A review on DNA barcoding for identification of insects

Spite the limitations of classical classification causes many Arthropods especially insect are not identified yet, Investigation of Biodiversity, Description, taxonomy and systematic of different living organisms like insects have been done with emphasis on morphological and behavioral characters since the time of Karl Linneaus about 250 years ago. In recent years DNA barcoding provides an alternative tool for species identification based on a short DNA sequence diversity.DNA barcoding is generally considered as a novel, rapid, accurate, reliable, cost-effective and easy molecular identification tool with a wide applicability across metazoan taxa especially insect. DNA barcoding has established as a mature field of biodiversity sciences filing the conceptual gap between traditional taxonomy and different fields of molecular systematics and have recently been proposed as solutions to the crisis of taxonomy. The method provide a framework for the taxonomy of poorly known groups and comprise large numbers of notorious pest species whose identification often requires highly specialized taxonomic skills and evenly  determine cryptic species. As well as it could be very useful to routinely identify difficult taxa of economic and medical importance.  In addition, DNA barcoding could be pivotal for the identification of certain life stages (e.g. eggs, larvae, nymphs or pupae), which are often impossible to identify otherwise. However, despite these highly positive claims, DNA barcoding also seems to suffer from a number of potential limitations when used for the identification of insects. The recent speciation, the prevalence of paraphyly and the regular interspecific hybridisation in many insect taxa, as well as their often poorly-established taxonomy and their high degree of infection by endosymbiotic bacteria such as Wolbachia  may all negatively affect the performance of insect DNA barcoding. Even more importantly, the reliability of insect DNA barcoding may be questioned because insects include >1,000,000 described species and probably millions of still undescribed taxa. This exuberant species richness may, indeed, severely constrain the ability of the DNA barcode reference databases to adequately represent the overwhelming insect taxonomic diversity. According to mentioned stated content, Integration of Molecular methods like DNA barcoding  is suitable to identify living organism especially insect.