PENNSYLVANIA INVERTEBRATES AND INVERTEBRATE COLLECTION METHODS
INVERTEBRATES IN PENNSYLVANIA (COMPILED IN 2005 BY THE PENNSYLVANIA BIOLOGICAL SURVEY) Summary 11,702 species recorded in Pennsylvania 282 are Species of Special Concern 37 are considered Extirpated 38 are known only from historical records Introduction Study of invertebrate animals in Pennsylvania has a long history. Most native species of invertebrates in Pennsylvania were named, but basic information on the biology of only a few species was published. The fauna of adjacent states (especially New York and New Jersey) has been well studied since the 1900 s. Despite a long history of study, no invertebrate group has been inventoried in Pennsylvania with the same rigor as the vertebrate groups. Although some aquatic taxa have credible baseline inventories, many invertebrate species are still documented only by original literature references. Invertebrates are present in every conceivable biotic habitat, and in most ecosystems they constitute the groups with greatest species richness. Invertebrates are involved with every biotic process occurring in natural communities, from pollination, herbivory, and predation to soil formation, disease transmission, nutrient cycling, and decomposition to name only a few. The overview of invertebrate taxa occurring in Pennsylvania is provided below. The Status of the Pennsylvania Invertebrates The total number of species of organisms in Pennsylvania is here estimated to be 21,884, of which 11,702 (53.2%) are invertebrates (including Protista other than algae), 5,143 (23.5%) are plants (including algae), 3,619 (16.5%) are fungi and lichens, and 710 (3.2%) are vertebrates. Insects constitute 46% of total biodiversity in the state, and at least 80% of those are terrestrial. Taxonomic Group Common Name Habitat/ General Information Phylum Porifera sponges 2-10 freshwater representatives (Spongilla) Phylum Cnidaria hydra 2-10 freshwater hydras and jellies (class Hydrozoa) Phylum Platyhelminthes Class Turbellaria Class Trematoda Class Cestoda flatworms flukes tapeworms 2-10 all parastic 2-10 all parasitic Phylum Nemertina nemerteans 1 freshwater species Phylum Rotifera rotifers/ wheel animals Phylum Gastrotricha gastrotrichs 2-10 freshwater Phylum Nematoda nematodes or round worms 101-1000 freshwater, soil, larvae parasitic Phylum Nematomorpha horsehair worms 2-10 freshwater, soil, larvae parasitic Phylum Acanthocephala spiny-headed worms 2-10 parasitic Phylum Mollusca Class Gastropoda Order Prosobranchia Order Pulmonata non-operculata snails slugs
Taxonomic Group Common Name Habitat/ General Information Class Bivalvia Order Schizodonta Order Heterodonta freshwater clams fingernail clams >65 freshwater 11-100 freshwater Phylum Annelida Class Polychaeta Class Oligochaeta Class Hirudinea polychaetes oligochaetes, earthworms leeches 2-10 freshwater 11-100 freshwater and terrestrial Phylum Tardigrada water bears 2-10 freshwater or terrestrial (mostly associated with mosses) Phylum Arthropoda Class Chelicerata Order Scorpiones Order Pseudoscorpiones Order Araneae Order Opiliones Order Acarina Class Crustacea Subclass Branchiopoda Subclass Ostracoda Subclass Copepoda Subclass Branchiura Subclass Malacostraca Order Mysidacea Order Isopoda Order Amphipoda Order Decapoda Class Entognatha Order Protura Order Entotrophi Order Order Collembola Class Insecta Order Archaeognatha Order Thysanura Order Ephemeroptera Order Odonata Order Phasmatodea Order Orthoptera Order Dictyoptera Order Isoptera Class Insecta Order Plecoptera Order Dermaptera Order Psocoptera Order Zoraptera Order Mallophaga Order Anoplura scorpions pseudoscorpions spiders daddy longlegs, harvestmen ticks and mites water fleas and kin ostracods copepods branchiurans mysidaceans wood lice, pill bugs amphipods crayfish, crabs, shrimp proturans diplurans springtails bristletails silverfish, firebrats mayflies dragonflies and damselflies walkingsticks grasshoppers, crickets, katydids roaches and mantids termites stoneflies earwigs booklice and barklice zorapterans or angel insects chewing lice biting lice 1 terrestrial 101-1000 terrestrial >10 terrestrial 101-1000 freshwater, terrestrial, parasitic 11-100 freshwater 2-10 freshwater or terrestrial 2-10 freshwater or terrestrial 1 freshwater 2-10 freshwater or parasitic 2-10 freshwater or terrestrial >230 freshwater >170 freshwater 11-100 terrestrial >136 freshwater 11-100 terrestrial 1 terrestrial 11-100 terrestrial
