Beating Sheets

A beating sheet should be made of durable cloth, preferably white, attached to a frame about 1 meter square, with two pieces of doweling or other light wood crossing each other and fitted into pockets at each corner of the cloth. An ordinary light-colored umbrella also may be used as a beating sheet. Place the beating sheet or umbrella under a tree or shrub and sharply beat the branches or foliage with a club or stick. Specimens will fall onto the sheet and may be removed from the light-colored material by hand or with forceps, a moistened brush, or an aspirator.

Locating specimens on the sheet is sometimes a problem because of leaves or other unwanted material dropping onto the sheet. Watching for movement will help locate specimens, as well as tilting the sheet so that the debris is displaced or even allowed to fall off, with the insects and mites left clinging to the cloth.

Beating sheets are especially useful in collecting beetles, true bugs, and larval Lepidoptera. Beating may be the best collecting technique when the weather has turned cold, or early and lat in the day, when normally active insects seek shelter in vegetation and are otherwise difficult to detect

Solid Killing Agents

The solid killing agents most often used in killing jars are the cyanides—

1) Potassium cyanide (KCN),
2) Sodium cyanide (NaCN)
3) Calcium cyanide [Ca(CN)2].

*very dangerous, rapid acting poisons with no known antidote*!!

Killing jars or bottles will last longer and give better results if the following simple rules are observed:

(1) Place a few narrow strips of absorbent paper in each jar or bottle to keep it dry and to prevent specimens from mutilating or soiling each other. Replace the strips when they become moist or dirty. This method is useful for most insects except Lepidoptera, which are too difficult to disentangle without damage.

(2) Do not leave killing jars in direct sunlight as they will sweat and rapidly lose their killing power.

(3) If moisture condenses in a jar, wipe it dry with absorbent tissue.

(4) Keep delicate specimens in separate jars so that larger specimens will not damage them.

(5) Do not allow a large number of specimens to accumulate in a jar unless it is to be used specifically for temporary storage.

(6) Do not leave insects in cyanide jars for more than a few hours. The fumes will change the colors of some insects, especially yellows to red, and specimens will generally become brittle and difficult to handle.

(7) If it is necessary to keep insects in killing jars for more than several hours, place the specimens in another container and store them in a refrigerator.

(8) Keep butterflies and moths in jars by themselves so that their hairs and scales will not ruin other kinds of insects.

(9) Never test a killing jar by smelling its contents.

(10) Old jars that no longer kill quickly should be recharged or disposed of by burning or burying.

Killing Jars or Bottles

Killing Jars

Jars for use with liquid killing agents are prepared in one of two ways. One way (fig. A) is to pour about 2.5 cm of plaster of paris mixed with water into the bottom of the jar and allow the plaster to dry. Enough of the killing agent is then added to saturate the plaster; any excess should be poured off. This kind of jar can be recharged merely by adding more killing agent.

The second method is to place a wad of cotton or other absorbent material in the bottom of a jar, pour enough liquid killing agent into the jar to nearly saturate the absorbent material, and then press a piece of stiff paper on it or a cardboard cut to fit the inside of the jar tightly. The paper or cardboard acts as a barrier between the insect and the killing agent, keeping the latter from evaporating too rapidly and also preventing the specimen from becoming entangled in loose fibers.

Among the liquid killing agents are ethyl acetate (CH3CO2 • C2H5), ether (diethyl ether, C2H5 • O • C2H5), chloroform (CHCI3), and ammonia water (NH4OH solution). Ethyl acetate is most widely used. All of these chemicals are extremely volatile and flammable and should never be used near fire. Children should only use them under adult supervision. Ethyl acetate is regarded by many as the most satisfactory liquid killing agent. Its fumes are less toxic to humans than those of the other substances. Although it usually stuns insects quickly, it kills them slowly.

Specimens that appear dead may revive if removed from the killing jar too soon, but a compensating advantage is that most specimens may be left in an ethyl acetate killing jar for several days and still be limp. If the ethyl acetate is allowed to evaporate from the specimens, they will harden. Killing jars with ethyl acetate are preferred by many entomologists, especially for infrequent use.

