https://www.youtube.com/watch?v=6MQnAaPQQ1U

Arianne Cease: Hi. My name is Arianne Cease. I’m fac­ul­ty in the School of Sustainability and the Founding Director of the Global Locust Initiative at ASU.

I was first exposed to grasshop­pers as a young far­m­girl. I grew up on a ranch in south­ern Oregon, with pas­tures tucked into moun­tains amidst oaks and ever­greens. I remem­ber rid­ing on the front buck­et of the trac­tor through our graz­ing fields, and see­ing grasshop­pers cov­er­ing the ground and jump­ing every­where. They com­pet­ed with our live­stock for grass, but I was most inter­est­ed in them as food for the pet pray­ing man­tis­es that my broth­er and I would catch.

While my par­ents chose the ranch­ing lifestyle, I did­n’t under­stand the val­ue of being a stew­ard of the land or grow­ing your own food. I vowed to move to a big city, and I did­n’t fore­see anoth­er ranch or farm in my future. I want­ed to see the world, and col­lege was my tick­et. I was cap­ti­vat­ed by biol­o­gy, but after grad­u­at­ing I still want­ed to trav­el and under­stand oth­er places and cul­tures.

So I joined the Peace Corps. I arrived in the hot, sandy inte­ri­or of Senegal as a sus­tain­able agro­forestry exten­sion agent in 2005. I lived in a small sub­sis­tence farm­ing vil­lage next to a tow­er­ing baobab tree grove. Come the dry sea­son, tree locusts descend­ed on the vil­lage. They seemed to appear from nowhere and they cov­ered every­thing; gar­dens, trees, mil­let stalk fences. I watched as vil­lagers tried to pro­tect the trees and gar­dens with machetes or pes­ti­cides. It was futile. In the end, the locusts ate every­thing, even the bark off the trees.

All locusts are grasshop­pers, but not all grasshop­pers are locusts. Locusts are grasshop­pers that when exposed to spe­cif­ic envi­ron­men­tal cues will form mass migra­tions and become a continental-level chal­lenge. The imme­di­ate impacts of locusts on agri­cul­ture are obvi­ous. For exam­ple, the desert locust plague in Western and Northern Africa that occurred between 2003 to 2005 cost an esti­mat­ed 2.5 bil­lion US dol­lars in crop loss­es.

However, per­haps the more pro­found impacts are long-term effects on liveli­hoods. For exam­ple, a study in Mali found that chil­dren born dur­ing locust plague years in vil­lages impact­ed by locusts were much less like­ly to ever start school rel­a­tive to chil­dren born in vil­lages not impact­ed by locusts. The effect was great­est for young women.

Even after I left Senegal and start­ed grad­u­ate school, I could­n’t for­get the locust-caused dec­i­ma­tion, the effect on farm­ers and fam­i­lies. I want­ed to under­stand what caused locust out­breaks, and what could be done to decrease the impacts or to pre­vent them. This was a major fac­tor that led me to China to study the Mongolian locust, sup­port­ed by an NSF fel­low­ship.

Initially, I thought the fac­tors dri­ving locust out­breaks would be sole­ly envi­ron­men­tal. However, it soon became clear that there was a strong human ele­ment. We would only find Mongolian locust out­breaks in fields heav­i­ly grazed by live­stock. Puzzlingly, the locusts would ignore the lush green grass on the oth­er side of the live­stock fence. And we could­n’t under­stand why.

We thought it might have some­thing to do with the nutri­ent con­tent of the grass. Classically, her­bi­vores pre­fer nitrogen-rich grass­es. But we found that the grass in heavily-grazed fields had a low­er nitro­gen con­tent. Overgrazing leads to loss of the top­soil, loss of organ­ic nitro­gen, and plants with a low­er nitro­gen con­tent. Because nitro­gen in plants is most­ly found in the form of pro­tein, that means plants with a low pro­tein and high car­bo­hy­drate con­tent. So feast­ing on over­grazed fields was like eat­ing a dough­nut diet for the locusts.

And what our research showed is that Mongolian locusts don’t just love the dough­nut diet, they thrive on it. This helped explain why heavy live­stock graz­ing led to locust out­breaks. The graz­ing was cre­at­ing a nutri­tion­al­ly opti­mal niche for the locusts. And, when eat­ing their dough­nut diet, the locusts were more like­ly to migrate. This means that soil degra­da­tion was not only pro­mot­ing locust out­breaks local­ly, but also migra­to­ry swarms. We went on to test this con­nec­tion between land use and locust plagues in Australia, Senegal, and more recent­ly Argentina and Bolivia. In each place, we’re find­ing that these dif­fer­ent locust species pre­fer the low-protein, high-carbohydrate dough­nut diet.

After find­ing the con­nec­tion between land use and locust out­breaks, I brought togeth­er a team of researchers across dis­ci­plines, from eco­nom­ics to geog­ra­phy and food secu­ri­ty, to under­stand the broad­er socioe­co­log­i­cal sys­tem around locust out­breaks. The Global Locust Initiative allows us to link our col­lec­tive knowl­edge and resources. And by tak­ing this inte­gra­tive approach, we can work togeth­er to find solu­tions that con­sid­er mul­ti­ple out­comes, includ­ing increas­ing farmer liveli­hoods, land­scape sus­tain­abil­i­ty, in addi­tion to keep­ing locusts at bay.

Going into the Peace Corps and then work­ing at ASU made me real­ize that sci­ence and sus­tain­able devel­op­ment don’t have to be sep­a­rate paths. By blur­ring these lines, I was able to return with a team to the region where I lived as a Peace Corps vol­un­teer, part­ner with the nation­al plant pro­tec­tion agency, local farm­ing groups, and togeth­er work toward solu­tions.

When I left my child­hood ranch, I thought I was leav­ing agri­cul­ture behind. Now I work with farm­ers all over the world. And I under­stand how crit­i­cal they are as stew­ards of the land, and pro­duc­ers. My access to edu­ca­tion led me to be able to devel­op the Global Locust Initiative. My hope is that our research can increase access to edu­ca­tion and improve liveli­hoods for peo­ple grow­ing up and liv­ing in locust-prone areas around the world. Thank you.


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