Saudi Arabia. July present. Desert Locust Information Service FAO, Rome Red Sea coast outbreak

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1 Saudi Arabia July present coast outbreak Desert Locust Information Service FAO, Rome Keith Cressman (Senior Locust Forecasting Officer) updated: 24 January 2017

2 undetected egg-laying (15 31 July) July 2016 July 2016 rainfall JUL 2016 Light showers commenced on the coastal plains in late June between and. This was followed by heavier showers at times between July, mainly in the area, extending north to and, to a lesser further north towards. Rains were particularly heavy between and on 28 July to 3 August, causing floods in some places. No surveys were carried out on the coastal plains in June and July. However, scattered mature solitarious were likely present and laid eggs from mid-july onwards in some areas that received rainfall. They may also have been supplemented by adult that arrived from adjacent areas in Yemen and laid eggs.

3 1st generation breeding (mid-july mid-sep) hatching: 3 Aug 22 Sep : 3 Aug 8 Nov fledging: 9 Sep 8 Nov : 9 Sep 25 Dec Aug 2016 August 2016 rainfall AUG 2016 Good rains continued to fall throughout the month on the coastal plains between and in many areas that had received heavy rain in July. Surveys were carried out on and August. Scattered immature solitarious were seen on the coast near while scattered mature solitarious were present near including one report of laying eggs on 16 August. It is also possible that adult may have arrived from adjacent areas in Yemen and laid eggs during August. Undetected first generation hatching probably commenced on 1 August and continued throughout the month. As a result, were likely present during August but they were not seen or reported.

4 1st generation breeding (mid-july mid-sep) hatching: 3 Aug 22 Sep : 3 Aug 8 Nov fledging: 9 Sep 8 Nov : 9 Sep 25 Dec Sep 2016 September 2016 rainfall SEP 2016 Good rains continued to fall for the third consecutive month between and mainly during the first half of September. As a result of continued breeding, concentrated and formed a few and small near. Fledging commenced during the second week and a few small adult formed shortly thereafter. Control operations near treated 3,000 ha of which 400 ha were by air. As surveys were only conducted near, the locust situation elsewhere was not known or reported but it is nearly certain that breeding was underway near and as well.

5 2nd generation breeding (mid-oct mid-jan) laying: 9 Oct 25 Dec hatching: 23 Oct 9 Jan : 23 Oct 14 Feb fledging: 7 Dec 14 Feb : 7 Dec 14 Mar Oct 2016 October 2016 rainfall OCT 2016 Breeding continued on the coast near, and where solitarious of all instars were present. Fledging continued and the new were maturing. It is likely that a second generation of egg-laying started during the second week but was not detected. Control operations near treated 3,420 ha. Although more surveys were undertaken in October than September, many areas were not monitored where breeding was most likely in progress. As a result, second-generation hatching commenced during the last week of October but was not detected.

6 2nd generation breeding (mid-oct mid-jan) laying: 9 Oct 25 Dec hatching: 23 Oct 9 Jan : 23 Oct 14 Feb fledging: 7 Dec 14 Feb : 7 Dec 14 Mar Nov 2016 November 2016 rainfall NOV 2016 Second-generation egg-laying and hatching continued along the coastal plains between and and early instar were present during the month. However the locust situation could not be confirmed due to a complete absence of surveys undertaken in November. Light rain fell in some areas at the end of the month, allowing ecological conditions to remain suitable for breeding and locusts to increase in number. This may have been supplemented by small adult appearing from adjacent areas of the northern coast in Yemen.

7 2nd generation breeding (mid-oct mid-jan) laying: 9 Oct 25 Dec hatching: 23 Oct 9 Jan : 23 Oct 14 Feb fledging: 7 Dec 14 Feb : 7 Dec 14 Mar Dec 2016 December 2016 rainfall DEC 2016 It became clear that an outbreak was developing on the coast because of good rains from July to mid- September that allowed two generations of breeding to occur so far. The situation was further complicated by irregular and incomplete monitoring during the period. The outbreak appears to have originated near and then subsequently extended to and areas. Breeding continued during December and first-generation were forming and laying eggs in some areas near while solitarious were seen laying eggs near. Ground teams treated 10 ha.

8 2nd generation breeding (mid-oct mid-jan) laying: 9 Oct 25 Dec hatching: 23 Oct 9 Jan : 23 Oct 14 Feb fledging: 7 Dec 14 Feb : 7 Dec 14 Mar 1-21 Jan 1-20 January 2017 rainfall JAN 2017 Second-generation of all instars began forming and from the second week of January onwards near, and. Hatching and the formation of third-generation hopper and is expected to take place from late January onwards while second-generation are likely to form an increasing number of immature and perhaps a few small. Ground teams treated 1,416 ha on 1 18 January.

9 second-generation hopper on the coast of Saudi Arabia (January 2017)

10 G3 hatching G3 G3 fledging G3 laying G2 G2 G2 G2 fledging G2 hatching G1 G1 hatching G1 G1 fledging G1 G2 laying G1 laying rain 20/6 4/7 18/7 1/8 15/8 29/8 12/9 26/9 10/10 24/10 7/11 22/11 6/12 20/12 3/1 17/1 31/1 14/2 28/2 14/3 28/3 11/4 26/4 BREEDING Estimates of egg, hopper and adult development rates based on rainfall, field data and the Egg & Hopper Development Model suggest that first generation (G1) breeding started in mid-july, second generation (G2) commenced in late October and a third generation is expected in early Heavy rains in late July and early August, supplemented by other rainfall between July and September caused ecological conditions to be come suitable for breeding on the coast between and.