Pesticide Residues in Coastal Tropical Ecosystems: Distribution, fate and effects - Chapter 15 doc

Pesticides in Jamaica and the Commonwealth CaribbeanTable 15.1 Agricultural use of land in different Commonwealth Caribbean countries Land use % Country Area km 2 Arable land Permanent

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Pesticides in Jamaica and the Commonwealth Caribbean 425

in an arc made up of the Windward (Grenada, St Vincent and the Grenadines, StLucia, and Dominica) and the Leeward (Montserrat, St Kitts and Nevis, Anguilla,and Antigua and Barbuda) islands and the British Virgin Islands to Jamaica andthe Cayman islands just south of Cuba, and include the Turks and Caicos islandsand the Bahamas to the north of Cuba The more than 4.5 million people wholive on these islands depend primarily upon agriculture, fishing, mining, and tourismfor their livelihoods Only Trinidad, with limited oil but enormous gas reserveshas developed a strong industrial economy

The islands are volcanic in origin and the land is composed of white limestone,metamorphic rocks, and alluvium Except for Trinidad, Barbados, and Antigua,

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Figure 15.1 Map of the Caribbean Basin showing major islands and island groups

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which are fairly flat, the other islands have rugged central mountain ranges, whichslope toward the coastal plains Rivers originate in the mountains and drain thevalleys and plains into the sea Annual rainfall ranges between 1,000 and 5,000

mm and temperatures between 25° and 35°C Antigua receives significantly lessrainfall than the other islands

Jamaica, the largest island in the Commonwealth (area 1,140,480 ha; 235 km

× 82 km), is situated between Lat 17°30´ to 18°30´N and Long 76°30´ to 78°30´W.The bird-shaped island is characterized by a central spine of rugged mountainranges, which extend from east (highest peak, 2,300 m) to west (300 to 900 m high)and slope into valleys and the coastal plains in the north and south (Figure 15.2).Almost half of Jamaica is 300 m above sea level Sixty percent of the land iscomposed of white limestone while the rest is made up of metamorphic rocks andalluvium The island has twenty watersheds that are drained by nineteen majorrivers, ten flowing generally north, eight south, one east and one west (Figure15.3) Most watersheds experience at least twice-weekly rainfall although thereare two defined rainy seasons, a minor one from May to June and a major onefrom September to early November The annual rainfall ranges from 1,200 to5,500 mm and the temperatures range between 23° and 33°C in the plains

L a n d u s e

Since the early days of European colonization, agriculture has been the mainstay

of the Caribbean economy, although only about 15 to 25 percent of arable land inthe different islands is cultivated In the mainland countries of Guyana and Belize,

Figure 15.2 Topography of Jamaica

a – Blue Mountain ranges, alt 1,500–2,135m surrounded by high mountains and valleys (alt 900–1,500m)

b – mountain ranges, alt 600–900m

c – cockpit country, alt 300–600m, limestone hills

d – coastal plains, alt 0–150m

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cultivated land is only 1 percent and 2 percent of arable land, respectively (Table15.1) Sugarcane is the major crop for the entire region except in Guyana where120,000 ha are under rice and only 44,000 ha are under sugarcane (Higman,1975) A century after its introduction in the region in 1872, bananas have become

a major crop in many islands, particularly in the Windwards Coconut, cocoa,citrus, vegetables, beans, coffee, cotton, peanuts, ornamentals, and a variety ofroot and other tropical crops are grown on a small scale on different islands.Jamaica has diversified its agriculture from sugarcane to bananas (in the 1870s),coconuts (around 1910), citrus and vegetables (in the 1920s), and to mangos andornamentals in the 1980s (Table 15.2; Figure 15.3) Although coffee plantationswere developed in the middle of the 1700s, their fortunes fluctuated until the1970s, when massive renewal and expansion of the crop were initiated

Agronomic practices introduced by the Europeans in the coastal plains haveremained essentially unchanged, although agriculture has since been extended tohillsides where slopes of up to 70° are cultivated In many areas land is still beingcleared by cutting trees and burning brush There is no terracing of land ormanagement of water flow Soil erosion on the different islands is undocumentedbut is probably not very different from Jamaica where the estimated loss of top soil

is about 13,000 T km–2 year–1 (Eyre, 1990)

