Rodrigo Diaz

Louisiana State University | LSU · Department of Entomology

Simple Summary: Privets (Ligustrum spp.) are popular hedge shrubs that escape from gardens and cause negative impacts by invading forests in the United States. The narrow host specificity of the seed-feeding weevil, Ochyromera ligustri, suggests that this weevil could be considered a fortuitous biological control agent of privets. To find out the h...

Vegetation dieback and recovery may be dependent on the interplay between infrequent acute disturbances and underlying chronic stresses. Coastal wetlands are vulnerable to the chronic stress of sea-level rise, which may affect their susceptibility to acute disturbance events. Here, we show that a large-scale vegetation dieback in the Mississippi Ri...

Phragmites australis is exhibiting extensive dieback in the Lower Mississippi River Delta (MRD). We explored the potential for restoration of these marshes by (1) characterizing the chemical profiles of soils collected from healthy and dieback stands of P. australis and from sites recently created from dredge-disposal soils that were expected to be...

Air potato, Dioscorea bulbifera L. (Dioscoreaceae), is an invasive vine that climbs into vegetation outcompeting native species and altering ecosystems in the southeastern USA. The biological control agent, Lilioceris cheni Gressitt and Kimoto (Coleoptera: Chrysomelidae), has been released in Florida since 2011 and in other states including Georgia...

The anthropogenic deterioration of aquatic ecosystems affects water resources due to agricultural malpractices, pollution from domestic septic tanks, recreational activities, and poor watershed management, among other factors. This study examines the management of Las Curias Reservoir, San Juan, Puerto Rico, after the 2016 arrival of the invasive a...

The Mississippi River Delta (MRD) is one of the largest wetlands in the world and is experiencing widespread dieback of its most prevalent plant species, Phragmites australis. The potential for revegetation of dieback sites was assessed by planting three genetically distinct lineages of P. australis at seven sites in the MRD that varied in water de...

Despite the success of the salvinia weevil (Cyrtobagous salviniae) at controlling giant salvinia (Salvinia molesta), its impact on the timing of reduction of giant salvinia cover and recovery of submerged aquatic vegetation (SAV) and dissolved oxygen remains unknown. A two-year field study (2016 to 2017) was conducted in coastal wetlands in southwe...

The metabolome represents an important functional trait likely important to plant invasion success, but we have a limited understanding of whether the entire metabolome or targeted groups of compounds confer an advantage to invasive as compared to native taxa. We conducted a lipidomic and metabolomic analysis of the cosmopolitan wetland grass Phrag...

Multiple importations of Lilioceris cheni, a defoliating beetle of the invasive air potato plant, were received by the ARS-Invasive Plant Research Laboratory from 2002 to 2012. The last two, in 2011 (China) and 2012 (Nepal), formed the basis of two colonies from which releases were made into six Southeastern U.S. States. Colony populations were exa...

Thermal tolerance greatly influences the geographic distribution, seasonality, and feeding habits of mosquitoes; this study aimed to examine the impacts of species, sex, and diet on thermal tolerance in mosquitoes. We found that Culex quinquefasciatus was inherently significantly more cold tolerant than Aedes aegypti, while Ae. aegypti had improved...

The recent decline of Phragmites australis stands in the Mississippi River Delta is due, in part, to damage from herbivory by the non-native roseau cane scale, Nipponaclerda biwakoensis. In Louisiana, P. australis communities, known locally as roseau cane, protect the marsh ecosystem from erosion and storm-related impacts, stabilize shipping channe...

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 di...

The invasive floating aquatic macrophyte giant salvinia (Salvinia molesta) can rapidly alter ecosystem stability by forming a thick vegetative mat on the water surface. Management efforts are often required to clear waterways, and field releases of the salvinia weevil (Cyrtobagous salviniae) has been successful in restoring aquatic systems. Measuri...

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 Lou...

