Weed In Florida Research Articles

Landscape and Fruit Evaluation of Three Privet (Ligustrum sp.) Cultivars in Florida

Chinese privet (Ligustrum sinense) has escaped cultivation in 20 states in the USA and is classified as a noxious weed in Florida, where its use is prohibited. There is confusion among producers and consumers surrounding the invasive status of its cultivars. In Florida, cultivars of an invasive wildtype species are also invasive unless proven otherwise and exempted from an invasive ruling. This study evaluated the fruiting and landscape performance of two cultivars of Chinese privet, ‘Variegatum’ (variegated privet) and ‘Sunshine’ (sunshine privet), and an interspecific hybrid of another form of privet, ‘NCLX1’ (L. × vicaryi, Golden Ticket®), planted in southwest, northcentral, and north Florida. ‘Sunshine’ and ‘Variegatum’ privet both performed well throughout the study with average quality ratings ranging from 3.2 to 4.9 (scale of 1–5) and a 100% survival rate during the nearly two-year study. ‘NCLX1’ privet also had a 100% survival rate at the southwest and northcentral sites, but 80% survival at the north Florida site. ‘Variegatum’ privet grew the largest in both height and width compared to ‘Sunshine’ and ‘NCLX1’ privet, that had similar heights. ‘Variegatum’ and ‘NCLX1’ privet flowered during the study, but ‘Sunshine’ privet did not. ‘Variegatum’ privet was the only cultivar evaluated to produce mature fruit and show clear signs of reversion back to its green wildtype form. The DNA content of all three cultivars suggests they are diploids, as is the wildtype form of Chinese privet. These results provide potential alternatives to Chinese privet for use in landscapes but recommend avoiding ‘Variegatum’ privet, due to its frequent reversion to the wildtype and its abundant fruit production.

Life history of the leaf‐feeding beetle Calomela intemerata, a potential biocontrol agent against Acacia auriculiformis

AbstractWe examined the biology and life history of Calomela intemerata Lea (Coleoptera: Chrysomelidae), to determine its potential as a biocontrol agent of Acacia auriculiformis A.Cunn. ex Benth. (Fabaceae), an environmental weed in Florida, USA. We analysed data from field surveys in northern Australia and determined life‐history parameters and larval feeding under controlled laboratory conditions. In the field, both larvae and adults of C. intemerata fed throughout the year on young shoots of A. auriculiformis. Two geographically isolated populations of C. intemerata were collected from Northern Territory and north Queensland, Australia. We examined developmental time, survival, and size of immature stages in the laboratory at 25 °C. Following development through four instars, larvae move to the soil for pupation. Egg‐to‐adult development was approximately 23 days. Adults were long‐lived – several individuals survived >8 months. Females began ovipositing about 8 days after emergence and laid on average >1000 eggs each. On the invasive Florida A. auriculiformis, larvae of the Northern Territory population performed better than the north Queensland population regarding leaf consumption and developmental rate. The biological attributes of C. intemerata such as short generation time, high fecundity, and a long adult life, combined with the extensive damage larvae and adults inflict to young vegetative growth when feeding, make it a promising candidate biocontrol agent for management of A. auriculiformis in Florida. Formal host specificity testing is currently underway in Florida.

Significant genetic structure in Macrobathra moths feeding on Acacia auriculiformis – implications for prioritising biological control agents

Acacia auriculiformis is a native Australian tree that has now become a category 1 invasive weed in Florida, USA. Previous research has identified Macrobathra moths as potential biological control agents for this weed, but little is known about the genetic diversity and structuring of these moths. In this study, we compared the genetic structure of four common Macrobathra moth species across the geographic distribution of A. auriculiformis and across regions where A. auriculiformis does not occur to assess whether any of these moth species may comprise unrecognised cryptic species. We found contrasting patterns of genetic structuring among the four moth species, indicating that host-specific cryptic species could be present in Macrobathra arrectella and M. diplochrysa. Furthermore, we identified a deep genetic disjunction in both M. arrectella and M. callipetala across the Gulf of Carpentaria, a pattern that is also found in A. auriculiformis. The geographic distribution and host plant associations of the distinct mitochondrial lineages of each of these moth species should be further evaluated with additional ecological sampling, and the species status of these lineages tested directly, using additional molecular screening and/or carefully designed cross-mating tests.