Figure 15.3 The watersheds of Jamaica and geographic distribution of the major

agricultural crops of Jamaica

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Pesticides in Jamaica and the Commonwealth Caribbean

Table 15.1 Agricultural use of land in different Commonwealth Caribbean countries

Land use (%) Country Area (km 2 ) Arable land Permanent Permanent Forests Coastline Area (ha) Area (ha)

Source: Adapted from Higman, 1975 with additional information from The CIA World Factbook, 2000

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from each Commodity Board or Association

Product Area (ha) Major pests Pesticides used a Mean application rate Pesticide load

(kg or L a.i.) (kg or L a.i year –1 ) Banana 34,000 Banana borer, thrips, I/N: ethoprophos, isazofos, 1.5 kg ha –1 ; 3 times per y 15 kg ha –1 y –1 ; 510,000 kg y –1

nematodes chlorpyrifos and other OPs Weeds H: paraquat, ametryn, 5 L ha –1 ; 3 times per y 4.5 L ha –1 y –1 ; 153,000 L y –1

glyphosate Sigatoka disease F: hexaconazole, chlorothalonil, 0.5 L ha –1 ; 6 times per y 3 L ha –1 y –1 ; 102,000 L y –1

tridemorph and others Cattle 1,500,000 Ticks, screw worm I/A: amitraz 0.003 L per animal per 0.078 L per animal per y;

spray; 26 sprays per y 117,000 L y –1

Citrus 12,000 Citrus root weevil, I: carbaryl 9 kg ha –1 ; 2 times per y 18 kg ha –1 y –1 ; 216,000 kg y –1

ants Leaf miner, aphids, I: malathion, dimethoate, 2.8 L ha –1 ; 3 times per y 8.4 L ha –1 y –1 ; 100,800 L y –1

scale insects diazinon Gummosis, scab, foot F: benomyl, fosetyl, 3.4 kg ha –1 and 2.6 L ha –1 ; 6.8 kg ha –1 y –1 ; 81,600 kg y –1

rot copper hydroxide 2 times per y & 5.2 L ha –1 y –1 ; 62,400 L y –1

Weeds H: paraquat, glyphosate 0.3 L ha –1 ; 2 times per y 0.6 L ha –1 y –1 ; 7,200 L y –1

Coffee 10,112 Coffee berry borer I: endosulfan 0.3 L ha –1 ; 2 times per y 0.6 L ha –1 y –1 ; 6,070 L y –1

Coffee leaf miner I: dimethoate, diazinon, 0.5 L ha –1 ; 2–4 times per y 1.5 L ha –1 y –1 ; 15,168 L y –1

carbofuran Coffee leaf rust, F: copper oxychloride 1.1 kg ha –1 ; 2 times per y 2.2 kg ha –1 y –1 ; 22,246 kg y –1

anthracnose and brown eye spot Weeds H: paraquat, glyphosate 0.6 L ha –1 ; 2–4 times per y 1.5 L ha –1 y –1 ; 13,651 L y –1

Ornamentals 300 Mites I: various OPs 0.35 L ha –1 ; 20 times per y 7 L ha –1 y –1 ; 2,100 L y –1

Rust F: copper – based 0.5 kg ha –1 week –1 26 kg ha –1 y –1 ; 7,800 kg y –1

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Product Area (ha) Major pests Pesticides used Mean application rate Pesticide load

(kg or L a.i.) (kg or L a.i year –1 ) Sugarcane 2 41,000 West Indian canefly I: fenitrothion, malathion 0.1–0.2 L ha –1 ; occasionally 40.5–80.9 L ha –1 y –1

Weeds H: 2,4 – D, ametryn/amitraz 1.5 & 6 L ha –1 ; 1.5 times per y 2.3 L ha –1 y –1 ; 94,300 L y –1

diuron 4.3 kg ha –1 ; 1.5 times per y 6.5 kg ha –1 y –1 ; 266,500 kg y –1

Vegetables 2,500 Mites, aphids, army- I: deltamethrin, λ- cyhalothrin, 1 L ha –1 ; 54 times per y 54 L ha –1 y –1 ; 108,000 L y –1

worms, semi loopers, malathion, profenofos, diamondback moth, other OPs

whiteflies, cucumber beetles

Note:

a Initials indicate: I-insecticide; N-nematicide; H-herbicide; F-fungicide; / indicates multiple use.

