Azalea Lace Bug Research Articles

Bioactivity of 54 Essential Oil Extracts Topically Applied to Adult Azalea Lacebugs Stephanitis pyrioides (Scott) [Tingidae:Hemiptera]: A Rapid Bio-Pesticide Discovery Program

Concern about genetic pest resistance and poisoning of non-target organisms are spurring the search for “softer” insecticides with greater selectivity and multiple modes of action. Essential oils are blends of secondary metabolites that serve plants as deterrents against insect herbivores, but remain relatively safe and even beneficial to vertebrates [1]. We used serial-time mortality bioassays to screen the essential oils from 54 representative plant species from 30 genera comprising 13 families of gymnosperms and angiosperms for bioactivity to laboratory-cultured azalea lace bugs, Stephanitis pyrioides (Scott). The principal developmental stages of bugs exposed to the essential oils were the adults-long-lived individuals that provide parental care to their leaf-infesting brood. Clevenger-type distillation extracted essential oils from dried plant material and lead components were purified and identified with gas chromatography-mass spectrometry (GC-MS). Oils were mixed with de-ionized water and a non-toxic emulsifier 0.9–9.0% dimethylsulfoxide (DMSO). All oil emulsions and sometimes their fractionated components were topically applied to adult bugs in randomized blocks at concentrations of 0, 650, 1300, 2500, 5000, and 10000 ppm. Overall bug mortality, as well as LD50, LD95 and LD99 values were calculated after 1, 2, 3, 4 and 5 hours of exposure. Mortality data were analyzed using multivariate probits [1] and preliminary data show that 1% emulsions derived from oil of Pelargonium (94.5% bug-mortality), Cinnamomum (91.4%), Hedychium (85.9%) and Tagetes (81.8%) were more efficacious than the malathion-DMSO emulsions (66.1%) and are four promising botanical sources from which to isolate compounds useful for developing new biorational crop protectants. Acknowledgements: We thank the many generous colleagues who supplied us with plant material and extracts: Ikhlas A. Khan (USA), K. Husnu Can Baser (Turkey), Betul Demirci (Turkey), Gulmira Ozek (Turkey), Temek Ozek (Turkey), Aruna Weerasooriya, (USA), Zengping Gao (China), Sui Zhang (China), Jian Zhang (China), Peng Nan (China), Zhijun Liu (USA), Hamidou Sakhanokho (USA), Cecil Pounders (USA), Sandra Gray (USA), Christine Murphy (USA), Eugene K. Blythe (USA).

Antifungal and Insecticidal Activity of two Juniperus Essential Oils

Essential oils of two Tibetan Junipers Juniperus saltuaria and J. squamata var. fargesii (Cupressaceae) were obtained by distilling dried leaves and branches using a Clevenger apparatus. Sixty-seven compounds from J. saltuaria and 58 from J. squamata var. fargesii were identified by gas chromatography-mass spectrometry (GC-MS). Both essential oils contained similar ratios of four abundant monoterpenoids: 44 and 35% sabinene, 13 and 9% elemol, 8 and 7% terpinen-4-ol, and 4 and 17% alpha-pinene, respectively. These oils had antifungal activity based on a direct bioautography assay of Colletotrichum acutatum, C. fragariae, and C. gloeosporioides, and insecticidal activity based on serial-time mortality bioassay of azalea lace bugs, Stephanitis pyrioides. Antifungal activity of Juniperus oils was weak when compared with commercial fungicides such as benomyl and captan. Whole Juniperus oils at quarter the dosage used against Colletotrichum species were more insecticidal than 10 mg/mL malathion, killing > or =70-90% adult lace bugs after 4 hours of exposure. Rf values of 0.18 for J. saltuaria oil and 0.19 for J. squamata oil indicated lipophilic monoterpenes which were the putative sources of biological activity.

