Causes of macrophyte mass development and management recommendations.

Aquatic plants (macrophytes) are important for ecosystem structure and function. Macrophyte mass developments are, however, often perceived as a nuisance and are commonly managed by mechanical removal. This is costly and often ineffective due to macrophyte regrowth.

Where are the seeds? Lack of floral morphs prevent seed production by the tristylous in South Africa.

Reproduction is a crucial part of the successful establishment and spread of an invasive species. Invasive plants often produce seeds prolifically to spread into new ranges, yet the invasive macrophyte, L., does not appear to produce seeds in South Africa, limiting its invasive potential.

Mind the gap: the delayed recovery of a population of the biological control agent Berg. (Hemiptera: Delphacidae) on water hyacinth after winter.

Cold winter temperatures significantly affect the biological control effort against water hyacinth, Pontederia ( = Eichhornia) crassipes Mart. (Pontederiaceae), in more temperate regions around the world. The population dynamics of the planthopper Megamelus scutellaris Berg.

Modeling Top-Down and Bottom-Up Drivers of a Regime Shift in Invasive Aquatic Plant Stable States.

The evidence for alternate stable states characterized by dominance of either floating or submerged plant dominance is well established. Inspired by an existing model and controlled experiments, we conceptually describe a dynamic that we have observed in the field using a simple model, the aim of which was to investigate key interactions of the shift between invasive floating and invasive submerged plant dominance, driven by the rapid decomposition of floating plants as a consequence of herbivory by biological control agents. This study showed that the rate of switch between floating and submerged invasive plant dominance, and the point in time at which the switch occurs, is dependent on the nutrient status of the water and the density of biological control agents on floating plant populations.

Two in one: cryptic species discovered in biological control agent populations using molecular data and crossbreeding experiments.

There are many examples of cryptic species that have been identified through DNA-barcoding or other genetic techniques. There are, however, very few confirmations of cryptic species being reproductively isolated. This study presents one of the few cases of cryptic species that has been confirmed to be reproductively isolated and therefore true species according to the biological species concept.

Unraveling the biogeographic origins of the Eurasian watermilfoil (Myriophyllum spicatum) invasion in North America.

Premise Of The Study: Using phylogeographic analyses to determine the geographic origins of biological invaders is important for identifying environmental adaptations and genetic composition in their native range as well as biocontrol agents among indigenous herbivores. Eurasian watermilfoil (Myriophyllum spicatum) and its hybrid with northern watermilfoil (M. sibiricum) are found throughout the contiguous United States and southern Canada, forming one of the most economically costly aquatic plant invasions in North America, yet the geographic origin of the invasion remains unknown.