Influence of Lantana camara and its removal on tree dynamics in a recently burnt wet Sclerophyll forest in Northern NSW

Lantana (Lantana camara) has adverse effects on plant communities across Australia. Fire, sometimes recommended as a management strategy for Lantana, is likely to have both beneficial and detrimental effects on Lantana and native trees. It is therefore important to evaluate the regeneration of Lantana‐invaded woody plant communities postfire. We examined the effect of Lantana removal by herbicide spray on both Lantana density and small tree (<5 cm diameter at breast height; DBH) attributes (abundance, height, DBH and diversity) in an area previously burnt. On a subset of the data, which was not sprayed, we also examined small tree attributes along a gradient of Lantana density. The herbicide treatment of postfire Lantana regrowth significantly reduced Lantana density compared to the areas left unmanaged by herbicide and increased the stem diameter of Celery Wood (Polyscias elegans). We found that, as Lantana stem density increased in no‐spray plots, the abundance of Poison Peach (Trema tomentosa), Celery Wood, and Eucalyptus and allied genera (Angophora and Corymbia) decreased. In addition, height of wattles (Acacia irrorata and A. maidenii) increased with increasing Lantana density. As postfire regeneration of Lantana reduced abundance of some species, additional control of Lantana was required to assist community regeneration.     

Management of Non‐Native Annual Plants to Support Recovery of an Endangered Perennial Forb,Ambrosia pumila

Invasive non‐native plants pose a ubiquitous threat to native plant communities and have been blamed for the decline of many endangered species. Endangered species legislation provides legal instruments for protection, but identifying a general method for protecting endangered species by managing non‐natives is confounded by multiple factors. We compared non‐native management methods aimed at increasing populations of an endangered forb, Ambrosia pumila, and associated native plants. We compared the effects of a grass‐specific herbicide (Fusilade II), hand‐pulling, and mowing in two degraded coastal sage scrub sites in southern California, U.S.A. At both sites, hand‐pulling had the greatest effect on non‐native cover, and correspondingly resulted in the greatest increase in A. pumila stems. Fusilade II application also led to an increase in A. pumila, but was not as effective in controlling non‐native plants as hand‐pulling and its effect varied with the dominant non‐native species. Mowing was not effective at promoting A. pumila, and its effect on non‐native cover seemed to be related to rainfall patterns. Although some methods increased A. pumila, none of our treatments simultaneously increased cover of other native plants. Hand‐pulling, the most effective treatment, is labor intensive and thus only feasible at small spatial scales. At larger scales, managers should take an experimental approach to identifying the most appropriate method because this can vary depending on the specific management objective (endangered species or whole native community), the dominant non‐natives, yearly variation in weather, and the timing of treatment application.     

Long-Term Environmental Correlates of Invasion by Lantana camara (Verbenaceae) in a Seasonally Dry Tropical Forest

Invasive species, local plant communities and invaded ecosystems change over space and time. Quantifying this change may lead to a better understanding of the ecology and the effective management of invasive species. We used data on density of the highly invasive shrub Lantana camara (lantana) for the period 1990–2008 from a 50 ha permanent plot in a seasonally dry tropical forest of Mudumalai in southern India. We used a cumulative link mixed-effects regression approach to model the transition of lantana from one qualitative density state to another as a function of biotic factors such as indicators of competition from local species (lantana itself, perennial grasses, invasive Chromolaena odorata, the native shrub Helicteres isora and basal area of native trees) and abiotic factors such as fire frequency, inter-annual variability of rainfall and relative soil moisture. The density of lantana increased substantially during the study period. Lantana density was negatively associated with the density of H. isora, positively associated with basal area of native trees, but not affected by the presence of grasses or other invasive species. In the absence of fire, lantana density increased with increasing rainfall. When fires occurred, transitions to higher densities occurred at low rainfall values. In drier regions, lantana changed from low to high density as rainfall increased while in wetter regions of the plot, lantana persisted in the dense category irrespective of rainfall. Lantana seems to effectively utilize resources distributed in space and time to its advantage, thus outcompeting local species and maintaining a population that is not yet self-limiting. High-risk areas and years could potentially be identified based on inferences from this study for facilitating management of lantana in tropical dry forests.     