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R e s e a r c h

From plantation days when naturalist Hans Sloane first recorded the Jamaican

citrus root weevil Exophthalmus vittatus L (Coleoptera: Curculionidae) in 1725 to

the 1970s, most research on plant protection in the Caribbean was restricted torecording and describing crop pests and their outbreaks The notable exceptions

to this trend have been the excellent work done on sugarcane pests by the CaroniSugarcane Research Institute in Trinidad and the Sugarcane Research Institute inJamaica The Imperial College of Tropical Agriculture, founded in Trinidad in

1921, did not have much impact on insect pest control research in the region Thistrend continued even when the college became the Faculty of Agriculture of thenewly founded University of the West Indies (UWI) in 1962 At about the sametime, a laboratory of the Commonwealth Institute of Biological Control, London,England was set up in Trinidad and two regional organizations – the CaribbeanAgricultural Research and Development Institute (CARDI) and the Inter-AmericanInstitute for Cooperation in Agriculture (IICA) funded by various internationalagencies – became active in different countries of the Commonwealth

In spite of the infrastructure, research on plant protection continued to be ofmarginal value The introduction of modern synthetic organic pesticides in theregion in 1945 further exacerbated the problems of local entomologists Pesticidesprovided an excellent cost–benefit ratio, much less dependence on a usuallyunreliable labor force, and the euphoria of being current with contemporarytechnology The practice of chemical pesticide reliance created a ‘mutant culture’within agriculture, the ‘pesticide subculture’, which has become deeply ingrainedand difficult to reverse even in agricultural policy makers

Until the 1970s, almost no data existed on any crop pest that could be used fordeveloping even short-term strategies for its control To develop this type of data,

A Mansingh established an Insect Toxicology and Physiology Laboratory in 1974,which in 1985 became an interdisciplinary Pesticide and Pest Research Group(PPRG) in the Faculty of Pure and Applied Sciences at the UWI, Mona, Jamaica.The group embarked upon the relevant research as outlined in Figure 15.4

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C ROP CARE F ATE OF RESIDUES IN ENVIRONMENT :

E COTOXICITY AND RISK ASSESSMENT

F IELD TRIALS ON EFFICACY ,

PERSISTENCE , TIMING , ETC ; &

I NTEGRATION OF ALL STRATEGIES R E - ENTRY PERIOD ,

QUALITY CONTROL ,

PACKING , LABELS ,

SAFETY GEAR , ETC

INTEGRATED MANAGEMENT OF PESTS AND PESTICIDES

A PPLICATION TECHNOLOGY ;

E QUIPMENT DEVELOPMENT

R ESIDUES IN HUMANS ,

ECONOMIC INJURY LEVEL

G ENERAL AWARENESS *** S PECIAL TRAINING OF HANDLERS , *** D EGREES AND

P UBLIC AND STUDENTS APPLICATORS , FARMERS , OFFICERS DIPLOMAS

Research aspect Occupational aspect

Developmental aspect

Legal

aspect

Research aspect

Legal aspect

Training

aspect

Training aspect Basic Applied

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Tr a i n i n g

It is unfortunate that training in pesticide use has traditionally been neglected bythe UWI, agricultural schools, and Ministries of Agriculture of the CommonwealthCaribbean Users have little appreciation of the occupational and environmentalhazards of pesticides Most receive training from their peers, which perpetuatesthe misuse and abuse of pesticides Very few farmers can read or understand themanufacturer’s instructions, which are usually printed in fine print Even mostextension and training officers have little knowledge of the three ‘W’s (why?, what?,and when?) and three ‘H’s (how much?, how?, and how often?) of pesticide use.Occasionally the UWI, CARDI, and the Caribbean Conservation Association(CCA) hold training programs on pesticide application for a few farmers, dependingupon availability of international funding

