Natural parasitism of Metaparasitylenchus hypothenemi (Tylenchida: Allantonematidae) on the coffee berry borer in Chiapas,Mexico

We assessed the parasitism of Metaparasitylenchus hypothenemi on its host, the coffee berry borer, in 20 coffee plantations of Mexico. A total of 23,568 adult borers were dissected, with 179 of these infected with nematodes (0.76% infection rate). Although the level of parasitism is not encouraging, the nematode is another natural enemy, which limits the population growth of this pest in Mexico.     

Manipulating tropical fire ants to reduce the coffee berry borer

1. The coffee berry borer Hypothenemus hampei (Coleoptera, Curculionidae) (Ferrari) is the most important pest of coffee production worldwide. 2. The hypothesis that the tropical fire ant, Solenopsis geminata Westwood, indirectly protects the coffee berry borer by suppressing other ant species that are the coffee berry borer's primary predators was tested. 3. It was found that removing S. geminata from coffee plots significantly increased the disappearance of adult coffee berry borer beetles from coffee berries compared with control plots. An average of 6% of beetles disappeared from plots with S. geminata whereas 23% of beetles disappeared from plots from which S. geminata was removed. This pattern was observed on two shade coffee farms with marked differences in ant species composition, one in the rainforest in central Costa Rica and one in the cloudforest in northwest Costa Rica. 4. If the results of this small‐scale study can be replicated on the farm level, then S. geminata suppression may represent a new management technique for the coffee berry borer throughout Central and South America.     

Alternative Hosts for Bethylid Parasitoids of the Coffee Berry Borer, Hypothenemus hampei (Coleoptera: Scolytidae)

Three species of bethylid wasps, Prorops nasuta Waterston, Cephalonomia stephanoderis Betrem, and C. hyalinipennis Ashmead, attack the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Scolytidae), by both predation and parasitism. C. hyalinipennis has only recently been reported to attack H. hampei. Its previously recorded hosts belong to the coleopteran families Curculionidae, Anobiidae, and Scolytidae. We evaluated five further coleopteran species, in the families Curculionidae, Bostrichidae, and Bruchidae, as alternative hosts. High proportions of all five species were both fed upon and oviposited on (normally by concurrent host feeding). Offspring developmental mortality varied greatly (12–95%) on different host species. Offspring production per host was about three times greater than on H. hampei when females were presented with the curculionids Caulophilus oryzae (Gyllenhal) and two species of Sitophilus. C. stephanoderis and P. nasuta are currently the main biological control agents of H. hampei: they have long been thought to be monophagous but C. stephanoderis has recently been reported to attack H. obscurus. We evaluated C. oryzae, as a potential host or prey for P. nasuta, and both C. oryzae and Sitophilus sp. for C. stephanoderis. Host feeding was very common in both parasitoid species. The majority of females also oviposited on C. oryzae (71% P. nasuta, 60% C. stephanoderis) and 20% of C. stephanoderis parasitized Sitophilus sp. Fifty-two percent of C. stephanoderis and 7% of P. nasuta offspring survived to adulthood when developing on C. oryzae. The lifetime fecundities of these parasitoids presented with these host species were, however, low (maximum 17 eggs, mean ≤ 8.25) and preoviposition periods were generally long (ca. 19 days). Adult female C. stephanoderis lived longer when presented C. oryzae rather than Sitophilus sp. Host feeding also increased longevity. We discuss these results in the context of mass rearing these bethylids for release as biological control agents.     

Altitude and coffee production systems influence extent of infestation and bean damage by the coffee berry borer

The coffee berry borer (CBB), Hypothenemus hampei Ferrari (Coleoptera: Curculionidae: Scolytinae), is one of the major insect pests of coffee worldwide. The present study was designed to assess the level of infestation of coffee berries at different developmental stages across different altitudes and coffee management systems. The experiment was carried out at three locations in southwestern Ethiopia under two coffee management systems and four coffee berry development stages with three replications. Results of the study showed significantly highest proportion of damaged berries (37.5%), number of holes per berry (10.88) and number of adult CBB per berry (7.55) on dried leftover berries at low-altitude study sites. On the other hand, the lowest mean percent damaged berries, number of holes per berry and number of adults were recorded at mid- and high-altitude study sites. The study also showed that, CBB caused significantly highest damage in plantation coffee management system than garden coffee. Results of this study highlight proper harvesting at red ripe stage in order to minimise incidence of CBB. It is also important to design integrated management strategies to mitigate CBB damage especially in lowland plantation coffee production systems.     

