`Oxitec CEO on Why Trial of its Genetically-Modified Olive Fly Should Go Ahead

Production

Oxitec CEO on Why Trial of its Genetically-Modified Olive Fly Should Go Ahead

Sep. 18, 2013
By Julie Butler

Recent News

oxitec-ceo-on-why-trial-of-its-geneticallymodified-olive-fly-should-go-ahead-olive-oil-times-parry
Hadyn Parry

The world’s first field trial of a genet­i­cally-mod­i­fied olive fly could start in Cat­alo­nia next year if a British biotech firm wins approval from rel­e­vant author­i­ties.

Gen­er­ally, we would look to out­num­ber the wild males by about 10 to 1- Oxitec CEO, Hadyn Parry

Oxitec pro­poses to do the trial in col­lab­o­ra­tion with — and on land belong­ing to — the Cata­lan agri­cul­ture, food and aqua­cul­ture research insti­tute IRTA.

Here, Oxitec CEO Hadyn Parry answers our ques­tions about the plan, which would also be the first field test of a GM insect in the Euro­pean Union.

What stage are you at in the appli­ca­tion process?

Advertisement

Hadyn Parry: It’s being con­sid­ered by the Cata­lan gov­ern­ment and at the Fed­eral level by the Span­ish National Biosafety Com­mis­sion. The next step is the pub­li­ca­tion of the call for pub­lic com­ment of which there are two processes:‭ ‬one at the Euro­pean Com­mis­sion Joint Research Cen­tre level,‭ ‬which is for infor­ma­tion,‭ ‬and the other for com­ments to be sub­mit­ted to the Cata­lan gov­ern­ment.

The first of these has already taken place and we are antic­i­pat­ing the sec­ond one shortly. At that stage any­one can com­ment on the appli­ca­tion. The Cata­lan author­i­ties then need to assim­i­late the com­ments and deter­mine if they need addi­tional infor­ma­tion from us or make a deci­sion. We antic­i­pate a deci­sion in the (north­ern) spring.

Would it be the world’s first such trial of a GM olive fly?

Yes, it would. But of course we have tri­aled our GM mos­qui­toes with great effect in Cay­man and Brazil.

Aside from poten­tially improv­ing olive pro­duc­tion, what impact could heav­ily reduc­ing or elim­i­nat­ing wild olive fly pop­u­la­tions have?

The impact of a reduc­tion in the olive fly pop­u­la­tion is the same no mat­ter what method you use to achieve it. If one was to release the Oxitec flies and then stop, the wild olive fly pop­u­la­tion would recover. In the same way, if you hit the pop­u­la­tion hard with pes­ti­cides and then stop, it comes back.

The key is species speci­ficity com­pared to other approaches. Longer term, we believe use of the Oxitec olive fly for a pest con­trol solu­tion will result in a smaller envi­ron­men­tal impact than con­ven­tional mass trap­ping or pes­ti­cide appli­ca­tions which are not species-spe­cific.

What do olive flies feed on and what feeds on them?

Adult olive flies feed on nec­tar, decay­ing fruit and, when avail­able, bird feces. The lar­vae develop in olives.

Oppor­tunis­tic gen­er­al­ists’ such as bird and rep­tile species might feed on adult life stages and ants on the pupae. But there are no key­stone’ species, that is ones that are pre­dom­i­nantly depen­dant on the olive fly.

What’s your response to sci­en­tific group Testbiotech’s fear the GM flies could escape and their lar­vae off­spring end up in olives in com­mer­cial plan­ta­tions?

Bear in mind this is a rel­a­tively iso­lated site and the trial is net­ted. Typ­i­cally they fly 50 – 300m and if mates and food are present they stay very local.

Notwith­stand­ing this, the Oxitec male olive flies are sub­jected to such a strong neg­a­tive selec­tive pres­sure from the inher­ited lethal­ity trait that they are not capa­ble of spread­ing and estab­lish­ing in the envi­ron­ment. The whole con­trol con­cept is based on not breed­ing effec­tively and not remain­ing in the envi­ron­ment.

What about the con­cern that it is not known how your insects will inter­act with chang­ing envi­ron­men­tal con­di­tions?

This is why one does step-by-step, care­ful tri­als. It’s crit­i­cal that these are done within the reg­u­la­tory process and we often use respected third par­ties to make sure the trial design and run­ning of the trial are done in the most pro­fes­sional way.

The process for test­ing phar­ma­ceu­ti­cals involves pre-clin­i­cal tests to gather as much infor­ma­tion as pos­si­ble then phased test­ing. Sim­i­larly, we do exten­sive lab­o­ra­tory and field cage test­ing and eval­u­ate the strain as far as pos­si­ble with­out an open release. Data from these tri­als show the strain per­forms well. Then at some point one must go into the field. Hence here we are doing this in a net­ted trial – and it is the pur­pose of this trial to deter­mine how the Oxitec olive flies inter­act with chang­ing envi­ron­men­tal con­di­tions.

Will you release your envi­ron­men­tal risk assess­ment for the pro­posed trial?

