Evaluation of criteria for species delimitation of bagworm moths (Lepidoptera: Psychidae)

Abstract

Abstract. Accurate identification of species is fundamental for biological research and necessary for species conservation. DNA barcoding is particularly useful when identification using morphological characteristics is laborious and/or unreliable. However, barcodes for species are dependent on the availability of reference sequences from correctly identified specimens. The traditional use of morphology to delimit the species boundaries of Finnish bagworm moths (Lepidoptera: Psychidae: Naryciinae: Dahliciini) is controversial because there is overlap in their morphological characteristics. In addition, there are no suitable molecular markers. We verified the delimitation of seven out of eight previously described taxa, by using the currently standardized COI barcode and phylogenetic inference based on fragments of mitochondrial (COI) and nuclear genes (MDH). Moreover, we compared the results of molecular methods with the outcome of geometric morphometrics. Based on molecular identification, our findings indicate that there are five sexual species (Dahlica and Siederia spp.) and two parthenogenetic species (D. fennicella and D. triquetrella) in Finland. We suggest that molecular methods, together with geometric morphometrics of male genitalia are an effective way of delimiting species of bagworm moths.

Molecular-based estimate of species number, phylogenetic relationships and divergence times for the genus Stenotaenia (Chilopoda, Geophilomorpha) in the Italian region

“…Assuming a low barcoding gap (1–6% of K2P distances) would be in agreement with a threshold around 1% between intra- and inter-specific distances, as more frequently found and applied in a large assortment of animal taxa, including vertebrates and some groups of arthropods ( Ratnasingham and Hebert 2007 , Chevasco et al 2014 ). However, in this case we should conclude that (i) almost every single specimen in our small sample would actually represent a distinct species, (ii) some of these species separated as recently as a few hundred thousand years ago, and (iii) at least nine species of Stenotaenia actually inhabit the Italian region.…”

“…For delimiting species in our sample through a DNA-barcoding approach, we calculated the pairwise distances of the COI sequences between all 12 Stenotaenia specimens in two alternative ways, namely by K2P distances (which is a standard for DNA-barcoding; e.g., Hebert et al 2003 , Ratnasingham and Hebert 2007 , Chevasco et al 2014 ) and p-distances (which is also used in arthropods; e.g., Montagna et al 2013 ), treating gaps with partial deletion and estimating standard errors by 500 bootstrap pseudoreplicates. The software MEGA 6 ( Tamura et al 2013 ) was employed.…”

Pre- and post-mating reproductive barriers drive divergence of five sympatric species of Naryciinae moths (Lepidoptera: Psychidae)

“…Traditionally, morphological identification has been based on males with a combination of genital morphology (specifically, the phallus–valva length ratio), male wing‐scale shape and presence of epiphyses on foreleg tibia (Sauter, ; Hättenschwiler, ; Suomalainen, ; Pro Natura, ; Hauser, ; Palmqvist, ). However, in all characters overlap has been noted (Sauter, ; Pro Natura, ; Hauser, ; Palmqvist, ; Chevasco et al ., ). Indeed, a phylogenetic study showed that grouping based on mitochondrial DNA (mtDNA) did not correspond with grouping based on morphology (Grapputo, Kumpulainen & Mappes, ).…”

“…Five sexual species that co‐occur in the same habitats have been recognized in Finland based on mtDNA (cytochrome oxidase I and II, COI and COII) grouping (Elzinga et al ., , ), although only four species were known based on morphology (Suomalainen, ; Palmqvist, ). Indeed, reliable morphological distinction of these five groups has not yet been possible (Chevasco, ; Chevasco et al ., ). Furthermore, sequence divergence in mtDNA between some of these groups is quite limited (COI minimum 2.72% compared with 1.91% within species divergence, this study), which questions whether all five groups should really be considered separate species.…”

Manatha albipes Moore (Lepidoptera: Psychidae), an emerging pest of banana and arecanut in South India, with notes on diagnosis, biology, natural enemies and DNA sequence data

“…Several species of bagworms in the tropics are economically important pests of cultivated crops but their biology and ecology are not well understood due to their cryptic habits (Kamarudin et al, 1994;Firake et al, 2018). Bagworms are notoriously difficult to study in view of their complex and often extended life cycles with similar ecological characteristics and their identification is extremely difficult due to the presence of apterous females, remarkable external similarity and reliance on male genitalia as the most dependable diagnostic feature (Yen et al, 2004;Rhainds et al, 2009;Chevasco et al, 2014). Chevasco et al (2014) observed that overlapping morphological traits and absence of unique features makes the identification of species of bagworm moths extremely difficult and bagworm moths are good candidates for species identification using DNA barcoding, since morphological differentiation is minimal with poorly resolved taxonomy.…”