Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2007
Publication Date: 12/1/2007
Citation: Virla, E.G., Cangemi, L., Logarzo, G.A. 2007. Suitability of different host plants for nymphs of the sharpshooter Tapajosa rubromarginata (Hemiptera:Cicadellidae:Proconinii). Florida Entomologist. Pages 766-769
Interpretive Summary: As natural enemies of glassy winged sharpahooter (GWSS) cannot control this pest, a survey of natural enemies has been conducted on leafhoppers closely related to GWSS in South America. During the studies, serious difficulties were found in rearing the South American sharpshooter in the laboratory delaying the progress of these studies. The objective was to test the viability of immatures of the main South American sharpshooter reared on sweet orange, corn, bermuda grass, rescuegrass, bur clover, cowpea, and a combination of mint plus oat as an attempt to determine a suitable substrate to rear this sharpshooter. Only two substrates were suitables allowing immatures to reach adult stage: cowpea and the combination of mint plus oat. However, based on the number of immatures that survived and reached the adult stage, cowpea was the most suitable substrate for rearing immatures of the main South American sharpshooter in the laboratory.
Technical Abstract: The glassy-winged sharpshooter (GWSS), Homalodisca vitripennis (Germar) has become a major pest in California primarily as a vector of Xylella fastidiosa, a bacteria that causes severe diseases to grapes. Owing to the uncertainty of the effectiveness of egg parasitoids native to California against GWSS, a neo-classical biological control approach is ongoing. The survey of natural enemies is conducted on leafhoppers closely related to the target pest in South America. In 2000, egg parasitoids of Tapajosa rubromarginata, a sharpshooter closely related to GWSS, were sought in regions in South America where climate types and habitats were similar to California. Difficulties in rearing these insects in the laboratory have been a barrier in the study of the pest and particularly its egg parasitoids. It is known that in the field, nymphs and adults have different nutritional requirements alternating host plant as a survival mechanism. Apparently, only a few host plants support the development of nymphs to maturity. In this study we tested the viability of nymphs of T. rubromarginata reared on sweet orange, corn, bermuda grass, rescuegrass, bur clover, cowpea, and a combination of mint plus oat as an attempt to determine a suitable substrate to rear this sharpshooter. We recorded a high mortality of the newly emerged nymphs maintained with rescuegrass, sweet orange, corn, Bermuda grass and bur clover. Nymphs successfully reached the adult stage only eating on cowpea plants and the combination of mint plus oat. Based on the observed survival rate and the number of individuals that reached the adult stage, cowpea was the most appropriate substrate for rearing T. rubromarginata in the laboratory.