FIELD ENTOMOLOGY : EEB 252

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Lecture 2: COLLECTIONS

 

Why make and maintain collections?

 

Therefore, the lack of good collections hampers our abilities to acquire correct identifications, which, in turn hampers or handicaps biological investigations.

 

Collections allow:

1. permanent record of our planet's biota -esp. for species that are extinct or soon will become extinct.

2. vouchers for research (see below)

3. ID to allow research (esp. as experts dwindle in numbers)

4. nomenclatural "tags" (type specimens) to stabilize names

5. depository of variation within & among species to allow taxonomic revisions

6. of both living & dead, represent a major educational resource for the public

7. excellent source of FUN that is also valuable to society

 

Types of collections:

1. exhibit collections (wonderful/beautiful specimens, e.g. T-rex skeletons)

2. teaching collections (high turn-over of specimens i.e. no permanence)

3. synoptic faunal collections (short series limited to one geographic region, e.g. Block Island)

4. research collections (long series, ca. relative to pop density?, expensive to maintain)

 

 

A few Research Collections worth knowing about:

(From: Arnett, R. H., Jr., G. A. Samuelson and G. M. Nishida. 1993. The insect and spider collections of the world. 2nd ed. Flora & Fauna Handbook No.11, Sandhill Crane Press, Inc. 310 pp.)

1. National Collection of Insects, Museum National d'Histoire Naturelle, 45, Rue Buffon, Paris 75005 FRANCE. [MNHN], 100 million specimens, the largest single collection in the world (ca. 400, 000 species).

2. Department of Entomology, and Department of Zoology (for spiders), The Natural History Museum, London SW7 5BD, UNITED KINGDOM. [BMNH], 30 million specimens (1.5 million species) more species than Paris but fewer specimens. second largest collection in the world.

3. United States National Entomological Collection, Department of Entomology, U. S. National Museum of Natural History, Washington, D.C. 20560, USA [USNM], 30 million specimens, said to be the second largest, but probably behind the BMNH.

4. Instituto Nacional de Biodiversidad, Santo Domingo de Heredia, 200 m Norte y 400 m Oeste del sementerio, COSTA RICA. (INBio) [INBC], A collection of only Costa Rican species, ca. 1.5 million specimens as of 1993, but growing at 60,000 specimens per month. This collection is the new standard and is acting as a model for other countries to develop biodiversity inventory collections. Every specimen is bar-coded and all the data is captured into a relational database.

5. Department of Ecology and Evolutionary Biology, Box U-43, University of Connecticut, Storrs, CT 06269-3043. [UCMS]. 115,000 specimens as of 1993. (Soon to be boosted to 117,000 specimens due to your efforts!)

 

The need for voucher specimens.

Always question the quality of identifications. No large collection is without misidentified specimens. The most reliable identifications are those produced by world authorities on the group (see det labels below), with the general trend being that the more recent the identification by an authority, the more likely it is to be correct. For this reason, any investigation that results in the publication of species names should also specify where the specimens have been permanently deposited. The names are only as good as the identifications and the quality of the identifications can only be verified if the specimens are readily available for inspection.

Another reason for the deposition of voucher specimens is the fact that as larger samples of biological variation within groups are analyzed in greater detail, taxonomic names often are changed to reflect our improved understanding. For example, what was once considered one species may be discovered to be two. If such a change is made then only by reidentifying the vouchers of previous studies can one determine which of the two species were studied. If the vouchers are lost then the value of that research might decline due to the new ambiguity surrounding the identity of the study organism(s).

A good voucher specimen should have two labels, one specifying the standard collection-locality data and the other (lower) label specifying in as much detail as possible the study or project that the specimens belonged to (see example below)

Voucher for study of
Odonate predation
J. N.Y.Ent.Soc.1988:1
pp.121-134. F. Shoels

 

Determination labels.

What is a "det label"?- A label that states the Genus & species (and often the describer) AND the name of the person who takes responsibility for the correctness of that identification with the year the determination was made. Preferably only experts should place a det label, however, many entomologists can properly determine specimens without being an expert in that group. Do not place det labels unless you are sure of your determination, if you are not sure either don't place a label or add one or more question marks. A typical det label might look like this:

Nicrophorus
nigrita (Mann.)
det. D. S. Sikes 1996

The year is important because taxonomy and expertise changes (a determination made by an expert before he/she became an expert is not the same as one afterwards; Also indicates when det was made in reference to some taxonomic publication on that group).

