nutritional indices of the willow leaf beetle, plagiodera versicolora laicharting, third instar larvae and adults were studied on four host plants including salix alba l., salix aegyptica l., populus caspica bornm.and populus alba l.at 22 ± 2 ºc, 70 ± 10% r.h., and a photoperiod of 16:8 h (l: d). the results showed that the highest consumed food by the larvae and adults (148.5 ± 18.0 and 175.21...

BACKGROUND There is a general belief that insect outbreak risk is higher in plant monocultures than in natural and more diverse habitats, although empirical studies investigating this relationship are lacking. In this study, using density data collected over seven years at 40 study sites, we compare the temporal population variability of the leaf beetle Phratora vulgatissima between willow plan...

The questions of how the indirect interactions mediated by herbivore-induced plant responses influence trait evolution of herbivores have been poorly investigated. We previously demonstrated that allopatric populations of the willow leaf beetle, Plagiodera versicolora (Coleoptera: Chrysomelidae) could evolutionarily develop divergent preference, according to locally distinct intensity of induce...

1. Managed systems harvested at intermediate time-scales have advantages over annual short-cycled systems in maintaining top-down control of insect herbivores, and the flexible harvest regimes in these systems provide opportunities for habitat management that can stabilize predator–prey population dynamics across harvests – resulting in reduced risk of pest outbreaks. 2. In a large-scale field ...

We investigated the effects of soil nutrient and water availability on the growth and chemistry of the silky willow ( Salix sericea Marshall), and on the performance of the imported willow leaf beetle ( Plagiodera versicolora Laichartig). Our major aims were to determine whether there are nutrient–water interactions on plant traits and whether this leads to parallel interactions for herbivore p...

Ecological specialization is widely recognized as a major determinant of the emergence and maintenance of biodiversity. We studied two critical facets of specialization – local adaptation and habitat choice – in the host races of the leaf beetle Lochmaea capreae on willow and birch. Our results revealed that there is asymmetric disruptive selection for host use traits, and host races achieved d...

The high energy quota and versatility of use make willows (Salix spp.) attractive as bioenergy crops. Insect defoliation constitutes a threat to the profitability of willow growers. Hitherto, the breeding for resistance against the main insect pests has been hampered by the fact that all known resistant willow clones are polyploids, and existing molecular breeding tools work most effectively fo...

Current streambank restoration efforts focus on providing bank stability, enhancing water quality, and improving woody habitat using native vegetation rather than traditional engineering techniques. However, in most cases harsh site conditions limit restoration success. A two-year field study was conducted at Twentymile Creek, in northern Mississippi, investigating edaphic factors governing the...

Signal-based induced indirect defence refers to herbivore-induced production of plant volatiles that attract carnivorous natural enemies of herbivores. Relationships between direct and indirect defence strategies were studied using tritrophic systems consisting of six sympatric willow species, willow leaf beetles (Plagiodera versicolora), and their natural predators, ladybeetles (Aiolocaria hex...

willow leaf beetle, plagiodera versicolora is an important pest of willow trees that feeds on the leaves both as larvae and as adults. -amylases (ec 3.2.1.1) are the major insect digestive enzymes that catalyze the endohydrolysis of long -1,4-glucan chains such as starch and glycogen. in the current study, -amylase activity was studied in the midgut of larvae and adults of p. versicolora. am...