Kalain Ho­sein

Cli­mate Change Con­sul­tant

kalain.ho­sein@guardian.co.tt

Ac­cord­ing to the Old Tes­ta­ment of the Holy Bible, lo­custs were the eighth plague af­ter God sent a se­ries of ten plagues to pres­sure the Pharaoh to re­lease en­slaved Is­raelites.

For those in south­ern and east­ern Trinidad, this bib­li­cal night­mare has be­come a near-an­nu­al re­al­i­ty for the last decade. Farm­ers and res­i­dents alike, from Ica­cos to Plum Mi­tan, now brace for these swarm­ing crea­tures, no more than a few inch­es long, which bring their com­mu­ni­ties to a halt and cause tens of thou­sands in dam­age.

Their ex­pand­ing foot­print across Trinidad is due to changes in land use and, ac­cord­ing to ex­perts, a chang­ing cli­mate.

Un­der­stand­ing

Trinidad’s lo­custs

Ac­cord­ing to Na­dia Ram­ta­hal-Singh, an agri­cul­tur­al en­to­mol­o­gist from the Min­istry of Agri­cul­ture, Land and Fish­eries, these grasshop­pers, col­lo­qui­al­ly called lo­custs, have been recog­nised as pests in Trinidad since 1918.

Ram­ta­hal-Singh ex­plained that these pests are “mi­gra­to­ry and gre­gar­i­ous, so they move in swarms,” which are char­ac­ter­is­tics of lo­custs. Hence, the ter­mi­nol­o­gy has been used in­ter­change­ably for these two species. There are two dom­i­nant species, the small­er Moru­ga Grasshop­per (or “Moru­ga Lo­cust”) and the larg­er Ce­dros Grasshop­per (or “Ce­dros Lo­cust”), both named af­ter their place of ori­gin.

In­creas­ing lo­cust out­breaks

While the Ce­dros Lo­cust tends to re­main in Trinidad’s far south­west, the Moru­ga Lo­custs have been mi­grat­ing fur­ther and fur­ther away along and from Trinidad’s south coasts and have been the fo­cus of re­search at the Min­istry of Agri­cul­ture.

His­tor­i­cal­ly, out­breaks of the Moru­ga Lo­cust were re­port­ed every 14 years, but as of 2010, swarms have been re­port­ed near­ly an­nu­al­ly. Ear­li­er in 2024, Guardian Me­dia vis­it­ed Bar­rack­pore, where res­i­dents said they were grap­pling with the in­fes­ta­tion of the Moru­ga Lo­cust that had in­un­dat­ed their homes, ve­hi­cles, and veg­e­ta­tion. When Guardian Me­dia vis­it­ed the com­mu­ni­ty, Julien Trace was stained with the rem­nants of thou­sands of dead hop­pers, crushed un­der the weight of pass­ing cars.

Res­i­dent Paul Rooplal said this was the first time the hop­pers had hatched in Plananite Trace, re­count­ing, “For three days now, the ba­by grasshop­pers have hatched. They are con­sum­ing every­thing, and we can­not even open our doors. We have to close up when cook­ing.”

An­oth­er res­i­dent, In­dra Bal­go­b­in, said she has been re­lent­less­ly spray­ing to kill the pests: “I spend a lot of time with my plants; it’s so sad to see how they eat them. I don’t know what to do. I called the (agri­cul­ture) of­fice, but no one came. The woman I called said they could not do any­thing, but I think they should come and spray.”

Since 2014, ac­cord­ing to agri­cul­tur­al en­to­mol­o­gist Ram­ta­hal-Singh, who has been con­duct­ing re­search on the Moru­ga Lo­custs, re­ports of these pests have spanned as far as 47 kilo­me­tres north­east of Moru­ga in­to Plum Mi­tan, just over half the length of Trinidad from the south coast.

