The following are the main protocols selected
by the Diptera TWIG for the present project.
Protocol for Setting Up Malaise
Traps and Handling Samples
Protocols for Culicidae
Protocols for Ceratopogonidae
Protocols for Dolichopodidae
Protocols for Asilidae
Protocols for Sarcophagidae
Protocol for Acalyptratae
(Stephen Marshall and Matthias Buck)
Protocols for Asilidae
Search for robber flies in a variety of habitats, but especially in
areas with relatively undisturbed forest or other primary - or late
secondary - growth vegetation. Asilids will be most abundant along edges
of forest, where the denser vegetation opens - up into trails and small
The "tree - fall light gap" is a particularly
rich habitat for Asilidae, and it deserves special attention during
the Diptera inventory in Costa Rica. This habitat occurs where a live
tree falls in dense forest, creating a small clearing or light gap (often
one tree brings down several other trees or large branches as well).
During the first 6 months or so, this light gap has intense robber fly
(and other insect) activity, especially on the exposed sides of the
fallen tree stems and larger branches, and on vegetation along the edges
of the clearing. As the tree decays (starts to lose bark), and as emergent
vegetation starts to cover or shade the stem of the fallen tree, this
habitat ceases to be very productive for robber flies.
The two main methods of collecting robber flies are: (1) hand collecting
with a net; and (2) malaise trapping. (Occasionally Asilidae are taken
at black lights; a few rare species have only been collected by this
Placing malaise traps in tree - fall light gaps
should be quite productive; place the trap adjacent to the fallen tree
(or even on top of it). Forest edges are generally very good locations
for traps also.
Preparation of Specimens:
Use conventional methods to prepare robber fly specimens
(1) Use paper
points to mount smaller specimens (ca. <10 mm.), and pins for larger
flies (ca. >10 mm.). Very slender Asilidae (e.g., Leptogaster) up to
15 mm. length should also be point - mounted.
(2) Use HMDS
to dry small specimens collected in alcohol (those to be point - mounted).
For larger flies in alcohol: first pin, then alcohol - dehydrate, then
treat with ethyl acetate. Care should be taken so the wings are not
allowed to dry in a position where their tips are too close to the top
of the pin (otherwise they will be easily damaged).
TWIG / Sampling
site selection /
Taxa selection / Products