Comment: NOTE: It is very important to obtain accurate measurements and a detailed view of the underside of individuals in this genus, showing the shape of the subgenital plates or pregenital sternite. There are three members of this genus that have been recorded in North Carolina, and a fourth species that could possibly be found here (C. robusta whitcombi, which has been recorded in Georgia). It can be very challenging to identify individuals of this genus. For example, females of accola cannot be distinguished from agricola, and distinguishing the males can be challenging too; however, accola is typically smaller and darker in color (though agricola can get quite dark too). See below for info on how to distinguish these species, taken from Hamilton 1998.
accola- males 2.3-2.6 mm long, females 2.5-3.0 mm. Males have very short subgenital plates. Female pregenital sternite indistinguishable from agricola.
agricola- males 2.6-3.1 mm long, females 2.8-3.3 mm. Adults tawny with brown markings usual for genus; coronal maculae and scutellar angles black. Some individuals can be very dark. Has long wings that extend past the abdomen. Female pregenital sternite indistinguishable from accola. Only whitcombi has male subgenital plates as long and as strongly tapered as agricola.
robusta whitcombi- males 2.3-3.0 mm long (usually 2.5-2.7 mm), females 2.5-2.8 mm. Males tawny with brown markings usual for genus; female pale, with brown veins. Only agricola has subgenital plates as long and as strongly tapered as whitcombi, but agricola has longer wings.
vulgaris- adults 2.5-3.0 mm long. Pregenital sternite half as long as wide. |