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Control Biologico de Plagas en la Zona del Caribe

Carlos Cruz and Alejandro Segarra
Crop Protection Department
College of Agricultural Sciences
University of Puerto Rico, Mayagüez
Mayagüez, Puerto Rico 00681

Biocontrol of plant pests in the Caribbean was almost completely neglected with the advent of pesticides which appeared to be the solution to all pest problems. However, due to the development of resistance in some major pests, as well as to public awareness of hazards posed to human health and the environment searches are being made for seemingly old alternatives.

The tropical environment in the Caribbean facilitates year round growing season and supports continuous generations of both pests and beneficial organisms. Agriculture is characterized by small subsistence farms, multiple crops and pests, pesticide problems and other problems common to production and marketing.

Biocontrol is now being acknowledged as a area for further research and is a component of a USDA initiative in sustainable agriculture. The ARS, the Entomology Department Administrators (1988) in U.S. Universities and the Experiment Stations have proposed working groups to prepare national biocontrol research programs. This has evolved as an effective alternative to the pesticide dilemma.

Biocontrol is one of the most thoroughly studied methods against insects, nematodes, diseases and weeds. Scientists are now increasing efforts and emphasis on pest control methods not aimed at wholesale eradication, but rather at maintaining pest populations below economic thresholds.

This has already started in the Caribbean, where efforts of national and international institutions have begun to emphasize and implement biocontrol programs. These efforts are directed at identification of research priorities and possible areas for cooperation within the region. At present, there are several institutions conducting individual research with little or no regional coordination. Biocontrol efforts and findings remain little known even between neighboring countries. This is due in large measure to inadequate communication between research and development organizations in the region. There are limited means to disseminate and exchange findings (scientific congresses, journals, meetings, seminars, etc.). Lack of funds for research and for attending local or international meetings is by far the greatest constraint to the development of biocontrol in the region. A workshop should serve to identify research needs and to promote interchange of knowledge within the Caribbean community.

There is evidence of the effective biocontrol successes worldwide and in the Caribbean (Cock, 1985). Bennet (1990) and Alam et al. (1990) summarized the most important cases of successful biocontrol in the Caribbean. The recent introduction of the citrus blackfly Aleurocanthus woglumi in Puerto Rico and its outstanding effective control with the subsequent introduction of the parasitioids Encarsia opulenta and Amitus hesperidum are a pertinent example (Medina et al. 1991). Chemical control of this pest has been impossible in most places; only biocontrol has been effective.

In Puerto Rico, as in many other Caribbean countries, biocontrol has been used for decades. Table 1 presents information regarding the introduction of parasites and predators into Puerto Rico in the 1900's. Most introductions were made during the 1930's, up to 1940, just before the pesticide era. As often occurs, data on many of these introductions are not available since relevant studies were never conducted.

Table 1: View in PDF format

Table 1: Parasites and predators of insect pests of Puerto Rico introduced in the 1990's.

Species

Natural Enemy

Success Level

Selenothrips
rubrocinctus

Dasyscapsus parvipennis

Partial

Dysdercus amdreae

Hyalomya chilensis
Acauloma peruviana

Unknown
Unknown

Aleurocanthus woglumi

Encarsia opulenta
Amitus hesperidum

Successful
Successful

Sipha flava

Coleophora inaequalis
Scymnodes lividigaster

Successful
Unknown

Asterolecanium
bambusae
and A. pustulans

Cladia nitdula
Chilocorus cacti

Successful
Successful

Clastoptera undulata

Carabunia myeresi

Successful

Pulvinaria psidii

Cryptolaemus
montrousiere

Partial

Saissetia oleae

Scutellista cyanea

Partial

Coccus viridis


Coccophagus caridei
Coccophagus fallax
Asya sp.

