Optimization of coffee berry borer, Hypothenemus hampei Ferrari (Col., Scolytidae), mass trapping with an attractant mixture

Mass trapping is a technique currently being considered to control the coffee berry borer (CBB), Hypothenemus hampei Ferrari (Col., Scolytidae), as part of the integrated management of its populations. However, the research undertaken in this field has variable and sometimes contradictory results. The purpose of this study carried out with a single type of trap (experimental model '1B') was to evaluate the technique and define parameters for its efficient use. The first result obtained was detection of the excellent attractant properties of the ethanol–methanol mixture, and its efficiency related to the proportion of the two alcohols. Coffee borers were not attracted to traps with caffeine, green coffee powder, freshly pulped and hulled coffee berries and ground CBB. It was shown that the ethanol–methanol mixture (1 : 1) release rate varied without affecting the capture rate, and that the red colour of the trap substantially increased CBB attraction. In terms of trap set-up, it was found that capture rates were three times better with a trap height at 1.2 m, than that for a position near ground level. In addition, the best density of traps for achieving efficient mass trapping was 22 units per hectare. These results show the importance of developing an attractant using pure compounds, and of improving the trap and the trapping technique in line with CBB behaviour.     

Interspecific competition between Cephalonomia stephanoderis and Prorops nasuta (Hym.,Bethylidae), parasitoids of the coffee berry borer, Hypothenemus hampei (Col., Scolytidae)

The competition between Cephalonomia stephanoderis and Prorops nasuta was studied in the laboratory, using coffee fruits infested with the host of these parasitoids, the coffee berry borer Hypothenemus hampei . Experiments were performed under different conditions, using: (a) three temperatures; (b) five densities of infested coffee fruits; and (c) introducing the parasitoids at different times. The effect of competition was determined according to the production of the progeny. When cultured together at the same time, C. stephanoderis produced in general, more progeny than P. nasuta under conditions of 29°C and alternating temperatures of 18–29°C. Nevertheless, there were significant differences at densities of 1 : 3, fruits : parasitoids ( F _0.05=8.9; d.f.=1, 12; P < 0.05) and 1 : 5 ( F _0.05=7.56; d.f.=1, 12; P < 0.05) at 29°C. Under alternating temperatures, there were differences at the same ratios as above in favour of C. stephanoderis , 1 : 3 ( F _0.05=20.08; d.f.=1, 12; P < 0.05) and 1 : 5 ( F _0.05=20.21; d.f.=1, 12; P < 0.05). Prorops nasuta was clearly more successful in all densities at 18°C. When C. stephanoderis was introduced 10 days before P. nasuta , the progeny production was markedly higher in eight from 10 densities at temperatures of 29°C and 18–29°C. Despite being introduced 10 days later, P. nasuta showed better performance at 18°C. When P. nasuta was introduced 10 days earlier than C. stephanoderis , there were significant differences in progeny production in favour of P. nasuta in 13 of 15 fruit densities under the three temperatures. Both parasitoids avoided ovipositing on previously parasitized hosts. Aggressive behaviour or interference was not observed when they were outside coffee fruits.     

Interactions among bethylid parasitoid species attacking the coffee berry borer,Hypothenemus hampei (Coleoptera: Scolytidae)

