Habitat manipulation in lucerne (Medicago sativa L.): strip harvesting to enhance biological control of insect pests
-
Published source details
Hossain Z., Gurr G.M. & Wratten S.D. (2001) Habitat manipulation in lucerne (Medicago sativa L.): strip harvesting to enhance biological control of insect pests. International Journal of Pest Management (formerly PANS Pest Articles & News Summaries 1969 - 1975, PANS 1976-1979 & Tropical Pest Management 1980-1992), 47, 81-88.
Published source details Hossain Z., Gurr G.M. & Wratten S.D. (2001) Habitat manipulation in lucerne (Medicago sativa L.): strip harvesting to enhance biological control of insect pests. International Journal of Pest Management (formerly PANS Pest Articles & News Summaries 1969 - 1975, PANS 1976-1979 & Tropical Pest Management 1980-1992), 47, 81-88.
Actions
This study is summarised as evidence for the following.
Action | Category | |
---|---|---|
Leave part of the crop or pasture unharvested or uncut Action Link |
-
Leave part of the crop or pasture unharvested or uncut
A replicated, controlled trial in 1997-1998 in a 4 ha alfalfa Medicago sativa field with strip- and conventional-harvesting in New South Wales, Australia (Hossain et al. 2001) found that predation and parasitism of Helicoverpa spp. (pest) eggs was higher in unharvested (36.7% eggs predated, 3.31% parasitised) than harvested strips (21.7% eggs predated, 0.85% parasitised). Total predator abundance (spiders (Araneae), red and blue beetles Dicranolaius bellulus and transverse ladybird Coccinella transversalis) was higher in the strip-harvested area (average 5.1-9.1 predators/0.4 m²) than the conventionally-cut area (1.2-7.6), and higher in unharvested than harvested strips. Helicoverpa spp. was less abundant in the strip- than conventionally-harvested area (0.1-9.2 individuals/0.4 m² vs. 0.7-27.6) but another pest, lucerne leaf roller Merophyas divulsana had similar numbers in both treatments (0.3-18.4 vs. 0.1-19.0); both pests were more abundant in unharvested than harvested strips. There were eight 200 x 14 m strips, split lengthways; one half cut a week before normal harvesting (harvested strip), one half cut two weeks later (unharvested strip). Subsequently, strips were cut when 10% alfalfa was flowering. Strips were vacuum-sampled five times. Helicoverpa spp. eggs were placed in strips to assess predation and parasitism rates. The 112 x 158 m conventionally-harvested block was cut three times, with three vacuum samples.
Output references
|