Unknown
Unknown
Unknown

Aspidiotus destructor





Cryptognatha nodiceps
Cryptognatha simillisima
Asya trinitatis
Scymmus seneipennis
Pentilia castenea
Aphytis lignamensis

Partial
Unknown
Partial
Unknown
Unknown
Partial

Pseudaulacaspis
pentagona

Encarsia berlesei
Chilocorus cacti

Failure
Partial

Icerya purchasi

Rodolia cardinalis

Successful

Dysmicoccus bonimsis

Aphycus terryi
Pseudaphycus mundus

Unknown
Unknown

Dysmicoccus brevipes


Hambletonia
pseudococcina
Anagyrus coccidivorus


Successful
Unknown

Nipaecoccus nipae

Cryptolaemus
montrousieri

Partial

Diatraea saccharalis



Metagonistylum minense
Paratheresia claripalpis
Lixophaga diatreae
Apanteles flavipes

Unknown
Failure
Partial
Unknown

Pectinophora
gossypiella

Bracon kirpatricki
Chelomus blackburni
Exeristes robator

Unknown
Unknown
Unknown

Leucoptera coffeella

Mirax insularis

Partial

Etiella zinckenella








Macrocentrus
ancylovorus
Bracon piger
Apanteles beaussetensis
Bracon pectoralis
Phanerotoma planifrons
Cyrtotyx lichtensteini
Bracon cajani
Icomella etiellae


Failure
Failure
Failure
Failure
Failure
Failure
Unknown
Partial

Cosmopolites sordidus

Plaesius javanus

Unknown

Phyllophaga spp.

Bufo marinus

Partial

Anastrepha suspensa

Parachasma crawfordi

Failure

Anastrepha obliqua




Dirhinus giffardii
Opius tryoni
Tetrastichusgiffardianus
Pachycrepoideus
vindemiae

Failure
Failure
Failure

Unknown

Mosquitoes

Gambusia affinis
Poecilia reticulata

Partial
Unknown

Haematobia irritans




Canthon pilualaris
Phanaeus triangularis
Copris prociduus
Onthophagus incensus
Spalangia endius

Unknown
Unknown
Unknown
Unknown
Unknown

 

Some exotic natural enemies have been recently introduced for the control of certain insect pests, such as citrus blackfly, the lima bean pod-borer, and the sugarcane borer and others such as nematodes, diseases and weeds (Cruz & Segarra, 1990). Also, several species of entomophilic nematodes for the control of root weevils were introduced and tested.

Some recent biocontrol attempts have been successful in Caribbean countries, i.e. the sugarcane borer, the citrus blackfly, the diamondback moth (to a certain level). On-going projects are devoted to control the coffee berry borer, Hipothenemus hampei (Baker, 1990). Two potential parasitoid candidates have been identified: Prorops nasuta and Cephalonomia stephanoderes. These parasitoids will be reared and increased for distribution in the areas where the pest has been identified: Colombia. Jamaica, Mexico, etc. Very positive results are expected from this initiative.

Important Crops and Insect Pests in the Caribbean

Several lists of important pests in the Caribbean have been compiled elsewhere. However, a partial list of crops and pests which are considered important in the Caribbean are presented in Table 2 and potential biocontrol agents are presented in Table 3. These are based mostly on experience and the literature. Among the most important crops grown in the Caribbean are coffee, sugarcane, bananas, plantains, root crops (sweet potato, yams, taniers, cassava), tomato, peppers, cabbage, cucurbits, citrus, pineapple, avocado, mango, pigeonpea and beans. There are important insect pests attacking these crops, some of them with a high potential for biocontrol.

Table 2: View in PDF format

Table 2: Some important crops and their main insect pests in the Caribbean.

Crops

Main Insect Pests

Sugarcane

Diatraea, Diaprepes, Phyllophaga

Coffee

Hypothenemus hampei, Leucoptera coffeella

Banana and plantains

Cosmopolites sordidus

Sweet potato

Cylas formicarius, Euscepes postfasciatus

Yams

Diaprepes

Cassava

Silva spp. (Stem shoot fly), mites

Citrus

Aleurocanthus woglumii, Diaprepes, scales

Pineapple

Batrachedra comosae (gomosis)
Dysmiococcus brevipes

Beans

Leafhoppers, whiteflies, pod borers

Pigeonpea

Pod borers, leafhoppers

Tomato

Heliothis, Liriomyza, Keiferia lycopersicella

Pepper

Anthonomus eugenii, Myzus persicae, Thrips palmi mites, etc.

