Residents in Boalkhali upazila of Chattogram are in a state of panic following giant mealybug infestation in the area for the past several days.

The pest, originating in Africa, is a small, oval-shaped insect that attacks trees and feeds on tree-sap during warm weather, said experts.

The recent heatwave triggered the mealybug attack, affecting a large number of trees in wards 8 and 9 under Boalkhali Municipality, Pachim Gomdandi, Gulzarpara, Samdar Talukdar Bari, Char Khidirpur, and Bande Ali Masjid areas, according to upazila agriculture officials.

This year, the bugs are considerably larger than previous year, said the officials, suggesting people to use pesticides to kill the bugs.

Locals said the bugs were also seen crawling up houses, shops and even Gulzarpara Government Primary School building.

"The affected areas have a previous record of giant mealybug infestation. Due to the heatwave, the bugs come out in large numbers, and disperse away after rainfall," said Durga Pada Deb, deputy agriculture officer in the upazila.

"This year, we have noticed that the bugs are bigger than the previous year and have infested big trees including those on the roadsides. At night, it releases a kind of fluid from its body that can cause itching to human skin. We have already told people to use pesticides to kill the bugs," he also said.

"However, individual effort cannot curb the pests. We need collaboration. We have informed our senior officers and mayor in this regard. Research should be done to prevent further attack of the pests," he added.

Earlier, giant mealybugs were reported to be found in Dhaka's Cantonment, Farmgate and Khamarbari areas and in some places in Panchagarh, Thakurgaon and Dinajpur districts during a survey in 2011. It made newspaper headlines again in 2014 following an outbreak at Home Economics College in the capital.

"After the rains on Sunday, the bugs disappeared. We are spreading pesticide to prevent further attack. We have already informed the UNO, agriculture and district livestock departments," said Md Jahrul Islam, mayor of Boalkhali municipality.

Contacted, Dr Md Shahidul Islam Khan, chief scientific officer of Regional Agricultural Research Station, said they were unaware about the matter.

"If we are informed, we will send our team to research," he added.