Phragmites australis is exhibiting extensive dieback in the Lower Mississippi River Delta (MRD). We explored the potential for restoration of these marshes by 1) characterizing the chemical profiles of soils collected from healthy and dieback stands of P. australis and from sites recently created from dredge-disposal soils that were expected to be...

The Mexican rice borer, Eoreuma loftini (Dyar), is an invasive herbivore that attacks many gramineous host plants. The species is an economic pest of several grass crops in North America including sugarcane (Saccharum spp.), rice (Oryza sativa), corn (Zea mays), and sorghum (Sorghum bicolor). The species was first detected in the United States in 1...

Taro (Colocasia esculenta) is a food cropcultivated in tropical areas of the world. However, whenuncultivated, taro is considered an invasive plant speciesdue to its ability to colonize aquatic and semi-aquaticareas and replace native plants. Disease symptoms wereobserved on uncultivated taro growing in water-saturated soil at the Bluebonnet Swamp...

Cold tolerance and potential distribution of Myllocerus undecimpustulatus undatus Marshall, a polyphagous pest in the United States, were investigated. Adult survivorship after 2 days at 0 °C and − 5 °C averaged 60% and 18%, respectively. Four days of exposure resulted in survivorship of 11% at 0 °C and 4% at − 5 °C, respectively. Summer-collected...

Schoenlandella Cameron, 1905 is the second largest genus of Cardiochilinae. Most members are recorded from the Old World, with a small number of species in the New World. Herein, the New World species of Schoenlandella are revised based on morphological data. This work entails a description of a new species: S. montserratensis Kang, sp. nov. and po...

Satellite remote sensing of wetlands provides many advantages to traditional monitoring and mapping methods. However, remote sensing often remains reliant on labor- and resource- intensive ground truth data for wetland vegetation identification through image classification training and accuracy assessments. Therefore, this study sought to evaluate...

Submerged macrophytes are an important component to the structure and function of freshwater ecosystems. Invasive, free-floating macrophytes can adversely impact native submerged macrophytes, and these impacts can be exacerbated by anthropogenic nutrient loading. Using a mesocosm study, we examined how the invasive macro-phyte, giant salvinia (Salv...

Many weed biological control programs suffer from large-scale spatial variation in success due to restricted distributions or abundances of agents in temperate climates. For some of the world’s worst aquatic weeds, agents are established but overwintering conditions limit their survival in higher latitudes or elevations. The resulting need is for n...

The non-native aquatic fern giant salvinia, Salvinia molesta Mitchell (Salviniaceae), poses a risk to freshwater ecosystems through limiting light penetration, decreasing submerged aquatic vegetation (SAV) abundance, altering water quality, and potentially leading to changes in macroinvertebrate community structure. Here, we conducted repeated quar...

Aquatic insects are important to the transfer of energy in freshwater wetlands. They link primary producers and organic matter to higher trophic levels, and pass energy from the aquatic environment to the terrestrial ecosystem via predation of adults. Introduction of the invasive free-floating aquatic fern giant salvinia, Salvinia molesta Mitchell,...

Taro [Colocasia esculenta (L.) Schott], also called dasheen or malanga is an important staple crop in many tropical and subtropical countries (Chaïr et al. 2016). In October 2020, taro plants showing foliar symptoms consisting of mosaic, feathery mottle, and vein clearing patterns were observed in the Hilltop Arboretum, the Bluebonnet Swamp Nature...

In 2016, widespread dieback of Phragmites australis was reported in the Mississippi River Delta (MRD), Louisiana. We conducted two common-garden experiments to investigate several potentially important factors associated with this dieback: scale insects, water depth, fertilization and P. australis genetics (three lineages: Gulf, Delta and invasive...

The impacts of different biotic and abiotic limiting factors on introduced biological control agents and their weed targets may result in geographically variable control, with implications for ongoing management and plans to improve efficacy. Geographic variability in control successes, however, may be underreported. Using the comprehensive catalog...

