Plagiodera

Abstract: From a survey of the toxins produced by the pronotal and elytral defensive secretions in 114 chrysomeline species (20 genera sensu Daccordi 1994), three major groups of species are recognized which are considered as natural supra-generic taxa. These ensembles, however, do not perfectiy fit existing classifications (e.g. Daccordi in Seeno and Wilcox 1982 or Daccordi 1994). Species secreting isoxazoHnone glucosides esterified by nitropropanoic acid are considered as Chrysomelina se/isu stricto which includes so far Chrysomek, Unaeidea, Plagiodera, Gastrophysa, Phaedon (including Hydrothassd), Prasocuris, Phaedonia and Phratora. This supra-generic taxon is supported by larval characters, i.e. serial defensive glands, and by mtDNA phylogeny. The co-occurrence of serial glands in larvae and the adult toxins is so constant that the existence of serial glands in larvae is enough to qualify beetles as members of this taxon (e.g. Mesoplatys or Gastrolina). However, Colaspidema is excluded from it. Species secreting cardenoHdes or polyoxygenated steroids are considered as ChrysoHnina sensu stricto, including so far Chrysolina {sensu Daccordi 1994), Ambrostoma, Zjgogramma, Cosmogramma, Calligrapha and Stihdes. Polyoxygenated steroids are only secreted by members of three Chrysolina subgenera, Sphaeromela, Hjpericia and Chalcoidea, which could be raised to disinct genera. Species secreting triterpene saponins are considered as Doryphorina sensu stricto, including so far Platjphora, l^ptinotarsa, luibidomera and Desmogramma. While the classification proposed here is based on a restricted number of genera, we believe it may be useful in the building of a new and more natural classification of chrysomeline leaf beetles.

Abstract: An artificial diet was developed for labortory rearing of the cottonwood leaf beetle, Chrysomela scripta F., and the imported willow leaf beetle, Plagiodera versicolira (Laicharting). To reduce microbial contamination of the media, procedures were developed for the separating egg masses and sterilizing egg surfaces. Cottonwood leaf beetle larvae reared from neonate to adult on this artificial diet had greater mortality, took longer to develop, and were smaller than larvae reared on fresh poplar foliage. Adult longeviety was similar for both diet-and foliage-reared larave. Survival and adult fresh weight of imported williow leaf beetle larave reared on the artificial diet were similiar to those of the cohorts reared on fresh poplar foliage. However, individuals reared on artificial diet took longer to develop and produced shorter-lived adults than cohorts reared on the foliage. Larvae of both species would not eat fresh foliage after being fed on the artificial diet. Adults of both species maintained on the artificial diet laid few eggs but resumed normal oviposition when fed fresh foliage. This artificial diet proved useful for rearing larvae and maintaining adults during perios when fresh foliage was limited.

Abstract: This article continues the study on leaf-beetles subfamily Chrysomelinae of the Latvian fauna (Bukejs 2009) and contains faunistical, ecological and bibliographical information on 10 genera: Leptinotarsa Chevrolat, 1836, Colaphus Dahl, 1823, Gastrophysa Chevrolat, 1836, Phaedon Dahl, 1823, Hydrothassa Thomson, 1866, Prasocuris Latreille, 1802, Plagiodera Chevrolat, 1836, Linaeidea Motschulsky, 1860, Entomoscelis Chevrolat, 1836 and Timarcha Latreille, 1829.