The coffee berry borer (CBB; Hypothenemus hampei) is a major pest of coffee responsible for significant crop losses worldwide. The entomopathogenic fungus Beauveria bassiana represents a natural means of controlling this insect pest; however, little is known concerning the molecular determinants that contribute to the virulence of the fungus towards the CBB. In order to examine genes involved in insect virulence, two expressed sequence tag (EST) libraries, representing germinating conidia and growing hyphae/mycelia of B. bassiana cells grown on cuticular extracts of the CBB were constructed and analysed. In total, 4186 cDNA transcripts were obtained, which included 2141 from the cuticle-germinated conidia and 2045 from the cuticle-grown mycelium libraries, respectively. The average sequence length obtained was 470 bp and transcript assembly resulted in a set of 1271 and 1305 unique gene sequences for the conidial and mycelia libraries, respectively. Around 50 % of the sequences in each library could be annotated by gene ontology terms. An analysis of the two generated libraries as well as a previously reported EST library of B. bassiana grown on chitin was performed. Between the cuticle-germinated conidia and the cuticle-grown mycelia libraries, 322 unique gene sequences were shared, of which 90 % could be annotated, leaving 949 unique cuticle-germinated conidial genes and 983 unique growing hyphae/mycelia genes of which around 65 % were annotated. ESTs shared between the libraries indicated a basic response pattern for B. bassiana against H. hampei, which included genes implicated in pathogenicity. The expression profiles of four genes were evaluated with a cyclophilin, an alkaline-like serine protease and a mitogen-activated protein kinase (MAPK), showing elevated expression during initial phases of infection, i.e. conidia germinating on insect extracts. These data provide clues and gene candidates for further exploration concerning the biology and molecular mechanisms of entomopathogenicity by this fungus.

Coffee is a worldwide commodity, and both coffee-producing and coffee-consuming countries have real concerns about environmental problems and economic growth strategies based on the efficient use of resources. Because this crop is a perennial, pests can significantly affect coffee production, causing considerable yield losses and threatening coffee supply and security. The presence of insects and control strategies for coffee pests is becoming a challenge. Environmental sustainability, conservation of biodiversity, and safety of the coffee seed must go hand in hand with the economic sustainability of coffee growers. This is especially important, as there has been an increase in demand for coffee and new consumer interest in differentiated quality coffee. Regular pest control methods based only on the use of synthetic pesticides are no longer effective or sustainable due to the development of insecticide resistance and negative effects on the environment, human health, and biodiversity. Thus, to ensure better control and ecological sustainability, it is crucial to reduce pesticide use by adopting original alternative strategies to maintain pest populations below the economic threshold level and towards reaching the European Green Deal. In this review, we collect information available for sustainable control of the principal coffee pests in Colombia: coffee berry borer (CBB), Hypothenemus hampei; Monalonion velezangeli; coffee root mealybugs; coffee leaf miner: Leucoptera coffeella; and the coffee red spider mite: Oligonychus yothersi. The control strategies include deep knowledge of the biology of insects and the coffee plant, their relationship with weather and habitats, as well as natural controllers. These control strategies do not involve the use of insecticides, are ecologically friendly and novel, and can be applied in other coffee-producing countries.

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.