Mauritania. 1 May 25 October Desert Locust Information Service FAO, Rome outbreak

Transcription

1 Mauritania 1 May 25 October 2016 outbreak Desert Locust Information Service FAO, Rome Keith Cressman (Senior Locust Forecasting Officer) updated: 26 Oct 2016

2 Zouerate oases May 2016 swarms bands groups May 2016 rainfall mm source: IRI RFE adults hoppers egg-laying no locusts MAY 2016 A few small groups of late instar hoppers at densities up to 60 hoppers/m 2 remained near Zouerate early in the month mixed with immature and a few mature solitarious and transiens adults at densities up to 8,500 adults/ha. Ground control operations declined against hopper and adult groups in northern Mauritania and adjacent areas in the southern portion of the Western Sahara in Morocco. As vegetation dried out, adults rapidly increased in density and several groups moved south to oases in western Mauritania. Other groups of immature and mature adults at densities up to 30,000 adults/ha arrived in the north and northwest and moved south to the oases in Adrar.

3 Zouerate N Beika Tidjikja June 2016 swarms bands groups June 2016 rainfall mm source: IRI RFE adults hoppers egg-laying no locusts JUNE 2016 Due to drying conditions and control operations, breeding nearly ended in northern Mauritania where only isolated late instar solitarious hoppers remained near Zouerate. However, immature and mature solitarious and transiens adults and a few groups from adjacent areas of southern Morocco mixed with local populations and moved south through several oases in Inchiri and Adrar towards the summer breeding areas. By late June, adults had reached Tidjikja and N beira in western Tagant. The summer rains began to fall in the extreme southeast of the country.

4 Zouerate N Beika Tidjikja July 2016 swarms bands groups July 2016 rainfall mm source: IRI RFE Nema adults hoppers egg-laying no locusts JULY 2016 During the first decade, residual hopper and adult populations remained near Zouerate and immature solitarious adults persisted in western Tagant. During the rest of July, an increasing number of scattered mature solitarious adults appeared in the summer breeding areas of southern Mauritania, which coincided with the onset of the seasonal rains throughout the south. Consequently, ecological conditions became favourable for breeding and small-scale hatching commenced in about mid-july near Nema and first to third instar hoppers were reported on the 30 th.

5 Aug 2016 swarms Tidjikja potential area of breeding (summer 2016) bands groups adults Aug 2016 rainfall Kiffa Aioun Nema hoppers egg-laying mm source: IRI RFE no locusts AUG 2016 Good rains fell over a widespread area of southern Mauritania and low numbers of mature solitarious adults were well distributed and scattered throughout this area and breeding on a small scale. Hatching was detected early in the month on the Atlantic coast north of the Senegal River and in the southeast, including the plateau east of Nema. It is likely that more locusts were present than reported since several areas where good rains had fallen were not surveyed. Similar to 2003, favourable ecological conditions and breeding may have occurred much further north than usual.

6 Atar Sep 2016 swarms A.Faye Tidjikja potential area of breeding (summer 2016) bands groups adults Sep 2016 rainfall Aioun Nema hoppers egg-laying mm source: IRI RFE no locusts SEP 2016 Low numbers of scattered solitarious adults at densities of less than 200 adults/ha continued to be reported in the south during September. Breeding was detected in the southeast between Aioun El Atrous and Nema and at one place on the Trarza coast. As the month progressed, an increasing number of mature solitarious adults appeared in the west, mainly in southwest Adrar. As vegetation dried out in the southeast, there was a sudden increase in densities to 1,500 adults/ha and a few small groups formed during the last week. Other immature and mature groups formed at densities up to 7,000 adults/ha in the west between Aguilal Faye and Atar, and some were laying eggs. Control operations treated 263 ha.

7 Zouerate locust situation unknown in N Mali due to insecurity potential area of breeding (Oct-Dec 2016) Atar potential movement on NE-E winds (early Oct) 1-19 Oct 2016 swarms A.Faye Tidjikja bands groups adults 17 Oct 2016 rainfall Nema hoppers egg-laying mm source: IRI RFE no locusts OCT 2016 Several swarms and groups of mature solitarious and transiens adults at densities up to 35,000 adults/ha (<4/m 2 ) and varying in size from 20 to 140 ha appeared in Trarza, Adrar and Inchiri early in the month. A very small swarm of 50 ha was reported near. Egg-laying was underway and hatching commenced, causing small first and second instar hopper bands to form at densities up to 80 hoppers/m 2. Adult groups at densities up to 7,200 adults/ha were also present in the southeast near Nema. Ground control operations treated more than 4,200 ha on 1-10 October. In southern Morocco, scattered adults appeared in the Adrar Settouf.