 

COLLECTING METHODS OVERVIEW

Collecting and ethics: low impact requires knowledge and concern. Information on permits, endangered taxa, take only the necessary vouchers (not entire populations). If your study is to simply document that a species occurrs in a given area you really only need 2-6 specimens. Fewer specimens taken means fewer pins and costs of time to process and means less negative impact on the population. However, some species can only be identified by using the reproductive parts of one sex (usually males). If you take few specimens you run the risk of not capturing any of the sex needed for identification....also, a taxonomist interested in studying the variation of a species wants the largest sample sizes possible (think of the variation in our species...it would take a large sample of humans to properly capture our species' full range of variation). And as Dave Wagner once said: "If you're going to kill something you owe it to that organism to properly prepare it and get it into a museum"

key word: EFFICIENCY. bottom line: information per dollar invested (and remember time=money). Understand the trade-offs, e.g. more unique information per specimen equals fewer specimens and slower processing. Whether 200 specimens with minimal data from 10 units of effort = 20 specimens with extensive data from 10 units of effort is dependent on the goals of the research.

If the mission is to document simply which species occur in a given region then one should maximize specimens captured and minimize unique specimen data. If the fauna is known (a complete species list is available) then one should maximize unique specimen data. Of course intermediate cases are common, in which case a balance should be struck.

Try to record effort invested and later relate to information captured. Effort can be measured many ways, the easiest but least informative is in dollars. Information can be measured as specimens, but this will undervalue the unique specimen data. Many studies fail to document any measure of effort.


Costs analysis:

The following should give you some idea about the costs involved in only the Processing of specimens, this report doesn't include the costs of collecting the specimens!

A RESOURCE MANAGEMENT REPORT: Snow Entomological Museum Participation In BOLIVIAN EXPEDITION BIOLAT Si/ MAB 1988: REPORT ON COSTS IN TIME AND MATERIALS

James S. Ashe
Snow Entomological Museum
Snow Hall
University of Kansas
Lawrence, Kansas 66045

 

Introduction In 1998, the Collection Manager of the Snow Entomological Museum, Robert Brooks, participated in the BIOLAT project in Bolivia. His primary responsibility on this expedition was to collect bees. However, in order to make the trip maximally productive, he also collected other taxa. It became the responsibility of the Snow Entomological Museum to prepare and label the material, sort all the specimens to morphospecies and identify to lowest possible taxon, then divide the material as indicated in prior agreements. A total of 13,200 specimens was prepared from 120 individual collections. This report documents the costs to the Snow Entomological Museum of completing the above mentioned task. A note on the preparation times indicated in this report is approximate. Our prepreparation times are long-term averages (a month or more) across all the individuals involved in the preparation phase of the program. In addition, all the aspects of preparation are included in the time estimate: sorting specimens from often dirty alcohol samples, washing and cleaning if necessary, typical pointing of dried specimens, etc. In addition, these estimates include the numerous other interruptions that decrease long term preparation figures: breaks to re supply unit trays, drawers, pins, point-paper and other expendables; to co-worker interruptions, and start-up and clean-up time for each work session. Additionally, the majority of our preparation program is based on work-study student help. This is very cost effective; however, since such individuals do not usually work long hours at a time, their relative long term productivity is decreased. Of course, some individuals are highly skilled and rapid, while others are less so. We believe that these preparation rates are a very accurate estimate of long-term production under these criteria. Clearly we would have achieved higher numbers had we only estimated hourly rates for our best pinner under ideal circumstances.

 

Cost of Materials:

Pins @ $.047/pin, for 13200 pins $620.40

100% rag paper @.07/page, for 80 pages $ 5.60

Laser printer @ . 10/page, for 80 pages $ 8.00

 

In addition there is cost associated with use of the computer to word process the labels which is not figured here.

