The exchange of plant material between the countries is essential to the enrichment of the genetic heritage, which is important for the generation of new agricultural varieties. It is estimated that in Brazil, about 80% of foods consumed have an exotic origin. However, not all aspects are positive: when the entrance of plant materials is performed without records or control, it can cause serious problems, such as the spread of organisms that are harmful to national agriculture. These organisms fit the concept of a pest, which applies to any species, breed or biotype of plant, animal or pathogenic agent that damages plants or plant products.

The increasing spread of agricultural pests around the world can be attributed to increased trade between countries, as well as to climate change. Studies conducted by Embrapa show that at least 65% of the cases of pest introduction in Brazil are directly related to human activity, through the transportation of infested plants, fruits or seeds.

Such scenario poses the challenge of developing means to prevent or control the spread of new pests, especially the ones called quarantine pests.

Quarantine pests

Quarantine pests are those that have potential economic importance for areas where they are either not present yet or are present but not widely distributed and under official control. The simple presence of living creatures (animals, plants or microorganisms) in given sites can compromise trade, as it damages or destroys crops, plantations and harvests, and hinders exports.

The list of quarantine pests in Brazil is established by the Ministry of Agriculture, Livestock and Food Supply (Mapa). This list today contains 12 species present in the domestic territory and over 500 species or genera considered to be absent. Out of these, dozens have already been reported in other South American countries and the Caribbean, with large likelihood of entering Brazil. Each pest offers differentiated risks, depending on their characteristics (reproduction, survival, dispersion capacity etc.), and thus specific control actions are necessary.

Quarantine pests in Brazil

Reports of introductions of agricultural pests in the country have increased in the last few decades. By 1960, the number of pests detected per year had been lower than one; it started to be above two in the 1990s and, in the last decade, this number has been close to four. Such scenario is due to the increase in cultivated area and to the international flow of people and commodities.

The most recently recorded case of introduction of a quarantine pest of high economic impact in Brazil was Helicoverpa armigera, which caused expressive losses in soybean, cotton and maize crops in the 2011/2012 and 2012/2013 harvests. Another example is the HLB or citrus greening (Candidatus Liberibacter spp.), which was identified in 2004. Recent introductions of eucalyptus pests have also generated great apprehension in the forest sector, namely red gum lerp psyllid (Glycaspis brimblecombei), detected in 2003, gall wasp (Leptocybe invasa) in 2007, and bronze bug (Thaumastocoris peregrinus) in 2008.

Asian soybean rust (Phakopsora pachyrhizi) is another introduced pest that still impacts national agriculture, as it is responsible for losses of around US$ 2 billion a year in soybean farming. In 2001, the year it was introduced, the disease generated losses of up to 70% in production.

Besides crop destruction and losses in agriculture, quarantine pests also cause serious social problems. The entrance of the cotton boll weevil (Anthonomus grandis) in the country was an example of that. The exotic pest originated from Mexico, crossed borders and was identified in Brazil in 1983. Shortly after that, if had spread to the main cotton producing areas, causing losses of up to 75%. The pest had many smallholders stop working in the fields due to the increased control costs, and it was responsible for changing the whole geography of cotton production in the country.

A similar phenomenon occurred with witches' broom disease (Moniliophthora perniciosa) in Bahia's cacao farms in 1989, which triggered a serious social crisis in the region. With the pest, Brazil stopped being a reference in cacao plantations. The problem was never overcome and the disease continues to represent a challenge for researchers in the area.

Nowadays, the North of Brazil has been considered the main gateway for new quarantine pests. In recent years, seven pests reached the borders through the Northern Brazilian states: carambola fruit fly (Bactrocera carambolae), detected in Amapá in 1996 and in Roraima in 2010; black Sigatoka (Mycosphaerella fijiensis), detected in Amazonas in 1998; citrus blackfly (Aleurocanthus woglumi), found in Pará in 2001; citrus hindu mite (Schizotetranychus hindustanicus), detected in Roraima in 2008; red palm mite (Raoiella indica), detected in Roraima in 2009 and Amazon in 2011; pink hibiscus mealybug (Maconellicoccus hirsutus), detected in Roraima in 2011, and acerola weevil (Anthonomus tomentosus), reported in Roraima in 2014.

The risk of entry through the Brazilian North is related to the vastness of the territory, which hinders fiscalization and better control with preventive measures. Despite the region's accounting for about 4% of total national agricultural production (BCB, 2012), the damage a quarantive pest can cause, should it spread to other Brazilian states, can be devastating and cause not only a reduction yields, but also the loss of export markets, once many countries do not accept crops from regions where there is a presence of quarantine pests.

Embrapa's role

Since its creation, in the 1970s, Embrapa has been conducting research and action on plant quarantine, management of newly-introduced pests, and official imports of exotic biological control agents (insects, mites, microorganismos) against quarantine pests that have entered the country. The goal is to inform biological control, territorial intelligence and preventive breeding measures. Moreover, in order to prevent the entrance and dissemination of agricultural pests, besides controlling previously established pests. However, the risk of new threats' entering the country is more and more concerning, which is why quarantine pests are part of Embrapa's institucional agenda.

With respect to plant quarantine activities, the Corporation has maintained a leading role that started with the establishment of the Quarantine Station at Embrapa Genetic Resources and Biotechnology, in 1977. The work of this station has already resulted in the interception of 80 pests in germplasms that had been imported for scientific research, thus preventing the introduction of such organisms in the country.

