The Relationship between Primary Parasitoids and Hyperparasitoids of Cereal Aphids: An Analysis of Field Data

• DOI: 10.2307/5478
• Publication Date: 2006-06-17T15:49:08Z
• Authors: Carsten Holler; Christian Borgeme...; Helmut Haardt; Wilf Powell
• Keywords: Sitobion avenae

1. We analysed data collected in 1985-89 from cereal fields to elucidate the relationships between primary parasitoids and hyperparasitoids of aphids. The analysis aimed establish whether or not interfere with impact on aphid populations. 2. From more than 10000 parasitized aphids, 14 parasitoid 18 hyperparasitoid species were reared. five most common attacked parasitoids, which, turn, frequently abundant species, Sitobion avenae (F.). 3. Levels parasitism never exceeded 33%, whereas levels hyperparasitism often reached 100% latter part season. However, low rates could have been solely result hyperparasitism: if females which emerged early continued deposit eggs before collapse populations, those should numerous enough parasitize large numbers their hosts pressure became high. 4. hypothesize that leave areas develop high densities. A multiple linear regression model was used test hypothesis. observed declines quantitatively related density. 5. results this study additional theoretical considerations are favour above other factors such as mortality due attack, aestivation acting together may also contribute abundance later