Cabbage

Plutella xylostella

Cucurbits

Diaphania spp.

 

Table 3: View in PDF format

Table 3: Some important insect pests and their potential for biological control in the Caribbean.

Insect pests

Biocontrol potential

The coffee berry borer
Hypothenemus hampei

Prorops nasuta, Sephanoderes cephalonomia

Whiteflies: Aleurocanthus woglumi,
Bemisia tabaci

Encarsia spp., Amitus sp.,
Eretmocerus serius

Lepidopterous pests:

Diatraea spp.




Cotesia flavipes,
Lixophaga diatraeae,
Metagonistylum minense,
Paratheresia claripalpis,
Trichogramma spp.,

Microbial control

Plutella xylostella


Cotesia plutellae,
Diadegma insularis,
Diadegma sp.

Leucoptera coffeella


Mirax insularis -augmentation Others - conservation, foreign exploration

Diaphania spp

Several: Conservation and augmentation

Heliothis spp

Many: Conservation and augmentation

Others:

Liriomyza spp

Many: Conservation and augmentation

Thrips palmi

Some: Foreign exploration, conservation and augmentation


The Sugarcane Borer

The sugarcane borer, Diatraea saccharalis, is under effective biocontrol in some countries, but it remains an important limiting factor in several others. Different natural agents have been successful on some countries, probably indicating the influence of varying habitats. This pest offers a good opportunity for classical biocontrol. Several natural enemies have been reported by Bennet (1990) and others. Currently, Cotesia flavipes, Lixophaga diatraeae, Metagonistylum minense and Trichogramma spp. are the most successful biocontrol agents. Research is needed to continue the improvement of the existing biocontrol agents.

Root Weevils

Historically, the sugarcane rootstalk weevil, Diaprepes abbreviatus, has been among the most difficult pest to control in the Caribbean. One contributing factor is the high reproductive potential (5,000 eggs/female), in a situation where very low egg survivorship is enough for it to be a pest (Armstrong, 1987). Several biological control attempts have failed, except for entomopathogenic nematodes. However, the search for other biocontrol agents continues Castro (1986) studied the ants species feeding on neonate larvae. She found seven feeding on the larvae. Of these, Pheidole subarmata borinquensis and Pheidole fallax demonstrated the greatest efficiency. In Cuba, Castineiras et al. (1990a, 1990b), reported P. megacephala controlling Cosmopolites sordidus and Cylas formicarius. Richman et al. (1983) reported the ants Monomorium floricola and Crematogaster ashmeadi preying on the egg masses of D. abbreviatus in Puerto Rico and Florida, respectively. Colón (1986) found 17 species of fungi associated with the larvae of D. abbreviatus. Pathogenicity tests demonstrated that half of then were able to kill the larvae. Gliocadium sp. and Fusarium sp. caused the highest mortality. Armstrong (1981, 1987) studied the efficiency of the egg parasitoid Tetrastichus haitiensis on D. abbreviatus eggs oviposited on sugarcane. He found a low efficiency of the parasitoid and concluded it was probably due to the difficulty of oviposition through the sugarcane leaves as compared to other hosts.

Several species of entomopathogenic nematodes have been tested for the control of the most important root weevils in Puerto Rico. Román & Figueroa (1985) reported effective control of the larvae of D. abbreviatus with Steinernema feltiae (=Neoaplectana carpocapsae). Figueroa & Román (1990) reported tests with S. glaseri, S. bibioni and Heterorhabditis heliothidis against D. abbreviatus. González (1986) observed some control using H. bacteriophora and H. heliothidis. Figueroa (1990) obtained excellent results with S. feltiae and S. biboni against C. sordidus. A graduate student is currently evaluating S. feltiae and H. heliothidis against C. formicarius. Several local strains or species of entomopathogenic nematodes recently found in Puerto Rico are being evaluated. Natural enemies against other curculionid pests such as Exophthalmus spp. and Pachnaeus spp. are being sought in some Caribbean countries.

