which occur in Costa Rican cloud forests: free-living
forms, saddle case makers, purse case makers, net spin-
ning or refuge makers, and tube case makers. Larvae
are primarily detritivores, although many feed pre-
dominantly on diatoms, other algae, or higher plants,
or are carnivores. They secrete silk, which is used in
constructing nets and portable cases out of sand grains,
small stones, leaf fragments, or tiny twigs cemented
together. Caddisfly cases protect the soft-bodied in-
sect from predators and aid in aquatic respiration
(Holzenthal 1988). Another group of larvae construct
fixed refuges of silk and detritus and spin silken nets
that they use to filter food particles from flowing water.
Other less well-known caddisfly larvae crawl freely on
rocks and prey on other aquatic invertebrates.
Most adult caddisflies are nocturnal and are rela-
tively short-lived. Mating generally takes place on
vegetation or on the ground and is often preceded by
swarming. Oviposition behavior is varied; eggs may
be dropped into the water during flight, deposited
below the water surface, or placed on objects above
the water after which the newly hatched larvae are
washed into the water by rain. The highest diversity
of caddisflies is found in unpolluted, cool, well-oxy-
genated rivers and streams, where they are important
in nutrient cycling and secondary production. Be-
cause they occupy a wide range of often narrow, well-
defined niches, they are useful as biological indicators.
4.2. Orthoptera: Katydids, Crickets,
and Grasshoppers
Paul Hanson
Katydids, crickets, and grasshoppers belong to one of
the more "primitive" (least specialized) orders of in-
sects, the Orthoptera. Members of this group are no-
table for their songs, which are typically performed
by males as part of their territorial and courtship
behavior. Katydids and crickets (Tettigoniidae and
Gryllidae) produce sound by rubbing the two front
wings together. Grasshoppers (Acrididae) in the sub-
family Gomphocerinae produce sound by rubbing the
front wing against the hind leg; band-winged grass-
hoppers (Oedipodinae) snap their hind wings in flight
(probably to startle predators); many other grasshop-
pers are mute. Katydids and crickets are often noc-
turnal, whereas grasshoppers are usually diurnal. The
production of sound implies the existence of hearing
organs in both sexes, which are located on the front
legs in katydids and crickets and at the base of the
abdomen in grasshoppers. Entomologists identify
species by their sounds in the same way that birders
identify birds by their songs. The songs are also heard
by predators, so they are brief to avoid detection.
Once a courting male has "won" a female, he copu-
lates with her, which usually involves the transfer
of large packets containing sperm and a substantial
amount of protein. After copulation, the female inserts
her eggs into plant tissue or in the ground, depend-
ing on the species. Juveniles and adults of most spe-
cies feed primarily on plants, although many katydids
and crickets are omnivorous, and some are predatory.
In Costa Rica, there are a dozen families of Orthop-
tera, of which at least nine are recorded from Monte-
verde: Suborder Ensifera (antennae usually long)—
Stenopelmatidae (Jerusalem crickets), Tettigoniidae
(katydids), Gryllidae (crickets); Suborder Caelifera (an-
tennae usually short)—Eumastacidae (monkey grass-
hoppers), Pyrgomorphidae (grasshoppers), Romalei-
dae (lubber grasshoppers), Acrididae (grasshoppers),
Tetrigidae (pygmy grasshoppers), and Tridactylidae
(pygmy mole crickets).
Many visitors to Monteverde encounter a 3-cm-
long wingless black "cricket," Stenoplemater (Steno-
plematidae), along roads (J. Longino, pers. comm.).
Although most sightings occur during daylight, mem-
bers of this family are generally regarded as noctur-
nal, spending the day hiding in tunnels that they
excavate in the ground. They are thought to be preda-
tors and/or scavengers. This species appears to be re-
stricted to cloud forests.
A notable katydid (Tettigoniidae) in Monteverde
is the lichen-mimicking Markia hystrix (Phaneropte-
rina; 1000-1650 m; Fig. 4.2), which is most frequently
seen at lights at night (J. Longino, pers. comm.). It
is 5 cm long, is whitish green with black mottling,
and has two median, laterally compressed horns on
the pronotum, with another one on the head. An-
other Monteverde species, Melanonotus powellorum
(Pseudophyllinae), is a sluggish, flightless species
that emerges at night to forage on the understory vege-
tation (Rentz 1975). Sphyrometopa femorata (Agroe-
ciinae), another flightless species, occurs in the Mon-
teverde Cloud Forest Preserve (MCFP) but is more
abundant lower in the community. The green nymphs
live on low herbaceous growth in small clearings; the
brown and gray adults move to dry leaves in primary
forest (Rentz 1976). Keys to the genera and a list of
species in Panama are in Nickle (1992b).
Very little information is available on the crickets
of Monteverde or of other Central American cloud
forests (Nickle 1992a). A checklist of Monteverde
grasshopper species is in Rowell (1983a). One of the
most impressive species in Monteverde is Tropidacris
cristata (Romaleidae), the "giant red-winged grass-
hopper," which measures up to 15 cm in length,
making it one of the largest grasshoppers in the world
(Rowell 1983d). Some acridid species present in Mon-
teverde also occur in La Selva, for example, Abacris98 Insects and Spiders