neem insecticidal soap (NIS @ 2.5 %) and horticultural mineral oil (HP spray oil 2% of solution) were found effective against major pests. In case of severe infestation imidacloprid (17.8 SL) a.i. 0.075 % and cartap hydrochloride 4G @ 100g/ tree resulted in their efficient suppression. As such these treatments were incorporated in grower specific IPM modules evaluated for two years. Amongst the tested modules, integrated module (M1) followed by pesticide module (M3) were found most effective. However, for resource poor farmers and non-disruptive cultural module M1 and organic growers M2 could be alternatively practiced. It was concluded that for scale and psyllids, the insecticide protection is necessary but the infestation by lace bug could be managed by non-disruptive methods.

Climate Change and Invasive Insects in Forest Ecosystems - Recent Examples from Türkiye

Recent climate changes -in contrast to changes in the past- are faster, and humans play a significant role in speeding up the process. Fauna usually responds strikingly to the changing climate; however, effects on animal species varies greatly. Indirect effects on insects through their host plants like the shifted shooting time, and the changed chemical composition and texture of the plant are significant. Direct effects like changes of the climatic elements (temperature, humidity) may cause a wide range of reactions, like change of the distribution area (e.g., northward shift) and/or change in the insects’ biology (e.g., swarming time, generation cycle). The presence of invasive insects is usually not associated with changing climatic factors. Their arrival is mainly human activity driven and the changing climatic factors may promote their establishment only. Introductions are accidental in most cases, but there are also plenty of examples of intentionally introduced species. In this paper, we demonstrate the effect of invasive insect species on the forest ecosystems in Türkiye through the examples of the western conifer seed bug (Leptoglossus occidentalis), the box tree moth (Cydalima perspectalis), the Asian longhorn beetles (Anoplophora glabripennis & A. chinensis), the chestnut gall wasp (Dryocosmus kuriphilus), the oak lace bug (Corythucha arcuata) and the black stem borer (Xylosandrus germanus). The importance of invasive forest insect monitoring is also discussed.

Using Two Types of Foliar and Root Fertilizers, in Both Normal and Nano Particles, to Reduce the Infection of Apple Trees with the Lace Bug Stephanitis pyri (Fabricius)

The results indicated the important role of the fertilization process in both nano and regular forms in protecting apple trees from infection with the embroidered reticulate bug, as the rate of leaves infected with the insect in the comparison treatment was 11.33, 4.78 and 9.75 leaves/tree for the three cultivars, respectively. Lace bug Stephanitis pyri (Fabricius). The mean of the trees treated with Terra Sorb was 0.67 and 0.78 leaf/tree for the nano and regular formulas, respectively, and the trees treated with Headland foliar fertilizer were 0.22 and 0.78 leaf/tree for the nano and regular formula, respectively. The root fertilizer PRESTIGE was 0.44 and 0.11 leaves/tree in the nano and regular forms, respectively, and the trees treated with root fertilizer Superior 0.33 and 0.56 leaves/tree in the regular and nano forms. These percentages represent the average of the three cultivars. The study also showed that there were significant differences between the trees treated with fertilizers in both nano and regular forms, compared to the comparison treatment in which water was used, in some characteristics and measurements such as leaf area, cuticle thickness on the lower surface of the leaf, and chlorophyll content of the leaves.

Nutrient stress can have opposite effects on the ability of plants to tolerate foliar herbivory and floral herbivory.

Discovering how organisms respond to the combinations of stressors they face in their environment is an enduring challenge for ecologists. A particular focus has been how natural enemies and abiotic stressors faced by plants may interact in their effect on the ecology and evolution of plant defense strategies. Here, we report on the results of an experiment measuring how reproduction in the clonal herbaceous plant horsenettle (Solanum carolinense) is affected by damage by leaf-feeding and by flower-feeding herbivores-as well as how horsenettle's tolerance of these different types of herbivory may be altered by nutrient stress. Leaf herbivory by lace bugs reduced horsenettle's seed production and root growth, and the relative impacts were greater in fertilized than in nutrient-stressed plants. In contrast, simulated-floral herbivory reduced seed production to a similar degree in fertilized and nutrient-stressed plants. However, compensation for floral herbivory through increased root growth occurred to a much greater extent in the fertilized than in the nutrient-stressed plants. These results can be explained in terms of the limiting resource model of plant tolerance, with leaf damage interpreted as exacerbating carbon limitation in the fertilized plants and floral damage ameliorating carbon limitation in the fertilized plants. These results can be extended to predicting patterns in the field: Although plants in a nutrient-poor environment may have overall low fitness, they are likely to be more tolerant of leaf herbivores-though this benefit may be countered by lower tolerance of any floral herbivores that share the environment.