Aphanogmus sp. (Hymenoptera: Ceraphronidae): a hyperparasitoid of the coffee berry borer parasitoid Prorops nasuta (Hymenoptera: Bethylidae) in Kenya

This is the first report of a hyperparasitoid of Prorops nasuta, a primary parasitoid of the coffee berry borer. Aphanogmus sp. is a gregarious ectoparasitoid of larval and pupal stages of P. nasuta, which was found in coffee berry samples collected on the ground of an organic coffee plantation in Western Kenya. The hyperparasitoid shows a clear pattern of emergence from year to year, following its host. Aphanogmus sp. parasitizes around 10% of P. nasuta immature stages under field conditions.     

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.     

Testing ant predation on the coffee berry borer in shaded and sun coffee plantations in Colombia

Soil‐dwelling ants, many of which are generalist predators, are more diverse in shaded than in sun coffee plantations without trees. We compared ant predation on the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae) in three shaded and three sun coffee plantations in Apía, Colombia, in both the wet and the dry seasons. We found that H. hampei adults exposed to ants for 5 days suffered higher removal in shaded plantations and in the wet season. In the laboratory, we observed that ants killed 74–99% of H. hampei adults over the course of 5 days. Ants appear to be important predators of H. hampei, particularly in shaded coffee plantations and in the wet season.     

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.     

Inoculation of coffee plants with the fungal entomopathogen Beauveria bassiana (Ascomycota: Hypocreales)

The entomopathogenic fungus Beauveria bassiana was established in coffee seedlings after fungal spore suspensions were applied as foliar sprays, stem injections, or soil drenches. Direct injection yielded the highest post-inoculation recovery of endophytic B. bassiana. Establishment, based on percent recovery of B. bassiana, decreased as time post-inoculation increased in all treatments. Several other endophytes were isolated from the seedlings and could have negatively influenced establishment of B. bassiana. The recovery of B. bassiana from sites distant from the point of inoculation indicates that the fungus has the potential to move throughout the plant.     

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.

     

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.     

Reproductive Biology ofCephalonomia hyalinipennis(Hymenoptera: Bethylidae), a Native Parasitoid of the Coffee Berry Borer,Hypothenemus hampei(Coleoptera: Scolytidae), in Chiapas, Mexico

The coffee berry borer,Hypothenemus hampei(Ferrari) (Coleoptera: Scolytidae), is the most important pest of coffee worldwide.Cephalonomia hyalinipennisAshmead (Hymenoptera: Bethylidae) was recently discovered naturally attackingH. hampeiin Mexico.C. hyalinipennisboth preys upon and parasitizesH. hampei.We report laboratory investigations on the reproductive biology ofC. hyalinipennisaimed at assessing the suitability of this parasitoid for culturing and release in biological control programs. Adult females lived up to 95 days (mean for mated females = 57 days), and risk of death increased with age. Mating status, reproductive effort, and female size influenced adult female longevity, but only weakly. The number ofH. hampeipreyed upon did not affect longevity. Rates of attack (predation plus parasitism) declined with age, but the proportion of attackedH. hampeithat were parasitized increased. Overall, about half of the attackedH. hampeiwere preyed upon and half were parasitized. Females received approximately 46 sperm per mating and 77% became sperm depleted before the end of their reproductive lives. Estimated mean lifetime fecundity was 88 eggs. Offspring survival from egg to adulthood was 60%, with batches of eggs tending to survive or die collectively; 21.2% of surviving progeny were males. These results suggest thatC. hyalinipennismay be suitable for mass rearing and release, but further work is needed to investigate interactions betweenC. hyalinipennisand other parasitoids ofH. hampei.     

Identification of a coffee berry borer‐associated yeast: does it break down caffeine?

Two yeasts isolated from laboratory reared adult coffee berry borers [Hypothenemus hampei (Ferrari) (Coleoptera: Scolytidae)] and from insects collected in the field in Colombia were identified as Pichia burtonii Boidin and Candida fermentati (Saito) Bai, based on sequencing of the nuclear large subunit 26S rDNA variable D1/D2 domain. Liquid culture experiments using P. burtonii in media containing different caffeine levels indicated that caffeine levels in a range found within coffee seeds can retard yeast growth. HPLC analysis shows that P. burtonii does not break down caffeine.     