The College of Agriculture in Jamaica offers a two-year diploma and year associate degree program after grade 10 of high school, which superficiallycover plant protection and pesticides The Faculty of Agriculture, UWI offers ageneral BSc degree in Agriculture and MSc and PhD degrees in different disciplines,including plant protection, but the program is weak The PPRG of the UWI,Jamaica offers quite extensive courses on insect taxonomy, ecology, physiology,and integrated management of pests and pesticides to final year undergraduatestudents Its graduate school trains at least three students per year, offering mastersand doctorate degrees in various fields

three-U S E O F P E S T I C I D E S

C o n s u m p t i o n

It is difficult to establish the trend in pesticide use over the decades or calculate apesticide load for the Commonwealth Caribbean countries as import data werenever recorded until the 1970s Even now, most countries record only the quantities

of formulations imported – each may contain from 5 to 80 percent a.i Data inTable 15.3 suggest that the relative consumption of different pesticide groups varieswith crop and country Consumption by group in Barbados and Trinidad isherbicides > insecticides > fungicides while in Jamaica and other islands the relativeranking is insecticides > herbicides > fungicides However, when the quantity ofa.i.(s) is considered, the use of herbicides in Jamaica is about 2- and 2.8-fold morethan fungicides and insecticides, respectively, while in Guyana, these differencesare 2.5- and 33.2-fold, respectively There may be a similar trend for a.i consump-tion in other Commonwealth countries depending on the mix of crops grown andlocal pest problems, although Belize currently uses more fungicides than herbicides

or insecticides

The greatest quantity of pesticides per hectare of cultivated land is utilized inthe cultivated fields of Barbados, followed by St Vincent > Dominica > St Lucia >others (Table 15.3) Pesticide loads (kg a.i ha–1 cultivated) in Belize (0.1), Guyana

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Table 15.3 Amount (kg) of pesticides imported into Commonwealth Caribbean countries

Quantity (kg) (and % of total) of pesticides imported

cultivated land Barbados b 125,943 (18.5) 362,183 (53.2) 28,315 (4.2) – c 164,208 (24.1) 680,649 53.08

a Quantity includes insecticides, nematicides, and acaricides.

b Data are on formulations with 5–80% active ingredient; Source: deGeorges, 1989; CCA/IRF, 1991.

c En dash (–) indicates no data available.

d Data in kg of active ingredient; Source: Gooding, 1980.

e Data in kg of (1) formulations and (2) active ingredient

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(0.39) and Jamaica (2.13) are much lower than that for the United Kingdom (3.9)

in 1977 (Gooding, 1980)

Estimates of the annual consumption (kg and L) of pesticides for specific cropsare available only for Jamaica (Table 15.2) The use order by crop is bananas(807,000) > citrus (130,000) > livestock (117,000) > vegetables (108,000) >sugarcane (50,000) > coffee (43,484) > ornamentals (9,900) The ranked pesticideload (kg or L ha–1 year–1) by crop type is vegetable fields (54) > ornamental (33) >banana (23.7) > citrus (12.5) > coffee (4.35) > sugarcane (1.2) > livestock (0.078 Lper head)

Environmentally however, the use of endosulfan and other pesticides in coffeemay be regarded as the most dangerous, because this crop is grown mainly inmountainous watersheds and highlands, where pesticide runoff into rivers is morefrequent Similarly, a high pesticide load in banana fields – particularly that ofisazofos, which is highly toxic to aquatic fauna – could contaminate rivers andcoastal waters With the banning of dieldrin in 1989, entry of the last persistent

OC into the Jamaican environment was stopped

I m p o r t a t i o n a n d s t o r a g e

Most of the pesticides imported into the region are formulations that may be sold

as is or diluted by reformulation at facilities in Jamaica Until the 1990s, therewere no regular or formal government inspections at ports of entry and storage inboth warehouses and retail stores was unregulated At home, small farmers usuallystore chemicals inside their houses, with the consequence of more than occasionalfood contamination and poisoning

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be disposed anywhere, including in rivers Empty pesticide containers and bagsare routinely disposed of as litter Disposal of chlorpyrifos-coated plastic bags usedfor covering developing banana bunches is largely indiscriminate, particularly inthe Windwards, where pesticides are eventually carried into rivers and streams bywind or torrential downpours This situation is improving to some extent on a fewplantations in Jamaica where the bags are now collected for burial or exported toCosta Rica for recycling

A p p l i c a t i o n

Pesticides are applied to control crop pests, termites, domestic pests, and mosquitoes.The US Drug Enforcement Agency (US DEA) sprays herbicides for marijuanaeradication and many ‘smart’ individuals throw insecticides into rivers for fishing.The timing and frequency of pesticide application are still based on routine calendarrecommendations and not on EIL or even sighting the pest For instance, coffeefarmers spray endosulfan twice a year and crucifers are sprayed twice a weekwithout ever checking for the presence of a pest (Table 15.2)

