AES BULLETIN, Vol. 49

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1 AES BULLETIN, Vol COLLECTING AND PRESERVING PHASMIDS by Phil Bragg (8737) INTRODUCTION There are many books and articles which tell entomologists about methods of collecting and preserving insects. Many of these offer advice on special techniques which are needed for particular orders of insects. A number of books offer advice on Orthoptera, however, I have yet to find one which offers useful advice specific to collecting and preserving Phasmids. Phasmids are a special case which require special methods. They are exceptional in several ways, all of which create problems with preservation. They are the largest insects, Pharnacia serratipes (Gray) is the world's longest insect and Heteropteryx dilatata (Parkinson) is a contender for the title of heaviest insect (Wood 1976); many have very soft bodies and bright colours which makes preservation difficult. In addition to all these problems, the order is largely nocturnal and relies on near perfect mimicry as its main form of defence. COLLECTING This one area where Phasmids have been briefly dealt with. Harman (in Brock 1985) gives general advice and I (Bragg 1988) have given advice on equipment for collecting in rain forests. While a few of the smaller flying species may be seen during the day, capture at night is the only realistic method of collecting Phasmids. Beating, suggested in the British Museum guide to collecting (Cogan & Smith 1974), is not worthwhile if you are mainly interested in Phasmids; you are unlikely to get very many unless you beat at night, in which case they are easy to see and collect by hand. Harman advises using a headtorch - my own experience is that it is foolish to go without one. Headtorches have the essential feature of leaving both hands free to move foliage and capture the insects. Without a headtorch it is necessary to work with a partner otherwise a significant number of insects escape while the hunter is trying to capture the insect with only one free hand. A short handled net should be carried and used to capture some of the flying species or to restrain insects while a container is opened. A long net is rarely of use and generally too cumbersome to be worth carrying. The most successful technique for capture is to hold the net under the Phasmid and lower your hand onto the insect from above. Many species drop off their perch into the net when disturbed.

2 272 DECEMBER 1990 The majority of Phasmids inhabit tropical areas, particularly rain forests. For the sake of comfort, in tropical countries it is best to carry as little equipment as possible, glass jars, heavy boxes etc. should be left behind. If it is intended to collect live specimens, the captured insects can be placed in a plastic bag with a sample of the plant on which they were found. The top of the bag can then be tucked into a belt worn round the waist. When a number of insects are in the bag, the neck of the bag should be tied with string and attached to the belt. On collecting trips of more than a few hours duration, or if large fragile species are caught, the insects should be placed in plastic boxes at intervals, rather than being left in plastic bags. KILLING I generally preserve specimens which are already dead as my main aim is to collect Phasmids alive in order to attempt captive breeding. However, I have found ethyl ethanoate (ethyl acetate) to be an effective killing agent. If the insect is left in too long some colours are damaged, especially fairly bright greens which tend to pale to yellow. Eggs can be killed by placing them in a deep freeze for a few hours. PRESER VA non OF DEAD SPECIMENS The bodies of Phasmids are relatively large, usually soft and decompose quickly which makes rapid drying essential. Freeze drying of Phasmids gives good results but is a method which is not usually available to the amateur and certainly not on a foreign collecting trip. One of the major problems is that as Phasmids are mainly tropical insects, most people can only collect them while on holiday where their facilities are limited. My method of preservation of captive bred specimens is to dry the insect in a heated cabinet at about 80 G C; this is not usually possible during a trip abroad. The usual method of drying insects in the tropical sun is not very suitable for Phasmids. Colours such as red and green rapidly become brown in the sun and the large specimens still have time to rot. Decomposition is a major problem even with small specimens which die of natural causes, as it may be some time before it is possible to deal with them. I have successfully used the following two methods in the tropics. (a) Evisceration and stuffing with cotton-wool This method has been suggested by some authors for large Orthoptera, e.g. large crickets or long-horned grasshoppers (Knudsen 1966) and Durkin (Durkin 1985) has outlined a method for Phasmids. It is a laborious process which gives excellent results with Heteropteryginae, which have thick cuticles. It also works well with the larger individuals of