The question of whether biological control is most likely achieved by deploying single or multiple species of biological control agents is much debated. While utilizing several natural enemies may enhance control, there is also the potential for disruptive inter-specific interactions. Such interactions may be studied in the laboratory by focusing on the details of the interactions themselves and attempting to infer population level consequences from their sum, or by focusing more directly on the overall effects on natural enemy populations: we term these approaches ‘reductionist’ and ‘holistic.’ Here we conduct a holistic laboratory study on interactions between three species of parasitoid wasps that are parasitoids of the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Scolytidae): Cephalonomia stephanoderis Betrem, C. hyalinipennis Ashmead and Prorops nasuta Waterston (all Hymenoptera: Bethylidae). We find evidence for both intra- and inter-specific resource competition. Interactions between C. stephanoderis and P. nasuta, both indigenous to Africa, appear to be approximately symmetrical, while C. hyalinipennis, naturally found in the coffee plantations of Chiapas, Mexico, may exert a disruptive influence. C. hyalinipennis also has a low population growth rate. We now consider it to be a detrimental invader of the Mexican coffee agro-ecosystem that should not be encouraged by augmentative release or introduced into other regions. Overall, the most successful species, in terms of both emergence and female production, was P. nasuta. We compare these results with those from prior reductionist and holistic studies, and with observations on patterns of establishment of these bethylid species in the field. Given that it is increasingly clear that disruptive inter-specific interactions are generally common when multiple species are deployed in biological control, screening of potential agents should consider such interactions alongside the more ‘traditional’ focus on host specificity.     

A review of the biology and control of the coffee berry borer, Hypothenemus hampei (Coleoptera: Scolytidae)

The coffee berry borer, Hypothenemus hampei Ferrari, is a serious problem for the majority of the world's coffee growers and has proved to be one of the most intractable of present day pests. Despite a great deal of research, control still depends largely on the application of the organochlorine insecticide endosulfan, which is damaging to the environment, or a series of cultural and biological control methods which give variable and unpredictable results. This review summarizes the most important aspects of the biology and ecology of H. hampei and its control and identifies weak points in the knowledge about this pest. Emphasis is placed upon an analysis of the non-chemical control methods available and suggestions are offered for novel ecological and environmental factors worthy of further research, in the search for viable and sustainable control methods.     

Bacillus thuringiensis serovar israelensis is highly toxic to the coffee berry borer, Hypothenemus hampei Ferr. (Coleoptera: Scolytidae)

A native collection of Bacillus thuringiensis strains was screened, once a reliable bioassay technique to assess the toxicity against the coffee berry borer (CBB) first-instar larvae was developed. A first round of bioassays with 170 strains indicated that the great majority of them showed no or very little insecticidal activity and that very few showed significant levels of toxicity. Interestingly, only those strains that had previously been associated with mosquitocidal activity were also toxic to CBB. Qualitative bioassays (using one high dose) were carried out only with those native mosquitocidal strains, corroborating their significant toxicity towards the CBB first-instar larvae. Most of these strains belong to serovar israelensis. In a second approach, strains from the Institut Pasteur type collection, whose mosquitocidal activity had been previously demonstrated, were also subjected to bioassays. Only those strains that showed a comparable protein content in their parasporal crystals to the israelensis type strain also showed high levels of toxicity towards CBB. Finally, an accurate LC(50) was estimated, using purified parasporal crystals from B. thuringiensis serovar israelensis type strain, at 219.5 ng cm(-2) of diet. All the statistical requirements for a reliable estimator were fulfilled. This is the first report of B. thuringiensis serovar israelensis being active against a coleopteran species.     

Reduced survival and infestation of coffee borer, Hypothenemus hampei (Ferrari) (Coleoptera: Scolytidae), on coffee fruits, in response to neem sprays in laboratory

Aqueous solutions of neem oil and aqueous extracts of neem seeds and leaves were sprayed on coffee fruits for laboratory evaluation of their efficiency in reducing infestation of the coffee borer, Hypothenemus hampei (Ferrari), in multi-choice preference assays in laboratory. Neem oil and extracts reduced infestation of fruits in a dose-dependent manner, acting as a repellent. At 0.5%, 1% and 1.5%, the oil reduced fruit infestation by 30.2%, 42.5% (P > 0.05), and 58.6% (P < 0.05), respectively, as compared with the control. Seed extracts at 1%, 2% and 4% (w/v) reduced infestation by 30.9%, 38.3% (P > 0.05) and 70.2% (P < 0.05), respectively; seed extracts at 0.15%, 1.5% and 15% (w/v) reduced fruit infestation by 16.5%, 38.5% (P > 0.05) and 56.9% (P < 0.05), respectively. Spraying the emulsifiable oil at 1% on coffee fruits and adult borers was compared with spraying on fruits or adults only. Adult-only spraying caused low mortality (P > 0.05) and low reduction on the number of damaged fruits (P > 0.05). Fruit-only spraying significantly reduced insect survival rates and the number of damaged fruits (P < 0.05). However, spraying on adults and fruits caused the greatest reduction in adult survival (55.6%; P < 0.05) and in fruit infestation (78.7%; P < 0.05), probably due to insect mortality and neem oil repellence acting together.     

