Plant quality of dioecious hydrilla was studied as a factor that may influence larval survival, growth, and development of the biological control agent Bagous hydrillae. Nitrogen content and stem toughness of hydrilla varied among the five sites studied and between summer and fall collections. The nitrogen content of hydrilla collected during summer ranged from 1.2 to 3.6% (dry weight) and duri...

Avian vacuolar myelinopathy (AVM) is a neurological disease affecting bald eagles (Haliaeetus leucocephalus), American coots (Fulica americana), waterfowl, and other birds in the southeastern United States. The cause of the disease is unknown, but is thought to be a naturally produced toxin. AVM is associated with aquatic macrophytes, most frequently hydrilla (Hydrilla verticillata), and resear...

Giant salvinia (Salvinia molesta Mitchell) is a nuisance, free-floating aquatic fern that can double biomass in 10 days through vegetative reproduction. Hydrilla (Hydrilla verticillata (L.f.) Royle) is a perennial submersed aquatic plant that can propagate from stem fragments, turions, and subterranean tubers representing a triple threat for management methods. Both plants disrupt water bodies ...

The objectives of this study were to (i) assess trace metal concentrations in Hydrilla verticillata and sediment from an estuarine creek in Alabama (USA), where high metal levels in biota were previously reported, and (ii) investigate the relationship between metal concentrations in H. verticillata and the sediment compartment. Our results indicate that sediment and H. verticillata exhibit mode...

Hydrilla (Hydrilla verticillata L.f. Royle) was introduced to the surface water of Florida in the 1950s and is today one of the most serious aquatic weed problems in the USA. As a result of concerns associated with the applications of pesticides to aquatic systems, fluridone is the only USEPA-approved chemical that provides systemic control of hydrilla. After a decrease in fluridone's efficacy ...

Vacuolar myelinopathy (VM) is a neurologic disease primarily found in birds that occurs when wildlife ingest submerged aquatic vegetation colonized by an uncharacterized toxin-producing cyanobacterium (hereafter "UCB" for "uncharacterized cyanobacterium"). Turtles are among the closest extant relatives of birds and many species directly and/or indirectly consume aquatic vegetation. However, it ...

A complex of abiotic and biotic factors is known to impact the establishment and success of biological control agents. Experiments using the ephydrid fly Hydrellia pakistanae Deonier have demonstrated that hydrilla, Hydrilla verticillata (L.f.) Royle, containing low protein content appears to impact larval development time and the number of eggs oviposited per female. Eggs per female were over ...

The phylogenetic composition of the epiphytic bacterial community of an invasive aquatic plant (Hydrilla verticillata) and a native species (Vallisneria americana [eelgrass]) of the Wakulla Spring (Florida) was investigated, along with the water column bacterial composition, using clone libraries of the 16S rRNA genes. The bacterial clones from three clone libraries were classified into 182 ope...

Hydrilla (Hydrilla verticillata) is one of the world's most problematic invasive aquatic plants. Although management of hydrilla overgrowth has often been based on use of chemical herbicides, issues such as the emergence of herbicide-resistant hydrilla biotypes and the need for in situ nutrient remediation strategies have together raised interest in the use of harvester machines as an alternati...

INTRODUCTION: Hydrilla verticillata (L.f.) Royle, a member of the Hydrocharitaceae, was introduced into Florida in the 1950’s (Schmitz et al. 1991). The introduction was the dioecious biotype with only gynoecious plants making up the original infestation. Today hydrilla has invaded at least 21 states either as dioecious or monoecious biotypes or both (Richardson 2008). Called “the perfect aquat...