Giant salvinia (Salvinia molesta Mitchell, Salviniaceae) is a free-floating fern native to Brazil that alters natural processes in aquatic ecosystems, causing ecological problems for water resource managers. Due to its ease of dispersal through fragmentation and rapid growth, giant salvinia can quickly become problematic, requiring persistent manag...

Die-back of Phragmites australis in the Mississippi River Delta (MRD), Louisiana, USA, is associated with large populations of nonnative Roseau Cane Scale (RCS), Nipponaclerda biwakoensis. Initial observations suggested different P. australis phenotypes displayed different susceptibilities to scale infestation and die-back, but the role of scale in...

Nymphaea mexicana Zuccarini (Nymphaeaceae) (Mexican waterlily) is an emergent floating-leaved aquatic plant from the southeastern USA that is invasive in South Africa. In invaded waterbodies this plant restricts water movement, increases siltation, decreases recreational activities, and can deplete water oxygen levels, which in turn negatively impa...

Invasion from giant salvinia (Salvinia molesta Mitchell, Salviniaceae) blocks sunlight entering waterbodies, reducing submerged aquatic macrophytes, thus lowering dissolved oxygen and stressing aquatic organisms. Due to its rapid growth and ease of dispersal through fragmentation, giant salvinia can quickly become problematic and difficult to eradi...

The biological control agent, Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae) (salvinia weevil), is being used for management of the highly invasive fern Salvinia molesta Mitchell (Salvinaceae) in Louisiana and Texas, USA. The weevils and plants are transported from the nurseries and rearing facilities to the field release sites...

Salvinia molesta (Giant Salvinia) is a highly problematic, non-native, invasive species in the southeastern United States. Other than introduced biological control agents, observations of natural enemies to Giant Salvinia are rare within the United States. We observed a native crayfish, Procambarus clarkii (Red Swamp Crayfish), feeding on Giant Sal...

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 t...

We compared the cold tolerance of three populations of the salvinia weevil, Cyrtobagous salviniae. When exposed to 0°C, lethal time to kill 90% of adults from the Bayou Nicholas population was greater than the Houma and Natchitoches populations. This weevil exhibited phenotypic plasticity which could be used in mass rearing.

Physiological limits of non-native species to environmental factors are critical for their establishment and spread in the adventive range. The crapemyrtle bark scale, Acanthococcus lagerstroemiae (Kuwana), is a major pest of crapemyrtles. Despite concerns on its rapid spread, there is a lack of information on potential distribution range of this s...

Despite the use of aquatic herbicides and release of the biological control agent salvinia weevil (Cyrtobagous salviniae Calder and Sands; Coleoptera: Curculionidae), giant salvinia (Salvinia molesta Mitchell) continues to hinder waterways in the Gulf Coast region of the United States. Outdoor mesocosm trials were conducted in April and August of 2...

Common reed, Phragmites australis (Cav.) Trin. Ex Steud., is the dominant emergent vegetation in the lower Mississippi River Delta (MRD), Louisiana, USA and is comprised primarily of introduced lineages of different phylogeographic origins. Dense stands of P. australis are important for protecting marsh soils from wave action and storm surges. In t...

Chemical and biological control methods are often integrated to manage unwanted plants. However, the application of 2,4-D near giant salvinia (Salvinia molesta Mitchell) may hinder biological control efforts by the salvinia weevil (Cyrtobagous salviniae Calder and Sands). Limited efforts have been made to examine the susceptibility of salvinia weev...

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 monophyleti...

Lilioceris cheni is a successful biological control agent on the invasive yam, Dioscorea bulbifera in many areas in Florida, Georgia, Alabama and Louisiana. Two biotypes are available for release and come from significantly different centres of origin. The Nepalese biotype was collected at higher altitude and latitude sites, whereas the Chinese bio...

Brazilian peppertree, Schinus terebinthifolia Raddi (Anacardiaceae), is a South American plant that is highly invasive in Florida. The impact of insect herbivores on the performance of Brazilian peppertree was evaluated at two locations in Florida using an insecticide exclusion method. Although 38 species of insect herbivores were collected on the...

