* Pest is spreading across southern Africa
* Tests confirm its presence in South Africa
* Region was hit by drought last year, now invasive pest (Updates with South African confirmation)
By Ed Stoddard
JOHANNESBURG, Feb 3 (Reuters) - South Africa's department of agriculture said on Friday that scientific tests have confirmed the presence of the invasive fall armyworm in the maize belt, the first time the crop-damaging pest has been detected there.
Countries with confirmed outbreaks can face import bans on agricultural products because the armyworm is classified as a quarantine pest. The pest can also cause extensive damage to crops and has a preference for maize, the regional staple.
The fall armyworm is an invasive Central American species that is harder to detect and eradicate than its African counterpart.
The South African samples were collected in the caterpillar stage and had to emerge as moths before positive identification could be done.
"This pest is a good flyer and cannot be contained in a specific area. Damage reported in South Africa so far is mainly on yellow maize varieties and especially on sweetcorn as well as maize planted for seed production," the department of agriculture said in a statement.
The outbreak of armyworms has spread to Namibia and Mozambique and is causing "considerable crop damage" in southern Africa, the U.N.'s Food and Agriculture Organisation said earlier on Friday.
Suspected outbreaks have also erupted in Zambia, Zimbabwe and Malawi. They follow a crippling El Nino-triggered drought which scorched much of the region last year, hitting crop production and leaving millions in need of food aid.
The FAO said an emergency meeting would be held in Harare from Feb. 14 to 16 to shape coordinated emergency responses to the armyworm threat and other potential hazards such as the spread of avian flu which has been detected in other African regions.
In Malawi, where 6.5 million people, more than a third of the population, are dependent on food aid until this year's harvest in March, the infestation has spread to all 28 districts in the country.
The armyworm moths lay eggs in maize plants and the caterpillars have also been known to march en masse across the landscape - hence the name. They have been known to destroy 90 percent of the crop in fields they infest.
South Africa's agriculture ministry is registering pesticides for use against the fall armyworm. (Editing by Ruth Pitchford)