The Phasmid Study Group
Chair: Mrs Judith Marshall Department of Entomology, The Natural History Museum Cromwell Road, London SW7 5BD Treasurer/Membership: Paul Brock (Phone 0753-79447) "Papillon", 40 Thorndike Road, Slough. Berks SL2 1SR Secretary; Adrian Durkin (Phone 0562-882420) 8 Foley Road, Pedmore, Stourbridge, W. Midlands, DY9 0RT
June 1990 NEWSLETTER NO. 43 ISSN 0268-3806
NEXT PSG MEETING 14th July in the Demonstration Room, The Natural History Museum, South Kensington. Bring food for yourself and food and boxes for sticks; also proof of membership to get in. Programme: 11.30 - 12.30 Informal gathering to exchange ideas, experiences, etc. Live and possibly dead species will be on view. 2.30 - 1.30 Formal meeting. 1.30 - 2.00 Lunch. 2.00 - 2.45 Livestock Co-ordinator*s informal species exchange. 3.00 - 3.30 Allan Harman (No. 189) will talk on his trip to Costa Rica last summer. Allan hopes to show a selection of live and dead specimens. 3.30 Phil Bragg (No. 445) will demonstrate and talk on stick photography.
EXHIBITIONS IN 1990 Update by Paul Jennings (No. 80) The North Insect Show - 10th June, 12 noon - 5 p.m., at Royton Assembly Hall, Oldham; two tables booked. Contact Phil Bragg (0602-222118) or myself (0582-583954) for further details. Amateur Entomologists' Society Exhibition - 6th October, 11 a.m. - 5 p.m., at Kempton Park Racecourse, Sunbury; three tables booked. Contact myself. Please try to visit the PSG stand if one of the above exhibitions is near to you. Members wishing to bring a display of livestock, photographs, etc, to any exhibition should please contact in advance the appropriate person above so that they know what to expect.
TWELFTH MIDLANDS ENTOMOLOGICAL FAIR Report by Paul Jennings (No. 80) On show at Leicester by the PSG were four live displays {containing a total of about 20 species), two photographic displays and several trays of dead specimens. A wide choice of some 20 species was also available through the Livestock Co ordinator. Thanks to all who brought livestock and took it away. Only two new members were recruited, reflecting the fact that only those seriously interested were encouraged to join - however, many application forms were given out. The stand was run by Angela Parwani (No. 419), Phil Bragg (No. 445) and myself. Many thanks to all who helped and visited the stand.
SOME OBSERVATIONS ON THE DISTRIBUTION AND FOODPLANTS OF SEYCHELLOIS STICK INSECTS, BY PAT MATYOT This article in the AES Bulletin (Vol. 48, pages 213-8) also gives a key to identifying the males and females. The distribution is on Mahe, and natural and other foodplants are given. 43:2
THE ORCHID MANTIS AND INSECTS OF MALAYSIA by Kazuo Unno (126 pp; published by Nippon Television Network Corporation, Tokyo, 1989, available from E.W. Classey Ltd, PO Box 93, Faringdon, Oxon SN7 7DR; price £18) Review by Paul Brock (No. 26) Kazuo Unno is a professional nature photographer and has apparently spent much time in Malaysia during the past 20 years. The book is a typical lavishly illus trated quality production from Japan. The attractive dust jacket appears to be back to front, and the book needs to be examined from the back first (hence the numbering is page 126 to 11). The contents are: The Orchid Mantis, Metamorphosis of Butterflies, Camouflage, Beetles of Malaysia, The Biggest Insects in the World, and Wonderful Insects of Malaysia. The photographs, mostly in colour but some in black and white (with text in Japanese), are quite outstanding and there are comments in English on the colour photographs. Indexes of scientific names and of English common names, and translations of the common names of insects (English-Japanese) are included. Our member Michael Yeh (No. 192) is listed in the acknowledgements. PSG members will mainly be interested in the phasmid section, and it is disappointing that the insects are usually not named. The author apparently is unaware of the existence of Phyllium giganteum Hausleithner (page 57, etc) as the Phyllium are listed as P. pulchrifolium. The two-page spread of Phyllium on guava (pages 58-59) is a shot of the insects in captivity (Penang Butterfly House). This spread appears to include at least two Phyllium species, including typically shaped P. bioculatum (there is some doubt about "differences" between P. bioculatum and P. pulchrifolium, and it has been suggested by Burghard Hausleithner (No. 132) and others that P. pulchrifolium may be just a variation of P. bioculatum; more research is needed to verify this). Pages 62 and 63 deal with Heteropteryx dilatata. Page 62 shows an adult female in defence posture (an insert depicts the egg) - this photograph deserves framing! Page 63 shows a monkey examining a female and what happens when the H. dilatata reacts! Finally, page 67 shows a female Pharnacia dangling from vegetation and a Lonchodes female. These are probably P. acanthopus and L. brevipes. To summarise, this is a beautifully illustrated book, well worth a place on members' bookshelves and a good basic introduction to the insect life of Malaysia.