Diversity of Bacillus thuringiensis strains isolated from coffee plantations infested with the coffee berry borer Hypothenemus hampei

The coffee berry borer Hypothenemus hampei Ferrari (Coleoptera: Scolytidae) was first reported infecting Costa Rican coffee plantations in the year 2000. Due to the impact that this plague has in the economy of the country, we were interested in seeking new alternatives for the biological control of H. hampei, based on the entomopathogenic bacteria Bacillus thuringiensis. A total of 202 B. thuringiensis isolates obtained from Costa Rican coffee plantations infested with H. hampei were analyzed through crystal morphology of the crystal inclusions and SDS-PAGE of 6-endotoxins, while 105 strains were further evaluated by PCR for the presence cry, cyt and vip genes. Most of the Bt strains showed diverse crystal morphologies: pleomorphic (35%), oval (37%), bipyramidal (3%), bipyramidal and oval (12%), bipyramidal, oval and pleomorphic (10%) and bipyramidal, oval and cubic (3%). The SDS-PAGE analyses of the crystal preparations showed five strains with delta-endotoxin from 20 to 40 kDa, six from 40 to 50 kDa, seven from 50 to 60 kDa, 19 from 60 to 70 kDa, 29 from 70 to 100 kDa and 39 from 100-145 kDa. PCR analyses demonstrated that the collection showed diverse cry genes profiles having several genes per strain: 78 strains contained the vip3 gene, 82 the cry2 gene, 45 the cry1 and 29 strains harbored cry3-cry7 genes. A total of 13 strains did not amplified with any of the cry primers used: cry1, cry2, cry3-7, cry5, cry11, cry12 and cry14. Forty-three different genetic profiles were found, mainly due to the combination of cry1A genes with other cry and vip genes. The genetic characterization of the collection provides opportunities for the selection of strains to be tested in bioassays against H. hampei and other insect pests of agricultural importance.     

Responses of coffee berry borer, Hypothenemus hampei (Ferrari)(Coleoptera: Scolytidae), to vertical distribution of methanol: ethanol traps

Captures of the coffee berry borer (CBB) Hypothenemus hampei (Ferrari) were assessed in traps in the field. IAPAR designed traps [plastic bottles (2 L) lured with methanol:ethanol (1:1) in a vessel] were placed either at 0.5, 1.0 and 1.5m high from the ground or simultaneously tested in the 2004 fructification season. Traps placed at the three heights trapped 5.5 times more CBB than the others, mostly at the traps placed at 0.5 m (75%). Treatments using the IAPAR designed trap placed at 1.2 m high; IAPAR trap with a white plastic plate above (IAPAR modified I) at 1.2 m high; IAPAR at 0.5 m high and two additional vessels at 1.0 and 1.5m high (IAPAR modified II) and T-163 trap [three red plastic cups (300 ml) and a red plastic plate as a cover] lured with M:E (1:1) at 1.2m height were compared in the vegetative (2005) and fructification (2006) periods. IAPAR modified II (dispenser vessels placed at 0.5, 1.0 and 1.5 m) trapped more beetles than the remaining types (2.72 times more beetles than IAPAR design); and IAPAR modified I traps trapped more beetles than T 163 and IAPAR traps in the vegetative period. In the reproductive period, IAPAR modified II trapped less beetles than IAPAR and IAPAR modified I. In 2007 vegetative season, IAPAR modified II trap were compared with IAPAR trap and trapped 2.8 times more beetles. The positive responses to a vertical distribution of the volatile attractants in the vegetative period of the planting allow the development of more efficient trapping systems for CBB.     

