[Edited_by_A._Ciancio,_C.N.R.,_Bari,_Italy_and_K.(Bookos.org)

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R. CAMPOS-HERRERA ET AL.
highest on the central ridge (2.4), with significantly fewer (1.7) in the central
flatwoods. To date, H. indica is the only species that has been encountered in
significant numbers in the coastal flatwoods. A propensity for H. indica to occupy
coastal habitats also has been noted in other parts of the Caribbean Basin (Fisher-Le
Saux, Mauléon, Constan, Brunel, & Boemare, 1998; Mauléon, Denon, Briand, 2006).
Little is known about the direct effects of soil physical and chemical properties
on the population biology of the Diaprepes root weevil. However, the various
findings reviewed above provide evidence for the hypothesis that patterns of D.
abbreviatus within and among Florida citrus orchards are partly regulated by the
ways in which soil properties affect the natural enemies of D. abbreviatus. More
explicitly, they suggest that EPNs might help regulate D. abbreviatus on the central
ridge to the extent that it is often a minor pest, whereas reduced EPN predation in
some flatwoods orchards may permit D. abbreviatus populations to attain highly
damaging levels. If the natural control of D. abbreviatus by endemic EPNs varies in
different regions of Florida, then understanding how these habitats influence EPN
diversity and efficacy could be especially worthwhile by indicating strategies for
conservation biological control through the manipulation of habitats to enhance the
biocontrol potential of EPNs.
Table 1. The frequency (% of samples) and average dominance (population density
as a percentage of all EPN in the sample) a of five entomopathogenic nematodes in
citrus orchards, in three regions of Florida b .
Species
Steinernema
diaprepesi
Ridge Central Flatwoods Coastal Flatwoods
F D F D F D
100 36 57 29 0 0
S. riobrave 0 0 5