All small and medium-sized farmers (<30 ha) use knapsack sprayers, althoughlarger farmers may have motorized sprayers Selection of an appropriate nozzle

or calibration of spray equipment has never been taught or practiced Aerialspraying in the Commonwealth Caribbean is restricted to large areas of sugarcane

in Trinidad, rice in Guyana, bananas in the Windwards and Jamaica, drugeradication by the US DEA, and mosquito control by the Ministry of Health.Few farmers wear any protective gear or consider the wind velocity and direction,the prospects for rain, the nearness to a river or people’s homes, the local topography,

or the height of target plants before spraying operations commence In theWindwards, aerial spraying is regularly carried out without any warning beinggiven to people living in homes within and on the periphery of plantations Theauthors have observed – on more than one occasion – that children, laundry, cookingware, livestock, and home gardens were exposed directly to settling from aerialpesticide sprays Also, drift and settling of aerial sprays occurs in various drainsand streams running through the plantations and discharging ultimately into thesea

L E G I S L AT I V E M A N A G E M E N T O F P E S T I C I D E S

Until the 1970s, pesticides were handled by the pharmaceutical division in theMinistry of Health for the various islands Jamaica passed a Pesticide Act in 1975that regulated registration, importation, transport, storage, retailing, and manu-facturing of pesticide formulations All highly toxic pesticides and OCs, exceptdieldrin and chlordane, were banned in 1973 A list of restricted use pesticideswas also prepared In the 1980s, chlordane and dieldrin were banned whileendosulfan and isazofos – two environmentally toxic compounds – continue to be

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listed among the restricted use pesticides Unfortunately, the registration ofpesticides and issuance of import permits were handled in a half-hearted mannerwhile other regulations were never enforced.

The existence of regulations ‘on the books’ did not satisfy international monetaryagencies who restricted funds for agricultural development to effect legal ‘active’control of pesticides In 1990, the World Bank invited A Mansingh to serve as aconsultant for developing policies and strategies for legislative control of pesticides

in Jamaica The German development agency, GTZ, later provided financial andtechnical assistance for the World Bank plan and in 1993, the Pesticide ControlAuthority of Jamaica (PCA) was formally established

The PCA is housed in the Ministry of Health and is managed by a board ofdirectors, which has members from the UWI and the Ministries of Agriculture,Environment, Health, Justice, and Commerce and Industry A registrar and twodeputy registrars execute the PCA mandate In three years, the PCA streamlinedand updated procedures for pesticide registration and issuance of import licences;prepared lists of banned, restricted use, unrestricted sale, and unused and unwantedstocks of pesticides; initiated registration of storage and manufacturing sites; andresumed programs for promoting pesticide awareness Efforts are currentlyunderway to train and license pest control operators Legislation covering thevarious phases of a pesticide’s life cycle is constantly being drafted A major mile-stone was achieved by the PCA in 1998 when all the identified stocks of unwantedpesticides in the island were exported to the USA for incineration

Full training of pest control operators and enforcement of most regulations isunlikely to be achieved in the near future Having voted down a proposal for a levy

on the sale of pesticides, the Government of Jamaica has restrained the activities

of the PCA by forcing it to be dependent upon meager budgetary allocations.Notwithstanding these constraints, the PCA, in collaboration with the NaturalResources Conservation Authority and the Customs Department and with technicalassistance and advice from the US EPA, has brought Jamaica to the forefront ofAfrican and Caribbean countries in the legislative management of pesticides.The chronology and status of pesticide management in Trinidad and Barbadoshave been very similar to Jamaica However, the eastern Caribbean states (theWindward and Leeward islands) with funding from the US AID have taken morethan five years to develop their common legislation, which has yet to be promulgatedand enforced, except in the case of the registration and importation of pesticides

