Morphological and Physiological Traits Associated with Agromyzid (Diptera: Agromyzidae) Resistance in Mungbean

Abstract

Morphological and physiological characters of three resistant and two susceptible mungbean accessions were studied to understand the nature of their resistance to agromyzid flies. The highly resistant accession had high trichome density on leaves and stems, purplish and smaller diameter sterns, and smaller unifoliate leaves. Agromyzid adults showed lower preference for visiting seedlings of resistant compared with susceptible accessions for feeding and oviposition, which were significantly positively correlated with insect infestation. Pupation of the agromyzid was delayed when larvae were feeding inside stems of resistant compared with susceptible accessions. Plant tissues of resistant accessions damaged by agromyzid feeding had significantly fewer larvae and pupae compared with similar tissues of the susceptible accessions. Larvae of Porthesia taiwana Shiraki and Heliothis armigera Hubner had greater mortality and reduced pupation when fed unifoliate leaves of resistant compared with susceptible mungbean accessions. A combination of several characters appears to be responsible for resistance.