Abstract In 2015, emerald ash borer (EAB) was detected in North Louisiana. There is no information on the potential effect of the EAB invasion on the native arthropods associated with green ash (Fraxinus pennsylvanica Marshall) trees in Louisiana. The objective of this study was to quantify the arthropod community associated with green ash using em...

A Chinese biotype of Lilioceris cheni Gressitt and Kimoto (Coleoptera: Chrysomelidae) is being mass reared and released in Florida for biological control of the invasive air potato vine, Dioscorea bulbifera L. (Dioscoreales). Another biotype from Nepal is under investigation for determining whether its release would benefit the ongoing biological c...

Cyrtobagous salviniae is widely used in several countries including the United States, South Africa and Australia for biological control of Salvinia molesta Mitchell (Salviniales: Salviniaceae). Despite considerable success in tropical and subtropical regions, the effectiveness of C. salviniae on S. molesta is inconsistent in temperate regions, ind...

The tawny crazy ant, Nylanderia fulva (Mayr) (Hymenoptera: Formicidae), has invaded states of the U.S. including Texas, Louisiana, Mississippi, Alabama, Florida, and Georgia. Native to South America, N. fulva is considered a pest in the U.S. capable of annoying homeowners and farmers, as well as displacing native ant species. As it continues to exp...

Crapemyrtle bark scale, Acanthococcus (=Eriococcus) lagerstroemiae (Kuwana) (Hemiptera: Eriococcidae), is a newly introduced insect pest on crapemyrtles, Lagerstroemia spp. (Myrtales: Lythraceae), one of the most popular flowering shrubs in the U.S. Since first detected in Texas in 2004, this pest has spread to twelve states causing losses to stake...

Emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera, Buprestidae), a metallic wood boring beetle, is an exotic pest of ash trees (Fraxinus spp.) EAB can attack all the ash species in North America disrupting local food webs and has caused more than 20 million ash tree deaths since 2002. In order to describe the insect community assoc...

Schinus terebinthifolia (Brazilian Peppertree) is a South American plant that has become invasive in many countries around the world. It was introduced into the US about 100 years ago as an ornamental. Escaping cultivation, it now occurs in Alabama, Florida, Georgia, Texas, California, and Hawai'i. This species is one of the most invasive weeds thr...

Water lettuce moth, Samea multiplicalis (Guenée) (Lepidoptera: Pyralidae: Pyraustinae), is a small moth widely distributed in the warmer regions of North and South America (Center et al., 1982). The larvae feed on several floating aquatic plants, including water lettuce, Pistia stratiotes L. (Araceae), mosquito fern, Azolla caroliniana Willd. (Azol...

Water lettuce moth, Samea multiplicalis (Guenée) (Lepidoptera: Pyralidae: Pyraustinae), is a small moth widely distributed in the warmer regions of North and South America (Center et al., 1982). The larvae feed on several floating aquatic plants, including water lettuce, Pistia stratiotes L. (Araceae), mosquito fern, Azolla caroliniana Willd. (Azol...

Schinus terebinthifolia Raddi (Anacardiaceae) (Brazilian peppertree) is one of the most serious terrestrial invasive plants in Florida. The leaf galling psyllid, Calophya latiforceps Burckhardt (Hemiptera: Calophyidae), was discovered feeding on Brazilian peppertree in Bahia, Brazil in 2010, and is being evaluated for release as a biological contro...

Bacteria associated with sap-feeding insect herbivores include not only symbionts that may increase their hosts' fitness but also harmful plant pathogens. Calophya spp. gall-inducing psyllids (Hemiptera: Calophyidae) are being investigated for their potential as biological control agents of the noxious weed, Brazilian peppertree (Schinus terebinthi...