The Effects of Stomatal Size on Feeding Preference of Azalea Lace Bug, Stephanitis pyrioides (Hemiptera: Tingidae), on Selected Cultivars of Evergreen Azalea

Azalea lace bug (ALB), Stephanitis pyrioides (Scott), is an important economic pest of azaleas in the southeastern United States. In this study, 33 commercially available cultivars of evergreen azalea, Rhododendron spp., were evaluated for S. pyrioides feeding preference in both choice and no-choice feeding bioassays. Mean stomatal length and area, which were hypothesized to affect ALB feeding preference, were also measured for each of 33 cultivars and results were correlated with indices of ALB feeding (mean feces) and fecundity (mean eggs). An azalea cultivar, Fourth of July, was least preferred by ALB in both no-choice and choice tests, whereas ‘Watchet’ was most preferred. Cultivars Fourth of July and Delaware Valley White had the smallest mean stomatal areas despite their disparate susceptibilities to ALB feeding. Although stomates through which ALB insert their proboscides vary in size among azalea cultivars, they confer no obvious resistance to ALB feeding preference. Therefore, the mechanism for lace bug resistance in azalea remains elusive.

Rapid, High-Throughput Detection of Azalea Lace Bug (Hemiptera: Tingidae) Predation by <I>Chrysoperla rufilabris</I> (Neuroptera: Chrysopidae), Using Fluorescent-Polymerase Chain Reaction Primers

Azalea lace bugs, Stephanitis pyrioides (Scott) (Hemiptera: Tingidae), are the most common pest of azaleas (Rhododendron spp.) in nursery production and the landscape. Although pesticides are commonly used to control lace bugs, natural enemies can be a significant source of lace bug mortality. Lacewings (Neuroptera: Chrysopidae) are natural enemies of lace bugs and easily consume them in laboratory studies. Field studies on lacewing biocontrol of azalea lace bugs are underway; however, monitoring lacewing predation in a nursery environment by direct observation is impractical. Here, we describe a fluorescent-polymerase chain reaction method to estimate S. pyrioides consumption based on the gut contents of lacewing predators. Lace bug DNA was detected in fed lacewings up to 32 h after ingestion. More than 80% of the ingested lace bugs were detected using our method with only one false positive result. The assay is both high-throughput and relatively inexpensive, making it a practical approach to documenting lace bug predation in the field.

Azalea Lace Bug, Stephanitis pyrioides (Scott) (Insecta: Hemiptera: Tingidae)

EENY-373, a 5-page illustrated fact sheet by Jamba Gyeltshen and Amanda Hodges, describes this pest of ornamental trees and shrubs. Part of the Featured Creatures series, this publication covers the distribution, description, life history, host plant, damage, management, and selected references. Published by the UF Department of Entomology and Nematology, May 2006. EENY-373/IN677: Azalea Lace Bug, Stephanitis pyrioides (Scott) (Insecta: Hemiptera: Tingidae) (ufl.edu)

Leaf Wax Extracts of Four Deciduous Azalea Genotypes Affect Azalea Lace Bug (Stephanitis pyrioides Scott) Survival Rates and Behavior

Azaleas (Ericales: Ericaceae: Rhododendron L.) are a staple plant in many landscapes of the United States and are largely resistant to predation by insects, with the exception of azalea lace bug [ALB (Heteroptera: Tingidae: Stephanitis pyrioides)]. Within deciduous azalea (Rhododendron: section Pentanthera G. Don) varying levels of resistance to ALB are observed with a continuous distribution from susceptible to highly resistant. In this study, epicuticular leaf wax from two ALB-resistant [R. canescens Michaux and R. periclymenoides (Michaux) Shinners] and two ALB-susceptible (`Buttercup' and `My Mary') deciduous azalea genotypes was extracted and re-applied to fresh azalea foliage. Leaf wax extracted from ALB-resistant genotypes and applied to ALB-susceptible genotypes conferred a high level of resistance to both ALB feeding and oviposition in the treated ALB-susceptible genotypes. Conversely, leaf wax extracted from ALB-susceptible genotypes and applied to ALB-resistant genotypes conferred susceptibility to the treated ALB-resistant genotypes. However, the effect was much less substantial than the effect of resistant wax extracts on susceptible genotypes and confined to ALB oviposition. When applied to the same genotype from which the extract was collected, leaf wax extract from ALB-susceptible genotypes had no effect on susceptibility, whereas resistant wax extract had a moderate effect on ALB oviposition rate. The results indicate that leaf wax serves as a primary mechanism of resistance of deciduous azalea to ALB.