Cost of time:

Making Points: Five-sixths of the collection is pointed approximately equaling 11000 specimens. It takes about 9 hours to make 2000 points. 11000 points takes 49.5 hours @ $5.00/ hour=$247.50 [ca. $0.02 per point]

Pointing Specimens: On the average 28 specimens are pointed per hour (this includes pouring them out of vials or whirl-pacs into a petri dish, taking them individually out of alcohol to a paper towel to dry, sonication for cleaning of soiled specimens, bending point tip, and affixing adhesive to the point). 11000 specimens @ 28 specimens/hour takes 393 hours @ $5.00/hour =$1965.00

Pinning Specimens: On the average 55 specimens are pinned per hour (this includes relaxing layered specimens and taking alcohol specimens from vials or whirlpacs as above). 2200 specimens @ 55 specimens/hour takes 40 hours @ $5.00/hour=$200.00

Labeling Specimens:

Preparation: To make labels it takes about an hour to cast and print 500 individual labels consisting of 10-15 different labels. The specimens require two labels each. For the 120 different collections it took about 10 hours to prepare the labels @ $5.00/hour=$50.00

Labeling: To cut and place labels (2/ specimens) it takes an average of one hour to label 75 specimens. 13200 specimens takes 176 hours @ $5.00/hour=$880.00

Labor Cost for Collecting and Sorting: Salary of collector on the actual expedition and time spent sorting collection (includes sorting to order, then family, then in many cases genus, then to species and for the entire collection to morphospecies and finally dividing the collection into three parts).

 

Collection Manager 420 hours

Museum Director 6 hours

Curatorial Assistant 10 hours

Museum Assistants 60 hours

$5149.34

 

Preparation of final report took 4 hours 0 $ 10.00/hour=$40.00

 

Mailing Costs:

Twenty Schmitt boxes @ $5.00/box=$100.00

Postage (library rate)=$12.55

Postage would be considerably higher with overseas or out of country mailing which would usually be the norm.

Packing Schmitts with specimens and putting in needed brace pinning and mailing them in 5 separate packages. 16 hours @ $5.00/ hour=$80.00

 

The Costs: The cost to the Snow Entomological Museum of collecting, preparing and sorting the 13200 specimens from the Bolivian Expedition was $9358.39. 404 hours of professional expertise and 777.3 hours of Work Study assistance was used. It should be mentioned that all of these costs were taken from the Museum's normal operating budget and not from grant sources. This report should serve to underscore the fact that the vast majority of the cost of an expedition is in preparation, sorting and curation of material. These costs must be taken into full account in any collaborative arrangement among museums.

These figures result in a cost of $0.71 per specimen. Thus 2000 specimens= $1,417.94

 


Collecting Methods: This is a brief introduction to various methods, some of which you will use/learn about in the field.

1. quantitative methods (trap sample/unit time)

pitfall traps "the perfect pitfall"
location location location
sloping down
to rainroof or not
NO EDGE
barriers
barriers around bait (fungi, rotting trees etc.)
propylene glycol as preservative (one cheap source: Sierra© brand anti-freeze)

 

flight intercept trap
"one of the best buys for your buck" (in specimens captured per unit time and dollar invested)

 

malaise trap (expensive FIT) some catches nonredundant with FITs, particularly among Diptera & Hymenoptera

 

yellow pan with propylene glycol for Hymenoptera

 

Lingren (hanging) funnels

all the above with baits:

light

carrion (beware scavengers)

dung

fermenting sugars (fruit/beer)

pheromones

 

2. qualitative methods (any quantitative method with no set trap units becomes qualitative)

nets--note that some mistakenly think these can be used quantitatively

trolling & car nets

beating sheet

shovels (large/small)

pry bar/large knife (for rotten wood)

Berlese (can be made quantitative, but is actually a hand-collecting method like sweep netting)

blacklighting

 

When collecting by hand: RULE of Nature -if you see a valuable looking insect on a plant or object and it drops to the ground, it is lost. Only if it is very colorful or large will you be able to find a dropped insect. The more valuable it is, the less likely you will be to find it. Thus, always put your hand or preferably your net under the insect before you disturb it (then, if it falls, it will fall into your net).

