The present study aimed at evaluating the
host-specificity, potential efficacy and optimum
densities of the two weevils (Neochetina
bruchi
and
N. eichhorniae)
as water hyacinth control agents in the Rift
Valley of Ethiopia. Density-plant damage
relationship was monitored for two years (2012
to 2014) in a factorial experiment by involving
the two
Neocthenia
weevils and four densities of herbivory. Feeding
multiple-choice and oviposition tests were used
to assess the two weevils host specificity. The
study showed highly significant (P<
0.01) impacts of the two weevils as well as,
their interactions on number of ramets, number
of leaves, damaged leaf area, petiole length,
number of defoliated petioles and biomass of
water hyacinth. Damaged leaf area (97%) and
total number of defoliated petioles (2.8) were
highest in plants that received three pairs of
N. bruchi
and two pairs of
N. eichhorniae.
The weevil density and water hyacinth biomass
showed convex relationship that could be
well-described by a negative log function
(R2=0.98). The study confirmed that the weevils
are sufficiently host-specific and therefore can
be safely released in the Rift Valley of
Ethiopia to control water hyacinth.
This is an open access article
published under the terms of the
Creative Commons Attribution
License, which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is
properly cited.
Cite this article as:
Firehun Y, Struik PC, Lantinga EA, Taye T
(2016). Pre-Release Evaluation of Neochetina
Weevils Potential for the Management of
Eichhornia Crassipes [Mart.] Solm. In The Rift
Valley of Ethiopia. Acad. J. Agric. Res. 4(7):
394-403.
