Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/12/2015
Publication Date: 5/29/2015
Citation: Solis, M.A., Metz, M., Scheffer, S.J., Lewis, M.L., Kula, R.R., Springer, T.L. 2015. A new cryptic species of Diatraea (Lepidoptera: Crambidae: Crambinae) feeding on eastern gama grass and a novel host association with a braconid (Hymenoptera) in the United States. Annals of the Entomological Society of America. DOI:10.1093/aesa/sav049.
Interpretive Summary: The southern cornstalk borer (SCB) is a pest of corn (Zea mays L.) in the southern United States to Mexico. It is also pest of sorghum, Johnsongrass, and sugarcane. A new species was discovered feeding on eastern gama grass that has been residing cryptically as the southern cornstalk borer. Morphological and molecular characters support its status as a new species. We confirm specimens from Kansas, Oklahoma, and Texas, but its distribution may be as broad as that of eastern gama grass. All the life stages are described and illustrated, and a novel host association with wasp parasitoid is reported. These results will be useful to biological control workers, farmers, and conservationists.
Technical Abstract: The genus Diatraea currently consists of seven species in the United States, including Diatraea crambidoides (Grote), an economic pest of corn. Larvae of D. crambidoides are also reported to feed on sorghum (Sorghum bicolor (L.) Moench.), Johnsongrass (Sorghum halepense (L.) Pers.), sugar cane (Saccharum officinarum L.), and are confirmed here to also feed on eastern gama grass (Tripsacum dactyloides (L.)L. in Maryland. A new species, Diatraea mitteri Solis, was discovered feeding on eastern gama grass on the proaxis phytomer or root/shoot and has been residing cryptically as D. crambidoides. Morphological and molecular characters support its status as a new species. Neighbor-joining analysis resulted in two distinct clades corresponding to D. crambidoides and D. mitteri. We confirm specimens from Kansas, Oklahoma, and Texas, but its distribution may be as broad as that of eastern gama grass. All the life stages are described and illustrated. A novel host association, Alabagrus imitatus Cresson (Hymenoptera: Braconidae), as a parasitoid of D. mitteri is reported.