Alpha-amylases of the coffee berry borer (Hypothenemus hampei) and their inhibition by two plant amylase inhibitors

The adult coffee berry borer (Hypothenemus hampei Ferrari [Coleoptera: Scolytidae]), a major insect pest of coffee, has two major digestive alpha-amylases that can be separated by isoelectric focusing. The alpha-amylase activity has a broad pH optimum between 4.0 and 7.0. Using pH indicators, the pH of the midgut was determined to be between 4.5 and 5.2. At pH 5.0, the coffee berry borer alpha-amylase activity is inhibited substantially (80%) by relatively low levels of the amylase inhibitor (alphaAI-1) from the common bean, Phaseolus vulgaris L., and much less so by the amylase inhibitor from Amaranthus. We used an in-gel zymogram assay to demonstrate that seed extracts can be screened to find suitable inhibitors of amylases. The prospect of using the genes that encode these inhibitors to make coffee resistant to the coffee berry borer via genetic engineering is discussed.     

Biological activity of five strains ofMetarhizium anisopliae,upon the coffee berry borerHypothenemus hampei (Col.: Scolytidae)

Five strains of the entomopathogenic fungusMetarhizium anisopliae (Metschnikoff) Sorokin were bioassayed against the coffee berry borerHypothenemus hampei (Ferrari) (Coleoptera: Scolytidae) under laboratory conditions (T=27±2°C; R.H.=90±5% and 12∶12 L∶D light cycle). The LC₅₀ values for the three most virulent strains, Ma4, Ma5 and Ma3, were 4.2, 5.9 and 6.7×10⁶ conidia/ml of suspension respectively and median lethal times (LT₅₀) observed were between 9.7 and 13.8 days. The maximum percentage sporulation was obtained with strains Ma3 and Ma4 both with 90% sporulation and Ma10 with 60.7%. These results suggest that the fungusM. anisopliae could be incorporated into an integrated control programme for the biological control ofH. hampei.

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Résumé Cinq souches du champignon entomopathogèneMetarhizium anisopliae (Metschnikoff) Sorokin, ont été évaluées dans les conditions du laboratoire, pour mesurer leur activité vis-à-vis du scolyte des fruits du caféierHypothenemus hampei (Ferrari) (Coleoptera: Scolytidae). Les résultats montrent que les souches Ma4, Ma5 et Ma3 sont les plus virulentes contreH. hampei, avec des valeurs de concentration létale moyenne (CL₅₀, valeurs minimales et maximales, ± limite de confiance à 95%) de 0,0226 (0,0195–0,00260), 0,0328 (0,0267–0,0390) et 0,0354 (0,0297–0,0417) équivalentes à 4,2, 5,9 et 6,7×10⁶ conidies/ml de suspension et un temps létal moyen (TL₅₀) entre 9,7 et 13,8 jours. Les pourcentages maximaux de sporulation ont été obtenus avec les souches Ma3 et Ma4 avec 90%, la souche Ma10 présentant le pourcentage le plus bas de sporulation (67%). Ces résultats démontrent queM. anisopliae peut être introduit dans un programme de lutte intégrée contreH. hampei.