There is also the “Costa Lima” Quarantine Laboratory (LQCL) at Embrapa Environment, accredited by Mapa in 1991 to inform classic biological control strategies. With the growth of international trade and the flow of tourists, quarantine activities have intensified, leading the Company to create, in 2014, a new Unit exclusively aimed at the activities: Embrapa Plant Quarantine.

The goal was to modernize the analysis of seeds and other propagation materials that are introduced in the country or exchanged with other research institutions. In 2017, Embrapa Plant Quarantine was integrated to Embrapa Genetic Resources, which today has a consolidated research group in the area of quarantine and plant health.

Embrapa Environment's "Costa Lima" Quarantine Laboratory (LQCL) has equally worked on several research projects by different Embrapa units, universities and in technical cooperation programs (e.g. the one celebrated with the Institute of Forestry Research and Studies (IPEF) Forest Protection Program (PROTEF)), to make contaminant-free imported material available for use in biological pest control of several fruit trees, eucalyptus, among others.

In the area of territorial intelligence, Embrapa Territorial has worked in partnership with the other Embrapa units to identify the likely means through which pests enter Brazil and through which their dissemination more easily occurs, e.g. federal and state highways, in order to support the prevention of the entrance and establishment of quarantine pests in the country. With regard to preventive genetic improvement, Embrapa has been investing in research for the early development of cultivars that are resistant to quarantine organisms that pose high risk to Brazilian agriculture.

The management of newly-introduced pests is another important field of the Corporation's operations. When faced with a new organism that is very harmful to national agriculture, Embrapa's course of action has included concentrated efforts towards collecting information on the pest's biology and ecology, the development of technologies that benefit control, and integrated actions to disseminate information and train target audiences.

An example was the reaction to the introduction of Helicoverpa armigera, in 2014, when in light of the gravity of the situation, Embrapa shortly mobilized the campaign named "Embrapa Caravan", which brought important information on the best strategies to control the pest to farmers, rural technicians and extension workers all over Brazil.

In 2016, Embrapa further concentrated the efforts in the development of research and technology transfer involving quarantine pests by establishing the Project Arrangement called Quarantine (Prevention of Entry and Management of Quarantine Pests in Brazil). The arrangement has aimed at elaborating methods and technologies that contribute to reducing the risks of quarantine pest entry, dispersion, economic impacts, developing management and contingency programs in Brazil, and supporting Mapa's public policy.

There is currently a project portfolio that contains about 10 ongoing research projects and studies involving 25 Embrapa Units, as well as international partners and private consultants.

The Quarantine Portfolio

It is a set of projects organized into four sections:

Prioritization: establishment of method to prioritize quarantine pests that will be the target of the detection, containment and/or mitigation activities as well as of the portolio's projects.

Detection: methodologies and identification of parameters for sampling and fast identification, with the purpose of speeding up early pest detection.

Mitigation: methods and actions to be taken to minimize the impacts of quarantine pests post-entry and/or eradication of the target pest, with the main aim of stopping from spreading outside the area of official control.

Communications and Technology Transfer: Diffusion of knowledge, methodologies and technologies on quarantine pests to public and private stakeholders.

Prioritization of quarantine pests

In 2007, Mapa published the Normative Instruction nº 52, which establishes the list of quarantine pests that are absent and present in the country. The publication of the list is one of Brazil's obligations as a party to the International Plant Protection Convention (IPPC). This convention establishes that the countries have to publish lists of regulated pests so that other countries and commercial partners can more clearly learn about the actions that each takes to prevent the introduction of pests, as phytosanitary measures have to be taken to regulate the pests.

In 2017, as a result of the work of the Quarantine Portfolio, Embrapa and Mapa elaborated  a list with the 20 priority absent quarantine pests for monitoring and research, which, if they enter the country, threaten crops like maize, soybeans, cassava, potato, rice and several fruits. Three of the pests listed already count on contingency plans.

The prioritization used the AHP methodology, ranking pests according to 20 criteria divided into three major groups: entry; establishment and dispersion; and estimated impact.

The 20 priority pests are:

African Cassava Mosaic Virus – virus (cassava)
Anastrepha suspensa – insect (guava)
Bactrocera dorsalis – insect (fruit trees)
Boeremia foveata – fungus (potato)
Brevipalpus chilensis – mite (kiwi, grapevine)
Lethal yellowing disease – phytoplasma (coconut)
Cirsium arvense – weed (wheat, maize, oats, soybeans)
Cydia pomonella – insect (apple)
Ditylenchus destructor – nematode (maize, potato)
Fusarium oxysporum f.sp. cubense 4 Tropical – fungus (banana)
Globodera rostochiensis – nematode (potato)
Lobesia botrana – insect (grapevine)
Moniliophthora roreri – fungus (cocoa)
Pantoea stewartii – bacteria (maize)
Plum Pox Virus – virus (peach, plum)
Striga spp. – weed (maize, cowpea)
Tomato ringspot virus – virus (fruits and tomatoes)
Toxotrypana curvicauda – insect (papaya)
Xanthomonas oryzae pv. oryzae – bacteria (rice)
Xylella fastidiosa subsp. fastidiosa – bacteria (grapevine)

The results of the pest prioritisation are useful both for the plant defense and for research activities. In the scope of the defense, it is possible to determine for which pests contingency plans will be developed, besides guiding decisions referring to the monitoring. With regard to research, the projects can be improved for the sake of, for instance, the development of diagnostic methods, the mapping of risk areas, the establishment of  preventive breeding projects, besides the development of exclusion and eradication methods.