Review and Evaluation of Lantana Biocontrol Programs

This paper provides a review of lantana (Lantana camara L.) biological control programs worldwide. Tables on the origins of the agents introduced for the biocontrol of lantana, are presented, including references to the biology and/or host-tests for each species. Establishment and control rates of the introduced agents and cases leading to partial control of lantana are discussed. From the review, feeding groups and species contributing to control were identified. Leaf-, flower-, and fruit-feeding species were the most successful feeding groups, and the leaf-mining chrysomelid, Uroplata girardi Pic, was the most successful control agent. The main factor preventing establishment was the number of individuals released, while cultivar preferences, parasitism and predation, and climate reduced control. The implication of these results for lantana biocontrol programs is discussed, and future research requirements are identified.     

The invasion of Lantana camara L. in Forty Mile Scrub National Park,north Queensland

Abstract Seventy-three per cent of dry rainforest in Forty Mile Scrub National Park and large areas in adjacent savanna woodland have more than 5000 individuals per ha of lantana (Lantana camara L.). Transect studies in dry rainforest and savanna woodland across varying intensities of lantana infestation show a negative correlation between the density of lantana and tree cover in rainforest. The density of pig rooting is very high in areas of the dry rainforest on deep soil that was not heavily infested with lantana. It is suggested that the digging activities of these animals may cause tree death and subsequent increased light penetration, which favours lantana. The species richness of the dry rainforest declines as the density of lantana increases. However, the saplings and seedlings and the soil seed bank of dry rainforest and savanna woodland tree species have comparable densities in heavy and light lantana infestations. The proliferation of lantana results in the build up of heavy fuel loads across the boundary of dry rainforest and savanna woodland. Recent fires have killed the canopy trees in a large area of dry rainforest within the Park. Active management of Forty Mile Scrub National Park is urgent and some initiatives are suggested.     

Restoration impacts on fuels and fire potential in a dryland tropical ecosystem dominated by the invasive grass Megathyrsus maximus

Ecological restoration often attempts to promote native species while managing for disturbances such as fire and non‐native invasions. The goal of this research was to investigate whether restoration of a non‐native, invasive Megathyrsus maximus (guinea grass) tropical grassland could simultaneously promote native species and reduce fire potential. Megathyrsus maximus was suppressed with herbicide, and three suites of native species—each including the same groundcover and shrub, and one of three tree species—were outplanted in a randomized, complete block design that also included herbicide control (herbicide with no outplantings) and untreated control treatments. Fuels were quantified 27 months after outplanting, and potential fire behavior (rate of spread and flame length) was modeled with BehavePlus. Compared with untreated controls, native outplant treatments reduced M. maximus cover by 76–91% and M. maximus live and dead fuel loads by greater than 92 and 68%, respectively. Despite reductions in M. maximus fuels, neither treatment‐level (grass + native) total fuel loads and fuel moistures, nor modeled fire behavior differed between outplant treatments and controls. The best performing native woody species (Dodonaea viscosa) had significantly lower average individual plant live fuel moisture (84%) than M. maximus (156%) or other native woody outplant species (201–328%), highlighting the need for careful species selection. These results demonstrate that restoring native species to degraded tropical dry forests is possible, but that ecological restoration will not necessarily alter the potential for fire, at least in the short term, making selection of species with beneficial fuel properties and active fire management critical components of ongoing restoration.     

马缨丹叶提取液对水葫芦叶片中超氧物歧化酶活性和过氧化氢积累的影响

水葫芦[Eichhornia crassipes（Mart）Solms]是世界上繁殖最快、危害最严重的多年生水生杂草之一。为了避免化学除草剂对水体的污染,生物防治已成为当前水葫芦治理的重要方向。马缨丹（Lantana camara）是马鞭草科的一种植物,其叶片提取物对水葫芦有很强的毒性。研究结果表明：经马缨丹叶提取液处理的水葫芦叶片中,超氧物歧化酶（SOD）活性与H2O2浓度均显著升高,但过氧化氢酶的活性受到抑制,膜脂过氧化程度明显增加。H2O2的组织化学染色结果表明H2O2在气孔细胞中有异常高的积累,H2O2过量产生同时导致水葫芦叶片失绿与细胞死亡。因此,氧胁迫可能是马缨丹提取液对水葫芦毒害的主要原因之一。     

Ecology and Impacts of the Invasive Species, Lantana camara, in a Social-Ecological System in South India: Perspectives from Local Knowledge