     

An alpha-amylase inhibitor gene from Phaseolus coccineus encodes a protein with potential for control of coffee berry borer (Hypothenemus hampei)

Plant alpha-amylase inhibitors are proteins found in several plants, and play a key role in natural defenses. In this study, a gene encoding an alpha-amylase inhibitor, named alphaAI-Pc1, was isolated from cotyledons of Phaseolus coccineus. This inhibitor has an enhanced primary structure to P. vulgaris alpha-amylase inhibitors (alpha-AI1 and alpha-AI2). The alphaAI-Pc1 gene, constructed with the PHA-L phytohemaglutinin promoter, was introduced into tobacco plants, with its expression in regenerated (T0) and progeny (T1) transformant plants monitored by PCR amplification, enzyme-linked immunosorbent assay (ELISA) and immunoblot analysis, respectively. Seed protein extracts from selected transformants reacted positively with a polyclonal antibody raised against alphaAI-1, while no reaction was observed with untransformed tobacco plants. Immunological assays showed that the alphaAI-Pc1 gene product represented up to 0.05% of total soluble proteins in T0 plants seeds. Furthermore, recombinant alphaAI-Pc1 expressed in tobacco plants was able to inhibit 65% of digestive H. hampei alpha-amylases. The data herein suggest that the protein encoded by the alphaAI-Pc1 gene has potential to be introduced into coffee plants in order to increase their resistance to the coffee berry borer.     

Biological control of the coffee berry borer Hypothenemus hampei (Coleoptera: Curculionidae) by Phymastichus coffea (Hymenoptera: Eulophidae) in Colombia

The potential of the eulophid parasitoid Phymastichus coffea LaSalle to control coffee berry borer Hypothenemus hampei (Ferrari) populations under field conditions in Colombia was evaluated. Parasitoid adults were released one, five and nine days after artificial infestations of 90-, 150- and 210-day-old coffee berries with H. hampei females. The position of the beetle inside the berry and the parasitism levels were assessed ten days after each P. coffea release. Parasitism of H. hampei by P. coffea was significantly affected by the age of the berries at the time of infestation, and by the position of the beetle inside the berries. Highest levels of parasitism were recorded in 150-day-old berries (75-85%) and in 90-day-old berries (75%) when P. coffea were released one day after the artificial infestation with H. hampei. In 150-day-old berries, highest levels of parasitism were recorded for H. hampei found in the outer layer of the endosperm followed by beetles penetrating the exocarp. Increasing the time of P. coffea releases after the artificial infestations with H. hampei led to decreased levels of parasitism in beetles attacking 90- and 150-day-old coffee berries. Low levels of parasitism were recorded in H. hampei females infesting older coffee berries because most of the beetles had already constructed galleries deep in the endosperm of the berries, i.e. out of reach of the parasitoid. The potential of P. coffea for biological control of coffee berry borer in Colombia is discussed.     

Increased pathogenicity against coffee berry borer, Hypothenemus hampei (Coleoptera: Curculionidae) by Metarhizium anisopliae expressing the scorpion toxin (AaIT) gene

Coffee berry borer (CBB) is the Worlds most devastating coffee pest causing an estimated US$500 million worth of losses annually through damage and control costs. Beauveria bassiana and Metarhizium anisopliae have been employed to control this pest but their low virulence (slow kill and large inoculums) is an important factor constraining their use. M. anisopliae (AaIT-Ma549) has been modified to express the scorpion toxin (AaIT) in insect hemolymph and this greatly increased pathogenicity against Manduca sexta and Aedes aegypti. Here, we demonstrate that AaIT-Ma549 was also dramatically more virulent against CBB, and we provide a much more comprehensive analysis of infection processes and post-mortality development than in the previous research. We evaluated several spore concentrations (10¹ through 10⁷ spores/ml) of both the wild type and recombinant strain. At concentrations of 10¹, 10² and 10³ spores/ml, the recombinant strain significantly increased mortality of CBB by 32.2%, 56.6% and 24.6%, respectively. The medial lethal concentration (LC₅₀) was reduced 15.7-fold and the average survival time (AST) was reduced by 20.1% to 2.98 ± 0.1 days with 10⁷ spores/ml. This is the first occasion that an entomopathogenic fungus has been found to kill CBB in less than 3 days. However, AaIT-Ma549 produces significantly fewer spores on cadavers than the parental strain.     

