Mexican fruit fly. Click the image for more
information about it.
Post-Harvest Orchard Cleanup May Deter Mexican
Fruit Flies By Alfredo Flores July 12, 2002
Research shows that grapefruit growers can help reduce the danger of
Mexican fruit fly infestation by removing all fruit remaining in trees and on
the ground after harvest. Lacking this fruit, wild Mexican fruit flies will
have to leave the area to find food and places to lay their eggs, and may die
This finding comes from Agricultural Research Service entomologists
David Robacker and Ivich Fraser at the Kika de la Garza Subtropical Agricultural
Research Center in Weslaco, Texas. The Mexican fruit fly plays havoc with
citrus crops in Texas, California, Florida, Mexico and Central America.
Ten-year losses from the pest in South Texas and northern Mexico alone have
been estimated at almost $7 billion from treatment costs, reduced crop yields,
export sanctions and lost markets.
The damage occurs when fruit fly larvae feed on the grapefruit pulp,
ruining the fruit for human consumption. But what perplexes scientists is that
theres new evidence that these flies do not naturally recognize
grapefruit as a host. Robacker and Fraser have investigated the factors that
attract the pest to an egg-laying site. Findings of how the fly perceives and
reacts to its environment will help in developing better monitoring and control
The researchers compared the responses of laboratory-raised and
wild-strain fruit flies when exposed to grapefruit. Before testing lab-raised
flies, Robacker placed grapefruit in cages with the flies for several days.
Later, those females were 400 percent more attracted to the fruit than were
flies without previous exposure.
This suggests that wild-strain Mexican fruit fly adults are likely to
feed on whatevers nearby when they emerge from the ground. So quick
removal of fallen grapefruit might send the pest searching for other, less
ARS is the U.S. Department of
Agricultures chief scientific research agency.