Taxonomic Group Common Name Habitat/ General Information Order Thysanoptera Order Homoptera Order Heteroptera Order Megaloptera Order Neuroptera Order Coleoptera Order Strepsiptera Order Mecoptera Order Trichoptera Order Lepidoptera Order Diptera Order Siphonaptera Order Hymenoptera thrips cicadas, aphids, leafhoppers true bugs dobson and salmonflies ant-lions, lacewings, owlflies beetles twisted-wing insects scorpionflies caddisflies moths and butterflies true flies fleas social insects, ants, bees, wasps 11-100 terrestrial 101-1000 terrestrial 101-1000 terrestrial 2-10 freshwater >1000 freshwater or terrestrial >312 freshwater >1000 freshwater or terrestrial >1000 freshwater or terrestrial >1000 terrestrial Class Diplopoda millipedes 11-100 terrestrial Class Chilopoda centipedes 11-100 terrestrial Phylum Pentastomida tongue worms 2-10 parasitic Phylum Bryozoa moss animal 2-10 freshwater Phylum Entoprocta entoprocts 1 freshwater http://www.altoona.psu.edu/pabs/invertebrates.htm Exotics or Invasive Invertebrate An increasing number of non-native invertebrates have been recorded in Pennsylvania, formally registered in the recently established North American Non-Indigenous Arthropod Database (NANIAD). In 1989 NANIAD listed 2,419 species of non-indigenous arthropods as having been reported from the United States, of which 152 species were cited specifically for Pennsylvania. Many European insects have long been known to have populations in Pennsylvania, but others are just being documented. Taxonomic Group Common Name Habitat/ General Information Phylum Arthropoda Order Coleoptera - Japanese beetle (Popilla japonica) - extensive damage in ornamental trees ($460 million annually), first observed in 1916 in NJ, metallic green or greenish-bronze color - Pine shoot beetle (Tomicus piniperda) - discovered in 1992 in Christmas tree farm in OH, attacks new shoots of pine trees, brown-black cylindrical body
- Emerald ash borer (Agrilus planipennis) - first identified in 2002 in MI, causes girdling and death of branches and trees, emerald green cylindrical adult - Exotic bark beetle (i.e. alder bark beetle Alniphagus aspercollis) - generally imported from Europe - Asian longhorned beetle (Anoplophora glabripennis) - first identified in NY in 1996, infests hardwood trees, native to China and Japan, very large insects (2.5-4cm long), shiny black with white spots, long antennae, feeds on poplar and willow trees Phylum Arthropoda Order Hymenoptera - Sirex wood wasp (Sirex noctilio) - invasive European wood wasp, first found in NY in 2004, significant damage to pine trees
Phylum Arthropoda Order Lepidoptera - Gypsy moth (Lymantria dispar dispar) - indigenous to Europe, introduced to North America in 1869, was purposefully introduce for hybridization with silk worms, larvae hang from foliage by silk threads, adults white to brown mottled Phylum Arthropoda Order Hemiptera - Brown marmorated stink bug (Halyomorpha halys) - native to China, Japan, Korea and Taiwan, orchard pest, introduced in 1988 - Hemlock wooly adelgid (Adelges tsugae) - native to East Asian, introduced in the USA in 1924, few methods of chemical control of this pest - Elongate hemlock scale (Fiorinia externa) - armored scale insect, first observed in 1908 in NY, wasp
parasitoids to be developed as biological control - Beech scale insect (Cryptococcus fagisuga) - imported from Europe, secondary infection through fungus Phylum Arthropoda Class Chelicerata Order Acarina - Varroa mite (Varroa destructor) - external parasitic mite that attacks the honey bee, can replicate only in honeybees and spread viruses - Tracheal mite (Acarapis woodi) - from Great Britain, commonly controlled with grease patties (veggie shortening with powdered sugar, attacks honey bees Phylum Annelida Class Oligochaeta - Non-native earthworms Phylum Nematoda - Potato cyst nematode - major pest in potato crops,
(Globodera pallida) damage to potato roots and plant senescence, 1mm round worm - Golden nematode (Globodera rostochiensis) - considered one of the most dangerous potato diseases, imported from Europe, US has imposed quarantine restrictions - Soybean cyst nematode (Heterodera glycines) - attacks roots of soybeans Phylum Mollusca Class Gastropoda - Giant African snail (Lissachtina fulica) - first imported as pets, damages native plants and crops
