The present study evaluated the taxonomy, morphology, and molecular variation of the egg parasitoids Paracentrobia subflava developing within eggs of the corn leafhopper Dalbulus maidis from Mexico, and Paracentrobia tapajosae developing within eggs of Tapajosa rubromarginata and eggs of D. maidis from Argentina. The parasitoids from the different host species were found to have a significant difference in body size and morphology of head, wings, ovipositor, and chaetotaxy. On the other hand, geometric morphometric analysis of the male genitalia showed no difference between parasitoids emerged from T. rubromarginata and D. maidis. Additionally, the COI and ITS2 molecular markers demonstrated that the parasitoids emerging from these two different hosts cluster into a single clade. This new information suggests the placement of P. tapajosae syn. nov. as a junior synonym of P. subflava.

A new Mexican leafhopper species, Amblysellus ravgozai sp. nov., is described and illustrated from western Mexico. Specimens were collected over perennial grasses. A key for all recognized species within the country is provided.

Summary Ufens niger (Ashmead) (Hymenoptera: Trichogrammatidae) is reported for the first time as an egg parasitoid of the corn leafhopper, Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae), which is one of the most important pests of maize in the Americas. In addition, eggs of D. maidis were found to be parasitized also by Anagrus nigriventris Girault (Hymenoptera: Mymaridae) for the first time in Mexico. Ufens niger was found in 2016 in El Grullo and A. nigriventris was found in 2013 in Zapopan; both sites are in Jalisco State in central Mexico. Sumario Por primera vez se reporta a Ufens niger (Ashmead) (Hymenoptera: Trichogrammatidae) atacando los huevos de la chicharrita del maíz Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae), quien es una de las plagas más importantes del maíz en el continente Americano. Además, se reporta por primera vez a Anagrus nigriventris Girault (Hymenoptera: Mymaridae) atacando los huevos de D. maidis en México. Ufens niger se encontró en 2016 en el Grullo y A. nigriventris se encontró en 2013 en Zapopan, ambos sitios están en el Estado de Jalisco, México.