Based on re­ports col­lect­ed by the Min­istry of Agri­cul­ture, there are four dis­tinct clus­ters where these swarms oc­cur—south­west­ern Trinidad from Siparia to Ica­cos (a mix of the Ce­dros and Moru­ga Lo­custs), with the Moru­ga Lo­custs dom­i­nat­ing in south-cen­tral Trinidad from Mor­rne Di­a­blo to Debe, Moru­ga to Tabaquite, and Rio Claro to Plum Mi­tan fur­ther east.

Cli­mate change’s role

Ac­cord­ing to the Min­istry of Agri­cul­ture, their be­hav­iour has changed to al­low them to mi­grate over long dis­tances, but their be­hav­iour is on­ly one of the cul­prits. Ram­ta­hal-Singh ex­plained that the top three rea­sons are cli­mate change, which leads to changes in how T&T ex­pe­ri­ences rain­fall and tem­per­a­tures, and hu­man en­croach­ment in­to and near forest­ed ar­eas. “We be­lieve the dif­fer­ence be­tween the dry and wet sea­sons is af­fect­ing the life cy­cle, and they’re mov­ing out of ar­eas they are ac­cus­tomed to be­ing okay,” Ram­ta­hal-Singh ex­plained.

Cli­mate change can be blamed for a host of im­pacts on our en­vi­ron­ment, but Ram­ta­hal-Singh elab­o­rat­ed that the changed cli­mate has al­so led to changes in the life cy­cle. Be­tween Ju­ly and Sep­tem­ber, they are typ­i­cal­ly im­ma­ture adults called nymphs or hop­pers and be­gin to move. By Oc­to­ber, they reach ma­tu­ri­ty and be­gin to meet, lead­ing to cop­u­la­tion.

These lo­custs gen­er­al­ly sur­vive one year and pro­duce one gen­er­a­tion, and once they mate, they die af­ter eggs are laid. How­ev­er, by De­cem­ber, ac­cord­ing to Ram­ta­hal-Singh, “If the rains come, the hatch­ing of the eggs will be de­layed, and it will be­gin in Jan­u­ary.” She added that the lo­custs will not fly in heavy rains, which can al­so quell swarms from mi­grat­ing far across the is­land in wet­ter months, but it pro­vides ide­al breed­ing con­di­tions.

In the lat­est up­date of cli­mate nor­mals from the Trinidad and To­ba­go Me­te­o­ro­log­i­cal Ser­vice, every month of the year now has a low­er av­er­age rain­fall ac­cu­mu­la­tion when the av­er­ages are com­pared from 1981-2010 and 1991-2020. Ac­cord­ing to pro­jec­tions from the In­ter­gov­ern­men­tal Pan­el on Cli­mate Change, the trop­ics are ex­pect­ed to be­come pro­gres­sive­ly dri­er in a warmer world.

Still, when show­ers, thun­der­storms, and trop­i­cal cy­clones form in our re­gion, they are like­ly to be more in­tense, caus­ing lo­cal ex­treme rain­fall to­tals. Based on da­ta from the Trinidad and To­ba­go Me­te­o­ro­log­i­cal Ser­vice, Trinidad and To­ba­go has been warm­ing at a rate of 0.24˚C per decade since 1946, with the last two decades be­ing the hottest on record.

In T&T, every sin­gle year since 1986, the tem­per­a­ture has been warmer than the 1961-1991 cli­ma­to­log­i­cal av­er­age. These crea­tures can eat or ex­ist in a va­ri­ety of tem­per­a­ture ranges, but their di­ges­tion is much more spe­cif­ic. Lo­custs can fill their stom­achs faster than they can di­gest food. Re­cent stud­ies have shown that lo­custs can as­sim­i­late far more en­er­gy in fu­ture cli­mates than cur­rent cli­mates, be­tween eight and 17 per cent more en­er­gy per wet sea­son than cur­rent­ly, pro­por­tion­al to how much warmer it is.

