FRIM Plant entomologist, Dave Moyo, told Zodiak Online on Saturday that using the natural resistant species is ideal to eradicate the blue gum Red gum lerp psyllid because it multiplies much higher than the population levels of the imported biological controls which are also expensive.

Moyo says for the past ten years, they have managed to reduce below the economic threshold two out of the three pests namely Bronze bug and Gall wasp through the biological controls which were imported from South Africa.

"The reason we are doing the species screening trials is to identify those species with natural resistance.

"Now officers are also on the ground monitoring the situation to ensure that the pests are contained. We are therefore calling upon blue gum farmers to be on alert and report to forestry offices once they have noticed an increase in pests’ population in their areas," Moyo said.

Professor of Forest Sciences at Lilongwe University of Agriculture and Natural Resources (LUANAR), Dr. Weston Mwase says the use of natural control enemies in reducing incidents of pests is very effective, only that it needs alot of commitment since it is long, expensive and not easy.

"It is effective, but not an easy approach, very expensive and involving, needs a lot of commitment that could be one of the challenges. But then that's one of the best methods in integrated pest management, rather than thinking of using some chemical insecticides," Dr. Mwase said.

It is reported that the pests have impacted negatively on the income of forest companies and smallholder farmers who rely on Blue gum trees for fuel-wood, household energy requirements and curing of tobacco.

Brown leaves and drying of trees are among common signs of blue gum trees attacked by the pests.