Figure 4.6. Winged male of an unidentified
species of scale insect (family Margarodidae)
copulating with a flightless female on their host
plant, Ocotea tenera. The wingless female dwarfs
the winged male. Photograph by Dan Perlman.
For those insects in which males compete aggres-
sively for partners, the customary big female pattern
is sometimes lost. For example, in many rhinoceros
beetles (Scarabaeidae-Dynastinae), adult males are
larger than their females; males use their horns as
weapons in battles over females (see Sec. 4.3). In con-
trast, the delicate males of the Monteverde scale insect
ignore each other in a race to find receptive females.
In this insect, the victory goes to the relatively swift
male with good pheromone detectors, which has con-
tributed to the evolution of the immense gulf between
the sexes in both size and behavior in this scale insect.
4.4. Coleoptera: Beetles
4.4.1. Introduction
Paul Hanson
Beetles (order Coleoptera) comprise more than 400,000
named species, which represent about 25% of all
described species of organisms. Adult beetles are
characterized by having the front pair of wings hard-
ened and forming protective coverings over the hind
pair of wings, the latter used for flying. They display
variation in color, shape, and size. In Monteverde, one
can find both the world's largest beetle, the Hercules
Beetle (Dynastes hercules, family Scarabaeidae;
Fig. 4.8), which is 160 mm long, including the horn
(see Sec. 4.4.3), and the world's smallest beetles, the
"feather-winged" beetles (family Ptiliidae), many of
which are 0.5 mm long.
Beetles undergo complete metamorphosis, and
their larvae usually live in concealed habitats such
as leaf litter, rotten wood, bracket fungi, and the rot-
ten cambial layer beneath the bark of logs or stand-
ing dead trees (Crowson 1981, Lawrence 1991). Many
of the most speciose families of beetles have phy-
tophagous (plant-feeding) larvae. Larvae of many
Scarabaeidae (white grubs, which are larval June
beetles) and Elateridae (wireworms, which are larval
click beetles) feed on roots of plants, while those of
many Buprestidae are leaf miners (Fig. 4.9). Larvae
of most Chrysomelidae (leaf beetles; see Sec. 4.7) and106 Insects and Spiders