3 AES BULLETIN, Vol other sub-families but is much more difficult as the colour is easily rubbed off the inside of the cuticle. Done well, the insect dries very quickly and the colour and body shape is retained. I have successfully used the following method for species of a similar size to Carausius morosus (Sinety), the common laboratory or Indian stick-insect. The procedure which I follow is to use a scalpel to make a transverse cut between the metathorax and the 1st abdominal segment, then I use a fine pair of forceps to remove the viscera. In long Phasmids I make another cut, usually between the 4th and 5th abdominal segments. The insect is stuffed with white cotton wool; although other colours may give a better looking result if the pigmentation is accidentally rubbed off, I feel white is better as it will not be mistaken for the natural colour. The actual stuffing is time consuming as it needs to be done with a number of small pieces, each one being carefully eased into place, trying to avoid rubbing the inside of the cuticle too hard. This method has the advantage that the eggs can often be recovered and although no use for rearing, they can be preserved with the specimen. The eggs of most species of Phasmid have never been described. (b) Injecting with 100% ethanol A fine hypodermic needle and a small (1-2ml) syringe can be used to inject the small or thin species. The needle is introduced between the metathorax and the 1st abdominal segment and ethanol injected until it emerges from the mouth and anus. If ethanol does not appear from both ends, a second injection should be given at the appropriate end to ensure the body cavity is thoroughly irrigated. The insects should then be left in a dark, well-ventilated container. some loss of colour results from the use of ethanol, some green pigmentation tends to become yellow in colour, however the loss of colour is generally less than that which occurs in the sunlig.lt. Whichever of the above methods is used the insect is placed somewhere dark and well-ventilated to dry. TRANSPORTING DEAD SPECIMENS Bringing large fragile insects back from your holiday can be a difficulty. Papering and re-setting at home should be avoided, damage is almost inevitable with such long thin insects. I set them on location, but without putting a pin through the body. When dry I place the insect on a stiff piece of card and cover it in cling-film; several insects can then be packed into a rigid box and safely sent home in your checked baggage. If the insects are pinned and Ll a storage box they will need to be carried as hand luggage to reduce the risk of damage.

4 274 DECEMBER 1990 SETTING AND STORAGE Setting in particular has to be a compromise with Phasmids, a balance between space occupied and appearance or ease of study. You need to decide the main aim of your collection. If it is to be a useful collection you need to be sure the legs and sides of the body are clearly visible. Also it is an advantage to have only one wing displayed - displaying one is sufficient from a taxonomic viewpoint and saves space. If you are making a general collection for display, a few Phasmids well spread out will probably be what you want. Due to their size, Phasmids require special consideration when pinning. The pin through the body is traditionally put through the prothorax or mesothorax of an insect. The pin is there to support the insect; to do this ideally it should pass through the centre of gravity. However, as Phasmids are not a traditional shape for an insect, the centre of gravity is often nowhere near the mesothorax. There is no reason to blindly adhere to tradition; the pin can go anywhere - there is no "right way" or "wrong way" to pin an insect, only "ways" and "better ways". The length of pin can be important in the case of bulky insects or when the length has caused it to sag at the ends. I always use continental length (38mm) pins; this of course means your cabinet must have deep drawers. The long legs of Phasmids are an important feature and worth giving some thought to. The positioning can matter. Most species rest with their middle legs pointing back towards the anus, this therefore seems to me to be the best way to display the insect. However, with a winged specimen setting the wings out generally hides the middle legs if they are set so they point backwards. As the legs are often an important characteristic in identifying Phasmids I usually set the middle legs forwards if the wings are set out. Care must be taken to ensure the legs do not move during drying. I have been known to use over 100 pins to hold the legs and antennae of large specimens in position. Another point to consider is that of space; if the legs are spread wide apart the Phasmid will take up a lot of storage space, perhaps more than ten times as much as when it is set with legs alongside the body! Displaying the Phasmid in the cabinet or store box can be difficult. I have specimens which are longer than the 43cm drawers of my cabinet; the only thing to do is to put it in diagonally or buy a larger cabinet! With something of this size, even when pinned through the centre of gravity, it is advisable to place pins on either side of the end of the abdomen to prevent the insect swinging when the drawer is moved. There is a growing tendency to store insects without any preservative or pest repellent. My advice on this is to use something - a large

5 REFERENCES Bragg, P.E. (1988). Rain forest safari. The Phasmid Study Group Newslel/er, 34: 8-9. Brock, P.D. (1985). The Phasmid Rearer's Handbook. AES Publications. Cogan, B.H. & Smith, K.G.V. (1974). Instructions for collectors No. 4a: Insects (5th edition. British Museum, Natural History. Durkin, A. (1985). Stuffing Larger Phasmids. Phasmid Study Group Newsleller, 22: 2-3. Harman, A. (1985). Collecting Phasmids. In Brock, P.D., (pages 36-38). Knudsen, J. W. (1966). Biological Techniques. Harper & Row, London. Wood, G.L. (1976). The Guinness book of animal facts and feats (2nd edition). Guinness, London. ABUNDANCE OF HOLLY BLUES IN SOUTHERN ENGLAND AND - IS THERE AN ALTERNATIVE FOODPLANT? by Arthur Cleverly (7265) Last year, in the south of England at least, the Holly blue, Celestrina argiolus, had a good year, and an even better one in These butterflies have been about in quite large numbers. They are very plentiful too in the Undercliff area of the Isle of Wight around Ventnor. Now in this area of the island, Senecio, the evergreen shiny leaved variety so often planted around toilets has been used as hedging and in that mild climate grows ten or twelve feet tall and being unrestrained by clipping, flowers well. Recently while there on holiday I saw quite a number of Holly blues laying eggs on the flower beds of these shrubs. I find no records of this shrub as a foodplant for this butterfly and wonder if this is common, or just restricted to that area.

Insect Collection Due Date:

Insect Collection Due Date: Assignment Description: Students will collect 40 different species of insects from at least 12 different Orders Each specimen should be correctly pinned and have complete labels