Figure 1.
Collection of specimens through a pheromone-based gypsy moth surveillance program.
A, Pheromone trap and B, trapped and damaged Lymantria dispar specimen (LMHRG001-06) (image A from USDA APHIS PPQ Archive, USDA APHIS PPQ, Bugwood.org).
Figure 2.
Barcode region of the cytochrome oxidase I (COI) gene.
The barcode region spans 658 base pairs near to the 5′ end of the COI gene and includes the two diagnostic restriction enzyme sites of the ‘NB system’ of Bogdanowicz et al. [24], referred to as N and B. An additional monomorphic NlaIII site is found in the 5′ region of the gene fragment and therefore a NlaIII enzyme digest of the barcode region would result in two (N−) or three (N+) bands (instead of 1 or 2 bands).
Table 1.
Key to the ‘NB system’ routinely used for gypsy moth diagnostics.
Figure 3.
Maximum likelihood tree for 36 species of Lymantria.
Tree was constructed with the barcode region of the COI gene for 518 individuals. The number of specimens collapsed into a single node is given in parentheses after the taxon name. Bootstrap support values >50% are listed above the corresponding node. Width of the triangles represents the sequence divergence within the cluster. Refer to Figure S1 for full tree.
Figure 4.
Combined histograms of pairwise Kimura 2-Parameter (K2P) sequence variation.
Blue vertical bars show intraspecific divergences for the 20 species of Lymantria with multiple individuals and green vertical bars show the interspecific divergences between all 36 species.
Figure 5.
Neighbour-joining tree of the gypsy moth Lymantria dispar.
Tree was constructed with 244 sequences of the COI barcode region. BOLD process IDs and collection localities are provided for each sequence. Surveillance specimens are denoted by a moth symbol.
Table 2.
Assignment of random and surveillance individuals to species and sub-species.
Figure 6.
Simulated gel electrophoresis for two restriction fragment length polymorphism assays.
The barcode region assay amplifies a ∼690 bp fragment, whereas the Bogdanowicz et al [24] assay amplifies ∼380 bp. The presence (+) or absence (−) of the NlaIII and BamHI restriction sites are provided for each assay, as described in the text. The digest and electrophoresis simulations were performed with New England BioLabs NEBcutter V2.0 (http://tools.neb.com/NEBcutter2).