Toward a push-pull strategy against invasive snails using chemical and visual stimuli.

Four invasive Mediterranean snails, i.e., Theba pisana (Müller, 1774), Cernuella virgata (da Costa, 1778), Cochlicella acuta (Müller, 1774) and Cochlicella barbara (Linnaeus, 1758) cost $170 million yearly to the grain industry in Australia.

Population-Specific Plant-To-Plant Signaling in Wild Lima Bean.

The exposure to volatiles from damaged plants can increase the resistance of the neighboring plants to herbivores. Studies have demonstrated that the strength of this response depends on the level of relatedness between the interacting plants. Indeed, a field study with found that the responses to induced volatiles were population-specific; individuals exposed to damaged conspecifics from the 'local' population exhibited greater resistance to herbivores than those exposed to damaged conspecifics from 'foreign' populations.

Can Estivation Preferences Be Used to Develop Novel Management Tools against Invasive Mediterranean Snails?

Terrestrial snails that live in hot and dry climates have developed strategies to cope with high summer temperatures. Several species estivate during the warmest months of the years by resting on vertical supports, typically in groups. Understanding how snails choose their estivation sites and aggregate may lead to the development of new management tools in areas where these snails are invasive.

A comparative study of plant volatiles induced by insect and gastropod herbivory.

Insect and gastropod herbivores are major plant consumers and their importance in the evolution of plant defensive traits is broadly recognized. However, their respective effects on plant responses have rarely been compared. Here we focused on plant volatile emissions (VOCs) following herbivory and compared the effects of herbivory by caterpillars of the generalist insect Spodoptera littoralis and by generalist slugs of the genus Arion on the VOCs emissions of 14 cultivated plant species.

Evolutionary changes in an invasive plant support the defensive role of plant volatiles.

It is increasingly evident that plants interact with their outside world through the production of volatile organic compounds, but whether the volatiles have evolved to serve in plant defense is still a topic of considerable debate. Unharmed leaves constitutively release small amounts of volatiles, but when the leaves are damaged by herbivorous arthropods, they emit substantially more volatiles. These herbivore-induced plant volatiles (HIPVs) attract parasitoids and predators that kill insect herbivores, and this can benefit the plants.

First Insights into the Chemical Ecology of an Invasive Pest: Olfactory Preferences of the Viburnum Leaf Beetle (Coleoptera: Chrysomelidae).

The viburnum leaf beetle (VLB), Pyrrhalta viburni (Paykull), is an invasive chrysomelid in North America where it infests native Viburnum shrubs in woody areas and managed landscapes. Despite its invasive and destructive nature, little is known about the chemical ecology of this beetle, and efficient chemical lures for monitoring and trapping this insect have yet to be developed. Using two of the main host plants of VLB in its native range, Viburnum opulus L.

Variation in Performance and Resistance to Parasitism of Populations.

Two major ecological factors determine the fitness of an insect herbivore: the ability to overcome plant resistance strategies (bottom-up effects) and the ability to avoid or resist attack by natural enemies such as predators and parasitoids (top-down effects). In response to differences in selection pressure, variation may exist in host-plant adaptation and immunity against parasitism among populations of an insect herbivore. We investigated the variation in larval performance of six different populations originating from four continents when feeding on a native Dutch plant species, One of the used populations has successfully switched its host plant, and is now adapted to pea.

Role of cyanogenic glycosides in the seeds of wild lima bean, Phaseolus lunatus: defense, plant nutrition or both?

Cyanogenic glycosides present in the seeds of wild lima bean plants are associated with seedling defense but do not affect seed germination and seedling growth. Wild lima bean plants contain cyanogenic glycosides (CNGs) that are known to defend the plant against leaf herbivores. However, seed feeders appear to be unaffected despite the high levels of CNGs in the seeds.

Molecular detection and quantification of slug parasitic nematodes from the soil and their hosts.

Terrestrial gastropod molluscs are widely distributed and are well known as pests of many types of plants that are notoriously difficult to control. Many species of nematodes are able to parasitize land snails and slugs, but few of them are lethal to their host. Species and/or populations of mollusc-parasitic nematodes (MPNs) that kill their hosts are promising for biological control purposes.