We explored how the forest-dwelling Soliga community of South India views and explains biological invasions, and how local knowledge can inform scientific knowledge on biological invasions. We used an interview schedule with open-ended questions to solicit Soliga opinion on Lantana camara (lantana) invasion. The Soliga cited three reasons for lantana spread: its prolific fruit output and wide seed dispersal, change in fire management, and historical extraction of grass and bamboo. The Soliga believe that lantana invasion has had negative effects on the ecosystem and their livelihoods. Tabling scientific knowledge with local knowledge has improved our understanding of lantana invasion. The role of existing lantana in colonizing neighboring areas, and the response of native tree communities to lantana were common to both local and scientific sources. However, the Soliga view provides a more nuanced perspective of the lantana-fire relationship (contextually based on lantana density) with fires suppressing lantana when lantana density was low. This is contrary to views held by foresters and biologists, that fires are uniformly detrimental and promote lantana. Our study shows that examining Soliga observations has improved understanding of the invasion process and presents avenues for future lantana management.     

Performance of established native seedlings in relation to invasive Lantana camara, rainfall and species’ habitat preferences in a seasonally dry tropical forest

Native species’ response to the presence of invasive species is context specific. This response cannot be studied in isolation from the prevailing environmental stresses in invaded habitats such as seasonal drought. We investigated the combined effects of an invasive shrub Lantana camara L. (lantana), seasonal rainfall and species’ microsite preferences on the growth and survival of 1,105 naturally established seedlings of native trees and shrubs in a seasonally dry tropical forest. Individuals were followed from April 2008 to February 2010, and growth and survival measured in relation to lantana density, seasonality of rainfall and species characteristics in a 50-ha permanent forest plot located in Mudumalai, southern India. We used a mixed effects modelling approach to examine seedling growth and generalized linear models to examine seedling survival. The overall relative height growth rate of established seedlings was found to be very low irrespective of the presence or absence of dense lantana. 22-month growth rate of dry forest species was lower under dense lantana while moist forest species were not affected by the presence of lantana thickets. 4-month growth rates of all species increased with increasing inter-census rainfall. Community results may be influenced by responses of the most abundant species, Catunaregam spinosa, whose growth rates were always lower under dense lantana. Overall seedling survival was high, increased with increasing rainfall and was higher for species with dry forest preference than for species with moist forest preference. The high survival rates of naturally established seedlings combined with their basal sprouting ability in this forest could enable the persistence of woody species in the face of invasive species.     

Antitermitic effect of the Lantana camara plant on subterranean termites (Isoptera: Rhinotermitidae)

Abstract The insecticidal effects of Lantana camara L. (flowers, leaves, stems and roots) and the soil where lantana had been growing, on foraging activity and survival of the subterranean termites Coptotermes formosanus and Reticulitermes flavipes were examined in a 3-week experiment. The soil in which lantana had been growing had no effect on termite tunneling and survival. Incorporation of chipped fresh lantana leaves and stems into soil had no effect on mortality but caused significant reduction in tunneling. The 5-cm wide barrier of soil with lantana tissue incorporated effectively repelled groups of both species from penetrating the barrier and thus prevented infestation of a piece of wood on the other side of the barrier. C. formosanus was more sensitive in avoiding the barrier than R. flavipes. Leaves, stems and flowers were more repellent than roots. These results provide preliminary evidence that fresh-cut lantana leaves, stems and flowers may have use as additives to garden mulches against termites.     

Experimental Manipulation of Restoration Barriers in Abandoned Eucalypt Plantations

Expansion of the nature conservation estate in northeastern New South Wales, Australia, has captured weed‐infested timber plantations amid a mosaic of high conservation value lands. We adopted a state‐and‐transition approach to test the hypothesis that restoration barriers restrict the natural regeneration of native species in Eucalyptus grandis plantations infested by Lantana camara in Bongil Bongil National Park, New South Wales. Plantation tree thinning and weed control were applied in factorial combination at three sites (totaling to 4.5 ha). Topsoil chemistry responses to these interventions were attributable to the “ash bed” effect, with temporary increases in topsoil pH_W and nitrate, particularly where canopy reduction was greatest. Other soil changes were minor, indicating that thinning and burning did not risk soil degradation. Plant species richness and functional group representation in the regenerating understorey were improved by the interventions. Regeneration of native potential canopy trees, understorey trees, shrubs and woody climbers, and perennial forbs all increased with canopy retention. Grass cover dominated the regeneration where canopy cover was less than 50%. In the absence of weed control, the cover of introduced shrubs increased with reduction in canopy cover, as did the rate of understorey regeneration generally. These responses indicate that thinning and weed control can reinstate succession, leading to structurally and compositionally diverse forest. Given the abundance of native woody regeneration under retained canopy, the lantana understorey was more important in inhibiting native regeneration. The experimental approach will promote efficient use of resources across the remaining 200 ha of low conservation value plantations in this national park.     

