Abstract
The life cycle, within-field distribution, crop damage and impact of natural enemies of the potato tuber moth, Phthorimaea operculella (Zeller) were investigated in two potato cropping systems. The two systems differed in soil type (sandy vs. loess) which in turn affected the choice of cultivars, irrigation programme, insecticide application method (ground vs. aerial), and planting and harvest times. From mid-April to the end of May, almost twice as many moths were caught in pheromone traps in sandy than in loess fields. Highest infestation of tubers was found before harvest, and infestation was greater in loess than in sandy fields. Larval densities in foliage and tubers were significantly higher at the margins of the fields than in the centre. A significant positive correlation was found between adult catch and larval infestation on foliage in sandy fields but not in loess. Tuber infestation in sand was positively correlated with foliage infestation. No such correlation was detected in loess. Five parasitic wasps emerged from P. operculella larvae collected from commercial fields and volunteer plants: Diadegma pulchripes (Kokujev) and Temelucha decorata, (Gravenhorst) (Ichneumonidae) and Bracon gelechiae Ashmead and two other unidentified Braconidae. The most abundant predators at the field site were Coccinella septempunctata Linnaeus (Coccinellidae), Chrysoperla carnea Stephens (Chrysopidae), Orius albidipennis (Reuter) (Anthocoridae) and four ant species (Formicidae). Parasitism rate reached 40% and predation was estimated at 79%. Results are discussed with regard to the development of an integrated pest management programme for this important pest.
Original language | English |
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Pages (from-to) | 309-315 |
Number of pages | 7 |
Journal | Bulletin of Entomological Research |
Volume | 90 |
Issue number | 4 |
DOIs | |
State | Published - 2000 |
Bibliographical note
Funding Information:We thank S. Cohen (Hebrew University) and A. Kadmon (Alon Agriculture Ltd) for help with fieldwork; R. Yonah for the help in manuscript preparation; Drs K. Horstmann (Zoologisches Insitut, Wurzburg, Germany) and J. Papp (Hungarian Natural History Museum, Budapest, Hungary) for the identifications of Ichneumonidae and Braconidae, respectively; and Alon Agriculture Ltd for the provision of pheromone traps. The study was supported in parts by the Israel Ministry of Agriculture, and USAID-CDR (grant TA-MOU-C14–126).