 

Labeling, in the field

Until a label is associated unambiguously with a specimen it is virtually worthless. A trip to Madagascar costing $2000 to collect specimens 50% of which are unknown to science can become a total waste of time and money if the specimens are not associated with labels. Never procrastinate labeling. Always place a Field label as soon as you are able into the collection sample. This label should be written with permanent ink on high-quality acid-free rag paper. Also, this label should include ALL the information that will go on the final permanent label. See the example below:

USA: CONNECTICUT

The more pertinent information, the better. Use this format for your labels. I am a stickler for consistency of format-be sure the date is written with the month in letters and abbreviated and in the middle, do not shorten the year.

A specimen with no label is valuable only for the teaching collection. A specimen with a poorly written label is bothersome, may become a large time drain to future researchers and might be worthless. Only a specimen with a properly made label is a valuable voucher specimen. DO NOT USE CODES e.g. Site 1, Site 2 etc., These would fall under the category "poorly written labels" because without the notebook to translate the codes into data the specimens are worthless. One note: once you've written a complete label a code may be valuable to (1) include extra data that won't fit on a specimen label or (2) denote a nest from which all individuals taken are given the code.

Field Note Book:

Depending on your project funding this book is either a simple reminder log or a consistently and very carefully kept account of all expenditures and activities involved with your project. Remember this: REDUNDANCY IS GOOD. Insurance against lost data is redundant back-ups, the same label data should be written on your field label, your notebook and in your computerized database (again, DO NOT USE CODES e.g. Site A1, Site A2 etc.....)

 

PROCESSING

storage & protection:

Your collection will be housed in a drawer and kept in a cabinet here in the lab. You will be given a portable box to transport specimens you've mounted at home to the lab. Our cabinet will contain an insect repellent. Repellents are necessary because certain insects, particularly Dermestid beetles feed on dried specimens and can reduce your collection to dust! There are three commonly used repellents: paradichlorobenzene, naphthalene (moth balls) and No-Pest© Vapona. Some people avoid these admittedly foul-smelling or potentially hazardous chemicals by storing specimens in very tight-fitting boxes/drawers and within equally tight-fitting cabinets. A consistent practice of visual inspection is becoming a popular pest avoidance method. Deep-freezing entire cabinets periodically is also an option.

mounting:

All mounting should be done with soft & flexible specimens. This means that if the specimens are not in alcohol they should be mounted within 24 hours after death. If in alcohol or a jar with ethyl acetate they can wait until a convenient time, but should be mounted while still wet (except if being pointed, see below, as the glue won't dry if they are wet).

pinning: (No. 3 sized pins only (smaller sizes too weak), stainless if possible,) Pin all insects larger than a ladybug, insects the size of ladybugs may or may not be appropriate for pins (the pin might destroy the specimen). Smaller specimens need to be pointed. Leave only enough room at the top of the pin to grab the pin (this allows more room below the insect for numerous labels that might build up over time). The insect should be at right-angles to the pin when viewed from the side and the front. Insects are pinned through the thorax so that the pin emerges BEHIND the first pair of legs and IN FRONT OF the last pair of legs. See the illustration below:

pointing: If an insect is in danger of being destroyed by a No. 3 sized pin (don't just use a smaller pin!) you must point the specimen. Pointing is the simplest (although once you try it you won't believe anything could be harder) of many techniques for dealing with small insects; it consists of gluing the specimen to a small triangle of paper called a 'point' that has been pinned. Pointing takes practice to master. Because 90% + of all insects in a random sample require pointing you should become skilled at this technique. Mastery of pointing is something to be proud of, don't give up. Use Elmer's© or some other water-soluble glue so that a researcher can remove the specimen from the point if needed, don't use Super Glue.