Using weed emergence and phenology models to determine critical control windows for winter-grown carinata (Brassica carinata)

AbstractAdoption of the new biofuel crop carinata (Brassica carinata A. Braun) in the southeastern United States will largely hinge on sound agronomic recommendations that can be economically incorporated into and are compatible with existing rotations. Timing of weed control is crucial for yield protection and long-term weed seedbank management, but predictive weed emergence models have not been as widely studied in winter crops for this purpose. In this work, we use observed and predicted emergence of a winter annual weed community to create recommendations for timing weed control according to weed and crop phenology progression. Observed emergence timings for four winter annual weed species in North Carolina were used to validate previously published models developed for winter annual weeds in Florida by accounting for temperature and daylength differences, and this approach explained more than 70% of the variability in observed emergence. Emergence of stinking chamomile (Anthemis cotula L.) and cutleaf evening primrose (Oenothera laciniata Hill.) followed biphasic patterns comparable to wild radish (Raphanus raphanistrum L.), which were predicted with previously published models accounting for 82% and 84% of the variation, respectively. Using the predictive models for weed emergence and carinata growth, critical control windows (CCW) were estimated for Clayton, NC, and Jay, FL, according to different planting dates. The results demonstrated how early planting coincided with the emergence of three competitive winter weeds, but early control could also remove a large proportion of the predicted emergence of these species. The framework for how planting timing will affect winter weed emergence and crop growth will be an instructive decision-making tool to help prepare farmers to manage weeds in carinata, but it could also be useful for weed management planning for other winter crops.

Assessment of pharmacological activities of Lygodium microphyllum Cav. leaves in the management of pain, inflammation, pyrexia, diarrhea, and helminths: In vivo, in vitro and in silico approaches

Lygodium microphyllum Cav. (Family: Lygodiaceae) is a perennial, snake fern and an invasive weed in Florida and also known as old world climbing fern. This study is intended to evaluate the antipyretic, analgesic, anti-inflammatory, antidiarrheal and anthelmintic activity of methanol extract of Lygodium microphyllum Cav. leaves (MELM) by in vivo, in vitro and in silico approaches. In addition, Biovia, PyRx autoDock Vina, UCSF Chimera have been applied to investigate the docking study in order to evaluate the binding interaction and an online tool was used to explore the ADME/T properties of selected bioactive compounds. In acetic acid induced writhing study, MELM inhibited 44.28% and 56.61% of writhes at 200 and 400 (mg/kg) respectively compared to standard drug Diclofenac-Na (10 mg/kg) (74.42% inhibition). In anti-inflammatory experiment by formalin triggered licking method, MELM caused significant (p < 0.05) inhibition of licking in both early phase (42.97%, 63.30%) and late phase (43.35%, 63.03%) at the doses of 200 and 400 mg/kg respectively, whereas reference drug Ibuprofen inhibited paw licking 77.18% in early phase and 76.86% in late phase. MELM also showed promising antipyretic potential where the maximum reduction of fever was produced by MELM 400 mg/kg whose fever lowering capacity is close to the prescribe drug Indomethacin 4 mg/kg, i.p. In Castor oil triggered diarrhea method, MELM delayed the onset time of diarrhea, continuous persistence of wet feces, and decreased the weight of wet feces remarkably. Defection inhibition was achieved 27.56% and 51.72%, for MELM 200 and at 400 (mg/kg) respectively while loperamide 2 (mg/kg) yields 55.17% inhibition of the diarrheal defecation. In anthelmintic bioassay, MELM took 5.83 ± 0.83 and 41.67 ± 1.78 min respectively for paralyzing and death compared to standard drug albendazole; (paralysis time 4.00 ± 0.73 min and death time 31,00 ± 1.71 min). Isoeleutherol, isoquercetin and quercetin were found prominent in molecular docking study and ADME/T analysis verified their drug likeliness. The research validates the moderate analgesic, anti-inflammatory, and remarkable antipyretic, antidiarrheal, anthelmintic activities of the plant extract which can be used an alternative source of novel therapeutics.

