Chapter 1 The Basics CONTENTS Page SE’M’ING THE STAGE *.** **** **0 *a****.****.************"*********************** 19 LOCWSTS AND GRASSHOPPERS ... ****. ***** *4*. *********************’S******* 19 Definitions . 22 Life Cycles: Eggs, Hop as, and Adults . 22 Behawor: Solitary and8 regarious Inswts .................,.... =..==.””+””.==.=”” 22 Geographic Distribution and Migration Patterns . ● ● ..,.. 23 LOCUST AND GRASSHOPPER UPSURGES, DECLINES, AND THE ROLE OFCLIMATE . .. ......”=...””.”””” 27 ORG~I~~ONSIWOLWDINLOCUST~DG~SSHOPPER CONTROL ● **9***9 ● ******** ● *.****** ● ****.*** .**.***** ..******* **.****.* ● *** 28 National Crop ProtectionServices and Other National andkal Groups . 28 Regional Organizations . ...........”+.. ● =..’..” 29 U.N. Food andAgriculture Organization . .. .. .. ... ..=. .+..=” 29 USAIDand OtherDonors . .........~~.~~””o ● -. 34 PASTANDCURRENTCONTROLMETHODSFORLOCUSTS ANDGRASSHOPPERS . .- 37 Boxes 1-A Methods ofThisOTAStudy . .. 20 1-B MajorS ciesofLocusts andRelatedAggregating Grasshoppers inAfrica andt reMiddleEast . ...*.-..? ● ..?... 21 1-C USAID’s OperationalResponsibility for Locust/GrasshopperProblems . 39 Figures 1-1 Life~cle oftheDesertLocust . 23 ies of Locust and Aggregating Grasshoppers in 1-2 ‘is%;::O:!f::&\:KEast . ......... =..=.-... 24 1-3 Major Plagues of the Desert Locust . 28 1-4 Movement of13esert Locust Swarms, January 1985-April 1989 . 30 1-5 Regional Organizations and FAO Commissions in Charge of Locust and Grasshopper Control . 35 Tables 1-1 Donor Assistance to Locust and Grasshop rControl Programs, 1986-89 . 32 1-2 Inde endent Regional Or animations an Theirr Member Nations . 34 1-3 Tota rArea Controlled in t ei Sahelian Countries in 1986 and 1987 . 37 1-4 U.S. Assistance to Locust/Grasshopper Programs, Fiscal Years 1986-89 . 38 1-5 Exam@es of Locust and Grasshopper Control Methods . 40 1-6 Insecticides Used Presently and in the Past Against Locusts and Grasshoppers in Africa and the Near East . 42 Chapter 1 The Basics SE!ITING THE STAGE In this study box l-A), OTA examines what happened duringti e 1986to 1989plagueyearsand In the late 1980s, several major species of locusts considers the implications of the longer-term is- as well as significant populations of various grasshop- sues. The major species of locusts and related a - pers simultaneously threatened Africa for the first regating grasshoppers in Africa and the Midd fe time in 50 years (93). This infestation began in 1985 kast (box 1-B) are the focus. From 1986 to 1989, through 1986 after rains ended a severe, several-year most international control efforts in Africa were drought and new, em vegetation allowed these directed at the Desert Locust and the Senegalese pest species to pro #“ crate. Grasshopper, so most examples in this report deal with these two species. Several grasshopper species in the West Afi-ican Sahel reached levels high enough to result in lar~e- LOCUSTS AND GRASSHOPPERS scale control efforts from 1985 to 1989. Also, a major plague of Desert busts began in countries around Locusts and aggregating grasshoppers have the Red Sea, with swarms moving west across the fascinated biologists and caused farmers anxiety for Sahelian (see app. A) countries. By November 1988, centuries because of their unusual behavior. This swarms of the Desert Locust extended from section details the insects’ biology and behavior. Mauritania and Senegal in the west to Iraq, Iran, and For readers with less need for detailed knowledge, Kuwait in the east, and some fragments of swarms the following information is critical to under- even reached the Caribbean. standing later sections of this report and to making informed policy choices: The last widespread Desert Locust plague ex- tended from 1949 to 1%3. Following that plague, ● Different locust andgrwhopperspeciescanbe the infrastructure to fight locusts and grassho ers difficult to identi~, yet the have distinct deteriorated, and the recent pla ue cau ht biologies that require dif i!’erent control unprepared and highly vulnerabF e. Forf onors,‘~ca m- strategies. including the U.S. Agency for International Development (USAID), the Desert Locust ● Eachinsectcaneatitsownwei tinvegetation plague, along with other locust and grasshopper each day. Damage mainlyP epends on the problems, caused shifts in funds, operations, and number of insects, how long they stay in a given programs to cope with the apparent emergency. area, which plants they eat (non-crop, commercial cro , subsistence crop) and the Despite earlier forecasts that the Desert plants’ stageof Cfenvelopment Locust plague mi ht continue for several more years, in April 1985 the United Nations Food and ● When crowded (by breeding or congregating in Agriculture Organization (FAO) announced that moist places) these