Download Breeding and Non-breeding Survival of Lesser Prairie

INVERTEBRATE SAMPLING
METHODS
Therese A. Catanach
Program in Ecology, Evolution, and Conservation
1816 South Oak Street, MC 652
Champaign, IL 61820
Bugs in a Wildlife Class?
► Invertebrates
provide food
for many wildlife and
game species
► Perform many
ecosystem services
► Disease vectors
► Indicators of ecosystem health
Deciding the Scope of the Question
► What
is the scope of your question?
 General questions
►Habitat survey:
what insects live here?
►Impact
of
management
 Species related
questions
►Feeding
surveys
►Prey availability
survey
Invertebrate Natural History
► Invertebrate natural
history is important
 Presence does not equal
availability
►Size
►Activity level
►Habitat preferences
 Many invertebrates are
toxic or mimic those that
are
Considerations for Invertebrate
Sampling
► Some
insects more likely to
be caught in a certain trap
than others
 Habitats frequented
 Activity periods
 Attractants used for trapping
Sweep Nets
► Collect
invertebrates in
vegetation or flying
► Difficult in thick vegetation
or when vegetation has
thorns/spines
► Can be general or targeted
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Hymenoptera
Diptera
Hemiptera
Lepidoptera
Orthoptera
Coleoptera
► Not
good for ground dwelling
invertebrates
Malaise Traps
► Passive
trap set up along flyways
► Placement
determines
catch
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Hymenoptera
Diptera
Some Hemiptera
Some Coleoptera
Flight Intercept Traps
► Similar
to Malaise Traps
► Targets insects that fall rather than climb when
barriers
encountered
 Beetles
 Orthoptera
Pan Traps
► Different colors
different insects
► Passive
Collecting
 Diptera
 Hymenoptera
 Hemiptera
attract
Sticky Traps
► Standardized trapping
effort
if placed similarly
► Positioning or damage can
make identification
challenging
► Targets
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Diptera
Hymenoptera
Hemiptera
Coleoptera
Vacuum Devices
► Ideal
for collecting
in grasses
► Separate
invertebrates from
litter using
emergence traps or
by hand
► Targets
 Hemiptera
 Hymenoptera
 Diptera
Light Traps
► Species
must be
attracted to light
► Different wavelengths
of light attract
different taxa
► Targets
 Lepidoptera
 Coleoptera
 Hemiptera
Aquatic Net
►
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Many methods
 Dragging through sediment
 Disturbing rocks and other
shelters
Targets
 Immatures of many orders
 Aquatic invertebrates
Beat Sheets
► Ideal
for
vegetation that’s
difficult to sweep
 Coleoptera
 Hemiptera
 Spiders
Attractant Traps
► Uses
attractants (C02,
pheromones, fermenting
fruits, etc.)
► Targets
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Mosquitoes
Social Insects
Certain Flies
Coleoptera
Ticks
Other methods
► Watching
individuals
► Cameras
► Examining
crop/fecal
contents
► Stable
isotopes
Proper Curatorial Techniques
► Specimen
Handling
and Preparation
► Specimen Storage
► Specimen
Identification
Specimen Handling
► Field
preservation
 Freezing
 Ethyl Alcohol (70%+)
►95%
for Molecular work
 Ethyl Acetate
 Ethylene Glycol
►Useful
for pitfall and
similar traps
► Handle
specimens carefully
 Even family level ID can require counting hairs
 If breakage occurs, keep pieces with specimen
Specimen Preparation
► Vouchers
should be deposited in a
entomological collection as a permanent record
► Each collecting event must be labeled
 Location (both written and GPS coordinates), date,
collecting method, brief habitat description, and
collector should all be included on label
ARGENTINA: Jujuy,P.N.
Calilegua, Arroyo 3 Cruces,
1110m, 23°41.629’S64°52.070'W
14.i.2008 TACatanach Hg vapor
light, grassland TAC2008/040
Storage
► Insects
typically either stored dry, or in ethyl
alcohol
 If stored dry, low humidity and temperature will help
with preservation and dermestid beetle
control
 If in ethyl alcohol
use 70%+ and
check frequently
for evaporation
Specimen Identification
► What
level of ID is
necessary to answer
the question?
► Species level is often
not feasible
► Be
aware that one hour of
collecting translates into
days of lab processing
SUMMARY
►
Invertebrate sampling requires knowledge of
invertebrate natural history and how it relates to
the study question or wildlife species of interest
►
Collecting techniques are varied and often specific
to habitats and target taxa
►
Specimen handling, storage, and identification are
integral parts of invertebrate sampling and a plan
for vouchers must be in place