INTRODUCTION TO INVETEBRATE COLLECTIONS There are two general categories in which collection methods may be placed: passive and active sampling. Passive techniques utilize devices left in the field to collect material without the collector present. Active sampling involves direct collection of specimens. Passive techniques are generally preferred in studies that aim to document the biodiversity of invertebrates in a given habitat because they maximize collection effort with minimum effort. Commonly used collection techniques are: Passive techniques: 1. Pitfall trapping/bait traps, 2. Yellow pan traps, 3. Light traps Active techniques: 1. Hand collecting/ netting, 2. Chemical knockdown PASSIVE TECHNIQUES 1. Pitfall and Bait Traps This is the most commonly employed sampling technique in biodiversity inventories. It is used for collecting terrestrial invertebrates that move at ground level but may also collect flying invertebrates especially if the trap is baited. Materials: - equal size jars/plastic containers (wide-lipped, 5-10cm diameter) with screw on lids - spade, trowel - killing solution with preservative e.g. propylene glycol - detergent (break up surface tension) - plant pot base or other plastic roof - wooden pegs, metal fencing or even similarly shaped stones Drawing from http://www.ypte.org.uk/animal/minibeasts/30, other websites to consult for pitfall traps are as follows: http://mississippientomologicalmuseum.org.msstate.edu//collecting.preparation.methods/pitfalls.htm http://soilbugs.massey.ac.nz/collection_pitfall.php http://www.animalethics.org.au/policies-and-guidelines/wildlife-research/pitfall-traps http://markgtelfer.co.uk/files/2010/03/pitfall-trapping-protocol.pdf Method: Fill a plastic jar with killing solution mixed with preservative (e.g. for terrestrial invertebrates a 50/50 mix of 30 ppt salt solution and 200 proof ethanol) sink it into the ground with rim flush with the surface. Invertebrates that are active on the ground fall into the trap are killed and preserved by the fluid. Place a roof over pitfall, to protect the trap from rain or debris. All of these traps can also be placed into flower pots and planters if you have them available on your deck. Bait Trapping: The pitfalls may also be baited to attract particular groups of invertebrates for example dung to attract dung beetles, sugar instead of salt solution for certain insects, beer for slugs and snails, molasses for moths and meat to attract flies and collect immatures. In case of bait traps there should not be any killing fluid inside the containers, just the bait. In addition the containers should be deeper,
so that the invertebrates cannot get back out. Containers should be checked on a regular basis, such as daily or every other day. Most likely to catch: Ants, spiders, beetles, snails, earthworms, harvestmen, springtails Tips: Put out more than one pitfall trap at each site. If you mark the location of each pitfall with flagging tape you will have an easier time finding the containers again. Make sure the rim of the pitfall is flush with the ground; some walking invertebrates have aversions to walking down or up a slope. When digging the holes transfer the dirt onto the pitfall roof as dirt will be later used to fill around the pitfall. If the ground is rocky it may be necessary to fill around the pitfall with stones before replacing the dirt. Trap problems: Depending on size of the container, pitfall traps may catch small vertebrates (bycatch) including, small lizards and frogs. Therefore, small pitfall traps (diameter 5-10cm) and roofs placed closely over the trap may serve in minimizing the amount of by-catch. 2. Yellow Pan Traps Yellow pan traps are similar in concept to pitfall traps, however, they are shallow and thus are mainly used to catch flying insects. The collection fluid attracts insects in search of water but more specifically many wasps and certain flies are attracted to the color yellow, which is essential for the method. This is an example of a pan trap. It is a common yellow picnic bowl secured to the ground with a skewer and partially filled with saline. It has caught a number of flying insects attracted to the color and the liquid (pictures obtained from: http://www.brynmawr.edu/biology/williams/williams_course_papers.html, http://ricehoppers.net/2010/02/farmers -day-for-ecological-engineering-to-restore-biodiversity-in-caibe-vietnam/, http://www.hymatol.org/hym_course/slideshow.php?directory=.¤tpic=68) Materials: - yellow colored plastic pans e.g. plastic picnic bowls or any kind of plastic tray with high sides e.g. baking tray (make sure that all trays used for the one sample are the same size) - if you cannot find any yellow trays get some spray paint and paint the pans/trays yellow - collection fluid for pan ideally salty water - detergent (break up surface tension, a drop is generally sufficient) - preservative for catch e.g. 75% ethanol - collecting jars/sample vials Method: Partially fill a yellow colored plastic bowl or tray with collecting fluid. Then place the pan onto the ground or even on a higher elevation. Add one or two drops of detergent to reduce water surface tension. At the end of the collecting period sieve the catch to remove the liquid and then transfer the contents to a long-term storage preservative such as ethanol.
