Crapemyrtle Bark Scale Research Articles

Plant-level establishment can result from a single female Acanthococcus lagerstroemiae propagule

Crapemyrtle bark scale (CMBS), Acanthococcus lagerstroemiae (Kuwana) (Hemiptera: Eriococcidae), is a non-native scale insect that has spread throughout many urban areas of the Southeast and Middle Atlantic regions of the United States following its initial detection near Dallas, Texas in 2004, severely reducing the aesthetic value and health of the popular ornamental crapemyrtle tree (Lagerstroemia spp.). We infested crapemyrtles with known numbers of CMBS to determine the minimum number of individuals required for establishment after initial arrival on plants. We also investigated how netting—implemented to understand differences in establishment when scale dispersal and predation are inhibited—influenced population growth. We determined that one female CMBS egg sac can successfully establish a new population ~ 92% of the time and that netting had negligible effects on establishment. Our results underscore the importance of surveying and managing CMBS and scale insects with similar biology when attempting to prevent infestation of nursery stock, which is widely implicated as a vector for long-distance dispersal of scale insects.

Quantifying the potential for wind and phoresy to drive off‐plant movement of crapemyrtle bark scale, Acanthococcus lagerstroemiae (Kuwana) (Hemiptera: Eriococcidae): Implications for spread in urban landscapes

Abstract After non‐native herbivores arrive in a novel habitat and establish, they must then disperse to new host plants to continue invading. While flight‐capable insect herbivores can expand their non‐native ranges by flying to new hosts, insects that lack wings, such as female scale insects, are often aided in their spread by wind and phoretic dispersal vectors such as birds and mammals. After being detected in 2004 in a Texas nursery, crapemyrtle bark scale (CMBS), Acanthococcus lagerstroemiae (Kuwana) (Hemiptera: Eriococcidae), has established in 15 different states across the Southeast and Middle Atlantic regions of the USA. We quantified the wind speeds leading to scale insect dislodgement and, in the laboratory and field, evaluated the willingness of CMBS nymphs to crawl onto vector proxies (bird feathers and mammal fur). Our findings demonstrate that CMBS nymphs can become dislodged from ecologically relevant substrates at low wind speeds (~7 m/s) and provided evidence that CMBS nymphs willingly, though not preferentially, crawl onto vector proxies, a final step before dispersing phoretically. Our results indicate that trees with high‐density infestations of CMBS are frequent sources of propagules, given that (i) wind speeds that shake small tree branches are likely to dislodge active crawlers and (ii) active crawlers appear willing to walk onto birds and mammals. The apparent ease of between‐tree spread by CMBS via multiple modes of dispersal presents challenges for preventing the spread of this insect, but field confirmation of these mechanisms is needed to understand their relative importance.

Winter Activity for Crapemyrtle Bark Scale, an Urban Landscape Pest

Scale insects are some of the most abundant and damaging pests of urban forests in North America. Despite their prevalence, scale insect emergence during the winter dormant season, which could contribute to their population growth and spread and thereby inform management, has not been thoroughly investigated. Crapemyrtle bark scale (CMBS), Acanthococcus lagerstroemiae (Kuwana) (Hemiptera: Eriococcidae), is a nonnative pest of a widely grown landscape tree, crapemyrtle (Lagerstroemia spp.). Now present throughout the Southeast and Mid-Atlantic regions of the United States, CMBS has spread rapidly since its initial detection in Plano, TX, USA, in 2004. The contributions of year-round activity to the insect’s widespread abundance and economic importance are unclear. Here, after infesting crapemyrtles with known numbers of CMBS in Summer 2021, we recorded the presence or absence of CMBS immatures on infested trees from Autumn 2021 to late Winter 2022. We found that active nymphs occurred throughout the entirety of these colder seasons. Additionally, average CMBS density drastically increased from October to March, growing from 28 ± 10 SE insects per plant to 554 ± 133 SE, respectively. Our results highlight previously unknown aspects of year-round crawler emergence by CMBS, which could provide opportunities for landscape managers to use targeted winter applications of less harmful pesticides such as horticultural oils.

