The Coffee Berry Borer (Coleoptera: Curculionidae): How Many Instars are There?

Abstract

ABSTRACT After more than a century since the description of the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae), and dozens of scientific articles on the basic biology of the insect, there is still debate on the number of female larval instars. This article analyzes the metamorphosis of H. hampei females through direct observations during its entire biological cycle in the laboratory, together with scanning electron microscope photos. Also, the size of the head capsule of wild larvae and prepupae was analyzed with Dyar's rule and a discriminant analysis was conducted. Only two instars were observed during H. hampei metamorphosis up to the adult stage. Contrasting morphological changes in the larvae occurred when they transformed into prepupae, with no previous ecdysis. The statistical analysis revealed that the width of the cephalic masses form two significantly distinct groups before transformation into pupa, confirming that the prepupal stage forms part of the second larval...