Border Patrol: Epicuticular Leaf Wax Mediates Resistance of Azalea Genotypes (Rhododendron spp.) to Azalea Lace Bug [Stephanitis pyrioides (Scott)

Azalea lace bug (ALB) is a significant pest on azalea, with feeding injury causing speckling and discoloration on affected leaves. Feeding damage also results in a reduction of stomatal gas exchange and leaf chlorophyll content, postulated to diminish growth and flowering rates. In azalea, specific lipid components of the plant cuticle have been implicated in ALB resistance of R. canescens. In this study, epicuticular leaf wax was extracted from the leaves of four azalea genotypes, divided into two groups: a resistant group including R. periclymenoides and `Fourth of July' and a susceptible group including R. austrinum and `My Mary'. Leaf wax was extracted and resuspended in solution for application to all entries in a full diallel manner, including controls of solution only and no treatment. Each genotype–solution treatment included 10 replications. The leaf wax solution was applied to each replication (leaf) by painting the solution on one side of the midrib, yet on both abaxial and adaxial surfaces. Two leaves attached to a stem and four female adult ALB were placed in separate 32-mL sealed cups. Experimental conditions were 24 °C and 12-hour daylength for 96 h, at which time the number of live adults, frass spots, and eggs were counted. Data revealed that application of leaf wax solution had an impact on the level of frass and egg deposition by ALB in both resistant and susceptible genotypes. The effect was most pronounced when a solution of resistant genotypes was placed on susceptible genotypes, as the application resulted in lower numbers of frass spots and eggs compared to the nil control. However, an increase in frass and eggs was observed when extract of susceptible genotypes was applied to resistant genotypes.

The Effect of Leaf Wax Extracts from the Leaves of Eight Azalea Genotypes (Rhododendron spp.) on Feeding and Oviposition by Azalea Lace Bug [Stephanitis pyrioides (Scott)

Azalea Lace Bug (ALB) is a significant pest on azalea species. ALB feeding injury causes a stippled appearance on the leaves of susceptible genotypes from late spring until leaf drop. To determine whether leaf surface lipids are a factor in determining resistance or susceptibility to ALB, epicuticular leaf wax was extracted from the leaves of eight azalea genotypes, half with resistance and half susceptible to ALB. Leaf wax from each genotype was extracted and re-suspended in an 2 ethanol: 1 water solution for application to all entries in a full diallel manner, including a control of solution only. Each treatment included three replications. The leaf wax solution was applied to each replication (single leaf) by painting the solution on one side of the midrib, on both abaxial and adaxial surfaces. By applying solution to one side of the leaf, the untreated leaf surface served as a control. Each leaf and two female ALB were placed in separate 50-mL sealed tubes at 24 °C and 12-hour daylength for 48 hours, at which time the number of live adults, frass spots, and eggs were counted. Frass and egg data were recorded separately for treated and untreated sides of each leaf. The application of leaf wax solution had an impact on the level of frass and egg deposition by ALB in all genotypes. The effect was most pronounced when solution of resistant genotypes was placed on susceptible genotypes, resulting in lower numbers of frass spots and eggs. The solution alone had little effect on frass or egg numbers. This research acknowledges that a major constituent of an azalea's resistance or susceptibility to ALB is via epicuticular wax components.

INTEGRATING CULTURAL MANAGEMENT PRACTICES AND BIOLOGICAL CONTROL TO SUPPRESS CITRUS MEALYBUG

INTEGRATING CULTURAL MANAGEMENT PRACTICES AND BIOLOGICAL CONTROL TO SUPPRESS CITRUS MEALYBUG

Shading Induced Variability in Azalea Mediates its Suitability as a Host for the Azalea Lace Bug

This study quantified how different shading levels alter the foliar nutrient, C:N ratio, chlorophyll content and key leaf characters in azalea `Delaware Valley White' Rhododendron mucronatum (Blume) (Ericales: Ericaceae), which influenced, in turn, feeding, oviposition, survival and development of the azalea lace bug, Stephanitis pyrioides (Scott) (Heteroptera: Tingidae). The mean contents of N, Ca, Fe, and Zn increased linearly with increases in the shading level, whereas P, K, B, Mn, and the C:N ratio of leaves were significantly decreased. Although injured leaves contained significantly less chlorophyll than uninjured leaves, the mean relative chlorophyll content of leaves increased linearly with the level of shading. Mean leaf area and moisture content of leaves increased linearly with increased degree of shading, while the mean trichome density decreased. The mean number of oviposited eggs and the percent of nymphs reaching adulthood increased linearly with the degree of shading. Azalea shoots suffered increased feeding injury as the season progressed, yet unshaded plants suffered more feeding injury than shaded plants. While the mean number of eggs laid, and the mean number of reared adults, were significantly and positively correlated with the mean leaf N, the mean feeding injury was negatively correlated with leaf N. Although these dependent variables were not correlated with K nor Ca, the mean number of eggs laid, and the mean number of reared adults were negatively correlated with the mean leaf P and with the mean C:N ratio. Mean feeding injury was positively correlated with leaf P and with the C:N ratio, but negatively correlated with N. This study shows that shaded plants are of better quality as hosts and that these plants can tolerate infestations by the lace bug.