INTRASEXUAL AGGRESSION IN THE STICK INSECTS DIAPHEROMERA VELIEI AND D. COVILLEAE AND SEXUAL DIMORPHISM IN THE PHASMATODEA, BY JOHN SIVINSKI Highlights by Michael and Frances (No. 3) This paper (in Psyche, 85 (1978) 4, 395-405) reports that, if another male approaches, a mating male bends the tip of the female's abdomen down upon itself with his clasper, thus denying most of the attachment site to his rival. Sometimes he strikes this rival with his fore legs. These two defences usually succeed in preventing the rival from attaching himself to the female, but sometimes they fail, particularly when the mated male has moved to one side of the female to feed. The two attached males then lean backwards and eventually become suspended by their claspers while rapidly hitting each other with their fore legs - in this case the take-over is usually eventually successful. The longer male is usually more success ful in such fights. When phasmid densities are high in nature, such fights are likely to become more important and so result in evolution towards longer males. In the nine species known to exist at high densities, the males are in fact somewhat longer than usual relative to the females. Alternatively, smaller males might evolve if the mating is for long periods, because this would enable the female to be more active (and so allow her male more easily to search for another female while mating); the male would also be less of a burden on the female, and camouflage could be better. Four species with relatively smaller than usual males have some of the longest mating times recorded in phasmids. 43:3
DIVERSITY OF AGGRESSIVE BEHAVIOURS IN EURYCANTHA CALCARATA ADULTS by Ilona Clail (No. 496) The following article describes the sequence of acts used in aggressive encoun ters in male-male (Part 1) and female-male (Part 2) insect bouts, in a mixed community of cohabiting insects. Diagrammatic representations of the common sequences in aggressive encounters are shown in Figures 1-6, diagrams for active and passive participants being constructed separately. Aggressive behaviour was more pronounced at the onset of dark than at the onset of light. Insects showed more aggression as they emerged from their shelters during the first 75 minutes of the dark period than entering their shelters during the last hour of the dark and the first hour of the light periods. During 20 observa tion periods, 30 aggressive encounters were observed during the first 75 minutes of the dark period (total time observed = 1500 minutes) whilst only 12 encounters were observed during the last hour dark/first hour light period (total time observed = 2400 minutes). Proportionally with respect to time there was thus approximately four times more aggression shown during the first 75 minutes of the dark period than during the last hour dark/first hour light period. The acts observed in aggressive encounters are defined as follows: Abdominal movements - As described in Newsletter 42, page 11. Only those movements making contact with an opponent were considered as aggressive. Advance - One insect approaches another directly, from either the front or the rear. The approach may be fast or slow and may involve reversing towards the opponent. Alert - One insect reduces the angle of its femur-coxa joints resulting in elevation of posture so that the body is higher than its opponent's. Antennation - The antennae move in the direction of the source of stimulation. Various forms are described in Newsletter 42, page 12. Combat - This behaviour involves high-level kicks with insects in constant contact, leading to insects' overturning each other and rolling along the arena floor/canopy whilst in contact. Defence - This is the defence posture, i.e. curled up S-shaped abdomen and hind legs extended wide apart. This behaviour was mainly observed with males but occurred in both male-male and female-male encounters. Disengage - Insects separate from one another, usually by some action of one partner, e.g kicks or quick turns, which lead to one insect's falling off the other or other wise cause separation. Face - One insect turns fully to face its opponent. Kick - One leg is fully extended applying force on to the opponent. This often leads to the opponent's loss of balance, e.g. from the canopy. Legs on opponent - One insect places one or more (up to five) legs on its opponent and remains in this posture for several seconds. Mount - One insect climbs directly above another - %he approach may be from any direction. Prostrate - One insect flattens its body against the supporting substrate - this may or may not induce the thanatotic posture. , Retreat - One insect moves out of its opponent's vicinity, usually with fast escape runs.