Most likely to catch: Flies, small wasps, bees, and certain groups of flying beetles. Tips: It is not advisable to leave the trap for more than 24 hours. This is because they are generally easy to disturb and secondly the saline water will evaporate, especially in hot conditions. If the pan is light-weight it may be necessary to burry it (shallowly) into the ground. Avoid using yellow pans near obvious burrows as rabbits enjoy destroying yellow pans. Problems: Pan traps can attract other animals that investigate the water. This may be avoided if you place the pans onto your deck rather than out into a field. 3. Light Traps A variety of flying insects are caught using light traps. For invertebrate/insect collections the traps may be modified depending on trapping of aquatic or terrestrial invertebrates. For terrestrial invertebrates you can easily suspend a collecting plate/tray with killing fluid underneath a house lamp to attract flying insects. For aquatic insects you may have to build a more sophisticated contraption (http://www.aquaticresearch.com/aquatic_invertebrate_light_traps.htm). Materials: - flying insect tray (brightly colored often help) - preservative for collecting container or trough eg saline water - detergent (break up surface tension) - collecting jars or sample vials Method: Flight intercept traps can be erected or hung anywhere. To maximise your catch though they are usually placed along probable insect flight paths. Insect flight paths include locations such as forest edges, riverbanks, trails in forests, and little open gullies. Most likely to catch: Flying insect groups such as beetles, bugs, flies, wasps, bees, moths and butterflies, dragonflies or aquatic insects, depending on which type of trap you design. Tips: Use in conjunction with yellow pan traps and pitfall/baited traps to receive largest variety of invertebrates, particularly flying insects. It is advisable to put a dash of detergent in collecting device to reduce surface water tension. Problems: Aquatic invertebrate traps tend to be quite expensive.
ACTIVE TECHNIQUES 1. Hand collecting This is the simplest (and most active) sampling technique for collecting invertebrates. Materials: - collecting jars or sample vials - preservative (preferably in a squeeze bottle) e.g. 75%, ethanol - forceps or flat-headed tweezers - artists paintbrush - head torch (if collecting at night) - anything to aid collection such as net (different nets available such as aerial and aquatic nets) Methods: Look for and collect invertebrates by hand (using forceps or flat-headed tweezers). Hold invertebrates in a sampling jar for identification. Depending on their mobility, some species will be easier to catch than others. Slow-moving invertebrates may simply be grasped with the forceps, or brushed into the sample vial with a paintbrush. More active species can be caught by placing the sample vial over them. Most likely to catch: Any invertebrate Tips: Good areas for collecting invertebrates include: under logs and rocks, tree trunks (above and beneath bark) and on leafy vegetation. Sampling at night will often produce a very different suite of species than if you only sample during the day. Try to avoid using your hands as there are many invertebrate mimics, with some potentially providing nasty stings. 2. Chemical Knockdown This technique is used for collecting invertebrates from plants. Materials: - safety equipment used to avoid contact with chemicals and inhalation. - sturdy stick for beating plant. - collecting jars or sample vials - collecting trays (we used 400mm pot plant bases) - knockdown chemical - plastic groundsheets, common sheets (white) - preservative eg 75% ethanol - clear plastic sheet Method: Cover or wrap all or part of the plant under investigation. Then apply a knockdown chemical to the plant. Collect the invertebrates as they fall by placing a sheet or tray under or around the area that is to be treated. After initial collection, it is a good idea to beat or shake the plant to dislodge any remaining invertebrates. There are many variations on this basic method with varying levels of sophistication, labour and expense. Simple knock down techniques use household insecticide spray, while the more complex methods used for sampling whole trees require misters or foggers. Most likely to catch: Beetles, bugs, spiders, mantids. Tips: Carry out early in the morning when flying invertebrates are more sluggish. Chemical knockdown is a very productive technique in terms of the number of specimens retrieved from a single plant. Be sure to obtain the appropriate knockdown chemical (dependent on invertebrate) as some are much healthy for the environment and us than others. Problems: Very weather dependent, and is unsuitable in wind and rain. Can be difficult and time consuming to collect specimens by hand from tray or drop sheet.