Madagascar locust update for the first dekad of February, 2011and a forecast for the next dekads

from US Agency for International Development
Published on 19 Feb 2011 View Original
Meteorological conditions

During the 1st dekad (1-10) of February, the outbreak and invasion areas in the south and southwest of Madagascar, including Tuléar and surrounding areas, received above average rains. Breeding areas in Manja and Ianakafy, Befandriana-Sud also recorded significant amount of precipitation and Sakaraha, Ankaraobato, Betioky and Ambovombe reported moderate rainfall during this period. In addition, Cyclone Bingiza that made a landfall on February 14th brought heavy rains to the east, southeast, southwest and other parts of the country during the early part of the 2nd dekad.

Locust situation

The locust situation continued further developing in the breeding and gregarization areas where numbers of hopper groups (flightless young locusts) and bands (groups of hoppers moving in tandem) continued increasing. Extensive survey operations by the FAO-CNA (the National Locust Control Center) detected some 49,000 ha infested with hoppers and adults. Dozens to hundreds of m² of hopper bands, mostly 4th instar, at densities varying from 20-100 insects/m2 spaced within 50 to 150 meters were observed. Mixed populations of solitary and transient hoppers at 10-30 hoppers/m2 and young (immature) adults were detected in about 20,000 ha north of the mouth of Mangoky River.

Impacts of current locust populations

No significant impact was reported as hoppers were in the natural vegetation. However, as the populations continue increasing and swarms begin forming, significant movements will be noticed in the coming months from outbreak to invasion areas where the threats to crops and pasture will likely be more substantial.


Aerial control treated/protected 19,500 ha (11,500 ha with Chlorpyrifos 240 ULV and 8,000 ha protected through barrier spraying with Nomolt 50 UL - an insect growth regulator) during this dekad. 22 hours and 20 minutes was logged during these operations (432 hours and 17 minutes of flight time have been logged since the current camping began in mid-October 2010). The cumulative total for areas sprayed/protected as of this dekad is 27,740 ha.

Ninety nine (99), 200 l empty metal drums are temporarily stocked at the storage facility in Tuléar under the supervision of the CNA for a safe disposal Madagascar locust update the 1st dekad of February, 2011at a latter date (a construction of a central pesticide storage facility that meets international standards is being contemplated for this location).


The torrential rains and gusty winds from Cyclone Bingiza that temporarily halted survey and control operations in Tuléar and the surroundings will likely slow down locust activities for a little while. However, the above average precipitation will create favorable conditions for further breed and increase in locust numbers over the dekads. Hoppers and bands as well as fledglings will continue appearing and gregarizing, particularly in Bekily-Fotadrevo, the Mahafaly plateau and around Androy. Active monitoring and rapid interventions remain essential to avoid any major impacts.

Inventory of resources

As of February 10th, CNA reported 90,260 l of Chlorpyrifos 240 ULV, 17,200 l of Nomolt 50 UL (IGR) and 600 kg of GreenMuscle (a biopesticide) in its inventory of recourse for the current locust campaign. Two helicopters are strategically placed in Tuléar and in areas close to most spray operations. Pre-positioning of pesticides in Ankoarabato was finalized.

FAO-CNA plans for the next dekad

Aerial survey and control operations that were temporarily halted in Tuléar and surrounding areas due to Cyclone Bingiza will resume as meteorological conditions improve. Control operations will commence along the mouth of the Mangoky River and the lowland of Tuléar and survey will proceed on the high basin of Mangoky and the Belomotra plateau as conditions allow. The team is working on dispatching pesticides to Befandriana-Sud.

Note: It was noted during a barrier spray operations that Nomolt 50 UL corroded the piping and joints of the spray system of the helicopter. The cause of the damage was attributed to a lack of reinforcement of these parts with Teflon to withstand ULV formulations. The helicopter company-PROCOPTER resolved the problem by rapidly dispatching Teflon reinforced spare pipes (source: FAO-CNA, 02/18/2011).

OFDA/TAG will continue monitoring the situation and issue updates and advice accordingly.