DNABarcoding as useful tool to identify crop pest flea beetles of Turkey

Abstract

Flea beetles (Chrysomelidae: Galerucinae: Alticini), with ~8,000 species worldwide, include pest species causing substantial economic damage to crops. The genera Phyllotreta and Chaetocnema include both pest and non‐pest species. An accurate and fast taxonomic identification approach is required for discriminating among taxa for non‐expert taxonomists; moreover, the utility of this approach spans from biodiversity conservation to the monitoring of pest species. DNA barcoding represents a reliable and easy identification tool based on the use of short DNA sequences. In this study, 45 new COI sequences of 13 Phyllotreta and five Chaetocnema species, representing ~30% and ~20% of the Turkish species belonging to these genera, were provided. These sequences increased by ~18% and ~25% the number of species of these genera whose sequences are available in BOLD. In order to test DNA barcoding efficiency in Phyllotreta and Chaetocnema species identification, we created a data set consisting of sequences belonging to species present in the Middle East and available in BOLD plus the sequences developed in this study (36 species). The efficiency of species identification, estimated using best close match analysis (with the ad hoc calculated optimal distance threshold of 1.5%), was 99%. The overall intraspecific and interspecific mean nucleotide divergences were 1.4% and 20%, respectively. Interestingly, COI sequences of Phyllotreta nigripes clustered into two well‐separated groups with a high value of the between‐group nucleotide distance (11.4%), which suggests the presence of cryptic species. In addition, information was provided on the crops exploited by the collected organisms and the observed damage.

Cryptic, sibling or neither of the two? Integrative species delimitation ofPsylliodesflea beetles with overlapping ranges

“…The genetic distance threshold at cox1 between P. kiesenwetteri and P. ruffoi was estimated at 9%. This value is much higher than that found between related species of chrysomelids using either the same threshold estimation function (genus Longitarsus , localminima value: 5.4%, Salvi et al, 2020) or different threshold estimation functions (genera Chaetocnema and Phyllotreta , threshVal value: 1.5%, Coral Şahin et al, 2019; European Chrysomelids genera, threshVal value: 1%, Magoga et al, 2018). Indeed, the maximum intraspecific distance observed within P. kiesenwetteri and P. ruffoi was 4.5%, whereas their minimum interspecific distance was 14.3%.…”

Lack of Genetic Structure Among Populations of Striped Flea Beetle Phyllotreta striolata (Coleoptera: Chrysomelidae) Across Southern China

“…Apart from sequences obtained in this study, we searched orthologous cox1 gene sequences from the NCBI nucleotide database and included those with sampling locations in our phylogenetic analysis (Pentinsaari et al, 2014;Hendrich et al, 2015;Nie et al, 2017;Coral şahin et al, 2018;Lalrinfeli et al, 2019) (Supplementary Table 1). Sequences with obvious errors were deleted, and others were used for follow-up analysis.…”