Tiny insects, big troubles: a review of BOLD's COI database for Thysanoptera (Insecta).

DNA Barcoding is an important tool for disciplines such as taxonomy, phylogenetics and phylogeography, with Barcode of Life Data System (BOLD) being the largest database of partial cytochrome c oxidase subunit I (COI) sequences. We provide the first extensive revision of the information available in this database for the insect order Thysanoptera, to assess: how many COI sequences are available; how representative these sequences are for the order; and the current potential of BOLD as a reference library for specimen identification and species delimitation. The COI database at BOLD currently represents only about 5% of the over 6400 valid thrips species, with a heavy bias towards a few species of economic importance. Clear Barcode gaps were observed for 24 out of 33 genera evaluated, but many outliers were also observed. We suggest that the COI sequences available in BOLD as a reference would not allow for accurate identifications in about 30% of Thysanoptera species in this database, which rises to 40% of taxa within Thripidae, the most sampled family within the order. Thus, we call for caution and a critical evaluation in using BOLD as a reference library for thrips Barcodes, and future efforts should focus on improving the data quality of this database.

Population structure and genetic diversity in Gynaikothrips uzeli (Thysanoptera: Phlaeothripidae): is there a correlation between genetic and geographic proximity?

Gynaikothrips uzeli (Thysanoptera: Phlaeothripidae) is a minuscule insect species, which forms galls, is subsocial, and parthenogenetic. It is associated with Ficus benjamina L. (Moraceae) and has a pantropical occurrence. The paucity of genetic studies on the order Thysanoptera led us to use inter-simple sequence repeat molecular marker to assess intra- and inter-gall, as well as intra- and inter-site, genetic variability and population structure of G. uzeli. Analyses indicated low genetic variability, probably related to haplodiploidy, genetic drift, the galling habit, and the low dispersal ability of G. uzeli. Populations were highly structured, with higher variation within populations than among them. Geographic distance does not appear to affect structure and genetic diversity, the latter being influenced by G. uzeli's bioecological traits, by numerous introductions during a short period, and by a possible recent, common ancestry.

Guerothrips moundi, gen. et sp.n. (Thysanoptera, Thripidae) from Chiapas, Mexico.

Guerothrips moundi gen. et sp. n., (Thripidae, Thripinae) is described from flowers of the herbaceus plant Waltheria indica (Sterculiaceae) found in Tapachula, Chiapas, Mexico. G. moundi is a member of the Frankliniella genus-group, but is distinguished by the presence of sternal discal setae on the abdomen. The available specimens are all brachypterous.

Population structure and genetic diversity analysis in Gynaikothrips uzeli (Zimerman, 1909) (Thysanoptera: Phlaeothripidae) by RAPD markers.

Thrips are small insects (0.5-3.0 mm) with distinct habits and life histories characterized by haplodiploid sex determination. In general, low levels of genetic diversity have been reported in haplodiploid insects, although most reports focus on the order Hymenoptera. Therefore, we used RAPD markers to evaluate the structure and both inter- and intra-population genetic variability of Gynaikothrips uzeli (Thysanoptera: Phlaeothripidae). Six populations, three from Paraná state, southern Brazil, and three from Bahia, northeastern Brazil, were studied. Similarly to other haplodiploid insects, the genetic diversity of G. uzeli was reduced. This result is putatively related to the haplodiploid sex determination system, which yields little genetic variation, and to ecological traits of the studied species, such as the low dispersal abilities and life mode in leaf galls. All individuals were homogeneously clustered in their respective collection sites, forming two main groups in which populations from similar environments were more closely related. The analyzed populations were highly structured, and the genetic variation was higher among than within populations.