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needed to address the particular requirements of their topography, size, climate,and agricultural practices Several natural features and aspects of human activityrender an island’s ecosystem prone to pesticide contamination (Mansingh, 1993).These include a thin (0.1 to 1.5 m) soil cover that favors leaching and runoff; cropcultivation and the use of agrochemicals on high mountainous slopes where mostrivers originate; tilling steep slopes with poor agronomic practices, which encouragessoil erosion; small holdings and a mixed crop system in which different pestcomplexes may require different pesticides; the vagaries of wind currents on slopesand in valleys, which promote aerial drift of spray particles; a pattern of frequentand intense rainfall, which facilitates the regular runoff of chemicals; complexdynamics of water-flow in unusually small and short rivers, which can transportresidues to coastal waters quickly; and the close proximity of farms, rivers, homes,and seacoast, which makes them all vulnerable to residue exposure

To reduce the ecological and environmental consequences of pesticide use,IPM is practiced by which insecticide applications are based upon an EIL Manycountries outside the Commonwealth Caribbean – with decades of research data– have established EILs for various pests and thus have reduced pesticideconsumption on many crops, e.g cotton, corn, and vegetables, by 50 to 70 percent.However, pesticides remain as the major element in their IPM programs.For tropical countries in general – and the Commonwealth Caribbean in parti-cular – there remains a paucity of the basic data needed for establishing EILs forindividual pests and for initiating IPM strategies against them Even internationaldata on cosmopolitan pests must be validated under local conditions The problem

is further exacerbated by the reluctance of small farmers to risk their meagerincome by adopting recommended alternate strategies In any case, partial or almosttotal reliance on organic pesticides is likely to continue globally, at least untilbotanical pesticides are popularized, their cost per application lowered, and newproducts developed for pests not currently targeted

So long as synthetic organic pesticides continue to be even a minor element ofIPM, equal or greater emphasis must be given to the management of pesticides,which includes their selection, application, fate, persistence, transport and runoff,ecotoxicity, and the environmental risk assessment of their residues Therefore, it

is proposed that rather than practicing IPM, a system, called Integrated ment of Pests and Pesticides (IMPP) and outlined in Figure 15.4, be adopted,practiced, and promoted in developing countries, particularly in island ecosystems(Mansingh, 1993)

Manage-I M P P i n t h e C a r i b b e a n

Recognizing the need for IMPP in the Commonwealth Caribbean and guided by

the philosophy that ‘the developing countries must focus their attention on developing an

intermediate technology for sustainable agricultural production, by integrating the practice of

“risk reduction” and “safe use” of pesticides, with indigenous technology, which is economical,

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effective and environmentally friendly’ (Mansingh, 1993), the PPRG laboratories have

generated significant data for IMPP in the region since 1974

Pe s t m a n a g e m e n t

In the 1970s, regional sugarcane entomologists achieved success in biological control

of the sugarcane moth borer Diatraea saccharalis Fabricus (Lepidoptera: Crambinae)

and eliminated the use of insecticides for this pest However, control of the

frog-hopper Aeneolamaia varia saccharina Fabricus (Heteroptera: Cercopidae) in Trinidad

is still dependent upon insecticides In the 1980s, Dr Gene Pollard initiated pestmanagement projects at the UWI, Trinidad CARDI also has a few pest manage-ment projects, which are in their infancy

Data on the life cycle, distribution, economic importance, alternate host plants,the natural enemy complex of major pests, and the laboratory and field efficacy

of pesticides against them are essential for developing IPM and IMPP strategies

Research on the management of cattle ticks including Boophilus microplus Canestrini,

Amblyomma cajennennense Fabricus, A variegatum Fabricus, and Dermacentor (Anocentor) nitens Neumann (Acari: Ixodidae) (Rawlins, 1977) and screwworm fly Cochliomyia hominivorax Coquerel (Diptera: Calliphoridae) changed the acaricidal usage pattern

in Jamaica and enabled investigators to propose strategies for managing theseparasites (Rawlins and Mansingh, 1987) The IAEA, FAO, and the Ministry ofAgriculture, Jamaica with technical involvement of the PPRG launched a five-year sterile-insect release program for screwworm eradication in Jamaica in late1998