Ether and chloroform are both extremely volatile and flammable and should not be used near an open flame or lighted cigarette. Their high volatility makes them serviceable in a killing jar for only a short time. Perhaps the greatest hazard with chloroform is that even when stored in a dark-colored jar, it eventually forms the extremely toxic gas phosgene (carbonyl chloride, COCI2). Chloroform, however, is useful when other substances cannot be obtained. It stuns and kills quickly but has the disadvantage of stiffening specimens.

Ethyl Alcohol (ethanol or ETOH) is widely used to kill small Coleoptera adults, small Hymenoptera, and many immature insects and soft-bodied insects. It is most commonly used at 70-80% concentration and many workers add 5% glacial acetic acid ("acetic alcohol") which helps penetration of the alcohol into the specimen and leaves specimens more relaxed. Isopropyl alcohol (rubbing alcohol) may also be used, and may be easier to find and purchase than Ethanol. However, Ethanol is preferred for most applications. Ethanol is used commonly in Berlese funnels and similar traps

Liquid ammonia is irritating to humans, and in general is not a particularly effective killing agent for most insects. However, it is highly recommended for use in small vials for dispatching microlepidoptera, and it has been used with variable success in blacklight traps, again for Lepidoptera. Specimens killed in ammonia tend to stay in a relaxed condition much longer than those killed by cyanide, allowing greater ease of spreading. Ammonia is readily available from many sources. Ammonium carbonate, a solid but volatile substance, also can be used.


References:

M. E. SCHAUFF. COLLECTING AND PRESERVING INSECTS AND MITES: TECHNIQUES AND TOOLS. Systematic Entomology Laboratory, USDA.

Collecting Nets

Sweeping Net- by Johari Jalinas

Collecting nets come in three basic forms:

1) Aerial Net- Collecting butterflies and other flying insects
2) Sweeping Net- Collecting butterflies and other flying insects
3) Aquatic Net- Collecting aquatic insects

Equipment and Collecting Methods

A field collecting kit.

The following items usually are included in the general collector’s bag:

(1) Forceps. Fine, lightweight forceps are recommended; if sharp-pointed forceps are used, care must be taken not to puncture specimens. If possible, grasp specimens with the part of the forceps slightly behind the points.

(2) Vials containing alcohol or other preservatives

(3) Killing bottles of various sizes.

(4) Small boxes or containers for storing specimens after their removal from killing bottles. These may be made of cardboard, plastic, or metal and should be partly
filled with soft tissue or cloth to keep specimens from rolling about. Do not use cotton because specimens become entangled in the fibers and may become virtually impossible to extricate without damage.

(5) Small envelopes for temporary storage of delicate specimens and/or gelcaps for tiny specimens.

(6) One or more aspirators .

(7) Absorbent tissue for use in killing bottles and aspirators.

(8) Notebook and writing equipment for jotting down notes and label data.

(9) A strong knife for opening galls, seed pods, twigs, etc and a pair of scissors for cutting labels.

(10) A small, fine brush (camel’s hair is best) for picking up minute specimens. Moisten the tip; tiny specimens will adhere to it and may be transferred to a killing bottle or vial.

(11) Bags for storing plant material, rearing material, or Berlese samples. For collecting much plant material, a botanist’s vasculum or tin box is advisable.

(12) A hand lens.

CENTER for INSECT SYSTEMATICS (CIS), UKM: Positive and Negative of Insects

CENTER for INSECT SYSTEMATICS (CIS), UKM: Positive and Negative of Insects

Journal-Serangga

volume 10 number1-2 November2005

A journal published by the Centre for Insect Systematics, Universiti Kebangsaan Malaysia in collaboration with Departments on Museums Malaysia, Ministry of Culture, Arts and Heritage, Malaysia

Published in Malaysia by
Centre for Insect Systematics
(Pusat Sistematik Serangga)
Universiti Kebangsaan Malaysia
43600 Bangi, Selangor Darul Ehsan,
Malaysia.