Biological Parameters of Crapemyrtle Bark Scale (Acanthococcus lagerstroemiae) Differ When Reared on Different Crapemyrtle Hosts

Crapemyrtle bark scale (CMBS; Acanthococcus lagerstroemiae Kuwana), a fast-spreading invasive insect, has been causing damage to popular landscape plants in at least 17 states in the United States since 2004. This invasive insect has a list of documented plant hosts in ∼23 genera, which includes its primary hosts, crapemyrtles (Lagerstroemia spp.), as well as other important plant species, such as pomegranates, apple, and the native plant American beautyberry. Previous studies have shown CMBS causes different levels of feeding damage among its plant hosts, while the underlining plant defense mechanisms toward CMBS attacks remain elusive. A better understanding of plant–CMBS interactions and how CMBS performs under different plants (e.g., a susceptible vs. a resistant host) can provide valuable guidance for integrated pest management. Therefore, in this study, we conducted the age-stage, two-sex table study analysis to evaluate the biological parameters of CMBS on different species or cultivars of crapemyrtle under laboratory conditions (25 °C and 250 μmol·m−2·s−1 light with a photoperiod of 12 hours:12 hours (light:dark). Crapemyrtle bark scale development was found to be greatly influenced by the hosts. This study aims to provide important biological and ecological data on CMBS using a comprehensive life table study to gain a thorough understanding of its development, survival, and fecundity on different crapemyrtle species or cultivars.

Mortality of the crapemyrtle bark scale (Hemiptera: Eriococcidae) by commercial biopesticides under greenhouse and field conditions

The crapemyrtle bark scale (CMBS), Acanthococcus lagerstroemiae, is an important pest of crapemyrtles, Lagerstroemia spp. Biopesticides are frequently used to control soft-bodied insects; however, there is no information on their efficacy against CMBS. The objectives of this study were to test the use of selected biopesticides against CMBS under different seasons, evaluate their pathogenicity to CMBS, and determine optimum temperature for spore germination. Commercial formulations of the fungal biopesticides Isaria fumosorosea PFR97, Beauveria bassiana ANT-03, and the bacterial biopesticides Burkholderia rinojensis A396 and Chromobacterium subtsugae PRAA4-1 T were tested in greenhouse settings and did not have significant treatment effect on immature mortality. Biopesticides containing I. fumosorosea PFR97, B. bassiana ANT-03, and B. bassiana GHA were applied to mature crapemyrtles grown in the landscape and naturally infested with CMBS, and the scale survivorship was determined in two trials at different seasons. When treatments were applied in winter, scale survivorship was significantly lower in the B. bassiana ANT-03 treatment compared to the control. When treatments were applied in spring, no treatment effect was observed. During another trial conducted in autumn using container-grown crapemyrtles, B. bassiana GHA treatment reduced scales survivorship when compared to the control. Pathogen re-isolation assays confirmed that scales collected in the spring trial were had all pathogens delivered; in addition, B. bassiana ANT-03 was the most recovered pathogen. In a temperature-dependent spore germination assay, the optimum temperature range for I. fumosorosea PFR97, B. bassiana ANT-03, and B. bassiana GHA was between 22.5 and 30 °C, with peak spore germination observed at 28 °C for all three pathogens. Results from this project suggest that biopesticides containing strains of B. bassiana can be included in the toolbox for CMBS control, provided that climate and product coverage are considered.

Life table construction for crapemyrtle bark scale (Acanthococcus lagerstroemiae): the effect of different plant nutrient conditions on insect performance

Crapemyrtle Bark Scale (Acanthococcus lagerstroemiae; CMBS) is an invasive pest species that primarily infest crapemyrtles (Lagerstroemia spp.) in the United States. Recent reports have revealed the dire threat of CMBS to attack not only crapemrytles but also the U.S. native species with expanded host plants such as American beautyberry (Callicarpa spp.) and Hypericum kalmianum L. (St. Johnswort). A better understanding of plant–insect interaction will provide better and environmental-friendly pest management strategies. In this study, we constructed the first comprehensive life table for CMBS to characterize its biological parameters, including developmental stages, reproductive behavior, and fecundity. The indirect effects of three plant nutrient conditions (water, 0.01MS, and 0.1MS) on CMBS populations were examined using the age-stage, two-sex life table. The demographic analyses revealed that the plant nutrient conditions had significantly altered CMBS development in terms of the intrinsic rate of increase (r), the finite rate of increase (λ), the net reproductive rate (R0), and mean generation time (T). Higher r, λ, and R0 were recorded under nutrient-deficient conditions (water), while CMBS reared on plants with healthier growing conditions (0.1MS) had the most prolonged T. Overall, CMBS shows better insect performance when reared on plants under nutrient-deficient conditions.