Native range surveys for host-specific Acacia auriculiformis biocontrol agents – A role for DNA barcoding

Acacia auriculiformis is a native Australian tree that has developed into a damaging environmental weed in Florida, USA. We conducted field surveys to collect insect herbivores from A. auriculiformis and three closely related allopatric congeners (A. crassa, A. leiocalyx, and A. concurrens) across the native distribution of each plant species. We collected over 800 specimens, comprising a diversity of herbivorous insect groups, and successfully sequenced 480 specimens for DNA barcoding to group them into molecular operational taxonomic units (MOTUs) as a first step in documenting this diversity. Most herbivores (85%) were found on only a single Acacia species, suggesting each Acacia species hosts its own unique herbivore complex. The Northern Territory and Far North Queensland A. auriculiformis populations are allopatric in relation to one another but hosted a similar suite of herbivores. Calomela intemerata and seven lepidopteran species (including three species of Macrobathra moths) were particularly abundant across both regions. These herbivores look promising as potential biological control agents, though their host-specificity and genetic diversity should be investigated further.

Foliar lifespan, phenology and seasonal dynamics of the invasive shrub Schinus terebinthifolia

AbstractSchinus terebinthifolia is a dioecious tree native to South America that has become an invasive weed in Florida, southern California, southern Arizona, Texas and Hawaii and has been naturalised in over 20 countries. Biological control is considered a viable long‐term control option for S. terebinthifolia because release from natural enemies appears to be at least partly responsible for its success in Florida. We examined leaf phenology of S. terebinthifolia over a period of 15 months at five sites in central and southern Florida to provide information that may help in predicting the impacts of potential biocontrol agents for this weed. We documented leaf lifespan, the seasonality of leaf development and abscission and the survivorship of leaves that emerged during either spring, summer or autumn. Average leaf lifespan was &gt;4.5 months at all sites, and leaf phenology followed the seasons closely. Although S. terebinthifolia possesses leaves throughout the year, leaf production was greatest from April to September, and most leaves were abscised in February and March. Spring‐ and summer‐emerging leaves were also longer‐lived than leaves produced during autumn. These results suggest that leaves of S. terebinthifolia would be most vulnerable to herbivory during the spring and summer months when newly growing leaf tissue is most plentiful. Biocontrol agents capable of damaging these tissues during spring/summer might be an effective means of controlling this invasive weed.

Tropical Soda Apple: Biology, Ecology and Management of a Noxious Weed in Florida

Revised! SS-AGR-77, a 5-page illustrated fact sheet by Brent Sellers, Jay Ferrell, J. Jeffrey Mullahey, and Pat Hogue, informs readers about this serious weed problem in perennial grass pastures and native areas of Florida. It details the weed's taxonomy, biology, ecology, chemical control, biological control and management. Includes further sources of information. Published by the UF Department of Agronomy, February 2009. SS-AGR-77/UW097: Tropical Soda Apple: Biology, Ecology, and Management of a Noxious Weed in Florida (ufl.edu)

Scrutinizing biological control survey data from the native range – the phylogeny and Lygodium fern host associations of Musotiminae moths

Lygodium microphyllum is considered one of the most damaging environmental weeds in Florida. Despite substantial efforts to control this fern, it continues to spread rapidly through the Greater Everglades ecosystem and other regions of Florida. Biological control is considered a critical component of the management strategy to control this weed, and foreign exploration for natural enemies is ongoing. A number of crambid moths from the subfamily Musotiminae are considered the most promising of the potential biological control agents found to date, because they are relatively abundant on Lygodium and apparently host-specific. We amplified three genes (COI, 18S rRNA and 28S rRNA) to assess the phylogenetic relationships among these moths in relation to geography. Limited genetic structuring was typical within each moth species, and no obvious signals of unrecognised host-specific cryptic species were detected, though further investigation is required, particularly for Eugauria albidentata. Our results emphasize the value of complementing initial field surveys with molecular screening, as such an approach provides valuable information on the biogeographic distribution, genetic structuring, and field host range of potential biological control agents.