insects undergo a the plague had dissipated (105). But longer-term chang-from living as scattered, sedentary issues remain. For example, expmts differ widely in individuals to becomin cohesive, gregarious their assessment of the significance of locust and bands ofhoppersorhi&mobile adult swarms. grasshopper outbreaks relative to other pest Swarms can migrate hundreds of miles in a few problems and in terms of the crop damage they weeks. cause on a national level; the information base on which major control decisions were based seems ● Locusts and grasshoppers’ life cycles have deficient; no sound technological alternatives exist three stages: eggs, hoppers, and adults. for chemical pesticides; and education and training Gregarious insects are most concentrated and for the next generation of experts to deal with vulnerable to control during the second stage future plagues seems inadequate. because hoppem cannot fly. 19 20 ● A Plague of Locusts Flowchart of Study Methods r ‘- ‘ —- ~ Congressional Request (Senate Committee on Appropriations and Subcommittee on Foreign Operations) L ..—— I Imtlal Research 1. Additional Internal OTA Research [.*I Inlhal external review — —— — I ~—– . —— L-—— , 1 Additional Review (24) USAID Review (12) 1 I (FAO, African, Other Experts) Meeting with IJSAID I Il. Revised Report (approx. 150 pp.) L I + [ Final Review (2) I J Revisions I I Ch. I-The Basics ● 21 22 ● A Plague of Locusts . Weather conditions affect insect behavior. “molt,” or cast off their skins, as they grow. Usually Outbreaks occur after rainfall. Predominant the insects molt five times, with the growth stages reasons for declines also relate to between each known as “instam.” After the last weather–unfavorable breeding conditions molt, the insects are considered “fledglings,” or (insufficient moisture, vegetation or low immature adults, but have developed win s strong temperature) or wind patterns. enough to fly (figure l-l). Desert Locusts five from 2.5 to 5 months (93) and, under optimal environ- Definitions mental renditions, populations probably can mul- tiply 10 times in each generation (71). Locusts belong to a large group of insects com- monly called grasshoppers-insects recognized by Various grasshopper and locusts ies differ in powerful hind legs adapted for jumping–in the in- important ways, such as the length or time eggs can sect order Orthoptera. Technically, grasshop~ers survive without rain and the insects’ vulnerabdity to and locusts belong to the superfamily Acridoldea natural enemies (predators, parasites, and within that order. Therefore, they are close biologi- pathogens). Desert Locust e~ are viable for up to cal relatives. 10 to 12weeks in soil that remains sufficient moist (118). On the other hand, Senegalese Grass1 opper Many scientists distinguish locusts from eggs can survive in dry soil for several years and hatch grasshoppers based on locusts ability to form dense when rains come (55). Grasshopper often fall prey groups comprised of large numbers of insects. In to natural enemies (99), but usually natural enemies some cases this distinction is not clear because only are significant sources of mortality for Desert “aggregating” grasshoppers can behave similarly. Locusts when populations are in decline for other Thus, the terms “locust” and “grasshopper” are reasons (93). Weather, however, is the most impor- sometimes ambiguous. tant natural cause of Desert Locust mortality. Also, the term “locust” is used nontechnically. In Behavior: Solitary and Gregarious Insects the United States, for example, cicadas-a different type ofinsectintheorder Homoptera-are sometimes Behavior patterns principally distinguish locusts called “locusts.” Different kinds of cicadas occur in from other grassho pers. Locusts behave as “typical” large numbers at regular 13- and 17-year intervals. ~asshoppers and ivef’ as solitaxy individuals when Unlike locusts, periodical cicadas do little damage to their po ulations are small. However, when locusts vegetation. People who have experienced their dense occur in1? argenumbers andhighdensity theyundergo hatching, however, know something of what locust a transformation to a gregarious phase, and move outbreaks are like. “bust”, in French, is “cnquet,” to ether in dense groups. Gregarious locusts are but theinsectsAmericans call crickets also differ from caf led swarms when composed of adults, and bands locusts and asshoppem although the three insect when composed of young ho pers. A swarm of adult types sharetK esamescientific order. Desert Imcustsmaycontain! Omillionto 150million individuals per square kilometer and spread over an Atleastl,500speciesof grasshop rsandlocusts area ranging from a few hectares to hundreds of exist in Africa, withawidespectrumo rcharacteristics.