Will the application of biocontrol fungi disrupt predation of Acanthococcus lagerstroemiae by coccinellids?

Insect predators are the most important natural enemies of the crapemyrtle bark scale (CMBS) in the USA. Mycopesticides (biocontrol fungi) are considered an IPM tool to increase CMBS mortality; however, their impacts on CMBS predators are unknown. The objectives of this study were to assess the abundance and diversity of CMBS natural enemies in Louisiana; evaluate the impacts of mycopesticides on survival of CMBS predators by life stage; and determine if entomopathogenic spores delivered to crapemyrtles are transferred to predators under field conditions. The mycopesticides Ancora® (Isaria fumosorosea PFR97), BioCeres® (Beauveria bassiana ANT-03), and BotaniGard® (B. bassiana GHA) were tested against the coccinellids Chilocorus spp. and Hyperaspis bigeminata under laboratory and field conditions. Adults and larvae of the coccinellids were treated with each mycopesticide and survival recorded over a 14-day period. The most common natural enemies on CMBS infested trees were the coccinellids Chilocorus cacti, C. stigma, and Hyperaspis bigeminata (Coleoptera: Coccinellidae). In laboratory bioassays BotaniGard® reduced survival of adults and larvae of both genera by at least 57%. BioCeres® reduced the survival of Chilocorus spp. adults by 40% and Ancora® reduced survival of H. bigeminata larvae by 69%. Under field conditions, CMBS infestations were sprayed with the mycopesticides and coccinellids were collected every other day for a two-week period. Spores of the applied mycopesticides were recovered from the coccinellids; however, it is not known if infection occurred in the field trial or spores were delivered to CMBS infestations by the coccinellids. We conclude that mycopesticides negatively impacted the survival of coccinellids in laboratory trials, and coccinellids can transport pathogen spores under field conditions.

Real-Time Feeding Behavior Monitoring by Electrical Penetration Graph Rapidly Reveals Host Plant Susceptibility to Crapemyrtle Bark Scale (Hemiptera: Eriococcidae).

Simple SummaryCrapemyrtle bark scale (CMBS; Acanthococcus lagerstroemiae), an invasive polyphagous sap feeder in the United States, has spread across 16 U.S. states in less than two decades, posing potential risks to the Green Industry. Confirming the host range is crucial for effective pest management of invasive insects. However, host range confirmation relying on greenhouse or field trials is often inefficient and time-consuming. In this study, we used the electrical penetration graph (EPG) to monitor the stylet penetration of CMBS in plant tissue in real-time. An R programming-based application was developed to better characterize the insect EPG waveforms recorded by EPG. By analyzing EPG-based EPG parameters, we demonstrated that CMBS has difficulty accessing the phloem tissue (salivation and ingestion) of a resistant plant compared to a susceptible plant. Importantly, we hereby present CMBS typical feeding behaviors on susceptible and non-susceptible plants comparatively, which provides direct evidence for revealing unknown hosts rapidly.Host range confirmation of invasive hemipterans relies on the evaluation of plant susceptibility though greenhouse or field trials, which are inefficient and time-consuming. When the green industry faces the fast-spreading threat of invasive pests such as crapemyrtle bark scale (Acanthococcus lagerstroemiae), it is imperative to timely identify potential host plants and evaluate plant resistance/susceptibility to pest infestation. In this study, we developed an alternative technology to complement the conventional host confirmation methods. We used electrical penetration graph (EPG) based technology to monitor the A. lagerstroemiae stylet-tip position when it was probing in different plant tissues in real-time. The frequency and relative amplitude of insect EPG waveforms were extracted by an R programming-based software written to generate eleven EPG parameters for comparative analysis between plant species. The results demonstrated that the occurrences of phloem phase and xylem phase offered conclusive evidence for host plant evaluation. Furthermore, parameters including the percentage of insects capable of accessing phloem tissue, time duration spent on initiating phloem phase and ingesting phloem sap, provided insight into why host plant susceptibility differs among similar plant species. In summary, this study developed a novel real-time diagnostic tool for quick A. lagerstroemiae host confirmation, which laid the essential foundation for effective pest management.