The Coffee Berry Borer

The coffee berry borer, H. hampei is threatening coffee production in the Caribbean. Biocontrol research has produced encouraging finding. Besides the two parasitoids mentioned in the introduction, other potentially effective parasitoids are under study. An example is Heterospilus coffeeicola, which has been classified as effective but difficult to rear in the laboratory. Other potential candidates such as: Phymasticus coffea, Aphanognus dictynnu (apparently hyperparasite of Prorops nasuta) and some microbial agents such as Beauveria bassiana, Metarhizium anisopliae and Paecilomyces spp. These are under study at various research centers worldwide (CENICAFE, Colombia).

The Coffee Leafminer

Another pest of coffee with a high potential for biological control is the coffee leafminer, Leucoptera coffeella. Gallardo (1988) and Wolcott (1947) have reported 15 parasitoids from Puerto Rico. Gallardo has proposed a biocontrol program utilizing the augmentation method using the parasitoid, Mirax insularis. This idea has extraordinary merit and should be pursued vigorously. There are many other natural enemies reported that could be considered when their efficacy and mass rearing techniques are determined. Foreign exploration is another potential alternative which has not been attempted for this pest, which supposedly originated in Reunion (Green, 1984).

The Diamondback Moth

The diamondback moth (DBM) Plutella xylostella is a lepidopteran pest of importance to the Caribbean with a significant number of natural enemies. It has outstanding potential for a successful biocontrol program. In Puerto Rico several parasitoids are particularly effective. Diadegma insularis, may have rates of parasitism up to 90% when protected from pesticides. One limitation is the very low economic injury level of the pest. However, the selection of planting dates, use of selective pesticides and the introduction (where not available) of the most effective parasitoids will undoubtedly improve the level of biocontrol.

Alam (1986) reported complete biocontrol with Trichogramma spp., and Cotesia sp. Bennett & Yasseen (1972) reported effectiveness of C. plutellae against DBM in Barbados, Montserrat, St. Vincent and Trinidad.

The Corn Earworm

The corn earworm (CEW) Heliothis zea is the limiting factor for sweet corn and other vegetable crops. Chemical control is very difficult, even with and effective insecticide. However, many natural enemies have been observed attacking the eggs and larval stages of this insect (King & Coleman 1989). The wasp Trichogramma sp. and the predator Orius pumilio are considered by Figueroa (1983) to be the most important natural enemies in Puerto Rico. In the US, CEW infestations are considered more severe in dry than in wet summers because moist conditions favor the development of several fungal and bacterial diseases. Also several species of predators and parasitic wasps attack it. Populations of these natural enemies can significantly reduce or almost eliminate CEW infestations early in the season. Therefore, early season sprays should be delayed in order to allow populations of natural enemies to develop. Frequent sampling and control measures are necessary in vegetables because even minimal damage by this and other pests can render produce unmarketable.

The Melonworm

Usually the melonworm Diaphania hyalinata (L.) is the most important insect pest of cucurbits in the Caribbean. Medina et al. (1989) observed several parasitoids and predators in Puerto Rico. No natural enemies have been studied in detail. In Barbados, Alam (1986) reported melonworm egg parasitized by Trichogramma pretiosum, the larvae by Eiphosoma dentator and by Cotesia sp., and the pupae by Brachymeria sp. There is a great potential for the biocontrol of this pest, particularly with microbial insecticides, which are already being used in some countries like Guatemala (Agrícola El Sol, 30 Calle 11-42, Zona 12, Guatemala).

Scale Insects, Whiteflies, Aphids and Thrips

The potential for biocontrol of small insects is well known. Since the introduction of Rodolia cardinalis in California in 1892 for control of the cottony cushion scale or the biocontrol of the citrus blackfly in the Caribbean, many outstanding examples have occurred. In Florida, a biocontrol project is seeking natural enemies for whiteflies. As a result several natural enemies have been recorded from Florida, California, the Caribbean, and Central and South America.

