New morphological key using male prothoracic leg characters to identify Helicoverpa (Lepidoptera: Noctuidae) species

Abstract

Since invasion of Helicoverpa armigera (Hübner) in South America, identification of Helicoverpa species became essential for Integrated Pest Management (IPM). Thus, we worked out on a pictorial key to identify tree important Helicoverpa species that occur in the Southern Cone of America, using new morphological characters from the prothoracic legs. Adult male and female of Helicoverpa zea (Boddie), H. armigera, and Helicoverpa gelotopoeon (Dyar) were used for identification. Prothoracic legs from moths were removed and images were taken (magnification of 25X) with scales and specialized scales. In addition, images (magnification of 50X) of prothoracic legs were used to measure the foretibia and epiphysis. The results showed that measurable characters were more reliable and accurate on male moths than female moths. For this reason, we will show only detailed results of male moths. Foretibia of H. zea were longer than H. gelotopoeon, but shorter than H. armigera. This size is visible with or without scales and specialized scales on males. Here, we show a first detailed description of protibial epiphysis. H. armigera has the longest epiphysis with fore margin pointed and with bristles terminating before the end of epiphysis. This illustrated pictorial key shown some first detailed descriptions of prothoracic legs. These characters are useful on integrated pest management programs of many crops to identify male representatives of Helicoverpa, which are captured on pheromone traps.