First Record of Crapemyrtle Bark Scale (Hemiptera: Eriococcidae: Acanthococcus lagerstroemiae) from Pennsylvania

Crapemyrtle bark scale (Acanthococcus lagerstroemiae (Kuwana, 1907)) is an adventive pest that feeds on crapemyrtle (Lagerstroemia Linnaeus). First detected in North America in Dallas County, Texas in 2004, crapemyrtle bark scale has since spread patchily across the southeastern United States. The specimens reported here are the first recorded in Pennsylvania and represent the most northern occurrence of the species.

Impacts of Crapemyrtle Bark Scale on Consumers and the Horticulture Industry

In this study, we conducted a nationwide online survey, including discrete choice scenarios, to understand consumers’ purchasing behavior for flowering trees and shrubs for home landscapes in the US. In particular, we studied crapemyrtle, which is the most popular summer flowering tree in the US. This research evaluates the change in consumer willingness to pay for crapemyrtle plants due to pest infestation damage. Our study showed that the consumer willingness to pay (WTP) for crapemyrtles will decrease, due to the changes in their attributes, such as flower density and bark color, if infested by crapemyrtle bark scale (CMBS). We also analyzed the effect of consumers’ personal characteristics, including their risk attitude, on their willingness to pay for crapemyrtle plants.

Evaluating Beautyberry and Fig Species as Potential Hosts of Invasive Crapemyrtle Bark Scale in the United States

Crapemyrtle bark scale [CMBS (Acanthococcus lagerstroemiae)], a newly emerged pest in the United States, has spread to 16 U.S. states and unexpectedly spread on a native species american beautyberry (Callicarpa americana) in Texas and Louisiana in 2016 since it was initially reported on crapemyrtles (Lagerstroemia sp.) in Texas in 2004. The infestation of CMBS negatively impacted the flowering of crapemyrtles. We observed the infestation on the two most commercially available edible fig (Ficus carica) cultivars Beer’s Black and Chicago Hardy in a preliminary trial in 2018. To help estimate CMBS potential in aggravating risks to the ecosystem stability and the green industry, we conducted a host range and suitability test using ‘Bok Tower’ american beautyberry as a positive control with other eight beautyberry (Callicarpa) species [mexican beautyberry (C. acuminata), ‘Profusion’ bodinieri beautyberry (C. bodinieri), ‘Issai’ purple beautyberry (C. dichotoma), japanese beautyberry (C. japonica var. luxurians), ‘Alba’ white-fruited asian beautyberry (C. longissima), taiwan beautyberry (C. pilosissima), luanta beautyberry (C. randaiensis), and willow-leaf beautyberry (C. salicifolia)] and three fig (Ficus) species [creeping fig (F. pumila), roxburgh fig (F. auriculata), and waipahu fig (F. tikoua)] over 25 weeks. All the tested beautyberry species and waipahu fig sustainably supported the development and reproduction of nymphal CMBS and were confirmed as CMBS hosts. Furthermore, comparing with the control, mexican beautyberry, ‘Profusion’ bodinieri beautyberry, taiwan beautyberry, and willow-leaf beautyberry were significantly less suitable, while ‘Issai’ purple beautyberry, japanese beautyberry, ‘Alba’ white-fruited asian beautyberry, and luanta beautyberry were as suitable as ‘Bok Tower’ american beautyberry. Thus, when using beautyberries in landscapes, their different potential to host CMBS should be considered to minimize spreading CMBS through the native ecosystems.