Biology and Management of Yellow (Cyperus escuelentus) and Purple Nutsedge (C. rotundus) in Ornamental Crop Production and Landscapes

This new six-page document provides insight on characteristics and management techniques for both yellow and purple nutsedge, prevalent and persistent weeds in Florida. Written by Debalina Saha, Chris Marble, Nathan Boyd, and Shawn Steed and published by the UF/IFAS Environmental Horticulture Department, March 2019. http://edis.ifas.ufl.edu/ep569

The complete chloroplast genome of the invasive fern Lygodium microphyllum (Cav.) R. Br.

The Old World climbing fern, Lygodium microphyllum, is a rapidly spreading environmental weed in Florida, United States. We reconstructed the complete chloroplast genome of L. microphyllum from Illumina whole-genome shotgun sequencing, and investigate the phylogenetic placement of this species within the Leptosporangiate ferns. The chloroplast genome is 158,891 bp and contains 87 protein-coding genes, four rRNA genes, and 27 tRNA genes. Thirty-three genes contained internal stop codons, a common feature in Leptosporangiate fern genomes. The L. microphyllum genome has been deposited in GenBank under accession number MG761729.

Taxonomy ofCalophya(Hemiptera: Calophyidae) Species Associated withSchinus terebinthifolia(Anacardiaceae)

Brazilian peppertree, Schinus terebinthifolia Raddi (Anacardaceae), native to Argentina, Brazil, Paraguay, and Uruguay, is one of the most invasive weeds in Florida. In its native range, at least 4 psyllid species of the genus Calophya (Hemiptera: Calophyidae) are associated with it. All 4 species are monophagous and constitute a likely monophyletic group that induce pit galls, usually on the upper leaf surface. Here we revise the taxonomy of these species, 2 of which are described as new, viz. C. lutea sp. nov. and C. praestigiator sp. nov. Morphological differences between the 4 species are detailed and relevant structures are figured. Keys for adults and the fifth instars are provided for the identification of the 8 species known to induce pit galls on Schinus species.

Effect of Plant Sex (dioecism) on the Performance ofApocnemidophorus pipitzi(Coleoptera: Curculionidae), A Stem Boring Weevil of Brazilian Peppertree, Schinus Terebinthifolia

Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae), is an ornamental dioecious shrub introduced from South America that has become one of the major invasive weeds in Florida. Anecdotal evidence from the literature suggests that crushed leaves from female plants produce a more pungent aroma, indicating these plants may be better defended chemically than their male counterparts. To test this hypothesis, we compared the performance (adult feeding and survival) of the South American stem boring weevil Apocnemidophorus piptzi (Faust) (Coleoptera: Curculionidae) by caging insects on foliage collected from both male and female Brazilian peppertree plants. Results showed that weevils consumed significantly less leaf tissue from female plants compared to male plants. Furthermore, the LT50 (average time required to cause 50% mortality of the weevils) was significantly shorter when weevils fed exclusively on female leaf tissue. Our findings confirmed male-biased plant herbivory on Brazilian peppertree by one of its folivorous natural enemies.

Development rate, consumption, and host fidelity ofNeostauropus alternus(Walker, 1855) (Lepidoptera: Notodontidae)

The Asian shrub Rhodomyrtus tomentosa (Aiton) Hasskarl (Myrtaceae) is an invasive weed in Florida and Hawaii, U.S.A. Surveys for natural enemies of this exotic shrub in Hong Kong, China resulted in the development of a laboratory colony and host range testing of Neostauropus alternus (Walker, 1855) as a potential biological control agent of R. tomentosa. Twelve critical test plant species were presented to larvae of N. alternus. Complete development was limited to R. tomentosa, the ornamentally important Myrtus communis Linneaus (Myrtaceae), and the Florida natives Myrcianthes fragrans (Small) (K.A. Wilson) (Myrtaceae) and Morella cerifera (Linneaus) Small (Myricaceae). Total development time was more than ten days faster with R. tomentosa versus M. communis and M. cerifera, with the latter species requiring an extra larval instar to reach the pupal stage. Consumption rates were similar among R. tomentosa and M. cerifera, but due to the longer development time, larvae consumed two-fold more leaf material on M. cerifera. Despite an apparent larval survival and development preference for R. tomentosa, it is clear that the physiological host range of N. alternus includes M. cerifera and M. communis. The generalized feeding patterns exhibited in this research indicate that additional resources dedicated to the development of N. alternus as a biological control agent of R. tomentosa in Florida are unwarranted.