Part 1: MALE-MALE ENCOUNTERS During the first 75 minutes of the dark periods, 19 male-male aggressive encoun ters were observed. The insect initiating an approach was considered to be the active participant whilst its opponent was considered to be the passive participant. Most encounters (58%) were terminated by the passive participant's retreating to the shelters/canopy. On 42% of the occasions, the active participant retreated to the shelters/canopy. However, the difference was not statistically significant, i.e. the active participant's actions did not result in a significantly greater number of retreats by the passive participant than would be expected by random chance. 43:4
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<•rP< di •H H «W < 1- Itl E Oi —z LzU r- c S 21 •H «. "jfl T5 O LU JJ O 9 > G •H CD O ro P 0) < X •aH u a •H .* JJ H ^ m fl T1 a, o 01 01 X H 4J R) E «P 0 0> > 4J •H 4) (A 0) U) n «J 0 U< IP fl) 0 4nJ 01 4J u ffl 3 0 c -H 0 > -H n) 4J £ «t (U > XI U 0) ai to > XI •rH 0 «90-<» to to tn 01 a> U JJ Oi 1 0 c < lp ^ 0 0 0 to in Ol 1— •H 4J E •H O rH w •H <4J X) n) IN 0) V( •gH . (14 43:5 Figure 1 shows that the most probable course in male-male encounters for the active participant was: nee ^Antennation > Kick/Defence/Retreat ^Prostrate > Alert Adv. ' 1 I whilst Figure 2 shows that the most probable course of acts for the passive male was: Antennation ^Kick ^Retreat ^Prostrate The flow diagram for the active participant in Figure 1 shows most (probability = 0.7) insects antennated as they advanced. Acts following antennation were highly branched, i.e. any of seven different types of aggressive acts were used on the opponent; each had a low probability value of occurring. The flow diagram also shows loops, i.e. acts where behaviour was cyclical and one act followed another success ively. Loops with behaviours Advance and Antennation occurred most frequently and many loops were observed. Some of the behaviours in the flow diagram occurred in a linear pattern. However, caution must be used when interpreting data, as with all the following flow diagrams, as the total number of acts observed was low and some may have occurred only once. The flow diagram for the passive participant in Figure 2 shows that all the insects antennated the active participant as he approached. Acts following antenna tion were again highly branched, with seven different types of aggressive acts used on the opponent, each with a low probability value of occurring. Again caution must be used when interpreting data for the above reason. When the total acts used by the active participant were considered, it was found that there was a statistically significant difference in the number of times a particular act was observed. Acts Defence, Kick and Retreat occurred with expected frequencies and may have occurred by random chance. Acts Advance, Alert, Antennation, Combat, Face, Legs on opponent, Mount and Prostrate did not occur at the frequencies expected by random chance. Advance and Antennation occurred more frequently than expected by random chance alone (but this would be expected for an active participant), whilst the remaining acts occurred less frequently than expected by random chance. When the total acts used by the passive participant were considered, again it was found that there was a statistically significant difference in the number of times a particular act was observed. Acts Defence, Face and Prostrate occurred at frequencies compatible with random chance, whilst acts Abdominal movements, Advance, Alert, Antennation, Combat, Kick, Legs on opponent, Mount and Retreat did not occur as expected by random