Monteverde : Ecology and Conservation of a Tropical Cloud Forest

Host plants are located primarily by means of ol-
factory organs within the elongated antennae. A suc-
cession of long-horned beetles appear to arrive at
fallen trees; chemical changes in the wood may have
a selective influence. In most subfamilies, oviposition
consists of little more than using the ovipositor to
place eggs in bark crevices or decomposed wood.
Species of Lamiinae tend to have more specialized
oviposition habits and often use their mandibles to
chew an oviposition site. Long-horned beetle larvae
usually feed and develop within the stems of woody
plants. Most often, they attack dying or dead stems,
but some species breed within living stems of larger
herbaceous plants (Table 4.1).
Larvae of a few species feed in roots and seeds.
Those that attack living or recently dead wood are
more host-specific than those that attack wood in later
stages of decay. In some long-horned beetles, the fe-
male harbors a yeast in intersegmental pouches of her
abdomen that aids in the digestion of cellulose. She
smears these microbes onto her eggs during oviposi-
tion; the larva obtains the yeast by eating the egg shell
soon after hatching. Long-horned beetle larvae are
cylindrical grubs, often slightly enlarged in the tho-
racic region. Prior to pupation, the larvae usually
construct a cell within the wood or just beneath the
bark, and the pupa rests in this "safe area" during
its most vulnerable stage. Lagocheirus (Lamiinae-
Acanthocinini) larvae cut a large elliptical piece from
the outer bark prior to entering the sapwood to pu-
pate. Heavily infested logs may have dozens of these
"bark cookies" scattered over their surface. Adult

emergence is often seasonal and correlated with rain-

fall patterns. Biology of long-horned beetles is dis-

cussed elsewhere (Duffy 1960, Linsley 1961).

4.4.6. High Altitude Leaf Beetles

(Chrysomelidae and Megalopodidae)

in Costa Rica

/?. Wills Flowers

Chrysomelidae is an immense family of over 37,000

described species, which is more than twice the

species richness of birds and mammals combined

(Klausnitzer 1981). Larvae and adults of most species

feed on living plant material. Many larvae are subter-

ranean root-feeders and some are leaf-feeders; stem-

boring, leaf-mining, and detritus-feeding are found

among few species. The vast majority of adults are

aboveground leaf, flower, or pollen feeders. Some are

important pests through direct feeding damage and

transmission of viruses; others are useful biological

control agents of weeds.

Worldwide, 19 subfamilies are recognized, of which

14 are represented in Costa Rica (Seeno and Wilcox

1982, Reid 1995). No formal studies on the altitudi-

nal distribution of tropical chrysomelid faunas exist,

although there are scattered references to the altitudes

of collecting localities. Leaf beetle diversity in low-

land areas is considerably higher than in cloud for-

ests and higher altitudes.

Beetles in the subfamily Megalopodinae resemble

aberrant long-horned beetles. In Megalopus, which

is regularly collected above 1300 m, the males have

Table 4.1. Larval hosts of Cerambycid beetles in the Monteverde area.

Beetle Host Plant

Cerambycinae

Anatinomma bispinosum (Hesperophanini)

Pempteurys sericans (Anaglyptini)

Ancylocera macrotela (Trachyderini)

Lamiinae

Anisopodus costaricensis (Acanthocinini)

Acrocinus longimanus (Acrocinini)

Adetus spp. (Adetini)

Eulachnesia smaragdina (Hemilophini)

Desmiphora hirticollis (Desmiphorini)

Ischiocentra monteverdensis (Onciderini)

Disteniidae

Distenia pilatei (Disteniini)

Billia colombiana (Hippocastanaceae); girdling living

branches

On girdled branches; Persea (Lauraceae) girdled by

Oncideres fulvostillata

Acacia girdled by Oncideres punctatus

Cacao (Theobroma, Sterculiaceae)

Ficus spp. (Moraceae) (beneath the bark)

Cucurbitaceae

Cacao (Theobroma, Sterculiaceae)

Cordia spp. (Boraginaceae)

Mandevilla veraguasensis (Apocynaceae)

Young coffee (Coffea, Rubiaceae)

115 Insects and Spiders