The Min­istry of Agri­cul­ture al­so said there are 20 tra­di­tion­al lo­cust egg beds in south Trinidad, av­er­ag­ing ap­prox­i­mate­ly 10,000 feet. How­ev­er, more egg beds are crop­ping up in non-tra­di­tion­al ar­eas due to for­est clear­ance. They al­so added that lo­cust bands in T&T are merg­ing rather than re­main­ing in sep­a­rate bands while the in­fes­ta­tions are spread­ing in non-tra­di­tion­al ar­eas be­cause of for­est clear­ance.

Trinidad’s man­age­ment strate­gies

The Min­istry of Agri­cul­ture said they work along­side key stake­hold­ers, in­clud­ing the pub­lic, for sight­ing re­ports, and they can spring in­to ac­tion, track­ing the lo­custs’ flight paths and lo­cat­ing their eggs. Once the eggs are lo­cat­ed, of­fi­cials use an “in­te­grat­ed pest man­age­ment” (IPM) strat­e­gy.

The “chem­i­cal man­age­ment strat­e­gy” is cur­rent­ly on­go­ing, chiefly us­ing two chem­i­cals. Ram­ta­hal-Singh ex­plained that the min­istry sprays Propox­ur, al­so known as Bay­gon, and Ethrine Plus, al­so known as Cyper­me­thrin. “Part of the IPM strat­e­gy is that we do mon­i­tor­ing and sur­veil­lance.

The lo­custs tend to go back to where they hatched, and the egg beds are. We mon­i­tor and sur­vey the ar­eas where we are ac­cus­tomed to see­ing them. Once the hatch­ing be­gins, we start the chem­i­cal con­trol,” Ram­ta­hal-Singh said.

She tout­ed the pro­gramme’s suc­cess so far, but she high­light­ed the caveat that they are on­ly able to reach the lo­custs that ex­it in the forest­ed ar­eas or at the edge of for­est re­serves. “We man­age with­in some ar­eas and farm­ing com­mu­ni­ties, but the ones that are deep with­in the for­est, we are un­able to ac­cess them,” she added.

She al­so cau­tioned those who would like to see spray­ing every­where: “Propox­ur is an in­sec­ti­cide that kills every­thing—in­clud­ing ben­e­fi­cial in­sects.” Re­search shows it is al­so high­ly tox­ic to many birds and hon­ey­bees and mod­er­ate­ly to slight­ly tox­ic to fish and oth­er aquat­ic species.

A new, safe, na­ture-based so­lu­tion

As a re­sult, Ram­ta­hal-Singh said the min­istry was now try­ing to use a “bi­o­log­i­cal con­trol agent” to make the en­vi­ron­ment safer for all flo­ra, fau­na, live­stock, and hu­mans. “We start­ed re­search back in 2022 on this bi­o­log­i­cal con­trol agent, metarhiz­ium acridum, an en­to­mopath­o­gen­ic fun­gi, which is be­ing man­u­fac­tured in oth­er coun­tries to con­trol lo­custs, specif­i­cal­ly desert lo­custs.”

She ex­plained that the Min­istry of Agri­cul­ture im­port­ed it, and lab­o­ra­to­ry tri­als be­gan at the Re­search Di­vi­sion in Cen­teno in 2022 and 2023. Ram­ta­hal-Singh added, “We test­ed NO­VACRID, an ac­tive in­gre­di­ent from the metarhiz­ium acrid­i­um, against adults and first stages. We had 100 per cent mor­tal­i­ty with­in eight days of the lab­o­ra­to­ry tri­al, so we knew it was a suc­cess.”

At the be­gin­ning of 2024, the Min­istry of Agri­cul­ture con­duct­ed a field tri­al us­ing NO­VACRID be­tween Jan­u­ary and March in Princes Town and Pe­nal. Ac­cord­ing to Ram­ta­hal-Singh, 100 per cent mor­tal­i­ty with­in five days was spe­cif­ic to lo­custs and grasshop­pers.

This sto­ry was pro­duced as part of In­ternews’ Earth Jour­nal­ism Net­work’s Re­port­ing Fel­low­ship.