ISSN:
1570-7458
Keywords:
integrated control
;
biological control
;
Brassica campestris
;
Nitidulidae
;
Finland
;
density dependence
;
mortality
;
fat reserves
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract High overwintering mortality was recorded forMeligethes aeneus in the field in Finland, ranging from 85 to 98% depending on the source of the overwintering population. The main factor explaining, variation in survival was the body weight of the beetles in the autumn: only the heaviest beetles survived. Body weight, on the other hand, was influenced by treatment of the rape field soil withBeauveria bassiana, resulting in a 50% decrease in winter survival compared with the reference. The soil treatment did not appear to have direct mortality effects (pathogenesis) on the beetle neither in the summer nor in the winter, and there was no apparent effect on survival of crowding of the insects at the overwintering site. Density dependence in overwintering survival ofM. aeneus may function through the availability of pollen food in the autumn, and intraspecific competition for it. Treatment of the rape field soil withB. bassiana may be a feasible way to increase, the winter mortality and to lower the pollen beetle populations, but requires further research.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02383433
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