8 it takes locusts at least 10 days to migrate from N Mali to NW Mauritania MAURITANIA Atar Akjoujt potential movement on NE-E winds (early Oct) locust situation unknown in N Mali due to insecurity Tidjikja Nema MALI 900hPa (900m) winds, 4 Oct 2016 at 1500h OCT 2016 The appearance of groups and swarms of yellow solitarious and transiens adults in NW Mauritania may suggest that the current infestations originated from summer breeding that took place in southern Mauritania as well as perhaps northeast Mali. In the latter area, good rains fell from June to September this year that allowed at least one generation of breeding to take place. However, national surveys could not be undertaken to confirm the situation due to insecurity. Nevertheless, if summer-bred adults formed groups by late September when vegetation would be drying out, it is possible that prevailing northeasterly and easterly winds could have carried them to NW Mauritania, a journey of more than 1,500 km over mainly uninhabited areas that would take about days. In the absence of data or sightings, it is only possible to hypothesize such a migration.

9 15-Jun Scenario 1: remnant spring-bred populations in oases Mature adult groups invade and lay eggs in oases of western Mauritania in mid-june (unlikely because before summer rains) egg hopper adult egg hopper adult 29-Jun 5-Aug 4-Sep 18-Sep 24-Oct 23-Nov Jul Scenario 2: second-generation hatching in early Oct Mature adult groups invade oases of western Mauritania in mid-june and lay eggs 3 weeks later (coincides with second-generation hatching seen on 8 Oct) egg hopper adult egg hopper adult 20-Jul 25-Aug 24-Sep 8-Oct 13-Nov 13-Dec Previous generation: egg-laying 7-May hatching 21-May 26-Jul Scenario 3: swarm(s) appear in early Oct Mature swarm(s) arrive in western Mauritania in early Oct (perhaps from undetected areas or N Mali?) egg hopper swarm egg hopper adult 8-Aug 14-Sep 14-Oct 28-Oct 3-Dec Jan BREEDING Three different scenarios are proposed in explaining the appearance of mature adult groups and swarms in NW Mauritania in early October: (1) spring-bred adults laid eggs in western oases as soon as they arrived from the north in mid-june but this is not very likely because it is before summer rains; (2) more likely is that they waited until early July when rains fell and the timing coincides with second generation hatching in early October; (3) groups and swarms that formed from egg laying and hatching in late July and early August respectively in southern Mauritania and perhaps northeast Mali are likely to have contributed to the early October infestations in NW Mauritania.

10 northern limit of potential breeding (summer 2016) unsurveyed area (Sep 2016) Nema SURVEYS Green annual vegetation development in the summer breeding areas of southern Mauritania peaked in September. Similar to 2003, green vegetation was located much further north than usual because of good, widespread rains this summer. Consequently, there were relatively large areas that were not surveyed in which Desert Locust populations may have been present, breeding and concentrating. This may also partially explain the appearance of mature adult groups and swarms in NW Mauritania in early October.

11 elocust3 ID elocust3 usage (5-12 Oct 2016) number of stops/day/team stops/day/team number of stops/day maximum /10/16 06/10/16 07/10/16 08/10/16 09/10/16 10/10/16 11/10/16 12/10/16 number of stops/day minimum actual total stops/day 5/10/16 7/10/16 9/10/16 11/10/16 elocust3 National survey and control teams record their field observations in a rugged handheld tablet that transmits this data in real time by satellite to the National Locust Centre (CNLA) in. The data is the foundation of the global early warning system and preventive control strategy. It is used by CNLA for decision-making and by FAO for analysis and forecasting. In early October, there were 12 CNLA teams in the field using elocust3. By evaluating the use of elocust3, it is possible to identify any shortcomings in survey efficiencies, timing and coverage. Using elocust3 effectively contributes to good monitoring, early warning and control.

12 Control operations against mature adult groups and small swarms in western Mauritania (7-10 Oct 2016)

13 Zouerate potential area of breeding (Oct-Dec 2016) Atar 1-21 Oct 2016 swarms A.Faye Tidjikja bands groups Nov 2016 rainfall forecast % of normal source: WCS Nema adults hoppers egg-laying no locusts NOV 2016 FORECAST Locusts will decline in southeast Mauritania as a few remaining groups form and move to the northwest where they will supplement egg-laying that started during the last week of September. Second-generation hatching that commenced in early October will continue until about early November, giving rise to hopper groups and bands throughout November. Fledging is expected to commence during the first week of November and continue until about mid-december, giving rise to immature adult groups and swarms from about mid-november onwards. Seasonal rainfall predictions suggest slightly above average rainfall in November and December that should allow the continuation of favourable conditions for locust breeding and survival.

14 3rd generation first dates: lay hatch fledge ADULTS fledging HOPPERS hatching EGGS laying first these are first generation summer-bred adults LAY last 16/9 26/9 6/10 17/10 27/10 6/11 17/11 27/11 7/12 18/12 28/12 7/1 18/1 28/1 7/2 18/2 NOV DEC 2016 FORECAST Estimated egg and hopper development rates suggest that 2nd generation hatching should conclude in early November. This means that hoppers will continue to form groups and small bands throughout November to about the third week of December. The hoppers should start fledging about the first week of November and new immature groups and small forms could start forming from about mid-november onwards. If conditions remain favourable, 2nd generation adults will be ready to lay eggs from about 1 December onwards that would result in a 3rd generation of hatching after mid-december.