A Beetle in a Haystack: Are There Alternate Hosts of the Coffee Berry Borer (<i>Hypothenemus hampei</i>) in Puerto Rico?

Abstract

Can the coffee berry borer (Hypothenemus hampei, or CBB) use host plants other than coffee for food and shelter? The use of fruits other than coffee has been reported. However, the validity of these reports depends on accurate identification of CBB, which is sometimes uncertain. In this study we sampled potential alternate hosts in coffee farms in Puerto Rico. Fruits with perforations were collected and examined for the presence of scolytid beetles (Coleoptera: Curculionidae: Scolytinae). Scolytids were identified by morphology and DNA barcoding of the COI gene. Association between the presence of Inga vera and Guarea guidonia trees and infestation rate of CBB in coffee fruits was evaluated. Food preference tests were performed in the laboratory. A total of 3563 beetles were found and 587 were identified as Hypothenemus spp.; of these, 85 identifications were confirmed by DNA barcoding. Twenty-seven of the beetles identified were H. hampei, mostly in I. vera fruits in periods between coffee crops. Most scolytids identified were H. obscurus. In preference tests, some CBB initially penetrated G. guidonia fruits, but eventually chose coffee. There was no evidence of feeding or reproduction in fruits of G. guidonia or Cajanus cajan. The results show that in Puerto Rico it is rare to find CBB in fruits of alternate hosts. The scarcity of coffee fruits in the off-season might cause some CBBs to take refuge in other fruits, but they did not feed or reproduce in them in laboratory tests. Understanding the refugia of CBB in the off-season may be useful for designing effective management strategies.

Keywords

• barcoding
• <i>coffea arabica</i>
• pest management
• feeding preferences
• monophagy
• polyphagy
• scolytidae