Trans-generational inheritance of herbivory-induced phenotypic changes in Brassica rapa.

Biotic stress can induce plastic changes in fitness-relevant plant traits. Recently, it has been shown that such changes can be transmitted to subsequent generations. However, the occurrence and extent of transmission across different types of traits is still unexplored.

The spitting image of plant defenses: Effects of plant secondary chemistry on the efficacy of caterpillar regurgitant as an anti-predator defense.

In the arms race between plants, herbivores, and their natural enemies, specialized herbivores may use plant defenses for their own benefit, and variation in plant traits may affect the benefits that herbivores derive from these defenses. is a specialist herbivore of plants containing glucosinolates, a specific class of defensive secondary metabolites. Caterpillars of are known to actively spit on attacking natural enemies, including their main parasitoid, the braconid wasp .

With or without you: Effects of the concurrent range expansion of an herbivore and its natural enemy on native species interactions.

Global climatic changes may lead to the arrival of multiple range-expanding species from different trophic levels into new habitats, either simultaneously or in quick succession, potentially causing the introduction of manifold novel interactions into native food webs. Unraveling the complex biotic interactions between native and range-expanding species is critical to understand the impact of climate change on community ecology, but experimental evidence is lacking. In a series of laboratory experiments that simulated direct and indirect species interactions, we investigated the effects of the concurrent arrival of a range-expanding insect herbivore in Europe, Spodoptera littoralis, and its associated parasitoid Microplitis rufiventris, on the native herbivore Mamestra brassicae, and its associated parasitoid Microplitis mediator, when co-occurring on a native plant, Brassica rapa.

Herbivore-induced plant volatiles accurately predict history of coexistence, diet breadth, and feeding mode of herbivores.

Herbivore-induced plant volatiles (HIPVs) serve as specific cues to higher trophic levels. Novel, exotic herbivores entering native foodwebs may disrupt the infochemical network as a result of changes in HIPV profiles. Here, we analysed HIPV blends of native Brassica rapa plants infested with one of 10 herbivore species with different coexistence histories, diet breadths and feeding modes.

Powdery mildew suppresses herbivore-induced plant volatiles and interferes with parasitoid attraction in Brassica rapa.

The co-occurrence of different antagonists on a plant can greatly affect infochemicals with ecological consequences for higher trophic levels. Here we investigated how the presence of a plant pathogen, the powdery mildew Erysiphe cruciferarum, on Brassica rapa affects (1) plant volatiles emitted in response to damage by a specialist herbivore, Pieris brassicae; (2) the attraction of the parasitic wasp Cotesia glomerata and (3) the performance of P. brassicae and C.

The Gastropod Menace: Slugs on Brassica Plants Affect Caterpillar Survival through Consumption and Interference with Parasitoid Attraction.

Terrestrial molluscs and insect herbivores play a major role as plant consumers in a number of ecosystems, but their direct and indirect interactions have hardly been explored. The omnivorous nature of slugs makes them potential disrupters of predator-prey relationships, as a direct threat to small insects and through indirect, plant-mediated effects. Here, we examined the effects of the presence of two species of slugs, Arion rufus (native) and A.

The Arabidopsis Pep-PEPR system is induced by herbivore feeding and contributes to JA-mediated plant defence against herbivory.

A number of plant endogenous elicitors have been identified that induce pattern-triggered immunity upon perception. In Arabidopsis thaliana eight small precursor proteins, called PROPEPs, are thought to be cleaved upon danger to release eight peptides known as the plant elicitor peptides Peps. As the expression of some PROPEPs is induced upon biotic stress and perception of any of the eight Peps triggers a defence response, they are regarded as amplifiers of immunity.

Floral volatiles interfere with plant attraction of parasitoids: ontogeny-dependent infochemical dynamics in Brassica rapa.

Background: The role of plant ontogeny on investment in direct defense against herbivores is well accepted, but the transition from the vegetative to the reproductive stage can also affect indirect resistance traits (i.e. attraction of the natural enemies of plant attackers).

Alien plants versus alien herbivores: does it matter who is non-native in a novel trophic interaction?

