Influence of the site of oviposition on the level of egg parasitism in the corn leafhopper, Dalbulus maidis (Hemiptera: Cicadellidae)

Abstract

The corn leafhopper Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae), transmits three important plant pathogens that adversely affect corn crop and ranges from the USA to Argentina. The vector has a rich natural enemy complex that generates high levels of parasitism, but its populations are persistent and prevalent. We characterized the oviposition sites of D. maidis on young corn plants in order to verify the hypothesis that the vector has an oviposition strategy for mitigating parasitism.Oviposition locations on plants were assessed in the laboratory and eggs within corn plants were exposed to natural parasitism in a cornfield. Eggs were located mostly laid in the unfolded leaves and were attacked by five parasitoid species. Parasitism was significantly affected by the class of leaf and the position of the egg in the leaf. Anagrus virlai Triapitsyn was the most abundant parasitoid species, which emerged significantly higher in the basal blade than other species. Our results suggest that leafhoppers minimize egg parasitism by laying their eggs within concealed locations on the plant.

Distribution of Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae) and incidence of maize rayado fino virus and Candidatus Phytoplasma asteris in corn succession planting systems

“…Corn plant forms a whorl during the vegetative stage, a funnel‐shaped structure used by the leafhoppers as shelter and food 30 . The whorl is a source of food and protection potentially advantageous to D. maidis at the beginning of the crop cycle 31 . Additionally, plant biochemical composition and its ability to produce defense compounds against herbivores changes according to its life cycle development, particularly in herb plants such as corn which can experience an increase in chemical defense throughout the life cycle 32–34 .…”

“…30 The whorl is a source of food and protection potentially advantageous to D. maidis at the beginning of the crop cycle. 31 Additionally, plant biochemical composition and its ability to produce defense compounds against herbivores changes according to its life cycle development, particularly in herb plants such as corn which can experience an increase in chemical defense throughout the life cycle. [32][33][34] Therefore, resource quality is lost in the final plant development stage, potentially harming D. maidis populations.…”

Population Dynamic of Hilda Cameroonensis Tamesse & Dongmo (Tettigometridae) Pest of Vernonia amygdalina Delile in Yaoundé-Cameroon

“…During the second year of study, we recorded also a positive and highly significant correlation for the number of eggs counted, 1 st instar larvae, and adults with the quantity of rainfall in our region (Tables 1 and 2). [19,20]. No significant difference was recorded between the numbers of eggs laid from one year to another; this result could reflect certain homogeneity of annual egg-laying by the female of H. cameroonensis on its host plant.…”

Miscelanea 152 (2024): Dalbulus maidis (Hemiptera: Cicadellidae), vector of corn stunt disease: Relevant biological aspects, with special reference to knowledge generated in Argentina

“…Estos datos, todos tomados en poblaciones del sur de Estados Unidos y México sugieren que el comportamiento de oviposición de D. maidis es prácticamente invariable. Sin embargo, en un reciente estudio (Luft Albarracín et al, 2021) se informó un comportamiento de oviposición diferente para poblaciones de la chicharrita del hemisferio sur, específicamente la llanura tucumana, con respecto a las poblaciones del hemisferio norte. En dicho trabajo se observó que la chicharrita despliega una estrategia distinta al ubicar sus huevos en diferentes partes de la planta, lo que le permite, en parte, evadir a sus parasitoides de huevos.…”