chance. Antennation, Kick and Retreat occurred more frequently than expected, whilst the remaining acts occurred less frequently than expected by random chance. During the last hour dark/first hour light observation periods, 12 aggressive encounters occurred (see Figures 3 and 4). Two-thirds of these involved the active male participant's approaching the passive male participant within its shelter. The passive participant adopted either: (a) The defence posture or, less frequently, (b) A prostrate position. If the defence posture was adopted, the active participant usually sooner or later left the vicinity whilst, with the prostrate position, the active male eventually mounted the passive participant and both insects adopted the thanatotic posture shortly after, sharing the shelter with the active participant positioned above the passive participant. ADVANCE (b) -r ANTENNATION ANTENNATION T 0-5 •-cm RETREAT "•0-1-*! ALERT COM BAT m in o <=-1-0J MOUNT •03-9 LEGS ON OPFCNfcNT «CM «05i O'ZB <-0^ Kl CK HD^ K I CK 0-5 O•2 0.7 •025- 3 kK^lHSSCN OPPONENT DISENGAGE DI SENGAGE M OUNT <0-25» 1 —0.5—r T -10- zu Figure 3. Probabilities of aggressive behaviours of active male participants in male-male fights with insects (a) in shelters and (b) on the arena floor (Data based on 2400 minutes observation in the last hour of dark and first hour of light, 12 fights) 43:8 p *-s 01 to +J +J •H X 0) X en to •IHP c IN •H •" 0) . 4J up +J •£. to -oH> 0 H f-i a IP 01 0 1 0 !__»' c P £C~14< 01 3 IP 0 0) X •o 4J to LU •cH P LU O •H < o *—10 . •P 2 O ***!• •0 LU 2 •p" 1c0 LL LU c LLl to (0 X u Q — •&H (0 0 •0 Q •H •P IP W 0 m (0 o a 3u 0) 0 .-( X +J g CO 01 10 rH •r>l (0 CO 4J 0) (0 X X 10 Ol 4J a -IHP •P. 0 to H 10 •rH •— X X> X (0 — <0 X! •p (0 oP -ac Oi (0 a • 01 I •H b 43:9 The most frequently observed sequence of acts by the active participant towards insects within shelters was: Advance ^Antennationr , ^Kick ^Disengage -^Legs on opponent t ^ Mount whilst the most frequently observed sequence of acts by the passive participant within its shelter was Defence ^Kick ^Disengage One-third of the 12 encounters took place on the arena floor. The most frequently observed sequence of acts by the active participant approaching the passive particip ant on the arena floor was: I I I Advance > Antennation > Kick ^Combat ^Disengage 4 Mount • —» i Z—JT- The most frequently observed sequence of acts by the passive participant was: AntennationnatioT n ^Retre^Retreaita t -KicKiokk . £ Disengage In Figures 3 and 4 the diversity of aggressive acts is less than those in Figures 1 and 2, with fewer loops observed, showing aggressive encounters were less complex and finished faster than those observed at the onset of the dark period. When the total acts used by the active participant (Figure 3) were considered, it was found that there was a statistically significant difference in the number of times a particular act was observed. Acts Combat, Disengage, Kick, Legs on opponent and Mount occurred at the frequency expected by random chance. Acts Advance, Alert, Antennation and Retreat did not occur as expected by random chance. Advance and Antennation occurred more frequently than expected by random chance alone, but this would be expected for an active participant. The remaining acts occurred less frequently than expected by random chance. When the total acts used by the passive participant (Figure 4, i.e. excluding Prostrate) were considered, there was no statistically significant difference in the number of times a particular act was observed. However, the acts Advance and Legs on opponent may not have occurred as expected by random chance: both