Biomethanation of lantana weed and biotransformation of its toxins

The utility of Lantana camara as a substrate for biogas production and the fate of its toxins after biomethanation process was studied. Both fresh and predigested lantana leaves along with cattle dung were subjected to anaerobic batch digestion for a period of 50 days. Fresh lantana did not produce any biogas. However, predigested lantana did produce biogas but only up to a concentration of 50% (w/w, on dry weight basis). Both, the quantity and quality of biogas was better when cattle dung was supplemented with predigested lantana. Biotransformation of lantana toxins (lantadenes) during the biomethanation process was noticed.     

Extirpation or Coexistence? Management of a Persistent Introduced Grass in a Prairie Restoration

Abstract Introduced perennial grasses are one of the greatest constraints to prairie restoration. Herbicides suppress but do not eliminate introduced grasses, so we explored the interaction of herbicide with two additional controls: heavy clipping (to simulate grazing) and competition from native species. A 50‐year‐old stand of the introduced perennial grass Agropyron cristatum (crested wheatgrass) in the northern Great Plains was seeded with native grasses and treated with herbicide annually for 7 years in a factorial experiment. Clipping was applied as a subplot treatment in the final 3 years. Both herbicide and clipping significantly reduced the cover of A. cristatum, but clipping produced an immediate and consistent decrease, whereas herbicide control varied among years. The cover of A. cristatum decreased significantly with increasing cover of a seeded native grass, Bouteloua gracilis (blue grama), suggesting that both top‐down (i.e., grazing) and bottom‐up (i.e., resource competition) strategies can contribute to A. cristatum control. No treatment had any effect on the seed bank of A. cristatum. Even in the most effective control treatments, A. cristatum persisted at low amounts (approximately 5% cover) throughout the experiment. The cover of B. gracilis increased significantly with seed addition and herbicide, and, after 7 years, was similar to that in undisturbed prairie. The total cover of native species increased significantly with clipping and herbicide, and species richness was significantly higher in plots receiving herbicide. Clipping season had no effect on any variable. In summary, no method extirpated A. cristatum, but clipping reduced its cover by 90% and doubled the cover of native species. Extirpation might not be a realistic goal, but relatively simple management allowed coexistence of native species.     

Habitat selection by a despotic passerine,the Bell Miner (Manorina melanophrys): When restoring habitat through Lantana (Lantana camara) removal is not enough

The Bell Miner (Manorina melanophrys) occurs in logged eucalypt forest in northern NSW with a dense understorey of the invasive Neotropical shrub Lantana (Lantana camara) that is used for nesting. The link between Bell Miners and Lantana is important as the birds aggressively exclude all smaller and similar‐sized birds from their colonies, reducing avian diversity in forest occupied by the species. We monitored the impact of Lantana removal on Bell Miner persistence in several plots in two logged forest sites, along with untreated control plots at one of the sites. Lantana control was successful over 7 years at both sites, with regeneration of native understorey, midstorey and canopy species compensating for the loss of live Lantana cover in the understorey. Bell Miner individuals vacated the treated plots in one site (Creek's Bend) but persisted in the control and treated plots at the second site (Toonumbar National Park). Bell Miner response was correlated with forest structure: birds vacated forest with a sparse understorey (<5 m) but dense midstorey (5–15 m) and canopy (>15 m) at Creek's Bend, but remained at the site with a dense understorey but sparse midstorey and canopy at Toonumbar. We therefore predict that forest restoration that simultaneously reduces Lantana understorey and increases midstorey density will be most successful in reducing the abundance of the despotic Bell Miner and increasing avian diversity in rehabilitated sites.     

