Monteverde : Ecology and Conservation of a Tropical Cloud Forest

Figure 4.7. (left) The mean number of calling females (black bars)

and copulating pairs (gray bars) of the Monteverde scale insect. Mean

numbers are based on 5-26 censuses of two clusters of females

(A/ = ca. 130 and ca. 200, respectively) made around 0830,1330,

1630, and 1730 hr between 21 February and 3 March 1989.

Figure 4.8. (below) One of the world's most massive insects, the

Hercules Beetle. Photograph by Robert Timm.

Curculionidae (weevils) feed concealed within plant
tissue or on roots in the soil.
Because of the scarce nitrogen in wood, many
beetle larvae that feed on dead wood have mutualis-
tic associations with fungi or other microorganisms,
as in "ambrosia beetles" (see Sec. 4.4.7). Other beetles
associated with wood include many Buprestidae (me-
tallic wood-boring beetles) and Cerambycidae (long-
horned beetles; see Sec. 4.4.5). Many groups of beetles
have larvae that feed on decomposing organic mate-
rial, such as leaf litter, dung, and carrion. Dung beetles
(Scarabaeidae: Scarabaeinae) can be collected with
pitfall traps baited with feces. Such traps yielded 22
species in Panamanian cloud forests (1000-1760 m),
with Ontherus didymus as the dominant species (Peck
and Howden 1984). In Monteverde, some of the more

common dung beetles include Canthidium sp., Copris

sp., Deltochilum mexicanum, Dichotomius carolinus

colonicus, and Uroxys sp. (B. Ratcliffe, pers. comm.).

Several beetles live in and feed exclusively on fun-

gal fruiting bodies. Examples include a few Staphy-

linidae (see Sec. 4.4.2), Pselaphidae (short-winged

mold beetles), Erotylidae (pleasing fungus beetles),

Endomychidae (handsome fungus beetles), and Ciidae

(minute tree-fungus beetles). A noticeable fungivorous

beetle in Monteverde is an unidentified species of

Endomychidae, which forms huge aggregations near

streams during the dry season (J. Longino, pers.

comm.).

Numerous beetles are predatory, often in both the

larval and adult stages. Examples include most Carabi-

dae (ground beetles), Cicindellidae (tiger beetles), most

107 Insects and Spiders