Blue willow beetle
Species of beetle
From Wikipedia, the free encyclopedia
The blue willow beetle (Phratora vulgatissima), formerly Phyllodecta vulgatissima, is a herbivourous beetle of the family Chrysomelidae. It is dark with a metallic sheen that ranges from a blue color to bronze. It is distinguished from P. vitellinae by the latter more commonly displaying bronze coloration. European Phratora species can be distinguished based on morphology of female genitalia.[1] The larvae undergo three instar stages from hatching to pupation.[2] This beetle is found throughout Europe and Scandinavia,[3] and occurs in China.[4]
| Blue willow beetle | |
|---|---|
| |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Coleoptera |
| Suborder: | Polyphaga |
| Infraorder: | Cucujiformia |
| Family: | Chrysomelidae |
| Genus: | Phratora |
| Species: | P. vulgatissima |
| Binomial name | |
| Phratora vulgatissima | |
Ecology
The blue willow beetle is found on willow (Salix) species, whose leaves contain low levels of salicylates[5][6] in fens, carrs and on river banks, but also often in willow short rotation coppice and other agricultural landscapes.[7] It often aggregates on host plants.[8] On Salix cinerea, it prefers and is more common on female than male trees despite higher egg predation exerted by the common flowerbug Anthocoris nemorum on female trees.[9] It is univoltine in Sweden[2] but can produce multiple generations per year in other parts of its distribution range.[10] Proliferation of larvae and egg production varies with vegetation.[11] It overwinters under lichens on trees and under tree bark.[12] Predators of blue willow beetle eggs include A. nemorum and Orthotylus marginalis. Larval predators include A. nemorum, the bug Rhacognathus punctatus,[10] a syrphid fly (possibly Parasyrphus nigritarsis)[13] and the wasp Symmorphus bifasciatus.[14] Adult beetles are parasitized by the wasp Perilitus brevicollis[15] and consumed by R. punctatus.[13]
As a pest
In Europe, the blue willow beetle can become a severe herbivore pest on willows.[16] For plantations of common osier (Salix viminalis), herbivory reducing biomass production by up to 40% has been estimated.[17] It is susceptible to Bacillus thuringiensis tenebrionis and also Spinosad when treatment is applied to affected plants.[18]