The coffee berry borer Hypothenemus hampei Ferrari (Coleoptera: Scolytidae)

threatened Jamaica’s coffee industry after accidental introduction to the island inthe mid-1970s Data from other countries on the biology of this pest were suspect,resulting in total dependence on the indiscriminate and excessive use of insecticides(Mansingh, 1991) Studies of its life cycle (Johanneson, 1983), infestation pattern,insecticidal susceptibility (Rhodes, 1987), boring behavior (Boothe, 1987), economicimportance, the field efficacy of insecticides, and cultural control practices (Reidand Mansingh, 1985; Reid, 1987) led to demonstration of a nutritional diapause

in the pest (Mansingh, 1991) This led to development of the first ever IPM modelfor the suppression of its population (Reid, 1987) This model reduced the use ofpesticides in coffee culture by 30 percent An expert computer system, developed

by Mansingh and Reichgelt (1997) in collaboration with the Pesticide and PestResearch Group, would further reduce insecticide use through computer-basedevaluation and recommendations to farmers

The citrus root weevil (CRW) complex Exophthalmus vittatus L and Pachnaeus citri

Marshall (Coleoptera: Curculionidae) has been the major pest of citrus crops inthe region Dieldrin, without justification, had been used for control of the pestbetween 1958 and 1989 Studies on susceptibility of the pest to various insecticides,the persistence of dieldrin on citrus plantations (Biggs-Allen, 1990), the potential

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of an entomopathogenic nematode against the pest (Myers, 1996), the role ofalternate host plants and egg and larval parasites (Clark-Harris, 1998), and theefficacy of botanical formulations (Robinson and Mansingh, 1999, unpublisheddata) have forced the discontinuation of dieldrin use This has led to the develop-ment of an IPM strategy that encompasses the use of alternate hosts as a trap-crop and treatment with an experimental botanical anti-feedant formulation, codenamed ‘Ashima’, developed by the PPRG

Traditionally vegetable farmers have used the greatest quantity of insecticidesper unit of land cultivated, yet little had been done by the region’s scientists toalleviate their problems Under the guidance of pesticide salesmen, vegetablefarmers fought pest resistance by increasing the dose of an insecticide before finallyswitching to a different chemical, which then provided only a temporary respite.The PPRG alleviated this problem by demonstrating the efficacy of two OP

pesticides and one Bacillus thuringiensis Berliner formulation (Forbes, 1995) Data

on population fluctuations of the diamondback moth (DBM) Plutella xylostella L (Lepidoptera: Plutellidae) and the cabbage looper Trichoplusia ni Hubner (Lepidop-

tera: Noctuidae), their natural enemies (parasitoids and predators, including spiders),EILs (Alam, 1996), the laboratory and field efficacy of insecticides (Forbes, 1995)and plant extracts (Wilson, 1993), the planting of tobacco within and mustardaround cabbage plots (Mansingh and Napier, 1998, unpublished data), and sprayingwith three experimental botanical formulations code-named ‘Ashima, Abhijai, andDejoun’ have provided enough information to allow cabbage cultivation withoutthe use of synthetic organic pesticides

Coconut mites Eriophyes guerreronis Keifer (Acari: Eriophyidae) have been

damaging the quality and quantity of nuts produced in the Caribbean for overtwo decades Vamidothion had been recommended for mite control but itspartitioning between coconut meat and milk and the persistence of its residues

inside the nut (Dasgupta et al., 1998) aborted plans to use this or any other insecticide

against the mite Recently McDonald (1999) has quantified the economic lossinflicted by the pest in Jamaica but found no effective natural enemy that could beutilized for suppressing its population

Weed management in the region has benefitted greatly from the work of DrRichard Braithwaite of the Faculty of Agriculture, UWI, Trinidad His colleagueDavid Hutton in Jamaica has contributed significantly to nematode management

in crops, planting materials, and ornamentals with recommendations on cides and alternate control techniques Research on the field management of plantdiseases has not been a priority of Jamaican scientists, although the use of fungicides

nemati-in the region is quite high

E c o l o g i c a l c o n s e q u e n c e s

The ecological consequences of pesticide use have largely remained undocumented

in the Caribbean except for the three ‘R’s – resistance, resurgence of pest

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tion, and replacement by secondary pests Various pests, ectoparasites, and diseasevectors in the Caribbean have acquired resistance to pesticides (Rawlins andMansingh, 1978; Biggs-Allen, 1990; Forbes, 1995; Sookhai-Mahadeo, 1997; Witterand Mansingh, 1997) Jamaican populations of cattle ticks have developed 15- to67-fold resistance to carbaryl and a few OP insecticides (Rawlins, 1977; Rawlinsand Mansingh, 1978) The CRW complex is extremely tolerant to dieldrin andother insecticides (Biggs-Allen, 1990) and the DBM has developed several thousand-fold resistance to most insecticides as compared to the susceptible Chinese strain(Forbes, 1995) The coffee berry borer is 300- to 700-fold resistant to endosulfan

