The Application of DNA Barcodes for the Identification of Marine Crustaceans from the North Sea and Adjacent Regions

During the last years DNA barcoding has become a popular method of choice for molecular specimen identification. Here we present a comprehensive DNA barcode library of various crustacean taxa found in the North Sea, one of the most extensively studied marine regions of the world. Our data set includes 1,332 barcodes covering 205 species, including taxa of the Amphipoda, Copepoda, Decapoda, Isopoda, Thecostraca, and others. This dataset represents the most extensive DNA barcode library of the Crustacea in terms of species number to date. By using the Barcode of Life Data Systems (BOLD), unique BINs were identified for 198 (96.6%) of the analyzed species. Six species were characterized by two BINs (2.9%), and three BINs were found for the amphipod species Gammarus salinus Spooner, 1947 (0.4%). Intraspecific distances with values higher than 2.2% were revealed for 13 species (6.3%). Exceptionally high distances of up to 14.87% between two distinct but monophyletic clusters were found for the parasitic copepod Caligus elongatus Nordmann, 1832, supporting the results of previous studies that indicated the existence of an overlooked sea louse species. In contrast to these high distances, haplotype-sharing was observed for two decapod spider crab species, Macropodia parva Van Noort & Adema, 1985 and Macropodia rostrata (Linnaeus, 1761), underlining the need for a taxonomic revision of both species. Summarizing the results, our study confirms the application of DNA barcodes as highly effective identification system for the analyzed marine crustaceans of the North Sea and represents an important milestone for modern biodiversity assessment studies using barcode sequence

A temperature-based model for predicting the immigration of Cacopsylla melanoneura and C. picta, vectors of the apple proliferation disease, in South Tyrol, Northern Italy (Hemiptera: Psylloidea)

: Insects in temperate regions usually emerge in spring, based on climatic cues. Temperature-based models that predict the first flight onset of pest insects in crop fields are therefore useful tools for agriculture and crop protection. Here, we calibrate and apply such a temperature-based model for Cacopsylla melanoneura and Cacopsylla picta (Hemiptera - Psyllidae) in South Tyrol, Northern Italy. These psyllid species are the main vectors of apple proliferation, an economically important phytoplasma disease. We found that the temperature associated with the onset (first presence) of the insects in the orchards differs between vectors and between different regions. For the regions Burggrafenamt and Vinschgau, the first adults of Cacopsylla melanoneura remigrants mostly occurred in January while first Cacopsylla picta remigrants mostly occurred in the orchard between March and April. The presented temperature-based immigration model may be used as a tool to predict the first vector appearance in apple orchards in South Tyro