Some like it hot: the influence and implications of climate change on coffee berry borer (Hypothenemus hampei) and coffee production in East Africa

The negative effects of climate change are already evident for many of the 25 million coffee farmers across the tropics and the 90 billion dollar (US) coffee industry. The coffee berry borer (Hypothenemus hampei), the most important pest of coffee worldwide, has already benefited from the temperature rise in East Africa: increased damage to coffee crops and expansion in its distribution range have been reported. In order to anticipate threats and prioritize management actions for H. hampei we present here, maps on future distributions of H. hampei in coffee producing areas of East Africa. Using the CLIMEX model we relate present-day insect distributions to current climate and then project the fitted climatic envelopes under future scenarios A2A and B2B (for HADCM3 model). In both scenarios, the situation with H. hampei is forecasted to worsen in the current Coffea arabica producing areas of Ethiopia, the Ugandan part of the Lake Victoria and Mt. Elgon regions, Mt. Kenya and the Kenyan side of Mt. Elgon, and most of Rwanda and Burundi. The calculated hypothetical number of generations per year of H. hampei is predicted to increase in all C. arabica-producing areas from five to ten. These outcomes will have serious implications for C. arabica production and livelihoods in East Africa. We suggest that the best way to adapt to a rise of temperatures in coffee plantations could be via the introduction of shade trees in sun grown plantations. The aims of this study are to fill knowledge gaps existing in the coffee industry, and to draft an outline for the development of an adaptation strategy package for climate change on coffee production. An abstract in Spanish is provided as Abstract S1.     

Coffee berry borer Hypothenemus hampei (Coleoptera: Curculionidae): searching for sustainable control strategies

The coffee berry borer Hypothenemus hampei (Ferrari) is the most serious pest of the world's most valuable tropical export crop. Since the last review on this insect was published six years ago, many new studies have contributed to an improved insight into the biology and ecology of the beetle, and have indicated new avenues for integrated and biological control. The latest developments in research, both laboratory and field, on the pest, its natural enemies and their implications for integrated control of H. hampei are summarized, with a particular focus on the situation in The Americas. Lately, the global coffee industry has changed radically; it has suffered a long cycle of lowest-ever world market prices caused by overproduction and technological change. At the same time, the advent of sustainable certification schemes has had a major impact on the industry. The role of integrated pest management and biological control of H. hampei in an era of changes in the coffee industry is discussed.     

Phylogenetic origins of African and Neotropical Beauveria bassiana s.l. pathogens of the coffee berry borer, Hypothenemus hampei

A phylogenetic epidemiological study of Beauveria bassiana s.l. was conducted for African and Neotropical pathogens of the coffee berry borer (CBB), Hypothenemus hampei, based on inferences from two nuclear intergenic regions, EFutr and Bloc. CBB pathogens were distributed among four terminal clades, however, the majority of African and Neotropical isolates cluster in a well-supported monophyletic group, informally designated AFNEO_1. Although the relationship between African and Neotropical AFNEO_1 is unresolved, the majority of alleles detected were exclusive to either the African or the Neotropical populations. These fixed genetic differences suggest that their disjunction predates the world trade in coffee. Neotropical AFNEO_1 have a broad host range and CBB pathogens are intermixed phylogenetically with isolates from diverse indigenous insects. Several Neotropical AFNEO_1 isolates were isolated from coffee plants as epiphytes or endophytes, thus plants themselves may potentially serve as reservoirs of pathogens against their insect pests. Topological incongruence between the EFutr and Bloc phylogenies of Neotropical AFNEO_1 may signify that individuals within this population are recombining.     

