Adult phenology and abundance of Froggatt's apple leafhoppper (Edwardsiana froggatti (Baker)) (Hemiptera: Cicadellidae) and its egg parasitoids, Anagrus spp. (Hymenoptera: Mymaridae), under three pest management programmes in Central Otago, New Zealand

• Published in: New Zealand entomologist 2011-02, Vol.34 (1), p.56-64
• Main Authors: Wearing, C. H., Attfield, B., Colhoun, K.
• Format: Article
• Language: English
• Subjects: Abundance; Adults; Agrochemicals; Anagrus; Anagrus spp; Biological control; Cicadellidae; Crop production; Damage; Edwardsiana froggatti; Egg laying; Egg production; Eggs; Hemiptera; Hymenoptera; Insecticides; integrated pest management; leafhopper; Malus; Management; Mymaridae; Natural enemies; organic production; Parasitoids; Pest control; Pests; Phenology; pipfruit; Populations; Seasons
• ISSN: 0077-9962; 1179-3430
• DOI: 10.1080/00779962.2011.9722210

Froggatt's apple leafhopper, Edwardsiana froggatti (FALH), is a minor pest of apples in New Zealand. The eggs are attacked by several species of the mymarid genus Anagrus. The phenology of the leafhopper and these parasitoids in Central Otago has not been previously described. Leafhopper and Anagrus spp. adults were monitored with sticky traps in apple blocks under conventional, integrated, and organic management at the Clyde Research Centre from 1995 to 2001. The leafhopper had two generations per year and timing was similar to that reported for Canterbury and Nelson, with first generation adults occurring each season from the end of November to the end of January, and the second generation from the end of January to late April/May. Apart from a small number of Anagrus spp. adults that emerged in October/early November, the first generation began at the end of November, coinciding with the start of adult FALH flight and hence egg-laying, and continued to late February. The second generation began shortly after this and continued through to May. In addition to the evident synchrony between Anagrus spp. flight and leafhopper egg production, the trap catches indicated a strong numerical response of Anagrus spp. to rising leafhopper populations following the removal of organophosphate insecticides under integrated fruit production. This contributed to circumstantial evidence that, after 3-4 seasons, these parasitoids were the primary natural enemies that reduced leafhopper populations below economically-damaging levels; this was supported by similar evidence from apple blocks under organic management. Further research is needed to confirm this evidence of biological control by Anagrus spp., and the roles of the different species in the apple-growing regions of New Zealand.