Seasonal Growth, Biomass Allocation, and Invasive Attributes Manifested by Dioscorea bulbifera L. (Air-Potato) Plants Generated from Bulbils in Florida

Dioscorea bulbifera is a serious invader of various ecosystems in Florida, where plants generated by its two morphotypes climb aggressively and smother supporting vegetation. There is a dearth of published research on its invasive biological attributes including vine growth and biomass production by plants generated from bulbils. Herein, we assessed these parameters in common garden studies by planting bulbils from four biomass categories (PBBCs I–IV) of both morphotypes. Vine lengths, longevity-based growth rates (VLGR), biomass, and quantities of leaves and daughter bulbils in both morphotypes showed positive correlation with the biomass of planted parental bulbils. This indicated similarity between corresponding attributes in two morphotypes. Total vine length showed strong positive correlation with VLGR, biomass, and quantities of leaves and bulbils. Overall vine longevity among plants from PBBCs I–IV did not significantly differ whereas the total vine lengths, VLGRs, number of branches, and quantities of leaves and bulbils increased with the biomass of the parental bulbils. Plants recruited by smaller bulbils allocated more biomass to leaves and tubers compared to stems and bulbils, whereas the plants recruited by larger bulbils allocated more biomass to leaves and bulbils compared to tubers and stems. Higher proportion of biomass allocation to leaves and bulbils presumably ensures immediate faster growth, longer vines, and a greater number of daughter bulbils for future recruitment of new plants. Vine length (associated with faster growth rate, capable of blanketing supporting structures and producing large quantities of bulbils) has been noted as the primary invasive biological attribute that facilitates D. bulbifera's status as a noxious exotic weed in Florida. Control measure that can reduce vine length should reduce or eliminate the invasive behavior of D. bulbifera in Florida.

Development Rate, Consumption, and Host Specificity ofCarea varipes(Lepidoptera: Nolidae)

The Asian shrub Rhodomyrtus tomentosa is an invasive weed in Florida and Hawaii, USA. Surveys for natural enemies of this exotic shrub in Hong Kong, China, resulted in the development of a laboratory colony and initial host range testing of Carea varipes Walker as a potential biological control agent of R. tomentosa . Twelve critical test plant species were presented to C. varipes larvae, but complete development was limited to R. tomentosa , the ornamental Myrtus communis , and the Florida native Morella cerifera . Total development time was >10 d faster when held with R. tomentosa and M. communis versus M. cerifera , with the latter species requiring an extra larval instar to reach the pupal stage. Total consumption levels over an individual’s larval stage were similar among R. tomentosa and M. cerifera but, when the longer development time associated with the latter host is accounted for, consumption rates indicate that larvae consumed >2 times more leaf material when held with the Florida native. Despite an apparent preference for R. tomentosa , it is clear that the physiological host range of C. varipes includes the Florida native M. cerifera and the ornamentally important M. communis . The generalized feeding patterns exhibited in this research indicates that additional resources dedicated to the development of this species as a biological control agent are unwarranted.

