The family Pseudococcidae or mealybugs (Hemiptera) are common pests in tropical region of the world and also considered as important pests on ornamental plants and fruit trees. The mealybug faunas in Cambodia and Laos were known to nineteen species and eight species, respectively (ScaleNet, 2014; CABI, 2015; FAO-IPM, 2014). Recently, we have collected thirteen mealybug species in Cambodia and Laos. Among them, seven species of mealybug are found for the first time: Phenacoccus solani (Ferris, 1918) and Rastrococcus iceryoides (Green, 1908) in Cambodia; Dysmicoccus neobrevipes (Beardsley, 1959) and Phenacoccus solenopsis (Tinsley, 1898) in both counties; Paracoccus invectus (Williams, 2004), Planococcus minor (Maskell, 1897) and Pseudococcus jackbeardsleyi (Gimpel & Miller, 1996) in Laos.

 ,  , Aleurolobus marlatti (Quaintance), Massilieurodes formosensis (Takahashi), and Pealius rhododendri Takahashi were found for the first time in Korea. This study provides a brief summary and photographs of the major characters of these species and an updated identification key to the whitefly species known to occur in Korea.

 ,  , The Indian wax scale, Ceroplastes ceriferus (Fabricius) is redescribed so that it can be distinguished from Ceroplastes pseudoceriferus Green, which it most nearly resembles and has been confused with in Korea. A dichotomous key, photographs, and DNA barcode information are also presented for identifying three Ceroplastes species from Korea.

 ,  , Two pupillarial species, Cryptoparlatorea leucaspis Lindinger and Fiorinia japonica Kuwana, are recorded for the first time in Korea. Both species were found on coniferous trees, Cryptomeria japonica and Torreya nucifera. Also an identification key, brief diagnoses, and photographs of Korean pupillarial species are provided to assist in their identification.

Two species of the genus Andaspis, Andaspis crawii (Cockerell) and Andaspis kashicola (Takahashi) are newly recorded in the Korean fauna of armored scales (Diaspididae). A key to species of Andaspis, illustrative photographs and information on the distribution and hosts of each species, are also provided to identify the specimens of Andaspis collected in Korea.

The legless mealybug, Antonina nakaharai Williams and Miller (Hemiptera: Pseudococcidae) is recorded from bamboos (Poaceae) in Korea. An identification key to adult females of three species of Antonina from the Korean Peninsula is also provided.

DNA barcoding uses a 650 bp segment of the mitochondrial cytochrome c oxidase I (COI) gene as the basis for an identification system for members of the animal kingdom and some other groups of eukaryotes. PCR amplification of the barcode region is a key step in the analytical chain, but it sometimes fails because of a lack of homology between the standard primer sets and target DNA. Two forward PCR primers were developed following analysis of all known arthropod mitochondrial genome arrangements and sequence alignment of the tRNA-W gene which was usually located within 200 bp upstream of the COI gene. These two primers were combined with a standard reverse primer (LepR1) to produce a cocktail which generated a barcode amplicon from 125 of 141 species that included representatives of 121 different families of Hexapoda. High quality sequences were recovered from 79% of the species including groups, such as scale insects, that invariably fail to amplify with standard primers. The current results show that primers designed to bind to highly conserved gene regions upstream of COI will aid the amplification of this gene region in species where standard primers fail and provide valuable information to design a primer for problem groups.

Although DNA barcode coverage has grown rapidly for many insect orders, there are some groups, such as scale insects, where sequence recovery has been difficult. However, using a recently developed primer set, we recovered barcode records from 373 specimens, providing coverage for 75 species from 31 genera in two families. Overall success was >90% for mealybugs and >80% for armored scale species. The G·C content was very low in most species, averaging just 16.3%. Sequence divergences (K2P) between congeneric species averaged 10.7%, while intraspecific divergences averaged 0.97%. However, the latter value was inflated by high intra-specific divergence in nine taxa, cases that may indicate species overlooked by current taxonomic treatments. Our study establishes the feasibility of developing a comprehensive barcode library for scale insects and indicates that its construction will both create an effective system for identifying scale insects and reveal taxonomic situations worthy of deeper analysis.

Thirteen species of mealybugs were intercepted in quarantine at Korean ports of entry on plant materials from China over the past 9 years (2000-2009). Of these, Phenacoccus madeirensis Green has been newly reported in China through this study. This list and key are provided to assist in identifying intercepted specimens of mealybugs from China.

Aleuroclava aucubae (Kuwana) and Aleuroclava euryae (Kuwana) are newly recorded in the Korean fauna of whiteflies (Aleyrodidae). A key to species of Aleuroclava is also provided with illustrative photographs.

Because mealybugs are one of the most economically damaging groups of insects on food crops and ornamental plants, some are regulated-species in quarantine with the foreign trade of agricultural products. However, the absence of morphological characteristics enabling the discrimination of early life stages often causes a significant delay or the rejection of a shipment when fruit is discovered containing them, causing much economic loss. A PCR-based method for species identification was developed for six mealybug species known from Korean pears including two regulated insects, Planococcus kraunhiae (Kuwana) and Crisicoccus matsumotoi (Siraiwa). Six sets of species-specific primers were designed based on the sequence comparison of the internal transcribed spacer 1 and 2 regions. Efficiency tests against many mealybug samples showed that this method could effectively discriminate different mealybug species regardless of their developmental stages. Blind tests against 11 field collected mealybug nymph samples indicated that a single PCR is enough to discriminate unidentified mealybugs collected on Korean pears. This new method will be useful in quarantine as well as pest monitoring by providing an easy, accurate way of identifying any life stage of these mealybugs.

Seventy two species of armored scale have been recorded from the Korean peninsula since late 1920s. Nine of these species were obtained from greenhouses. Of these 9 armored scale species, 7 species are considered to have failed to colonize fields or greenhouses and 2 species, which were collected from pineapple plants, Tillandsia plants and cactus trees in greenhouses, were never taken from the exterior environment.