ably high when compared to the well-known fauna
of other regions (Whittaker 1970, Hamilton 1982).
Nymphs feed on underground roots, and spittle masses
have also been found on epiphytes of the genus
Peperomia (Piperaceae) 15m above the forest floor.
The spittle mass partially protects nymphs from
desiccation and natural enemies (Whittaker 1970).
Spittlebugs construct these shelters from their copious
feeding wastes by using abdominal action to add hun-
dreds of tiny bubbles that are stabilized by the pres-
ence of mucopolysaccharides (Marshall 1966) and
polypeptides (Mello et al. 1987). Nymphs invest in this
elaborate defense because they exploit a relatively poor
food source (xylem sap) that is energetically expensive
to extract (Raven 1983). They require up to seven weeks
to mature (Weaver and King 1954, Peck 1996).
Some spittlebugs of the family Aphrophoridae are
communal in this defense. As many as 69 individu-
als of Cephisus siccifolius have been observed work-
ing together to create voluminous arboreal spittle
masses, which cover up to 15 cm of host twigs and
drip from the canopy. Sometimes individuals are
blown from the branches, but older nymphs can re-
form spittle masses on plants on the ground and sur-
vive to the adult molt. These spittlebugs also aban-
don their refuge and run along the branches as a
potential secondary defense against opportunistic
vertebrate predators such as the Yellow-throated
Euphonia (Euphonia hirundinacea). Once the distur-
bance has ceased, they quickly return to the shelter
of the original spittle mass.
Spittlebugs occur on a wide variety of plants (Ap-
pendix 5). Nymphs use a broad range of substrates
including stems, leaf axils and twigs, soil surfaces, and
epiphytic roots. Although spittlebugs are not host-
specific, their diet breadth is constrained by a com-
bination of host and habitat characteristics. For ex-
ample, the group has an affinity for nitrogen-fixing
host plants (Thompson 1994). On a particular host,
the suitability of feeding sites is reduced by mechani-
cal barriers such as tissue hardness (Hoffman and
McEvoy 1986) and the presence of trichomes (Hoff-
man and McEvoy 1985,1986); unavailability of xylem
vessels (Hoffman and McEvoy 1986); poor quality of
shelter (McEvoy 1986); low amino acid concentration
(Horsfield 1977); and unsuitability of growth habit
(e.g., lack of secondary roots and poor microclimate;
Ferrufino and Lapointe 1989).
Young nymphs of Prosapia sp. near bicincta (Cer-
copidae) are largely restricted to the surface roots of
forage grasses in the litter layer of pastures. As indi-
viduals mature, they move to construct spittle masses
on mature stems (Peck 1996). Nymphs of the Piper
Froghopper, Iphirhina quota (Cercopidae), make their
first spittle masses on soil surface roots of Piper auri-
tum (Piperaceae). As the nymphs mature, they can
emigrate a meter or more above the ground to support-
ive leaf axils. The Heliconia Spittlebug, Mahanarva
costaricensis (Cercopidae), produces spittle masses in
the cuplike, water-filled bracts of Heliconia tortuosa,
an aquatic environment in which nymphs resist desic-
cation (Fish 1977, Thompson 1997).
Nymphs molt to adults within spittle masses of a
drier texture that are often constructed de novo to
provide an airy cave for the new adult's exoskeleton
to complete hardening. Upon emergence, froghoppers
generally feed on the same host species as nymphs,
but they no longer produce spittle. Instead, adults
crawl, hop, and fly to evade enemies. Cephisus sicci-
folius adults rely on crypsis to avoid detection. In
contrast, most adults of the family Cercopidae have
bright warning coloration that advertises their abil-
ity to "reflex bleed." The orange and blue warning
colors of the Heliconia Froghopper make it one of the
most impressive local species. These adults reach 2.1
cm long and are conspicuous diurnal feeders on the
flower stalks of Heliconia tortuosa. If grabbed by hand
from their feeding sites, they exude droplets of am-
ber-colored and distinctive-tasting hemolymph (up to
8.5 (il) from the tips of all legs, probably serving as a
general deterrent that startles potential enemies and
permits the froghopper to escape by hopping. Reflex
bleeding has been observed in 30 cercopid species at
Monteverde, most aposematic.
Females lay eggs in or near their host plants. Eggs
of some of these species have the ability to enter dia-
pause to survive adverse conditions. The eggs of Pro-
sapia sp. near bicincta are laid in the soil of pastures
at the base of host grasses. These eggs enter diapause
to endure the dry season. First-instar nymphs of the
new generation are detected just after the arrival of
the rains in May (Peck 1996).4.3.3. Leaf hoppers of Costa Rican
Cloud Forests
Carolina Godoy
Leafhoppers (Cicadellidae) are the largest family of
Hemiptera. Because of their relatively small size (3—
30 mm long), leafhoppers are often overlooked even
though they are present in nearly all habitats and are
sometimes extremely abundant (e.g., in grasses). Leaf-
hoppers vary in color from dull brown (most Agallinae)
to green (Hortensia, Cicadellinae) to strikingly colored.
Among the common cloud forest species, Barbinolla
costaricensis (Cicadellinae) is bright blue with a yel-
low-orange collar; Colladonus decorus (Deltocepha-
linae) is mostly black with bright yellow markings.
There are 18 subfamilies of leafhoppers in Costa
Rica. The three largest subfamilies are Cicadellinae,102 Insects and Spiders