With the widespread introduction of the nitrogen-fixing legume sesbania, Sesbania sesban (L.) Merril, in agroforestry systems, the defoliating beetle Mesoplatys ochroptera Stål has become a serious pest of the trees in Africa. To determine within-field and within-plant spatial distribution of M. ochroptera on both seedlings and trees of sesbania, distribution statistics were computed using Iwao's mean crowding regression model. In 1- to 3-mo-old seedlings, the model accounted for 29.8, 32.2, and 61.0% of the variation observed in mean crowding to mean relationships in egg masses, larvae and adults, respectively. The model slopes of the regression were greater than unity for all stages indicating aggregated spatial distribution. Values of the intercept were greater than zero for egg masses, larvae and adults indicating that the basic components of the population are groups of individuals. The highest density (>80%) of mating and feeding adults was found in the upper third of 1- to 2-mo-old seedlings, while most of the egg masses were found in the lower half of seedlings. In trees, >60% of the individuals of all stages were found in the lower third of the foliage canopy, while
DOI:
https://doi.org/10.1603/0022-0493-95.2.499Puntuación Altmetric:
Dimensiones Recuento de citas:
Año de publicación
2002
Autores
Sileshi G W; Baumgartner J; Sithanantham S; Ogol C K P O
Idioma
English
Palabras clave
sesbania sesban, sampling, spatial distribution
Geográfico
Zambia