Se caracterizaron cuatro poblaciones de Calophya spp. (Hemiptera: Calophyidae) recolectadas en Brasil usando métodos moleculares y morfológicos. El examen de los adultos reveló la presencia de 2 morfotipos que se identificaron como C. latiforceps y C. terebinthifolii. Sin embargo, el examen morfológico de las ninfas del quinto estadio detectó difer...

Imperata cylindrica (Cogongrass, Speargrass) is a diploid C4 grass that is a noxious weed in 73 countries and constitutes a significant threat to global biodiversity and sustainable agriculture. We used a cost-effective genotyping-by-sequencing (GBS) approach to identify the reproductive system, genetic diversity and geographic origins of invasions...

Field surveys revealed that in south Florida the recently established Mikania micrantha Kunth (Asterales: Asteraceae: Eupatorieae) had a lower diversity of monophagous insect herbivores compared to the native Mikania spp. or Chromolaena odorata (L.) R. M. King & H. Rob. (Asterales: Asteraceae: Eupatorieae). In addition, Mikania micrantha served as...

A chironomid midge, Cricotopus lebetis (Sublette) (Diptera: Chironomidae), was discovered attacking the apical meristems of Hydrilla verticillata (L.f. Royle) in Crystal River, Citrus Co., Florida in 1992. The larvae mine the stems of H. verticillata and cause basal branching and stunting of the plant. Temperature-dependent development, cold tolera...

Brazilian 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 th...

Background/Question/Methods Air potato, Dioscorea bulbifera L., (Liliales: Dioscoreaceae) is an invasive herbaceous vine. It does not produce fertile flowers in the U.S. and instead reproduces via aerial bulbils, vegetative propagules that form in the leaf axils and dehisce as this deciduous plant senesces in the fall. Bulbils and persistent subt...

The most critical step during a weed biological control program is determination of a candidate agent’s host range. Despite rigorous protocols and extensive testing, there are still concerns over potential non-target effects following field releases. With the objective to improve risk assessment in biological control, no-choice and choice testing f...

Leucospilapteryx venustella (Clemens) (Lepidoptera: Gracillariidae) is a small, mostly light brown moth that, during its larval stages, creates mines in the leaves of plants in the family Asteraceae. Feeding damage by the early instars is characterized by serpentine mines that are expanded by later instars to form tentiform or blotch mines. This 4-...

Native range and life history studies of an agent provide critical information during the early stages of a weed biological control programme. Brazilian peppertree is considered to be one of the worst invasive trees of Florida uplands because of negative environmental impacts and lack of effective long-term control methods. A potential biological c...

Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae) (hereafter Schinus), is one of the worst invasive species in Florida and Hawaii. The thrips Pseudophilothrips ichini Hood (Thysanoptera: Phlaeothripidae) is being considered as a potential biological control agent of Schinus. Two populations of this thrips were collecte...

Tropical soda apple (Solanum viarum Dunal) (Solanaceae) is a small shrub native to South America that is invasive in pastures and conservation areas across Florida. Dense patches of tropical soda apple not only reduce cattle stocking rates and limit their movement, but also serve as reservoirs for pests of solanaceous crops. A classical biological...

Tropical soda apple (Solanum viarum Dunal) (Solanaceae) is a small shrub native to South America that is invasive in pastures and conservation areas across Florida. Dense patches of tropical soda apple not only reduce cattle stocking rates and limit their movement, but also serve as reservoirs for pests of solanaceous crops. A classical biological...

Native range and life history studies of an agent provide critical information during the early stages of a weed biological control programme. Brazilian peppertree is considered to be one of the worst invasive trees of Florida uplands because of negative environmental impacts and lack of effective long-term control methods. A potential biological c...

Gall forming insects are highly specialized herbivores. Because of their specificity and damage to the host, gall formers have been used in several weed biological control programs. As an initial step towards understanding the suitability of leaf galling psyllids as potential biological control agents of Brazilian peppertree, we determined the life...