Efficacy and Duration of Control of Soil-Applied Insecticides Against Crapemyrtle Bark Scale, 2020–2021

Efficacy and Duration of Control of Soil-Applied Insecticides Against Crapemyrtle Bark Scale, 2020–2021

Green lacewing <i>Chrysoperla rufilabris</i> (Neuroptera: Chrysopidae) is a potential biological agent for crapemyrtle bark scale (Hemiptera: Eriococcidae) pest management

Crapemyrtle bark scale (CMBS; <italic>Acanthococcus lagerstroemiae</italic>), an invasive sap-sucking hemipteran, has spread across 16 US states. Infestation of CMBS negatively impacts the flowering and reduces the aesthetic quality of crapemyrtles. The widespread use of soil-applied neonicotinoid insecticides to suppress the CMBS infestation may be hazardous to pollinators and other beneficial insects. Natural enemies of CMBS are important agents for developing integrated environmentally friendly management strategies. This study evaluated the performance of larval green lacewing (<italic>Chrysoperla rufilabris</italic>) as a biocontrol agent of CMBS. Predatory behavior of the larval <italic>C. rufilabris</italic> upon CMBS was documented under a stereomicroscope using infested crapemyrtle samples collected from different locations in College Station (Texas, USA). Predation potential of <italic>C. rufilabris</italic> upon CMBS eggs and foraging performance using Y-maze assay were investigated under laboratory conditions. Results confirmed that larval <italic>C. rufilabris</italic> preyed on CMBS nymphs, eggs, and adult females. The evaluation of predation potential results showed that 3^rd instar <italic>C. rufilabris</italic> consumed significantly more CMBS eggs (176.4 ± 6.9) than 2^nd (151.5 ± 6.6) or 1^st instar (11.8 ± 1.3) in 24 hours. Results from the Y-maze assay indicated that larval <italic>C. rufilabris</italic> could target CMBS in the dark, indicating that some cues associated with olfactory response were likely involved when preying on CMBS. This study is the first report that validated <italic>C. rufilabris</italic> as a natural predator of CMBS and its potential as a biological agent to control CMBS. Future investigation about the olfactory response of larval <italic>C. rufilabris</italic> to CMBS would benefit the development of environmentally friendly strategies to manage CMBS.

Confirmation of New Crapemyrtle Bark Scale (Acanthococcus lagerstroemiae) Hosts (Spiraea and Callicarpa) through DNA Barcoding

Crapemyrtle bark scale (CMBS; Acanthococcus lagerstroemiae Kuwana) is an invasive insect that was first discovered in the United States in 2004. The polyphagous feeding habit of CMBS has allowed it to infest a wide range of plant species beyond its primary host, Lagerstroemia. Using molecular approaches, we studied the genetic relationships between CMBS specimens and their hosts from different geographic locations. Naturally occurring CMBS infestations were confirmed on American beautyberry (Callicarpa americana L.), a native plant species in the United States, and spirea (Spiraea L.). The new infestation of CMBS found on Spiraea raises the alarm that other economically important crops in the Amygdaloideae subfamily (subfamily under Rosaceae) might be susceptible to CMBS attacks.

Inventory and Food Web of Arthropod Fauna Associated with Lagerstroemia spp.1 in Texas

Sustainable, effective management of crapemyrtle bark scale, Acanthococcus lagerstroemiae (Kuwana), a non-native pest from Asia, probably will include biological control. Before this strategy can be implemented it is necessary to examine relative abundance and distribution of arthropod species associated with the scale in the area targeted for biological control. In Texas, crapemyrtle ecology from two varietal groups of crapemyrtle trees (Lagerstroemia spp.) were surveyed in Tarrant and Brazos counties during six consecutive seasons in 2018-2019. A rich arthropod community was discovered. Most common predators were spiders, coccinellids, and chrysopids. Insects of the families Eriococcidae, Aphididae, and Thripidae were common herbivores on Lagerstroemia spp. Insects in the order Psocodea were consistently recovered, and numerous phytophagous and mycophagous mites also were collected. The herbivores constitute a reservoir of alternative prey for generalist predators that also might feed on A. lagerstroemiae. A seasonal Shannon index was calculated at each location. Values differed depending on season and location. A food web was constructed to illustrate direct and indirect effects of predators on A. lagerstroemiae in Texas. This approach is meant to identify gaps in species occurrence and abundance for release of natural enemies that could lead to effective and sustainable biological control. Common biological control agents such as coccinellids and chrysopids were recovered during the course of the survey. Scale predators found in previous studies such as Chilcorus cacti (L.), Harmonia axyridis (Pallas) and Hyperaspis spp. were also found in this study. This was the first study to systematically survey for A. lagerstroemiae parasitoids in the U.S., and no parasitoids of A. lagerstroemiae were recovered. This indicates a classical biological control program featuring non-native parasitoid introductions is worth investigating.