Tribe Acalyptaini (Hemiptera: Tingidae: Tinginae) Revisited: Can Apomorphies in Secondary and Tertiary Structures of 18S rRNA Length-Variable Regions (LVRs) Support Tribe Validity?

The lace bug tribe Acalyptaini (Tingidae: Tinginae) includes five genera, Acalypta, Derephysia, Dictyonota, Kalama, and Recaredus, and it was recently resurrected based on morphological and karyological characters. We aimed to validate the distinctiveness of this tribe using 18S rDNA sequences, which have not been used in previous Tingidae phylogenomic studies. Our results confirmed the monophyly of the tribe. Moreover, the monophyly of the subfamily Cantacaderinae and its basal position within the family Tingidae were indicated, as well as the position of the tribe Litadeini as sister to all other Tinginae. In addition, we attempted to determine the apomorphic morpho-molecular characters in the secondary and tertiary structures of length-variable regions of the 18S rRNA sequences of the analysed species. The results showed that two LVRs (LVR X and LVR L) of the hypervariable region V4 exhibited significant variability in the number of nucleotides and could be considered for apomorphic recognition.

Study on the Ecology, Biology and Ethology of the Invasive Species Corythucha arcuata Say, 1832 (Heteroptera: Tingidae), a Danger to Quercus spp. in the Climatic Conditions of the City of Sibiu, Romania

This scientific paper examines the impact of climate change on the spread and survival of the invasive species Corythucha arcuata Say, 1832 (oak lace bug, or OLB) in Romania. The OLB is native to the Eastern USA and Canada, and in its native habitat, it coexists with minimal impact to the preferred host plant species Quercus. However, in Europe, the OLB in high density causes early defoliation, slowing tree growth. As Quercus spp. is a keystone species, the impact of the OLB on European forests is significant. This paper aims to address several gaps in knowledge about the OLB by presenting findings from a study conducted by the Lucian Blaga University of Sibiu (ULBS) in Romania. The study identified the species’ chronology of spread, ecology, ethology and biology of the species, in addition to foliage classification to determine the extent of attack. The study found a direct link between the temperature and the speed of the generational lifecycle. The findings support the thesis that climate change is enabling the healthy, rapid density growth of OLB, which is a danger to the Quercus spp. Further research is needed in the area of the thermal tolerance of the OLB, and the research conducted by the ULBS represents the first documented research into the thermal constant of the insect. The paper concludes that further research must be in the direction to understand how and where these insects survive during winter to find future management measures and identify chemical or biological methods as solutions to eradicate and stop the expansion of the invasion of the OLB, and the potential consequences for the Quercus sp.

Cold tolerance of the invasive oak lace bug, Corythucha arcuata

Abstract The North American oak lace bug (OLB), Corythucha arcuata, is an invasive species in Europe and a serious threat to oak‐dominated forests. Survival at low temperatures is one major factor determining the spread of invasive insects. Thus, we studied key traits, that is, cold‐tolerance strategy, supercooling points (SCP) and chilling‐related mortality, of overwintering adults to assess their potential to withstand harsh winters. Samples for SCP measurements were collected once a month from November 2020 until March 2021 at three different locations in Hungary; specimens for chilling experiments were sampled in November 2020, January 2021 and March 2021. SCPs of overwintering adults ranged from −29.68 to −7.49 °C, with only moderate variation among months; C. arcuata is a freeze‐avoidant species. Mortality rates of adults exposed to two sub‐zero temperatures above the SCP (−3 and −5 °C) for 1, 2 and 3 weeks ranged between 0% and 69.1%, suggesting that OLB has a moderate risk to die from chilling injuries. Exposure time and sampling date affected mortality, with lowest survival rates after 3 weeks, collected in March 2021.