Metaparasitylenchus hypothenemi n. sp. (Nematoda: Allantonematidae), a parasite of the coffee berry borer, Hypothenemus hampei (Curculionidae: Scolytinae)

Metaparasitylenchus hypothenemi n. sp. (Nematoda: Allantonematidae) is described from the coffee berry borer, Hypothenemus hampei (Ferrari) (Curculionidae: Scolytinae), in Chiapas, Mexico. This species differs from other members of the genus by its small size, annulated cuticle, lateral fields with 3 ridges, free-living stages with an excretory pore located between the pharyngeal gland orifices, a distinct stylet with basal swellings in free-living females, a postvulval uterine extension, a thin stylet lacking basal swellings in males, 2 separate spicules, a gubernaculum, and a peloderan bursa. Parasitic females are white, with a straight or slightly curved body and are ovoviviparous. Third-stage juveniles emerge from parasitized beetles and molt twice before reaching the adult stage. Because the coffee berry borer is the most important pest of coffee throughout the world and this parasite partially or completely sterilizes female beetles, it is worthy of further investigation as a potential biological control agent.     

Evaluation of Beauveria bassiana (Ascomycota: Hypocreales) as a control of the coffee berry borer Hypothenemus hampei (Coleoptera: Curculionidae: Scolytinae) emerging from fallen,infested coffee berries on the ground

The effects of Beauveria bassiana strains on coffee berry borers (CBB), which emerge from infested berries left on soil, and its impact on the infestation of coffee berries on tree branches were evaluated at two Experimental Stations (Naranjal-Caldas and Paraguaicito-Quindio) in the Colombian coffee zone. Using a completely randomized design with 10 repetitions, 50 coffee berries artificially infested with CBB were placed on the base of a coffee tree. Four treatments including B. bassiana strain Bb9205, a mixture of Cenicafé strains (Bb9001, Bb9024 and Bb9119), a commercial formulation of B. bassiana and a control (water) were sprayed with 1×10⁹ conidia per tree. After 30 days, all fungal strains lowered the infestation levels of the coffee berries on the trees at both locations. The mixture of Cenicafé strains decreased the tree infestation between 50 and 30% at both locations. In the berries dissected from each treated tree, insect mortality was about 40% at both locations compared to 15% in the control. B. bassiana strains also decreased the insect population inside the newly infested berries on the trees by 55–75%. The mixture of Cenicafé strains was the most effective for decreasing insect populations. B. bassiana significantly decreased CBB populations that emerged from fallen, infested, coffee berries and reduced future insect generations.     

Effect of Beauveria bassiana and Metarhizium anisopliae (Deuteromycetes) upon the coffee berry borer (Coleoptera: Scolytidae) under field conditions

The effect of three strains of the fungus Beauveria bassiana (Balsamo) Vuillemin and two strains of Metarhizium anisopliae (Metschnikoff) Sorokin upon the coffee berry borer, Hypothenemus hampei (Ferrari), was studied in three coffee farms at different altitudes (450-1,100 m above sea level) in Soconusco, Chiapas, Mexico. The maximum average percentage mycosis varied according to altitude. At 450 m asl (El Rincon) mycosis was 14.3% for B. bassiana and 6.3% for M. anisopliae; at 880 m asl (Santa Anita) mycosis was 40.6% for B. bassiana and 12.6% for M. anisopliae, and at 1,100 m asl (Alpujarras) 33.9% for B. bassiana and 22. 1% for M. anisopliae. The effect of fungal mycosis through time was not significant (P > 0.01) in any of the farms, but there was a significant difference between the strains of the fungus (P < 0.01); the best strains being Bb25 and Ma4 at the lower altitude, Bb26 and Ma4 for the middle altitude and Bb26 and Ma4 at the higher altitude. Environmental factors such as temperature, relative humidity and rain were not correlated with the percentage mycosis caused by B. bassiana and M. anisopliae. However, in the case of B. bassiana there was a significant, positive correlation (P < 0.01) between the infestation levels of the pest and the mycosis response of the entomopathogen.