Functional Response of the Azalea Plant Bug (Heteroptera: Miridae) and a Green LacewingChrysoperla rufilabris(Neuroptera: Chrysopidae), Two Predators of the Azalea Lace Bug (Heteroptera: Tingidae)

Azalea plant bug (Rhinocapsus vanduzeei Uhler) Þfth instars and a commercially obtained green lacewing (Chrysoperla rufilabris Burmeister) Þrst and second instars exhibited a type II functional response when caged with varying densities of fourth or Þfth instar azalea lace bug, Stephanitis pyrioides (Scott), prey. Attack coefÞcients for combined fourth and Þfth instar prey were statistically similar for R. vanduzeei and C. rufilabris (0.052 and 0.057, respectively). The handling time was signiÞcantly greater for R. vanduzeei (3.96 h) than C. rufilabris (2.41 h). Search efÞciency generally declined for both predators as initial azalea lace bug density increased. C. rufilabris killed signiÞcantly more fourth and Þfth instar prey than R. vanduzeei (8.0 and 6.0, respectively) in 24 h. Results indicate that C. rufilabris is a more suitable candidate for augmentative, not inoculative, release for azalea lace bug control than R. vanduzeei. However, R. vanduzeei can effect reductions in azalea lace bug populations in the landscape as a component of the guild of lace bugOs natural enemies and should be considered in conservation efforts.

Using aesthetic assessments of azalea lace bug (Heteroptera: Tingidae) feeding injury to provide thresholds for pest management decisions.

Research on consumer, grower, and landscape manager perception of azalea lace bug, Stephanitis pyrioides (Scott), feeding and on plant productivity parameters, including gas exchange and growth, has increased our understanding of the nature of feeding injury. These studies made it possible to develop decision-making guidelines for cost-effective maintenance of aesthetically pleasing azaleas. Criteria were considered for three management situations: a 0.41-ha (1-acre) nursery production system that may use either insecticidal soap, acephate, or imidacloprid to control lace bugs; a landscape planting of a group of 10 azaleas; or maintenance of a single azalea in the landscape. Lace bug thresholds were calculated using a hybrid economic injury level (EIL) formula. Pesticide application decisions were determined using survey-based data from grower, landscape manager, and consumer perceptions of unacceptably injured azaleas at point-of-purchase for the nursery situation. Additional landscape scenarios incorporated the perceptions of growers, landscape managers, and consumers for those levels of lace bug feeding-injury that prompted the desire for treatment. Hybrid EIL determinations are appropriate for lace bug management in landscape systems where landscape professionals manage large plantings of azaleas and as a component of pest management among nursery production systems. Aesthetic considerations are more appropriate in determining control thresholds among a few or individual azaleas in the landscape.

Azalea growth in response to azalea lace bug (Heteroptera: Tingidae) feeding.

The effects of azalea lace bug, Stephanitis pyrioides (Scott), feeding injury on azalea growth and development were investigated using 'Girard's Rose' azaleas during a 2-yr field study in Georgia Low, medium, and high injury treatments, which corresponded to 6, 8, and 14% maximum canopy area injury, were compared with control azaleas that received no lace bug infestation. Flower number, whole-shrub leaf and stem dry mass, and dry mass and size of new growth tissues were unaffected by treatments. In contrast, growth index measurements, a general measure of variability frequently used for horticultural differentiation, showed significant reductions for all treatments in comparison to control azaleas after 20 wk. Though not directly quantified, this apparent discrepancy may be explained as an artifact of lace bug feeding-induced leaf abscission. Growth index measurements had considerable variability and may not be the most reliable measurement of size. In July 1998, plant canopy densities among azaleas maintained in the high injury treatments were approximately 15% less full than the canopies of control shrubs. Predaceous insects had a significant negative association with azalea lace bug number during the 2-yr study. Flower and new tissue production, measured destructively during two growing seasons, revealed azalea tolerance to 14% of maximum canopy area lace bug feeding-injury levels.