The scarlet-bodied wasp moth, Cosmosoma myrodora (Dyar), is a beautiful native insect. Because of its striking adult coloration, including a bright red thorax and abdomen, and transparent wings patterned with black, this moth immediately stands out in Florida landscapes. Larval feeding is restricted to two native plants in the genus Mikania, family...

Tropical soda apple (Solanum viarum Dunal) is a major exotic weed in pastures and conservation areas in subtropical regions. Anthonomus tenebrosus Boheman (Coleoptera: Curculionidae) was found feeding on the flowers of tropical soda apple in southern Brazil and was considered a potential biological control agent. The objectives of this study were t...

A new species, Cremastobombycia chromolaenae, is described from Florida and Texas, USA. The larva is a leaf miner on Chromolaena odorata (L.) King and H. Robinson, a 2–3 m tall perennial shrub of the family Asteraceae, whose native range extends from south-ern Florida south to northern Argentina (Fig. 1). The plant is also known to occur in Africa,...

Tropical soda apple is a prickly shrub native to South America that is a major problem in pastures and conservation areas. So a multi-agency program supported the rearing, distribution, and release of more than 250,000 tropical soda apple leaf beetles across Florida from 2003 to 2011. This 4-page fact sheet was written by Rodrigo Diaz, William A. O...

Tropical soda apple is a prickly shrub native to South America. First reported in Glades Co., Florida in 1988, it later spread to Georgia, Alabama, Louisiana, Texas, Mississippi, Tennessee, North Carolina, and South Carolina. It is a major problem in pastures and conservation areas. Negative impacts of tropical soda apple include reduction of cattl...

This leaf feeding beetle was recently introduced into Florida from China for biological control of air potato. This 4-page fact sheet provides information on the distribution, appearance, life cycle, host range and importance of the beetle. Written by Rodrigo Diaz, William A. Overholt, and Ken Hibbard, and published by the UF Department of Entomolo...

The yellowmargined leaf beetle, Microthecaochroloma (Stål) (Coleoptera: Chrysomelidae ), is an adventive pest of cruciferous crops in the southeastern United States. Despite its pest status, there is limited information about the infiuence of temperature on development and survival of M. ochroloma. The objectives of this study were to assess the ef...

Rising atmospheric CO2 levels could have drastic effects on the performance of invasive weeds and their insect herbivores. Despite the importance of biological control as an effective management tool for environmental weeds, there have been few studies on the potential impact of climate change on the future efficacy of biological control. The objec...

Successful establishment of a biological control agent is a prerequisite for effective reduction of an invasive weed. Niche-based species distribution models can generate valuable information about the potential spread of a biological control agent and help to predict its distribution. The Maximum Entropy Species Distribution Model was used in our...

Arthropods associated with the exotic weed tropical soda apple were collected in Florida. We found that tropical soda apple is a suitable host for several insect pests of agricultural and ornamental plants. Additionally, we report several predators, parasitoids and entomopathogens of Gratiana boliviana, a biological control agent of tropical soda a...

Abstract Brazilian peppertree, Schinus terebinthifolius Raddi (Anacardiaceae), native to South America, has invaded different habitats throughout south and central Florida. In recent surveys of natural enemies conducted in Salvador, Brazil (native range), a new species in the genus Paectes (Lepidoptera: Euteliidae) was found feeding on foliage of B...

Phragmites are a tall, perennial, wetland grasses, occurring in both fresh and brackish waters. This 3-page fact sheet discusses the three genetic lineages: native, Gulf Coast, and Eurasian; and the threat posed to Florida ecosystems by an invasion of the exotic Eurasian type. Written by W. A. Overholt, R. Diaz, M. Hanson, and D. Williams, and publ...

The sustainable management of tropical soda apple (TSA) below levels that cause economical/ecological damage will be based on the implementation of a combination of biological (insects, pathogens), chemical herbicides, mechanical control (mowing), cultural, and regulation of movement of livestock, contaminated hay, sod-grass, seeds (e.g. Bahia gras...