Brazilian Collections and Laboratory Biology of the ThripsPseudophilothrips ichini(Thysanoptera: Phlaeothripidae): A Potential Biological Control Agent of the Invasive Weed Brazilian Peppertree (Sapindales: Anacardiaceae)

Abstract Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae), is one of the most invasive weeds in Florida and Hawaii. In the invaded range, this fast-growing weed from South America poses a threat to agriculture and cattle production and decreases the biodiveristy of natural areas. The thrips Pseudophilothrips ichini (Hood) (Thysanoptera: Phlaeothripidae) is being studied as a potential agent for the biological control of this weed. The laboratory life history and native range of P. ichini in Brazil were examined over 10 yr. The thrips life history includes 2 feeding larval stages that occur on the plant and 3 non-feeding pupal stages that occur in the soil. Development time, body length, and distinct features of each life stage are described. The larva-to-adult development required 20 d, and adults lived for an average of 50 d. Pseudophilothrips ichini had a wide latitudinal range in Brazil along the eastern coast from Bahia (11.4°S) south to Santa Catarina State (27.1°S). It...

Host specificity testing and examination for plant pathogens reveals that the gall‐inducing psyllid Calophya latiforceps is safe to release for biological control of Brazilian peppertree

AbstractBrazilian peppertree, Schinus terebinthifolia Raddi (Anacardiaceae), is one of the worst upland exotic weeds in Florida, USA. Foreign exploration for natural enemies led to the discovery of a pit‐galling psyllid, Calophya latiforceps Burckhardt (Hemiptera: Calophyidae), in the state of Bahia, Brazil, in 2010. Crawlers of C. latiforceps stimulate the formation of galls on the leaves of S. terebinthifolia resulting in leaf discoloration and in some cases leaf abscission. To determine whether C. latiforceps is a safe candidate for biological control of S. terebinthifolia, host specificity and the presence of selected plant pathogens were examined. Adult oviposition, gall formation, and adult survival of C. latiforceps were examined on 89 plant species under no‐choice and choice conditions. We found that C. latiforceps laid eggs on plants in seven families; however, crawlers stimulated gall formation and completed development to adult only on S. terebinthifolia. All crawlers on non‐target plants died, likely due to starvation caused either by the absence of a feeding stimulus or by a hypersensitive plant response. Under no‐choice conditions, 10% of adults lived for 19 days on the target weed, but adult survival was reduced to &lt;3 days on non‐target plants. Choice testing revealed that females preferred to oviposit on S. terebinthifolia compared to non‐target plants. Molecular methods and indicator host inoculations did not detect the presence of ‘Candidatus Liberibacter solanacearum’, ‘Ca. L. asiaticus’, ‘Ca. L. americanus’, ‘Ca. L. africanus’, or plant viruses in adult C. latiforceps. We conclude that releasing C. latiforceps in the USA will have extremely low risk to non‐target plants, and provides another tool for the management of S. terebinthifolia.

The broad host range of Metharmostis multilineata precludes its use as a biological control agent of Rhodomyrtus tomentosa

Rhodomyrtus tomentosa is an invasive weed in Florida and Hawaii, USA. Host range testing indicates that the stem-mining lepidopteran Metharmostis multilineata, collected from Hong Kong, China aggressively feeds and completes development on R. tomentosa as well as New World species in three other genera. The unsuitability of M. multilineata as a biological control agent and details of the newly described species' biology are addressed.

Description and Evaluation ofMetharmostis multilineata(Cosmopterigidae) andIdiophantis soreuta(Gelechiidae) (Lepidoptera: Gelechioidea) For Biocontrol Of Downy Rose Myrtle,Rhodomyrtus tomentosa(Myrtaceae)

Two species of Gelechioidea (Lepidoptera), Metharmostis multilineata Adamski, n. sp. (Cosmopterigidae), and Idiophantis soreuta Meyrick, 1906 (Gelechiidae), were collected in southeastern Asia for evaluation as potential biocontrol agents against downy rose myrtle, Rhodomyrtus tomentosa (Aiton) Hassk. (Myrtaceae), which has become an invasive weed in Florida, USA. Metharmostis Meyrick is reviewed and transferred from Yponomeutidae to Cosmopterigidae (Antequerinae). All life stages of M. multilineata are described and illustrated, with notes on its biology. In addition, protocols for rearing and host testing of M. multilineata are described in detail. Idiophantis appears to be associated with Myrtaceae, and the adult stage of I. soreuta is redescribed. Neither species was suitable for release in Florida.