Scale insects threaten Davao lanzones industry-A A +A
Sunday, July 10, 2011
THERE is a marked decrease in lanzones production in Davao Region for the past two years, and experts said this could be attributed to the massive scale insects infestation in most lanzones orchards of the region.
In a survey entitled "Assessment of the prevalence and distribution of the Lanzones Scale insects in the Davao Region," conducted by Drs. Alfredo M. Cayabyab and Susan T. Razo, et al, it was found out lanzones plantations in the region are highly infested with the scale insects.
"Davao del Sur and Davao City registered the highest prevalence of the scale insects infestation, with 100 percent and 94 percent of the trees infested, respectively, followed by Davao Norte, Davao Oriental and Comval Province, with 74, percent, 72 percent, and 63 percent, respectively," Razo said during the recently conducted 24th Department of Agriculture (DA) In-House Research and Development Review at the Grand Men Seng Hotel, Davao City.
"Scale insects are insects that sucks the plant sap, reduces fruit quality and defoliates the lanzones trees," Razo said.
Razo also said that scale insects attack all types of varieties of lanzones, especially at the flushing and bearing growth stages of the plant. The growers, he added, do not know the appropriate technique on how to control the insects' population.
"At first, the growers resorted to chemical spraying as the best control method, but later on, when they observed lack of or lesser positive results, they began to doubt its effectiveness," Razo reported.
Razo then revealed a promising bio-control method of scale insect infestation using the black lady beetle.
"Black lady beetles are found to be effective natural enemies of scale insects, and we have made initial efforts along this line by allowing these beetles to reproduce in the laboratory and distributing the beetles in selected lanzones orchards in the Region," Razo said.
Experts further recommended the following in controlling the scale insects infestation: a combination of control methods such as pruning of trees and sanitation of surroundings; beefing-up the agricultural technicians' technical information regarding the control of scale insects and other pests infestations; and production of more natural enemies of the scale insects such as the black lady beetle or C. nigreta, to be released in the major lanzones plantations in the region, among others.
Scale insects assessment is just one of the 14 research studies presented during the in-house review sponsored by the DA-Southern Mindanao Integrated Agricultural Research Center, Bago Oshiro, Davao City.
Published in the Sun.Star Davao newspaper on July 11, 2011.