SOME CRITERIA FOR BIOCONTROL TARGET SELECTION

Because there are many biocontrol success stories and the many introduced pests in the Caribbean, primary emphasis (or first step) should be given to classical biocontrol. The main task is to identify biocontrol agents (Fry 1989) and introduce them where the target species are present. There are many known effective biocontrol agents that still have not been established in countries where target pests are causing crop losses. It is only recently that many species of important pests have been introduced into Puerto Rico and several other Islands, e.g., the citrus blackfly, A. woglumi, the pepper weevil, Anthonomus eugenii, the beet armyworm Spodoptera exigua, the tomato pinworm, Keiferia lycopersicella, the imported fire ant, Solenopsis invicta, Thrips palmi, the sugarcane thrips, Fulmekiola serrata, and the avocado lace wing bug, Pseudacysta persea. Most recently an apparently new race of the whitefly, Bemicia tabaci has invaded the Caribbean, being more destructive and with a wider range of plant hosts than the common whitefly.

Designating priority to pests should be an important goal of local and regional efforts to establish biocontrol programs. Pests, needs, and goals will vary among Caribbean countries. Therefore, a system to evaluate candidate pests should be developed based primarily on three main components: 1) an assessment of current or potential impact of the pest to the regional economy; 2) a thorough appraisal of institutional policy and logistic capabilities; and 3) an evaluation of prior biocontrol achievements against the pest. When applied within the context of local conditions, these criteria should insure that the initial phases of a biocontrol initiative in the Caribbean will be as risk free as possible.

Pests should be targeted according to crop importance, impact on the crop, and finally a cost and benefit analysis. Those pests which attack a major commodity with highly predictable temporary consistency, where current management methods are no longer effective, and which are not under quarantine regulations are excellent candidates. Similarly, pests with high economic injury levels, that are non-vectors and which are sole 'key' pests ought to be given reference as targets. Finally, if funds are scarce, priority should be given to pests with natural control agents which have proven effective elsewhere in contrast to projects requiring more expensive operations like mass rearing or foreign exploration.

The depth of biocontrol achievements against the pest should be the final component of its assessment as a target. Pests where natural enemy taxonomy is well known as well as those where the study of natural mortality is available should be considered first. Targets where successful programs exist abroad should be favored initially.

REFERENCES CITED

Alam, M. M. 1986. Vegetable pests and their natural enemies in Barbados, West Indies, Proc. 22nd. Caribbean Food Crops Society, 25-29 August, 1986. St. Lucia.

Alam, M. M., J. C. Reid, and G. Mulle. 1990. The present status and future needs of biological control in the Caribbean community, Caribbean Meetings on Biological Control, 5-7 November 1990, Guadeloupe, F.W.I.

Armstrong, A. 1981. Distribución de Diaprepes abbreviatus L. (Coleoptera:Curculionidae) y Tetrastichus haitiensis Gahan (Hymenoptera:Eulophidae) en las áreas cañeras del norte y noroeste de Puerto Rico. M.S. Thesis, RUM-UPR. 83 pp.

Armstrong, A. 1987. Parasitism of Tetrastichus haitiensis Gahan on egg masses of Diaprepes abbreviatus in Puerto Rico. J. Agric. Univ. P.R. 71(4):407-409.

Baker, P. 1990. Biological control of the coffee berry borer, CARAPHIN News, No. 2., IICA, Trinidad and Tobago.

Bennett, F. D. 1990. An overview of Classical Biological Control in the Caribbean and some examples of the utilization of entomophagous insects. Caribbean Meetings on Biological Control, 5-7 November 1990, Guadeloupe.

Bennett, F. D. and M. Yasseen. 1972. Parasite introduction for the biological control of three pests in the Lesser Antilles and British Honduras. PANS 18:468-474.

Castineiras, A., A. Borges, and O. Obregon. 1990a. Biological control of Cylas formicarius elegantulus (Summ.) Caribbean Meetings on Biological Control, 5-7 November 1990, Guadeloupe.

