Generally though they confirmed the very low level of genetic variability in this insect, but detected enough differences to suggest that H. They further suggest that there were three separate introductions to the Americas, two into Brazil which spread to the rest of Latin America and a third into Peru and Colombia. All three strains are found in Colombia. Gauthier however, used nine polymorphic microsatellite loci to look for differences between H.
Five different sub-groups were distinguished, which are so distinct that they might even be different species. Jamaica seems to have representatives from two groups, suggesting that it was invaded twice. The broad category of group v suggests that Java, India and the Pacific were infested originally from W Africa, perhaps by the introduction of infested Robusta berries in the early part of the 20th century.
It shows a marked preference for older berries if they are available. The endosperm is the site of oviposition but is only suitable for development of the brood if it is solid, i. Barrera and P. This stage of development of the berry may only be arrived at after about 16 weeks after flowering depending on ambient temperature. Thus if the female attacks a berry with a young watery endosperm, it penetrates only to the mesoderm and waits in a short tunnel, sometimes for several weeks, whilst the berry matures.
Studies suggest that mortality of the borer is high when it attacks young berries, presumably because it is only in a superficial position and thus more exposed to natural enemies and pesticides applied by the farmer Baker, This is easily diagnosed by the presence of a white powdery patch at the apex of the berry with a dead female underneath.
When the endosperm has hardened, the borer enters and begins to excavate irregular tunnels and galleries in which she lays clusters of eggs. These eggs develop to adult over a period that may range from as little as 25 days to more than 60, depending on temperature and the consistency of the endosperm. The female stays with her brood and does not leave to start another one in another berry Baker et al. When the progeny reach adulthood, the females which out-number males by about mate with their dwarf flightless brothers.