Investigating Producers’ Preferences for Crapemyrtle and Their Perceptions Regarding Crapemyrtle Bark Scale

Crapemyrtle (Lagerstroemia spp.) is the most popular summer flowering tree in the U.S. Its total value sold has almost doubled since 1998. Consumers prize crapemyrtles for their beauty and being relatively pest free. However, current crapemyrtle production and use might be affected by crapemyrtle bark scale (CMBS; Acanthococcus lagerstroemiae), which has been confirmed in at least 14 U.S. states after its first sighting in Texas in 2004. In this study, we conducted interviews of business representatives. Our survey results indicate that producers anticipate a significant decrease in the value of crapemyrtle if infested with CMBS, and suggest industry demand for CMBS control. An important finding of our research is that a majority of businesses support science-based CMBS control research. Another important finding from our study is that most producers believed that benefits of CMBS control outweigh the costs. We used a relative importance index to illustrate the ranking of different attributes of crapemyrtles that producers consider while making decisions about growing/purchasing the plants. Flower color was found to be the most important attribute, followed by disease resistance. The most popular landscape plants that can potentially serve as alternatives to crapemyrtle, in the opinion of producers we surveyed, are Vitex agnus-castus (Texas lilac), Magnolia spp., and Hibiscus spp.

Host Suitability for Crapemyrtle Bark Scale (Acanthococcus lagerstroemiae) Differed Significantly among Crapemyrtle Species.

Simple SummaryAn exotic insect, crapemyrtle bark scale (CMBS, Acanthococcus lagerstroemiae), has spread across 14 states of the U.S. The infestation of CMBS has negatively impacted the growth, flowering, and even fruiting of some Lythraceae plants to various extent, including cultivars of Lagerstroemia indica, L. fauriei, and Punica granatum. This raises concerns that CMBS would threaten other crapemyrtle species and native Lythraceae plants. Understanding the host range and the host suitability for CMBS would help evaluate the potential risks to landscapes and other ecosystems. Information on the host suitability provides beneficial information for breeding resistant cultivars. In this study, we conducted a host range test on six Lagerstroemia species (L. caudata, L. fauriei ‘Kiowa’, L. indica ‘Dynamite’, L. limii, L. speciosa, and L. subcostata) and a native Lythraceae plant in California (California loosestrife, Lythrum californicum) over 25 weeks. The infestation of CMBS was observed on all the tested Lythraceae plants. The suitability for CMBS differed significantly among the Lagerstroemia species. Lagerstroemia limii was the most suitable, whereas L. speciosa was the least suitable. This study expands the current knowledge on the host range for CMBS. Our results suggest that L. speciosa could be utilized in developing new cultivars with low CMBS suitability.Crapemyrtle bark scale (CMBS, Acanthococcus lagerstroemiae), an invasive polyphagous sap-sucking hemipteran, has spread across 14 states of the United States since 2004. The infestation of CMBS has negatively impacted the flowering of ornamental plants and even the fruiting of some crops. Host identification is critical for determining potential risks in ecosystems and industries and helps develop strategic management. A host confirmation test was performed over 25 weeks using six Lagerstroemia species (L. caudata, L. fauriei ‘Kiowa’, L. indica ‘Dynamite’, L. limii, L. speciosa, and L. subcostata) and California loosestrife (Lythrum californicum). The 25-week observations confirmed all tested plants as the hosts. The repeated measures of analysis of variance (ANOVA; Tukey’s HSD, = 0.05) indicated that the average number of CMBS females differed significantly between L. limii and L. speciosa. The highest number of the females observed on L. limii was 576 ± 25 (mean ± SE) at 17 weeks after inoculation (WAI), while the highest number was 57 ± 15 on L. speciosa at 19 WAI. In addition, L. subcostata and L. speciosa had significantly high and low numbers of males, respectively, among the Lagerstroemia species. Our results suggest that L. speciosa could be incorporated in developing new cultivars with low CMBS suitability.

Feeding Preference of Crapemyrtle Bark Scale (Acanthococcus lagerstroemiae) on Different Species.

