Morphology and Structural Changes in Flight Muscles of <I>Hypothenemus hampei</I> (Coleoptera: Curculionidae) Females

Abstract

The coffee berry borer, Hypothenemus hampei (Ferrari), is the major pest of coffee (Coffea spp.) worldwide. After adult eclosion, female borers leave the coffee fruit and disperse to colonize and oviposit in new host fruits. During this process, the flight muscles of females play a crucial role. The objectives of this work were to describe the morphology of the flight muscles of H. hampei females, to quantify changes occurring in the flight muscles during colonization in relation to age and oviposition, and to investigate hormonal control of flight muscle degeneration. Microscopic studies showed that H. hampei females have seven kinds of flight muscles: median dorsolongitudinal, oblique dorsolongitudinal, tergosternal, tergo-trochantinal, sterno-basalar, coxo-basalar, and coxo-subalar. Digital imaging of micrographs revealed that the surface area of flight muscles was significantly greater in flying females than in individuals that had oviposited in fruits. Both age and status of oviposition appear to affect the extent of flight muscle degeneration in this beetle species. Topical application of 2 μg of methoprene, a juvenile hormone analog, induced loss of muscle. This suggested that flight muscle degeneration is controlled hormonally in the coffee berry borer.