Efficacy of plant essential oils against two major insect pests of coffee (Coffee berry borer,Hypothenemus hampei,and antestia bug,Antestiopsis intricata) and maize weevil,Sitophilus zeamais

Coffee berry borer, antestia bug and maize weevil are serious pest of coffee and maize, respectively. Bioassays of plant essential oils were conducted with coffee berry borer, antestia bug and the maize weevil. Essential oils of Thymus vulgaris, Aloysia sp., Ruta chalepensis, Chenopodium ambrosioides and Cymbopogon nardus resulted in 80%–90% mortality of coffee berry borer, whereas essential oils of C. ambrosioides, T. vulgaris and R. chalepensis achieved 87.5%–92.5% mortality of antestia bug. Essential oils of C. ambrosioides caused significantly the highest percentage mortality of the maize weevils (95%) with “Lethal Dose” (LD₅₀) values of 2.202 ml 100 ml^?1 within 24 h after treatment, whereas essential oils of Mentha spicata, T. vulgaris and R. chalepensis resulted in 82.5%, 77.5% and 73.5% mortality, respectively. The potential of plant essential oils for the management of coffee berry borer, antestia bug and maize weevil for the small-scale farmers is discussed.     

Evaluation of potential entomopathogenic fungus,Beauveria bassiana,for controlling the coffee berry borer Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae) in Taiwan

Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae), a coffee berry borer (CBB), is a serious pest of coffee fruits and causes economic losses in the coffee industry. With the concerns of chemical control, an alternative eco-friendly management strategy such as microbial control has emerged as the times require. Herein, a total of thirty-three fungi were isolated from CBB cadavers. Two entomopathogenic fungal isolates, NCHU-271 and NCHU-272, which showed fast insect-killing activity, were subjected to molecular identification and named “Beauveria bassiana-NCHU-271” (Bb-NCHU-271) and “Beauveria bassiana -NCHU-272” (Bb-NCHU-272). Moreover, a virulence test of Bb-NCHU-271 and Bb-NCHU-272 against CBBs was also performed. Both Bb-NCHU-271 and Bb-NCHU-272 caused 100% mortality at 8 days post inoculation (d.p.i.) and a LT₅₀ of Bb-NCHU-271 by spraying 10⁸ conidia/ml was less than Bb-NCHU-272. Therefore, histological evidence of Bb-NCHU-271 infected CBBs was provided to proven the infection process of B. bassiana in CBBs. Furthermore, an infestation test was performed to evaluate the differences in CBB control efficacy between the treatments of “Borers exposed to EPF first” or “Berries exposed to EPF first”. The results revealed that the “Borers exposed to EPF first” of Bb-NCHU-272 caused significantly lower survival rates and higher mycosis rates than those of Bb-NCHU-271. Only slight control effects of Bb-NCHU-271 and Bb-NCHU-272 were also observed in the “Berries exposed to EPF” treatment. In conclusion, Bb-NCHU-271 and −272 showed controlling ability to the CBBs either before or after CBB infestation into coffee berries, while application of EPFs before the CBBs bored into coffee fruits could enhance the control effect.     

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.     

Natural occurrence of Beauveria bassiana in Hypothenemus hampei (Coleoptera: Curculionidae) populations in unsprayed coffee fields

Three unsprayed coffee farms (farm 1, 2 and 3) were studied for the natural occurrence of the insect pathogenic fungus Beauveria bassiana in Hypothenemus hampei populations throughout the rainy season of 2004 (July-November) and 2005 (July-December). B. bassiana infections were found during most sampling dates in both years, on all three farms. The B. bassiana infection levels were higher in 2005 than in 2004 with mean prevalence of 12.1% and 2.7%, respectively. No consistent significant differences in infection level between farms were found in any of the years. B. bassiana infection levels fluctuated widely throughout the season, and peaked at 13.5% on farm 3 in 2004 and at 44.0% on farm 1 in 2005. The H. hampei population was significantly higher in 2004 than in 2005, with 6.9% of the berries infested in 2004 and only 0.7% in 2005. In both years, the H. hampei infestation level was significantly higher on farm 2. No consistent significant differences in H. hampei infestation levels were found between sampling dates on any of the farms. H. hampei infestation levels fluctuated throughout both seasons, and peaked at 15.3% on farm 2 in 2004 and 2.2% on farm 2 in 2005. No consistent density dependent correlation between H. hampei infestation level and B. bassiana infection level was found. Correlations between climatic conditions and B. bassiana or H. hampei were not found.