Collection and preservation of insects

1. Lab. No.1 Collection and preservation of insects

2. Introduction • Insects are arthropods • Arthropoda: "jointed feet“ • General characteristics of insects: The body is comprised of 3 distinct body regions -- head, thorax, and abdomen • The thorax of adults bears 3 pairs of legs and 2 pairs of wings

3. Collection • The purpose of the insect collection is to: • Learn to locate and capture specific insects in their habitats. • Learn the correct methods of preservating insects for study or reference • Use diagnostic characters to identify insect encounter • Form a reference collection for you future use.

4. Equipment for collection of insects • Forceps • Vials containing alcohol or other preservatives • Killing bottles of various sizes. • Small boxes or containers • One or more aspirators

5. A strong knife and a pair of scissors for cutting labels • A small, fine brush • Notebook • A hand lens • Bags.

6. Collection methods • Hand collecting: • For large insects • Holding them by the sides of the thorax so that they can not reach skin with their jaws and/or stingers • For slowly movement of insects • Forceps must be used.

7. Collecting Nets: • Collecting nets come in three basic forms: Aerial, sweeping, and aquatic. • Aerial net: • For collection of butterflies and other flying insects.

9. Sweeping net: • Sweep nets are made of heavier-weight and sturdier materials and are better suited for collecting plant-infesting insects like bugs, beetles and other chewing and sucking insects of medium-small to large sizes. • Bags are made entirely or partially from heavier cotton cloth.

11. Aquatic nets: • Aquatic nets are used for gathering insects from water • An aquatic net should offer minimum resistance when dragged through water but have a fine enough mesh to capture small specimens. • The bag of the net need not be deep, and should be made of a synthetic mesh such as nylon

12. Transparent material is preferable, to make viewing of the catch possible. • The shape of the net: • Removable, rigid D-shape farm 30cm across, mesh bag with thick cloth rim. Metal pipe handle with rubber grip at the end.

14. Beating sheets: • This method is useful for collecting sessile or wingless groups such as some beetles and bugs, stick insects, spider and mites.

17. Insect aspirator known as a‘pooter,’ • Is a convenient and effective device for collecting small insects and mites.

19. Berlese funnel • Berlese funnel is a good tool to collect small insects from leaf litter • Barleys funnel consists off a funnel with a coarse screen on the inside and a dish of alcohol below to catch the insects as they move out of the plant material.

21. Traps • Is defined as anything that impedes or stops the progress of an organism, this subject is extensive, including devices used with or without baits, lures, or other attractants. • Trap depends on: • location, time of year or day, weather, temperature, and kind of attractantused, if any.

22. Light Traps • This is the most common method of collecting nocturnal specimens that hide or rest during the day in places where they are unlikely to be seen.

24. Sticky Traps • In this type of trap, a board, piece of tape, pane of glass, piece of wire net, cylinder, or other object, often painted yellow, is coated with a sticky substance and suspended from a tree branch or other convenient object.

27. Water trap: Fly water trap

29. Suction trap: • They are used to collect ballooning spider and small flying insect such as flies, aphids and wasps.

31. Food trap:

32. Killing and temporary storage: • Killing should be done immediately after capture. • Killing and storage methods vary according to the type of arthropods that has been collected.

33. Killing methods • Use of liquid: • All soft bodies insect (e.g. aphids and termites) and all eggs and all larvae must not be allowed to dry out once they are dead. They should be placed directly into a liquid preservative usually 70%

35. The following insects should NEVER be placed in liquid: those • With scales in their wings (e.g. Lepidoptera) • Insect covered with a waxy bloom ( some Coleoptera)

36. The liquid killing agents are: • Ethyl acetate (CH3CO2 • C2H5) • Ether (diethyl ether, C2H5 • O •C2H5) • Chloroform (CHCI3) • Ammonia water (NH4OH solution).

37. Refrigeration and Freezing • Medium to large specimens may be left in tightly closed bottles for several days in a refrigerator and still remain in good condition for pinning as will smaller specimens if left overnight.

38. Dry preservation • It is standard practice to place many kinds of insects in small boxes, paper tubes, or envelopes for an indefinite period, allowing them to become dry. • It is not advisable to store soft—bodied insects by such methods.

39. Diptera should never be dried in this manner because the head, legs, and most of all the antennae become detached very easily.

40. Methods of preservation • Pinning Right Wrong Wrong

42. Double mounting

45. Setting: • The wings of certain insect must be spread, because the wing venation or wing pattern is important for identification

46. A small spreading block.

48. The End