Female Medfly Found in Sun Valley Close to Area Targeted Earlier

The war on the Mediterranean fruit fly spread to a new area of the eastern San Fernando Valley on Wednesday after a female fly was found in a trap north of Interstate 5 and below the Verdugo Mountains.

Officials with the state and federal Cooperative Medfly Project, which is overseeing the eradication effort, said they are considering whether to order aerial pesticide-spraying to begin later this month over an area up to 15 square miles.

The unmated, female fly was discovered in a trap in a lemon tree on residential property in Sun Valley, according to project officials, who are battling Southern California’s worst-ever Medfly infestation. Aerial spraying now covers an area of 300 square miles, mainly in Los Angeles County.

Medfly project officials said the location of the discovery is just outside the North Hollywood spray zone, which is scheduled to be treated Monday. But project official Dorthea Zadig said there probably is not enough time to draw up the boundaries of any new treatment zone before next week. As a result, the new zone would not be sprayed for the first time until late this month, if a decision to spray is made.

The latest find of a female fly just outside a previous spray zone continues a pattern that has baffled scientists associated with the state and federal Medfly project. The scientists believe they should be trapping more males and that it is curious that so many recent fly finds have occurred close to the borders of previous spray zones.

The pattern led members of the project’s Scientific Advisory Panel of Medfly experts, which is consulting with the Medfly project, to speculate in a private meeting in early December that so-called “biological terrorists” may be purposely spreading the fly. A letter threatening that action was sent to Mayor Tom Bradley in November by a group calling itself the Breeders.

The letter said the group was angry over the aerial spraying.

Scientists also are unable to fully explain why they have not found larvae in large quantities in the infestation areas. A larva is an immature stage of the Medfly. For an infestation as large as this one, scientists think there should be more larvae.

So far, most of the larvae found have been near Whittier, where some of the experts think the infestation began in late September.

One important difference between this and previous discoveries, is the fact that the fly found Wednesday near Burbank was an immature, unmated female. The discovery of a mated female is an automatic trigger for spraying. But in cases of so-called satellite infestations, spraying can be ordered without the finding of a mated female.

Medfly project officials said that because Wednesday’s find was so close to another spray area, the new zone could be considered a satellite infestation. BATTLING THE MEDFLY Los Angeles County will conduct aerial spraying of malathion tonight. Area: 48 square miles encompassing Bell, Cudahy, Huntington Park, Lynwood and parts of Athens, Bell Gardens, Commerce, Compton, East Los Angeles, South Gate, Vernon, Walnut Park and Watts, from 9 p.m. to 3 a.m. Precautions: Stay indoors; keep animals indoors; wash animal dishes and toys left outside; cover cars; keep doors and windows closed. Information: Toll-free numbers for the Agricultural Commissioner: (800) 356-2894; (800) 225-1346.