Figure 4.10. Dynastine scarab beetles of Monteverde. 2: Ancognatha vulgaris', 3: Cyclocephala carbonaria',
4: Cyclocephala wi Ilia mi', 5: Cyclocephala weidneri; 6: Heterogomphus mniszechi', 7: Strategusjugurtha] 8: Dynastes
hercules] 9: Gologa costaricensis.
sites that also attract females (Eberhard 1979, 1980).
Horns are used in combat to pry a rival male from his
perch.
Dynastine females deposit their eggs in humus,
litter, soil, or decaying wood. The egg stage lasts from
two to three weeks. The larvae of Dynastes, Golofa,
Heterogomphus (Fig. 4.10, panel 6), Strategus (panel
7), Xyloryctes, Phileurus, and probably those of Mega-
ceras, Barutus, and Ligyrus are found in rotting logs,
compost, or decayed trees where they feed on organic
debris, including the spores and hyphae of fungi.
Larvae of other dynastines, such as Cyclocephala, feed
on plant roots. Larval dynastines are C-shaped white
grubs (Fig. 4.11). Larvae of most species remain to-
tally unknown.
Species of dynastinae have several natural enemies.
Fungi, bacterial diseases, parasitic wasps, and vari-
ous mammals attack larvae and adults. Individuals
attracted to lights are often preyed on by vertebrates,
especially the introduced Marine Toad, Bufo marinus
(Bufonidae). The greatest threats facing nocturnal in-
sects such as dynastines are forest clearing and light
pollution. Many nocturnal insects are attracted to
lights. Street lights and the floodlights of hotels and
other commercial establishments serve as "sinks"
where insects are attracted, fail to reproduce, and then
die. For the first several years insects are attracted to
the lights in abundance, but then they become fewer
and fewer. Ultimately, the area becomes a sterile,
nearly insect-free desert as local populations of all but112 Insects and Spiders