The reg­u­la­tory author­i­ties are still review­ing the file‭ ‬but once they are ready the risk assess­ment can be requested by any party directly from them.

The envi­ron­men­tal‭ ‬risk‭ ‬assess­ment is a key part of the process and was car­ried out fol­low­ing the (2012) EFSA‭ (‬Euro­pean Food Safety Author­ity‭) ‬draft guid­ance doc­u­ment for con­duct­ing an envi­ron­men­tal risk assess­ment of genet­i­cally mod­i­fied ani­mals.

Once a wild olive fly pop­u­la­tion was heav­ily reduced or elim­i­nated, how would this be main­tained?

In the pro­posal, weekly or twice weekly releases are dis­cussed. The num­bers depend on many fac­tors but gen­er­ally we would look to out­num­ber the wild males by about 10 to 1. So if there were say 100 wild males (which could well be the case) in each plot then we’d look to release 1,000 in each plot.

Longer term, there are options — one can con­sider an area wide use – where you aim to con­trol the olive fly and keep it at a low level through­out the year in an area with repeated releases.

Another option is to use this approach in autumn as the olive fruit is about to form and poten­tially again in spring – in other words to reduce the pest threat at the time of year when num­bers and dam­age would oth­er­wise esca­late.

Alter­na­tively, it could be com­bined with other inter­ven­tions as part of an over­all inte­grated pest man­age­ment plan.

The annual cycle of the olive fly‭ ‬is such that‭ ‬there is a big adult pop­u­la­tion peak as the fruit‭ ‬forms in autumn and a small adult pop­u­la­tion peak in the spring which is reliant on the olives which remain on the trees after the pre­vi­ous har­vest.

The most obvi­ous con­trol sce­nario in my view is a pat­tern of releases in the pre-peak part of the year‭ (‬August, Sep­tem­ber, Octo­ber‭ ‬– but‭ ‬the tim­ing depends on tem­per­a­ture to an extent‭) ‬that pre­vents that adult pop­u­la­tion peak occur­ring.‭ ‬Reduc­ing that peak also will have knock on con­se­quences of reduc­ing the over-win­ter­ing pop­u­la­tion and hence con­tribute to the fol­low­ing year‭’‬s con­trol.

In almost all crop pro­tec­tion sit­u­a­tions there is a dam­age thresh­old‭ ‬– you rarely try and elim­i­nate.‭ ‬What you do is assess the‭ ‬planned mar­ketabil­ity of the crop,‭ ‬the‭ ‬cost of‭ ‬poten­tial‭ ‬dam­age‭ ‬and‭ ‬the cost of inter­ven­tion, and then make a deci­sion as to‭ ‬the crop pro­tec­tion strat­egy.‭

Why did you choose Tar­rag­ona and not, say, Andalu­sia, where most of Spain’s olive oil sec­tor is located?

We did talk to‭ ‬stake­hold­ers‭ ‬in Andalu­sia and they were very pos­i­tive.‭ ‬But when look­ing around sites we wanted a rel­a­tively small, iso­lated site so we didn‭’‬t have a nearby farmer spray­ing insec­ti­cides.‭ ‬The poten­tial sites we looked at in Andalu­sia were all very large sites.‭ ‬Cat­alo­nia made more sense‭ ‬from a prac­ti­cal trial per­spec­tive.

The trial would basi­cally involve six plots on one site, each plot being about 0.14ha (e.g. 12m x12m) and hav­ing four trees.

Would any pay­ment or other rec­om­pense for this trial be made to any per­son or orga­ni­za­tion in Spain or the Euro­pean Union?

We‭ ‬expect to cover‭ ‬local con­trac­tor or actual trial run­ning costs‭ ‬(labor costs,‭ ‬con­sum­ables,‭ ‬etc.‭)‬ but‭ ‬we are not expect­ing any addi­tional costs or‭ ‬fees.

Are sim­i­lar tri­als planned else­where?

Farm­ers in other coun­tries such as Greece and Italy have con­tacted us as they are very inter­ested in this method of con­trol of olive fly.‭ ‬Hence we‭ ‬included‭ ‬in the appli­ca­tion that we may seek approval for‭ ‬fur­ther coun­tries in due course.

Do you have any cost­ings to show how using the GM olive fly com­pares to using pes­ti­cides to con­trol wild olive flies?

No sorry,‭ ‬we don‭’‬t.‭ ‬It is really early days at the moment.‭ ‬But the Inter­na­tional Atomic Energy Author­ity has long had olive fly as one its key tar­gets for radi­a­tion based ster­ile insect con­trol and they,‭ ‬in the past,‭ ‬have pub­lished their eco­nomic fea­si­bil­ity stud­ies.

Clearly we think our approach will‭ ‬have sig­nif­i­cant ben­e­fits over cur­rent inter­ven­tions and‭ ‬be cost effec­tive.‭ ‬We see advan­tages, too, over a radi­a­tion based approach,‭ ‬should that be fea­si­ble.‭ ‬Our olive flies are also marked, mak­ing mon­i­tor­ing sim­ple and effec­tive.



Related News