Residual Effects of Glyphosate Herbicide in Ecological Restoration

This study assesses the risks in ecological restoration arising from transplanting into soil containing glyphosate residues. Four Australian restoration species were grown for 60 days in nonadsorbing media treated continuously with glyphosate to establish threshold concentrations for damage. Visual signs of injury were observed in three species, and severe effects on root growth in all species, at solution concentrations as low as 18 mg/L. Only the perennial grass Themeda sp. died at this concentration, with other species surviving at concentrations in the range 36–360 mg/L, beyond which all plants died. Fourteen days exposure followed by removal of glyphosate from root media produced similar effects. Field and glasshouse experiments with the relatively tolerant tree species Angophora costata showed that application rates in the range 10–50 L/ha of herbicide product (360 g/L) would be needed to sustain damage to young plants transplanted into soil typical of local restoration sites. The volume of spray delivered using a hand‐operated sprayer varied between operators by 5‐ and 10‐fold to complete the same tasks, at the high end presenting a potential risk to the most tolerant species under field conditions, even when spray concentrations follow label instructions. For all but the most sensitive species, the risk of glyphosate residues in ecological restoration should be minimized by training operators of unregulated applicators to deliver controlled volumes of herbicide when spot spraying prior to transplanting.     

Management history determines gene flow in a prominent invader

Invasive plants pose substantial threats to protected areas globally. Although management can limit impacts, spread and reinvasion from neighbouring areas into protected areas are a major and an on‐going problem for land managers. However, identifying the main sources of propagules and the dimensions of invasion pathways is challenging. This study used population genetic markers [inter simple sequence repeats (ISSRs) and amplified fragment length polymorphisms (AFLPs)] to infer the source(s) of re‐colonization and dispersal patterns for a typical invader of riparian and terrestrial habitats (Lantana camara) along the Sabie‐Sand catchment, one of the most important river systems flowing into and across South Africa’s flagship protected area, the Kruger National Park (KNP). Results indicate that populations located along the lower reaches of the Sabie and Sand tributaries harboured substantially higher genetic diversity than those in the upper Sabie catchment. Bayesian assignments indicated that the upper Sabie tributary contributed far fewer propagules than the Sand tributary to the lower Sabie River. Current invasion patterns are due to a combination of a major flood event in 2000 and differences in the degree to which the upstream reaches were managed after the flooding. The major flood of 2000 effectively cleared lantana from the riparian areas. However, whereas on‐going management efforts against riparian species in the KNP have been effective, rendering the upper Sabie relatively clear of lantana, only a small part of the Sand tributary falls under jurisdiction of the KNP and has received consistent management attention. The reinvasion of the lower Sabie in the KNP was therefore almost entirely by propagules from the Sand tributary. The study highlights the important role that molecular tools can play in determining dispersal dynamics and directing invasive species management. For invasive plant species that invade both riparian habitats and landscapes away from rivers in protected areas, such as lantana, management must focus on all major sources of propagules to limit reinvasion.     

Biology, host range, and risk assessment supporting release in Africa of Falconia intermedia (Heteroptera: Miridae), a new biocontrol agent for Lantana camara

The ornamental hybrid shrub, Lantana camara L. (lantana), is a serious environmental weed and has been targeted for biological control in South Africa since 1961. The established biocontrol agents cause insufficient levels of damage and additional natural enemies are required to reduce the invasiveness of this weed. The lantana mirid, Falconia intermedia (Distant), is a promising new agent that was imported from the Caribbean for life history and host-range studies. The nymphs and adults are leaf-suckers that cause chlorotic speckling, which reduces the photosynthetic capacity of the plant. Biological studies indicate that F. intermedia has considerable biocontrol potential, in that it has a high intrinsic rate of increase, the potential for multiple generations a year, highly mobile adults, and a high level of damage per individual. Host-specificity trials indicated that the lantana mirid has a narrow host range, with L. camara being the most suitable host, but several indigenous African species in the closely related genus Lippia are suitable alternative host plants. Under multiple-choice conditions, adults showed a significant and strong oviposition preference for L. camara over the Lippia species. A risk assessment of potential nontarget effects indicated that three Lippia species could sustain damage levels in the field. The relatively low probability of damage to indigenous species was considered a justified trade-off for the potentially marked impact on L. camara. The regulatory authorities accepted the results of this study and F. intermedia was released against L. camara in South Africa in April 1999.     