Wildflower plantings have mixed effects on insect herbivores and their natural enemies

Flower strips are advocated as a strategy to promote beneficial insects as well as the services they deliver to adjacent crops. Flower strips have, however, often been developed separately for pollinators and natural enemies and, additionally, little consideration has been given to effects on insect herbivores. We sampled insect herbivores, their natural enemies and parasitism of pest eggs using vacuum sampling, sticky cards and egg cards in nine pairs of bee-attractive wildflower plantings and control field borders, as well as in adjacent tomato and watermelon crop fields in Yolo County, California 2015–2016. Control field borders had a higher total number of herbivores on sticky traps than did wildflower plantings, a pattern that was driven by more aphids, hoppers, psyllids and whiteflies, whereas wildflower plantings had more lace bugs and Lygus bugs. The total number of herbivores in the adjacent crop fields did not differ between treatments, but there were more leaf beetles near (at 10 m but not 50 m from) wildflower plantings. Control field borders had a higher total number of predators, driven by more big-eyed bugs, lady beetles and minute pirate bugs, whereas spiders were more common in wildflower plantings. The total number of predators in adjacent crop fields was, however, higher in those next to wildflower plantings, which was driven by more minute pirate bugs. Parasitoid wasps were more common in wildflower plantings and at 10 m but not 50 m into adjacent crop fields. Stink bug egg parasitism rate did not differ between treatments, either in the borders or in the crop fields. In conclusion, wildflower plantings clearly affect the insect herbivore and natural enemy community, but do so in a highly taxon-specific manner, which can lead to both positive and negative outcomes for pest control as a result.

Further Spread of Corythucha arcuata (Hemiptera; Tingidae) in Croatia

Corythucha arcuata (Hemiptera; Tingidae), i.e. oak bug is an invasive alien species from North America that has rapidly spread in Europe. It was first reported in Croatia in 2013, and in the following years it has spread rapidly toward the west of the continental part of the country, infesting 200,000 ha of Quercus robur L. forest stands. Oak lace bug causes losses in chlorophyll, which has a negative influence on photosynthesis and transpiration activity, as well as on the health status of oak trees. We conducted our study on two sites in the Mediterranean region in Istria, Croatia, where infestation with oak lace bug has not been recorded. Results showed new records of oak lace bug in Istria. Q. pubescens Willd. is the dominant tree species in Sub-Mediterranean forests in Istria, so it will be interesting to follow the spread and preferences of oak lace bug for Q. robur and Q. pubescens in Istria, as well as in other coastal Q. pubescens and Q. ilex L. forests in Croatia. We assume that the negative influence of oak lace bug coupled with other biotic and abiotic stressors in the Mediterranean region will probably have some influence on the health status of oak trees.

Descriptions of three new species and one subspecies of Physatocheila (Heteroptera: Tingidae) from China and the Russian Far East, with an identification key to the species of the Russian fauna

Three new species of the lace bug genus Physatocheila Fieber, 1844 (Heteroptera: Tingidae) from China (Sichuan and Yunnan provinces) are described: Ph. explanata sp. nov., Ph. angusta sp. nov., and Ph. potanini sp. nov. A new subspecies Ph. miyatakei latiuscula subsp. nov. is described from China (Sichuan Province) and the southern part of the Primorskiy Territory, the Far East of Russia. A key for the identification of Physatocheila species of the Russian fauna, including the new taxa, is presented. The distributions of all species are briefly summarised in the key. The species discussed herein are provided with original photographs.

Impact of early insect herbivory on the invasive oak lace bug (Corythucha arcuata Say, 1832) in different oak species

Insect herbivores co-occurring on the same host plant interact in various ways. In particular, early-season insect herbivory triggers a wide range of plant responses that can determine the performance of herbivores colonizing the plant later in the course of the season. But the strength and direction of such effects are debated, and virtually unknown in the case of novel interactions involving exotic insects in their introduction range. We conducted an observational field study in SW France, a region recently invaded by the Oak Lace Bug (OLB, Corythucha arcuata Say). We measured early chewing damage and subsequent OLB damage in four oak species (Quercus robur, Q. pubescens, Q. cerris and Q. ilex). We set up a complementary non-choice experiment in the laboratory, feeding OLB with leaves with or without prior herbivory. The four oak species differed in their sensitivity to OLB damage, Q. ilex being broadly resistant. Prior herbivory promoted OLB damage in the laboratory experiment, but not in the field. However, prior herbivory did not alter the rank of oak resistance to the OLB. Our results suggest possible synergistic effects between spring defoliators and the OLB. This study brings insight into herbivore-herbivore interactions and their possible implications for forest management.