Sensitive detection and discrimination of stored-product pests of genus Liposcelis (Psocoptera: Liposcelididae) and Lepinotus (Psocoptera: Trogiidae)

Psocids of the genus Liposcelis (Psocoptera: Liposcelididae) are commonly associated with human dwellings, commodity stores, food and feed processing and storage facilities, and museums containing animal specimens. Psocids of genus Lepinotus (Psocoptera: Trogiidae) are known stored-product pests. Some species from these genera, namely, Liposcelis bostrychophila, L. decolor, L. brunnea, L. obscurus, L. pearmani, and Lepinotus reticulatus have emerged as serious stored-product pests in the last two decades. Conventional morphological discrimination of Liposcelis adults and immatures is difficult because of their small body size and expertise required for identification. A method for quick, accurate, and sensitive identification of stored-product psocid pest species would be extremely beneficial for pest management professionals during detection, identification, and management of pest outbreaks, and for plant health officials who inspect products from quarantined locations. Six specific PCR primer sets were designed targeting consensus sequences from multiple alignments of CO1 gene of Liposcelis species. Web-interface applications Primer3, mFOLD and BLASTn, and validated thermodynamic parameters were used during primer design. Exclusivity and inclusivity assays were also performed to confirm the high specificity of the primers. PCR products were cloned and sequenced to confirm identity. All primer sets allowed accurate detection of L. bostrychophila, L. decolor, L. brunnea, L. obscurus, L. pearmani, and L. reticulatus with amplicon size 204 bp, 242 bp, 140 bp, 100 bp, 115 bp, and 119 bp, respectively. The described PCR assays are accurate, rapid, sensitive, and useful for stored-product psocid pest detection and discrimination, and have applications in biosecurity and forensics.