Composting One Invasive Species to Control Another

The need for research and development of effective approaches to weed control continues to increase globally. Adaptive protocols using diverse control methods are often required in ecological restoration as recruitment of native species is highly site‐specific, species‐specific, and experimental. The use of composted weed refuse to control other weeds may be a practical option; yet, the option is not well studied due to the accompanied risk of introducing weed propagules to areas where weed control is desired. Here, we tested the effectiveness of different physical control techniques including the use of mulch made by composting weed refuse on‐site. English ivy (Hedera helix), a non‐native, invasive species in the Pacific northwestern United States, was removed from a heavily invaded site, shredded, and composted. The mulch was compared with other methods of suppressing herb Robert (Geranium robertianum), another invasive species on‐site. Five treatments were tested: flame‐weeding, hand‐pulling, mulching, hand‐pulling followed by mulching, and flame‐weeding followed by mulching. The mulch and pull/mulch treatments were the most effective, reducing G. robertianum cover by 92 and 86% of pre‐treatment levels, respectively, and suppressing G. robertianum 2.9 and 1.6 times more than the control, respectively. The mechanism behind the effectiveness of the mulch is uncertain, but may be related to weed seed burial or the allelopathic potential of the mulch. Composting one invasive species to use as mulch to control another can be effective and merits trial elsewhere.     

Herbicide and Tillage Effects on Volunteer Vegetation Composition and Diversity During Reforestation

Fraxinus pennsylvanica (green ash) is commonly used for reforestation of agricultural lowlands in the midwestern and eastern United States. We evaluated the effects of herbicide (untreated, glyphosate, and sulfometuron methyl) and tillage (tilled and no‐till) on F. pennsylvanica success and composition of associated volunteer vegetation 3 years after the treatment applications and reforestation of a formerly cultivated field in southern Illinois. Tillage had no effect on F. pennsylvanica growth, whereas both herbicides increased all measures of tree performance. The response of associated native and non‐native species cover was affected by an interaction between the herbicide and tillage treatments. In the presence of herbicide, cover of native species was greater in the no‐till treatment, whereas non‐native cover was higher in the tillage treatment. Both native and non‐native cover were unaffected by tillage in the absence of herbicide, and there were no differences in cover among the herbicide treatments in the presence of tillage. Total diversity was higher in the tillage treatment than the no‐till treatment, and diversity was lower in the sulfometuron methyl herbicide treatment than the control and glyphosate herbicide treatment. Lower diversity in the sulfometuron methyl treatment was attributed to greater cover of a native perennial grass, Andropogon virginicus (Broomsedge), which was inversely related to total diversity. We conclude that a single glyphosate herbicide application can enhance F. pennsylvanica growth and conserve associated species diversity in this system. Furthermore, species‐specific responses of the associated vegetation should be included in management considerations, particularly if silvicultural treatments influence dominance and diversity in the establishing understory community during reforestation.     

Evaluation of differential antitermitic activities of Lantana camara oven‐dried tissues against Reticulitermes virginicus (Isoptera: Rhinotermitidae)

Abstract Chemical‐treated soil or physical barriers have been the most commonly used approach for termite management. We hypothesized that a barrier of soil incorporated with oven‐dried Lantana camara L. tissues could prevent termite infestation. We first examined the antitermitic effects of the dried tissues from two cultivars (‘Mozelle’ and ‘New Gold’) on the subterranean termite, Reticulitermes virginicus (Banks) (Isoptera: Rhinotermitidae). Results show that all of the tissues of Mozelle had greater antitermic activity than corresponding tissues of New Gold, and leaves had greater termiticidal effects than flowers and stems. When termites were exposed to the test materials in a no‐choice bioassay, the 24‐day test resulted in a significant reduction of survival (52.5%–88.6%), running speed (18.2%–37.3%), live weight (21.8%–53.5%) and body water content (33.2%–56.2%) compared to the control. The consumption of leaves and flowers was exiguous. When used as 25% tissue mulch‐barrier, the oven‐dried lantana tissues decreased termite tunneling and wood consumption and increased termite mortality. The decreased survival, vigor, and low consumption indicate a toxic and anti‐feeding property of the materials tested. The results therefore support our hypothesis that the dried lantana tissues possess antitermitic activities.