1. The point must be on the insect's right side, only ants are properly pointed with the point on the ventral surface.

2. Avoid excess glue that will coat the specimen and obscure important parts.

3. Use only stiff paper (e.g. from 3X5" cards) and use a Point-Punch that is supplied to cut the points.

4. The insect should again be at right angles to the pin when viewed from the front and the side.

 

carding, the gluing of an insect to a card is not recommended unless it is for temporary, glueless positioning. Many European Entomologists card insects. This is done because the legs can be moved into symmetric position, the insect's parts are well protected by the card and the head and abdomen that might 'curl-under' out of view are forced into view. By using a temporary card that is removed after the insect has dried all the advantages are gained except the protection factor. However, the disadvantage to carding is that the undersurface of the insect is permanently hid from view and often this obscures important characters.

glassine envelopes: Odonate adults (Dragonflies & Damselflies) are properly collected alive into glassine envelopes where they stay for ca. 24 hrs so they void the intestinal track, later killed in an acetone bath and stored permanently in a plastic envelop with a 3x5" collecting card label. The handout on Odonates will include more detailed information.

slide mounting: any Meiofauna (<1mm length), e.g. mites, Protura, Tardigrades, some Crustacea. We will not be covering this particularly advanced technique.

preservation in liquid: vials: Soft-bodied insects, insect larvae and non-insectan arthropods (spiders, centipedes, isopods, Opiliones) are not pinned, but are preserved in vials containing 70-95% Ethanol & some glycerin (which maintains softness if alcohol evaporates), use a cap that doesn't leak (avoid screw-caps and cork stoppers, use green rubber stoppers).

In the field: Most of these taxa can be collected directly into vials of ETOH, however, insect larvae must not be placed directly into ETOH. Insect larvae should be preserved with a strong fixative such as a weak formalin solution or dropped into almost boiling water. The formalin or the hot water denature digestive and autolytic enzymes that would otherwise continue activity into death and damage the specimen (many shrivel and turn black). These larvae should be kept alive until they can be properly fixed.

Place only one species in a vial (although many individuals of one species in a vial is preferable). Labels for vials should be written with permanent ink (e.g. with a Micron Pigma © pen) on acid free paper and should be wide enough to wrap around the inside of the vial once, not overlapping. These labels should be placed in the vial so that they can be read through the glass. Do not put identifications on the locality label -- place a separate identification label (the ID may change!). Vials should be stored separately from your pinned material to avoid the possibility of a vial coming loose and destroying your pinned specimens.

 

Distinguish temporary storage from permanent:

Whirl-Paks© are an excellent and inexpensive means to temporarily store alcohol-collected specimens. These should be kept in the freezer. Over time the bags will absorb Oxygen and expand, to prevent this some people immerse the whirlpacs into a large container filled with alcohol.

Permanent Labels:

Label-making has evolved rapidly in the last few years following computer technology improvements. Two major advances, the laser printer and customized databases, have increased collection processing efficiency. With laser printers, small labels of excellent quality can be made (in contrast with photo-copy reduced labels that usually produce very low-quality and difficult-to-read labels). Traditionally, one would have to type all the label data and then later retype this information into a database if the collection data were to be electronically captured. Now this redundancy of effort can be eliminated by typing the data into a customized Collection manangement database that simultaneously captures the label data and allows one to print specimen labels.

Label quality is very important. Both the ink and paper have to be of a quality that will enable the data to be readable hundreds of years into the future. Thus the paper should be stiff, at least 80-lb weight and acid-free (do not use ordinary cardstock). The size of the label is dependent on the size of the specimen. If the specimen is large (e.g. 9 cm long) the label may also be as large, but not larger than the specimen. If the specimen is small then the label must also be small, but no smaller than 14mm long by 5 mm wide. With many small specimens, it is the size of the label that limits how many can fit into a drawer, thus smaller labels allows more specimens per drawer and saves space and money.

What to put on the labels? Some argue that the country should be on the labels, however, rarely do you see a label with USA on it. The reason few people use the country is that the space is needed for other information. I think we can reasonably get away without putting USA on every label, although there are few other countries as large as the US (maybe Australia) and smaller, more obscure countries should put the country on the label. The label should follow the same format as your field label and if you took the time to write complete labels in the field, when it comes time to database and print labels you can work quickly.

Try to maximize the number of specimens per unique label for greater efficiency. Producing 100 labels that are identical is a LOT easier than producing 100 unique labels. This is why I am not putting student names on the labels. If you like you may produce a separate label stating "your name Collection" or "your name Coll."


FIELD ENTOMOLOGY : EEB 252

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