(Witter and Mansingh, 1997) and Trinidad populations of the mosquito Aedes aegypti

L (Diptera: Culicidae) – the vector for yellow fever – have also developed resistance

to several OP insecticides (Sookhai-Mahadeo, 1997)

The resurgence of DBM populations and outbreaks of the cabbage looper inthe 1990s in areas of heavy insecticide use around Jamaica have been attributed todeep declines in the populations of their natural enemies (Alam, 1996) Likewise,regular calendar-based spraying of endosulfan in the 1980s against the coffee berry

borer has caused a minor and occasional pest of coffee, the leaf miner Perileucoptera

coffeella Guérin-Méneville (Lepidoptera: Lyonetiidae), to become a regular and

often serious pest in the 1990s (Dalip and Mansingh, 1995)

E n v i r o n m e n t a l c o n s e q u e n c e s

The consequences of pesticide use are difficult to assess because baseline data onbiodiversity before the pesticide era are unavailable The ecotoxicity of pesticideresidues on selected terrestrial and aquatic fauna in Jamaica have been documentedand will be discussed later in this chapter

Pe s t i c i d e m a n a g e m e n t

Pesticide management requires a collaborative approach by entomologists,ecologists, biologists, chemists, physiologists, mechanical engineers, soil scientists,and lawyers for investigating and developing legislative management initiativescovering all phases of the pesticide life cycle Further, collaboration by variousstakeholders is required for developing more effective and environmentally friendlyformulations; improving the efficiency of application equipment; establishingguidelines for occupational safety; determining the impact on non-target species;investigating the fate, persistence, and partitioning of residues in differentenvironmental matrices; monitoring environmental contamination from pesticideresidues; developing residue management techniques; assessing occupational andenvironmental risk from the residues; and integrating these findings within IPMmodels for specific pests This should lead to the development of IMPP modelsand strategies (Figure 15.4) Further promotion of awareness programs for thegeneral public, universal training of pesticide users, and improved efficiency ofextension services would ensure implementation of IMPP

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L e g i s l a t i v e m a n a g e m e n t

Scientists have a large share of responsibility for the legislative management ofpesticides in the Commonwealth Caribbean A Mansingh has played a key role indeveloping policy and strategy for the establishment of the PCA in Jamaica and as

a USAID consultant reviewing pesticide regulations and developing policy onenvironmental health risks for the eastern Caribbean states Members of the PCAboard regularly discharge responsibilities including the assessment of pesticides forregistration, categorization of a pesticide as restricted use or banned for a certaincrop or certain geographical areas, and providing technical advice to legislatorsfor drafting new legislation

Regrettably, the Pesticide Boards in the Commonwealth Caribbean still do notpay due attention to labeling practices for pesticides, which ought to focus more

on instructing the user rather than simply satisfying registration requirements.The print size on labels must be large enough to be easily readable by a normalperson, color coded to indicate toxicity, instruct farmers not to use the produceuntil the EIL has been reached, and warn applicators of environmental hazards(Mansingh, 1993)

P u b l i c a w a r e n e s s

The PPRG can justifiably claim credit for initiating and implementing pesticideawareness programs in the Commonwealth Caribbean during the 1970s and 1980sthrough printed and electronic media, seminars, and direct training of farmers.This responsibility now rests with the Pesticide Control Boards or Authorities inthe various islands and countries

in Jamaica (Williams, 1991; Wilson, 1993; Williams and Mansingh, 1993; Mansinghand Williams, 1998) Partial chemical characterization of the active compoundshas been accomplished for some of them (Williams and Mansingh, 1995) andsome formulations have been tested successfully in the field (Wilson, 1993; Williams

and Mansingh, 1993) Extracts of several plants, including Artocarpus altilis Park,

Azadirachta indica A Juss and Hibiscus rosa-sinensis L., show great promise as acaricides

(Blair et al., 1995; Mansingh et al., unpublished data).

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