New Zealand Journal of Ecology (1992) 16(2): 69- 75

Honeydew standing crop and production over 24 hours in Nothofagus solandri forest in Canterbury

Research Article
Dave Kelly  
David J. Stirling  
Gavin R. Hunt  
Claire L. Newell  
Christine E. Jarvis  
  1. Plant and Microbial Sciences, University of Canterbury, Christchurch 1, New Zealand

The standing crop and daily production of honeydew by Ultracoelostoma brittini on Nothofagus solandri: var solandri was measured on 28-29 August 1990 near Oxford, Canterbury. In 64 quadrats of 125 cm², all 740 active individual insects were mapped by their anal threads and honeydew production was recorded every three hours over 24 hours. Mean production of honeydew per insect over 24 hours was 0. 1 69 mul, but ranged from zero (4% of all active insects) to 11.5 mul. Standing crop Peaked just after dawn, and production was apparently higher at night. Removing drops every three hours and covering the quadrats to exclude animals had no significant effect on honeydew production. The greatest variation was between the 16 trees. Ultracoelostoma densities were higher on trees with higher daily honeydew production per insect. The honeydew production per unit area over 24 hours represented 3.2 to 23.0 times the standing crop, depending on what time of day the latter was measured; for the daylight samples, production was 11.5 times the mean standing crop.