Evaluation of Green Lacewings for Suppressing Azalea Lace Bug Populations in Nurseries

Abstract Greenhouse and nursery studies were conducted to determine an optimal release rate and efficacy of green lacewing (glw) larvae, Chrysoperla carnea (Stephens), for suppression of azalea lace bug (alb), Stephanitis pyrioides (Scott). In a greenhouse study, different densities of lace bugs (40 or 80 per plant) did not influence the percent mortality caused by green lacewings. However, greater numbers of green lacewing larvae released resulted in higher lace bug mortality (5 and 20 glw per plant resulted in an average lace bug mortality of 79% and 97%, respectively). Lacewing larvae released in a production nursery, at rates of 5/plant and 10/plant, and acephate (Orthene) significantly reduced lace bug populations, with green lacewings at 10/plant and acephate reducing lace bug densities more than green lacewings at 5/plant. In a second nursery trial, lacewing larvae released into production blocks of azaleas resulted in a 97% reduction in lace bugs. These studies suggest that augmentative release of green lacewing larvae may provide an alternative control tactic that can be integrated into lace bug pest management programs.

Management strategy, shade, and landscape composition effects on urban landscape plant quality and arthropod abundance.

Intensity and type of management, the cultural variable shade, and the combination of woody and herbaceous annual and perennial plants were evaluated for their effect on key landscape arthropod pests. Azalea lace bugs, Stephanitis pyrioides (Scott), and twolined spittlebugs, Prosapia bicincta (Say), were most effectively suppressed in landscape designed with resistant plant species of woody ornamentals and turf. Landscapes containing susceptible plant counterparts were heavily infested by these two insect species in untreated control plots. A traditional management program of prescribed herbicide, insecticide, and fungicide applications effectively suppressed azalea lace bug and produced a high-quality landscape. Targeted integrated pest management with solely horticultural oils resulted in intermediate levels of azalea lace bug. Neither program completely controlled twolined spittlebug on hollies or turf. Carabidae, Staphylinidae, Formicidae, and Araneae were not reduced by any management strategy. Lace bugs (Stephanitis) were more common in plots with 50% shade than those in full sun. Spittlebugs (Prosapia) were more common in the shade during 1996 and in the sun during 1997. Spiders and ants were more often collected in full sun plots. Carabids, staphylinids, and spiders were more commonly collected from pitfall traps in turf than in wood-chip mulched plant beds, whereas ants were equally common in both locations. The addition of herbaceous plants to the landscape beds had little effect on pest insect abundance.

Evaluation of Components of Vegetational Texture for Predicting Azalea Lace Bug,Stephanitis pyrioides(Heteroptera: Tingidae), Abundance in Managed Landscapes

The relationship between azalea lace bug, Stephanitis pyrioides (Scott), abundance and components of vegetational texture were examined in managed landscapes to determine which component(s) best explained patterns in lace abundance. In managed landscapes, azalea lace bug is a key pest of azaleas and its abundance varies dramatically in time and space. The components of vegetational texture examined were light exposure, plant species diversity, evenness and richness, host patch size, and structural complexity of the landscape. The best habitat predictors of lace bug abundance were structural complexity and light exposure explaining 54 and 53% of lace bug variation, respectively. Three of the remaining four components also were significantly related to lace bug abundance. Further examination of light exposure revealed that afternoon readings explained more of the variation (52%) in lace bug abundance than morning readings (9%). Of the five vegetational strata that comprise structural complexity, the overstory tree layer and ground cover/turf layer (76%) were the best predictors of lace bug abundance. The implications of this work are that landscapes can be evaluated for susceptibility to lace bugs and perhaps other pests. It also provides information for designing landscapes that support fewer pest problems, resulting in low-input sustainable landscapes.