Castineiras, A., T. Cabrera, A. Calderón, M. López, and M. Luján. 1990b. Lucha biológica contra Cosmopolites sordidus, Caribbean Meetings on Biological Control, 5-7 November 1990, Guadeluope, F.W.I.

Castro, S. 1986. Hormigas depredadoras de larvas neonatas de Diaprepes abbreviatus (Coleoptera:Curculionidae), M.S. Thesis, RUM- UPR. 72 pp.

Cock, M. J. W. 1985. Review of Biological Control of Pest in the Commonwealth Caribbean and Bermuda up to 1982. Commonwealth Inst. Biol. Cont. Tech. Comm. #9:244 pp.

Colón, I. 1986. Estudio preliminar de generos de hongos aislados de larvas de Diaprepes abbreviatus en el área oeste de Puerto Rico y su evaluación como control biológico. M.S. Thesis, RUM-UPR. 30 pp.

Council of Entomology Department Administrators. 1988. Research Initiatives, A Research Agenda for Entomology, Prepared by the Subcommittee on Research Initiatives, T. Don Conerday, Chairman, Univ. of Georgia, Ga.

Cruz, C. and A. Segarra. 1990. Recent biological control experiences in Puerto Rico, Caribbean Meetings on Biological Control, 5-7 November 1990, Guadeloupe, F.W.I.

Figueroa, W. 1990. Biocontrol of the banana root borer weevil, Cosmopolites sordidus (Germar), with steinernematid nematodes. J. Agric. Univ. P.R. 74(1):15-20.

Figueroa, W. and J. Román. 1990. Parasitism of entomophilic nematodes on the sugarcane rootstalk borer, Diaprepes abbreviatus L. (Coleoptera:Curculionidae), larvae. J. Agric. Univ. P.R. 74(2):197- 202.

Figueroa, E. 1983. Ciclo vital y enemigos naturales de Heliothis zea en maíz. M.S. Thesis, RUM-UPR. 110 pp.

Fry, J. M. 1987. Natural enemy data bank. CAB International Institute of Biological Control, United Kingdom, 185 pp.

Gallardo, F. 1988. Faunal survey of the coffee leafminer (Leucoptera coffeella) parasitoids in Puerto Rico. J. Agric. Univ. P.R. 72(2):255-62.

González, N. 1986. Evaluación de dos nematodos entomófagos Heterorhabditis heliothidis y H. bacteriophora (Rhabditoidea: Heterorhabditidae) en el control de la larva de Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae), M.S. Thesis, RUM-UPR. 36 pp.

Green, S. D. 1984. A proposed origin of the coffee leafminer Leucoptera coffeella (Guérin-Méneville) (Lepidoptera:Lyonetidae). Bull. Entomol. Soc. Am. 30:30-31.

King, E. G. and R. J. Coleman. 1989. Potential for biological control of Heliothis species. Annu. Rev. Entomol. 34:53-75.

Medina, S., E. Abreu, F. Gallardo, y R. Franqui. 1989. Natural enemies of the melonworm, Diaphania hyalinata L. (Lepidoptera: Pyralidae), in Puerto Rico. J. Agric. Univ. P.R. 73(4):313-320.

Medina, S., A. Segarra, and R. Franqui. 1991. La mosca negra de los cítricos, Aleurocanthus woglumi Ashby (Homoptera: Aleyrodidae) en Puerto Rico. J. Agric. Univ. P.R. Submitted.

Richman, D. B., W. F. Buren, and W. H. Whitcom. 1983. Predatory arthropods attacking the eggs of Diaprepes abbreviatus (L.) (Coleoptera:Curculionidae) in Puerto Rico and Florida. J. Georgia Entomol. Soc. 18:335-342.

Román, J. and W. Figueroa, 1985. Control of the larva of the sugarcane rootstalk borer, Diaprepes abbreviatus (L.) with the entomogenous nematode Neoaplectana carpocapsae Weiser. J. Agric. Univ. P.R. 69(2):153-158.

Wolcott, G. 1947. A quintessene of sensitivity: The coffee leaf miner. J. Agric. Univ. P.R. 31:215-219.