Introductions of both plants and herbivorous insects have had tremendous impacts on the world's ecosystems. Novel herbivorous insect-plant interactions are important consequences of introductions of either plants or herbivorous insects. We contrast novel herbivorous insect-plant interactions that arise due to plant versus insect introductions with the aim of understanding whether the causes and consequences of the interaction depend on which party is non-native.

Do plant defenses predict damage by an invasive herbivore? A comparative study of the viburnum leaf beetle.

The impact of plant defenses on insect herbivores is widely accepted, but their relative effects on oviposition choice, survival, and larval growth in preventing pest damage, especially for invasive insects, is not fully understood. Here, we examined the potential for plant defenses to reduce the economic and environmental impacts of an invasive herbivore, the viburnum leaf beetle, VLB (Pyrrhalta viburni), on Viburnum species in North America. We used a common garden with 15 host Viburnum species of North American, European, and Asian origin and evaluated oviposition preferences, twig defense against oviposition (a reaction that crushes VLB eggs), larval performance in the lab and field, and foliar damage to mature shrubs in two consecutive years.

Alien interference: disruption of infochemical networks by invasive insect herbivores.

Insect herbivores trigger various biochemical changes in plants, and as a consequence, affect other organisms that are associated with these plants. Such plant-mediated indirect effects often involve herbivore-induced plant volatiles (HIPVs) that can be used as cues for foraging herbivores and their natural enemies, and are also known to affect pollinator attraction. In tightly co-evolved systems, the different trophic levels are expected to display adaptive response to changes in HIPVs caused by native herbivores.

Herbivory and floral signaling: phenotypic plasticity and tradeoffs between reproduction and indirect defense.

Plant defense against herbivores may compromise attraction of mutualists, yet information remains limited about the mechanisms underlying such signaling tradeoffs. Here, we investigated the effects of foliar herbivory by two herbivore species on defense compounds, floral signaling, pollinator and parasitoid attraction, and seed production. Herbivory generally reduced the quantity of many floral volatile organic compounds VOCs) in Brassica rapa.

Switched after Birth: Performance of the Viburnum Leaf Beetle [Pyrrhalta viburni (Paykull)] after Transfer to a Suboptimal Host Plant.

Host plant switching is common among phytophagous insects. Once optimal food sources have been depleted, immature insects may resort to use of suboptimal hosts in order to complete their development. Such host switching may have dramatic consequences for insect fitness.

Oviposition strategy as a means of local adaptation to plant defence in native and invasive populations of the viburnum leaf beetle.

Herbivores have been hypothesized to adapt locally to variation in plant defences and such adaptation could facilitate novel associations in the context of biological invasions. Here, we show that in the native range of the viburnum leaf beetle (VLB, Pyrrhalta viburni), two populations of geographically isolated hosts-Viburnum opulus and Viburnum tinus-have divergent defences against VLB oviposition: negative versus positive density-dependent egg-crushing wound responses, respectively. Populations of beetles coexisting with each host show an adaptive behavioural response: aggregative versus non-aggregative oviposition on V.

Evolutionary history predicts plant defense against an invasive pest.

It has long been hypothesized that invasive pests may be facilitated by the evolutionary naïveté of their new hosts, but this prediction has never been examined in a phylogenetic framework. To address the hypothesis, we have been studying the invasive viburnum leaf beetle (Pyrrhalta viburni), which is decimating North American native species of Viburnum, a clade of worldwide importance as understory shrubs and ornamentals. In a phylogenetic field experiment using 16 species of Viburnum, we show that old-world Viburnum species that evolved in the presence of Pyrrhalta beetles mount a massive defensive wound response that crushes eggs of the pest insect; in contrast, naïve North American species that share no evolutionary history with Pyrrhalta beetles show a markedly lower response.

Pupation by Viburnum leaf beetle (coleoptera: chrysomelidae): behavioral description and impact of environmental variables and entomopathogenic nematodes.

Pyrrhalta viburni (Paykull), a new landscape pest in the United States, feeds in both the larval and adult stages on foliage of plants in the genus Viburnum. The insect is univoltine, with larvae active in spring and adults throughout the summer months. Experiments were conducted to determine the depth of pupation in the soil; the impact of substrate texture, moisture content, and temperature on pupation success; and ability of entomopathogenic nematodes to kill larvae when they enter the substrate to pupate.