Crapemyrtle bark scale (CMBS; Acanthococcus lagerstroemiae) is an exotic pest species that causes aesthetic and economic damage to crapemyrtles and poses potential threats to other horticultural crops in the United States. Although previous studies reported the infestation of CMBS on several alternative hosts across multiple families in Asia, its potential threats to other documented alternative hosts remain elusive and yet to be confirmed. In this study, feeding preference studies of CMBS were conducted on forty-nine plant species and cultivars in 2016 and 2019, in order to gain insight into the expansion of CMBS distribution in the United States, as well as other regions of the world. The infestations of CMBS were confirmed on apple (Malus domestica), Chaenomeles speciosa, Disopyros rhombifolia, Heimia salicifolia, Lagerstroemia ‘Spiced Plum’, M. angustifolia, and twelve out of thirty-five pomegranate cultivars. However, the levels of CMBS infestation on these test plant hosts in this study is very low compared to Lagerstroemia, and may not cause significant damage. No sign of CMBS infestation was observed on Rubus ‘Arapaho’, R. ‘Navaho’, R. idaeus ‘Dorman Red’, R. fruticosus, B. microphylla var. koreana × B. sempervirens, B. harlandii, or D. virginiana.

Seasonal Population Patterns of a New Scale Pest, Acanthococcus lagerstroemiae Kuwana (Hemiptera: Sternorrhynca: Eriococcidae), of Crapemyrtles in Texas, Louisiana, and Arkansas.1

Abstract The crapemyrtle bark scale, Acanthococcus lagerstroemiae, is an invasive scale insect pest of crapemyrtles. Crawler populations were monitored using double-sided sticky tape on established crapemyrtle trees in Tyler (TX), Huntsville (TX), Dallas (TX), College Station (TX), Shreveport (LA), and Little Rock (AR) from 2015 - 2017 to determine crawler activity and determine if degree-day models could predict the first peak in crawler activity. Difference in crawler densities on upper and lower branches of trees was also determined by using double-sided sticky tapes. The first peak in crapemyrtle bark scale crawler activity was between March 26th and May 22nd across all locations and years, with multiple subsequent peaks per season frequently found, suggesting multiple generations. Using the average date (May 2nd) to predict the first peak crawler activity resulted in the lowest variance and was subsequently considered a better predictor compared to any degree-day model. There was no apparent difference in crawler activity between upper and lower branches of crapemyrtle trees across an entire season. This study provides the first set of population dynamics data for crapemyrtle bark scale in the U.S. and will help with future bark scale management decisions. Index words:, Crapemyrtle bark scale, invasive insect, population dynamics, Lagerstroemia spp Species used in this study: Crapemyrtle bark scale (Acanthococcus lagerstroemiae Kuwana); Crapemyrtle (Lagerstroemia spp.)

Temperature-Dependent Development and Host Range of Crapemyrtle Bark Scale, Acanthococcus lagerstroemiae (Kuwana) (Hemiptera: Eriococcidae)

The crapemyrtle bark scale, Acanthococcus lagerstroemiae (Kuwana) (Hemiptera: Eriococcidae), is an invasive pest of crapemyrtles, Lagerstroemia spp. L. (Lythraceae) in the southeastern USA. Information about its temperature-dependent development and host range is limited. The objectives of this study were to evaluate the effects of temperature on the immature development of A. lagerstroemiae, and to determine plant species suitable for immature development and reproduction. Developmental time and survival of eggs were evaluated at 7 constant temperatures from 17.5 to 32 °C, and of nymphs at 20, 25, and 30 °C. Results suggested that 27.5 °C was the optimum temperature for egg hatching with the shortest time (10 d) and the highest hatching rate (95%). The developmental time for A. lagerstroemiae from nymph to prepupa and gravid female was 56 d and 68 d at 30 °C, respectively. Five plant species besides crapemyrtle (Lagerstroemia indica × fauriei L.) were able to support the immature development and reproduction of A. lagerstroemiae under no-choice conditions, including Lawsonia inermis L., Heimia salicifolia Link, Punica granatum L., Lythrum alatum Pursh (all Lythraceae), and Callicarpa americana L. (Lamiaceae). At wk 12 from inoculation, the density of gravid females was 482 ± 92 (mean ± standard error) on L. indica × fauriei, 200 ± 70 on C. americana, and < 150 on other species. Using data from developmental time and host range, integrated pest management (IPM) practitioners can implement preventive strategies for A. lagerstroemiae.