Strymon melinus Hubner is a gorgeous butterfly and a crop pest. The names we give species not only describe the species, but also describe us. Such is the case with this species. The North American Butterfly Association (NABA), publisher of American Butterflies and Butterfly Gardner, in their checklist of North American Butterflies calls this species the Gray Hairstreak. The Entomological Society of America (ESA), publishers of: The Journal of Integrated Pest Management, Journal of Economic Entomology, and Arthropod Management Tests (among others) calls this species the Cotton Square Borer. NABA has named the adult, The ESA has named the larvae. Of course, the name that Hubner gave the species refers to both.
In this instance, common name committees did not recognize each others authority to decide the common name. Both names have faults: numerous hairstreaks are mostly gray and the NABA committee gives the name Scrub-hairstreak to other members of the genus Strymon; the ESA common name does not recognize the fact that this insect feeds on developing fruits of many members of the Malvaceae – in addition to plant species in many other families and has a geographic range far greater than cotton in North America.
Strymon melinus: it is not that hard to say or spell and it communicates precisely the insect to which you are referring – whether it is crop pest or beautiful adult.