DUBAI Dirty homes in multi-level residential buildings render pest control treatments useless, even as cockroaches develop resistance to commonly-used pesticides, experts said.
“When one unit in a multi-level building is treated at a time, the treatment is virtually ineffective,” said Santhosh Balachandran, an expert at Dubai-based EHS Consultants, which provides pest-control advice to businesses and pest-control firms.
“A piecemeal treatment is expensive in the long term,” he added. This, he explained, is partly due to the ability of cockroaches to multiply rapidly or lay eggs in crevices or areas that cannot be reached by pesticides. Or they take refuge in the next unit.
Millions of dollars have been spent on developing better pesticides, but more resistant cockroach strains have emerged, he said, citing certain strains of the German cockroach — known carriers of pathogenic micro-organisms — that have developed resistance to most common pesticides.
“When pest-control professionals use the same methods again and again, these creatures develop an ability to fight them off or absorb them in their system,” said Balachandran.
A Rutgers University study in 2004 found a German roach strain with a high level of resistance to common gel baits. Further research in Malaysia and the US showed that roaches are able to change the way they respond to gels. Female cockroaches are also found to possess a greater resistance to poisonous baits.
The best solution is actually quite simple — but ironically also the hardest to follow.
Cleanliness best defence
“The first step and the best form of pest-control is to keep your premises clean,” Dr El Mahi El Talib Gubran, a toxicologist at Dubai Municipality’s Public Health Pest Control Section, told XPRESS.
Dr Gubran said cleanliness is man’s best defence against infestation, and the starting point for any integrated pest management (IPM). However, when XPRESS called up 10 pest-control firms and all of them said no thorough clean-up of the house was required before treatment. “If there are too many cockroaches, we use both gel and spray. You stay out and come back after three hours, open the windows, mop it (chemical spray) out — and that’s it,” said a staff at a Dubai pest-control firm.
Pest-control companies charge between Dh150 for treating a one-bedroom unit and Dh500 for a villa, with many offering warranties of up to six months.
Sharjah resident Mansour Mohammad, however, complained that such warranties are worthless as roaches turn up within three months or less.
A pesticide warranty is deceptive, explained Balachandran. “Roaches — the only creatures reportedly able to withstand a nuclear winter — also use nature for their protection. When a mother cockroach lays eggs, up to 40 cockroaches are contained inside an ootheca, a capsule-like membrane. This membrane is selectively permeable, sort of like the amniotic fluid that protects a baby inside a mother’s womb. It allows only oxygen in and keeps toxins out.”
This is why, he said, a pesticide bombardment won’t have any effect. When handled improperly or by untrained hands, the chemicals can lead to lethal consequences: In 2011 seven people — including five-month-old twins — died in Dubai and the northern emirates.
While many pest-control firms recommend gel baits, roaches can develop resistance over time to these. “Pesticide resistance is a biological reality,” said Dinesh Ramachandran, Dubai-based technical director of National Pest Control (NPC), one of the biggest pest-control organisations in the UAE. “A quick-fix solution does not work, that’s why we don’t give warranties,” he said.
Lack of training
The other problem is employing untrained hands or the do-it-yourself pest control medicines available off the supermarket shelve. “Simply using gels and chemical sprays won’t help in the long-term for cockroach control,” said Ramachandran.
Moreover, a number of problems arise when gel and sprays are used together. They render each other ineffective (tainted gels lose their appeal) while roaches have also developed resistance to gels, researchers show.
He said it is wrong to assume the pest-control people alone can control pests. “People must cooperate through cleanliness, housekeeping, storage and waste management.”
While chemicals are the usual way to fighting the menace, high-pressure steam (heated at above 60 degrees C) is also used. While this treatment uses no chemicals and is fairly quick, it is expensive and involves having to turn your house ‘upside down’.
“It’s actually very simple,” said Dr Gubran. “If you deprive pests of their food and shelter, they simply go away — or die.
“The best way is to regularly clean your home free of pests. Applying a pesticide is just one option, but not the only solution.”