Feeding Injury of the Azalea Lace Bug (Heteroptera: Tingidae)

Azalea lace bug, Stephanitis pyrioides (Scott), feeding rates were investigated in controlled laboratory bioassays. Individual newly-eclosed nymphs were transferred to cut stems of ‘Girard's Rose’ azaleas and maintained at either 20°C for 26°C for the duration of their lifetimes. Feeding rates, determined using computer assisted image area analysis, were calculated for both nymphs and adults. In both trials, females caused significantly more feeding injury per day than males. However, the overall amount of injury inflicted during lace bug lifetimes was similar for males and females at both temperatures. During adulthood, feeding injury by individual lace bugs resulted in a mean (±SD) of 6.35 ± 4.61 cm2 leaf area injury at 20°C and 3.93 ± 2.06 cm2 leaf area injury at 26°C. Nymphal feeding was a small fraction of the injury inflicted by the adults and averaged 0.43 ±0.15 cm2 at 20°C and 0.30 ±0.10 cm2 at 26°C. The determination of azalea lace bug feeding-injury potential is critical to the development of decision-making guidelines.

Whole-plant gas exchange, not individual-leaf measurements, accurately assesses azalea response to insecticides

A comparison of whole-plant and individual-leaf gas exchange measurements was undertaken among azaleas, Rhododendron spp., treated with insecticides used to control the azalea lace bug, Stephanitis pyrioides (Scott). Azaleas in individual-leaf trials received 3 insecticide treatments during three 21-day trials. The whole-plant study included 2 insecticide treatments and was conducted during a 21-day trial. Individual-leaf studies indicated that insecticidal soap and acephate application at higher than recommended rates caused short-term reductions in gas exchange. However, variability among individual-leaf measurements prevented consistent conclusions. Whole-plant gas exchange measurements provided consistent results and confirmed that insectidical soap caused short-term reductions in P net and R dark. Additionally, whole-plant gas exchange measurements enabled growth analyses and demonstrated a reduction in carbon use efficiency attributed to insecticidal soap treatments. Neither acephate nor horticultural oil significantly affected whole-plant gas exchange. Gas exchange parameters for treatments in all trials were not significantly different from the controls by Day 21.

044 Screening for Resistance to Azalea Lace Bug among Deciduous Azalea Progeny from a Cross between a Highly Susceptible to a Highly Resistant Genotype

Azalea lace bug, Stephanitis pyrioides (Scott), is a major pest on azalea. Adults and nymphs feed and oviposit on the underside of the leaves, causing a stippled appearance when viewed from above. Previous field and laboratory screenings of 17 taxa of deciduous azalea, including representatives of 11 species, have identified a range of resistance to lace bug. One of the most resistant plants observed was of the species R. canescens. The interveinal region on the underside of the leaves of this plant is highly pubescent. This plant was crossed to a susceptible plant of R. viscosum (formerly R. serrulatum), which was glabrous on the lower leaf surface. The resulting seeds were planted in 1996, and the seedlings were transplanted to the field in 1998. In Sept. 1999, a laboratory bioassay was conducted to determine the resistance levels of these progeny. Five cuttings, each with two leaves, were collected from each plant, including the parental genotypes. Two female lace bugs were transferred onto the leaves of each cutting and the leaves were enclosed in a plastic cup with mesh for ventilation. After 5 days, the number of live bugs and number of eggs per cutting were counted. The percent damage from feeding was estimated. To determine whether pubescence was correlated with lace bug resistance, two terminal leaves were collected from each plant, and interveinal leaf hair density was calculated. Results from the laboratory bioassays revealed a high degree of susceptiblity to lace bug among these seedlings. Most of the progeny were pubescent, indicating no relationship between leaf hair density and resistance.

Whole-plant CO2 exchange measurements on azaleas injured by azalea lace bug (Heteroptea: Tingidae) feeding.

Whole-plant gas exchange was measured continuously for 24 h on rooted cuttings of Girard's 'Pleasant White' azaleas. Azalea treatments were azalea lace bug, Stephanitis pyrioides (Scott), feeding injury levels that averaged 6, 13, or 31% leaf-area injury throughout the plant canopies. Gas exchange parameters, including net photosynthesis, dark respiration, carbon use efficiency, and growth, were compared with undamaged control plants. Responses of Girard's 'Pleasant White' azaleas suggested that azaleas were tolerant of lace bug feeding injury levels above the aesthetic threshold. Azalea tolerance can be incorporated into an integrated management plan to reduce chemical inputs into the urban landscape.