Overwintering Biology of Egg Parasitoids of Dalbulus maidis (Hemiptera: Cicadellidae) on Perennial Grasses, Volunteer Maize, Stubble, and Drip-Irrigated Maize

Abstract

Dalbulus maidis (DeLong & Wolcott) (Hemiptera: Ciaadellidae) is the most important leafhopper vector of maize plant pathogens in the Americas. However, until now, no study has investigated the overwintering biology of its egg parasitoids. The objective in this study was to find egg parasitoids of D.maidis in perennial grass, volunteer maize, stubble, and drip-irrigated maize habitats in the winter season. Two-week-old D. maidis females were allowed to oviposit on young maize plants for 72 h under laboratory conditions. The oviposited healthy D.maidis eggs (sentinel eggs) on the young maize plants were exposed to natural parasitism maintained on perennial grasses, volunteer maize, and stubble 2 mo after the onset of winter, and on perennial grasses, volunteer maize, and drip-irrigated maize at the end of winter. The abundance of D. maidis adults in these habitats was also determined. Two months after the start of winter, D.maidis eggs were parasitized by the wasp Oligosita sp. from perennial grasses and volunteer maize, whereas at the end of winter, the eggs were parasitized by the wasps Oligosita sp. and Anagrus columbi Perkins from perennial grasses, volunteer maize, and drip-irrigated maize. Overall, more adult parasitoids of D. maidis eggs were found on perennial grasses. Adult corn leafhoppers were absent from perennial grasses at the end of winter; however, other Deltocephalinae leafhopper species were present, suggesting that egg parasitoids of D. maidis use another leafhopper host during winter. Furthermore, adults of five Deltocephalinae species were parasitized by dryinids and strepsipterans throughout the 2012–2013 winter in perennial grasses.

Diversity and Density-Dependence Relationship between Hymenopteran Egg Parasitoids and the Corn Leafhopper (Hemiptera: Cicadellidae) in Maize Agroecosystem vs. Teosinte Wild Habitat

“…Emerged (Triapitsyn 2015;Hill et al 2019). Previous studies found a complex of multiple species of egg parasitoids that attack D. maidis on sentinel maize plants in maize crops cultivated in Mexico, Central America, and South America (Virla et al 2009;Moya-Raygoza et al 2012Moya-Raygoza & Becerra-Chiron 2014;Triapitsyn 2015;Luft Albarracin et al 2017). In accordance with the present study, these studies also found A. virlai (which first was identified as Anagrus breviphragma Soyka [Hymenoptera: Mymaridae] and then as A. incarnatus) and Paracentrobia sp.…”

Egg Parasitoids ofDalbulus maidis(Hemiptera: Cicadellidae) Within Maize Agroecosystems and in the Edge Zones of Maize Fields, and on Maize Varieties During the Wet Season in Mexico

“…Seasonal maize habitats are very common in tropical America, but little is known about the egg parasitoids that attack corn leafhoppers within maize fields and in their edge zones during the wet (growing) season. It has been previously reported that parasitoids attack the eggs ( Moya-Raygoza and Becerra-Chiron 2014 ), nymphs, and adults ( Becerra-Chiron et al 2017 ) of the corn leafhopper in edge habitats throughout the winter, when the maize crop is absent. In the present study, we found that once maize is planted during the wet season, egg parasitoids attacking D. maidis eggs are most abundant in the maize field and almost absent affecting the abundance of egg parasitoids on the edges, because it is possible that parasitoid species are abundant affecting eggs of another leafhopper species in the edges.…”

“…In central Mexico, corn leafhopper adults disperse temporally from November to January to green grasses that inhabit the maize field edges ( Pinedo-Escatel and Moya-Raygoza 2015 ) or move to volunteer maize, uncultivated maize found during winter in several countries of the Americas ( Summers et al 2004 , Carloni et al 2013 , Oliveira et al 2013 ). Edge grasses and volunteer maize are overwinter habitats for D. maidis egg parasitoids such as Mymaridae and Trichogrammatidae species ( Moya-Raygoza and Becerra-Chiron 2014 ).…”

Effect of the Oviposition Period and Age of the Females of Dalbulus maidis (Hemiptera: Cicadellidae) in the Emergence of Egg Parasitoids

“…The parasitoid wasps Anagrus columbi Perkins and Anagrus virlai Triapitsyn (both Hymenoptera: Mymaridae) (Triapitsyn 1997) are found abundantly in maize fields (Moya-Raygoza & Becerra-Chiron 2014;. They are solitary and have short life cycles (Meyerdirk & Moratorio 1987;Corbet & Rosenheim 1996), take approximately 17 d to develop, and the average life expectancy of adults is 5 d, whereas few adults survive more than 12 d (Virla 2001).…”