these acts occurred less frequently than expected. HANDLING ADULT MALE EURYCANTHA CALCARATA by Stephen Thomas (ex No. 53) From Newsletter 14, page 3 I have just discovered (or think I have discovered) a way to handle an E. calcarata adult male without bleeding to death in the process! Gently press the hind legs together with thumb and second finger, whilst holding down the abdomen with the fore finger and, hey presto, you have an immobilised E. calcarata1 MORE ON SHELTER PREFERENCES IN EURYCANTHA CALCARATA ADULTS by Milena Ktihnau (No. 728) The males are a dark brown, nearly black colour and every day normally hide all together one on top of the other in the corners of the cage walls, about 20 cm above the cage floor. The females are a grey-to-greenish colour and only go there in their nymphal stages; adults hide on the floor that is covered with dead leaves. They may rest alone or in small groups, but do not return every day to the same place as the males do. (see also Newsletter 42, page 10. - Eds] 43:10 FLYING BEHAVIOUR OF THE "THAILAND WINGED" SPECIES (PSG 103) by Alain Deschandol (No. 238) In Newsletter 41 (page 17) Heinz van Herwaarden (No. 478) suggests that these insects are good fliers. I agree with this because I have seen several of mine flying in their cage. Males are very good fliers as they are able to go up from the bottom to the top of the cage (they are the only stick insects I have seen do this). Their jump is very fast. Females use their wings to break their fall when they drop. They are heavier and, in my opinion, unable to fly upwards like the males. I have verified this by tossing a male and a female in a room. The male flies away to a wall in a straight line, and the female falls to the ground very quickly like Sipyloidea sipylus. ANISOMORPHA BUPRESTOIDES EGG LAYING by Michael and Frances (No. 3) We sometimes see our paired females laying eggs while on the cage walls or food- plant, so they do not always follow the digging and burying behaviour described in Newsletters 19 (page 2) and 40 (page 19). ANISOMORPHA BUPRESTOIDES TAPPING by Michael and Frances (No. 3) This sound was first reported in the Newsletter (No. 6, page 2) by Richard Warran (ex No. 33). It is due to adult males (sometimes unmated) pattering their feet when other males or pairs come too close. ACTIVE DEFENCE BY LONCHODES BREVIPES FIRST-INSTAR NYMPHS by Ingrid Lorrain (No. 539) As the adults of this species are inactive when picked up, I was very surprised when I picked up a first-instar nymph and it bit my finger while also depositing a drop of white liquid on my skin. This did not hurt much, but it did sting. This is nothing if not "active defence"! MULTIPLE "MATING" MAXIMUM? by Michael and Frances (No. 3) Six males were found clasping a single female Carausius alluaudi in the Seychelles, with a seventh male close by - and these males, being wingless, had to walk to get to the female! (See Bolivar and Ferriere in Trans. Linn. Soc. Lond. (Zool.), (2) 15 (1912) 295.) PIGGYBACK STICK INSECTS by Stan Pack (No. 99) On visiting a friend I noticed that his first and second instars of Heteropteryx dilatata had all taken to riding on the backs of various ages of Eurycantha calcarata - this had been going on for some weeks. Has anyone else noticed this? It would be interesting to find out if they returned to the same host each time. QiJe've seen the inverse, i.e. small E. calcarata sitting on larger H. dilatata. - Eds] UNUSUAL STICK INSECT SWAYS by Michael and Frances (No. 3) Extatosoma tiaratum sway with an apparently random, not regular, period and Anisomorpha buprestoides have a low-frequency (about 1 cycle/second) high-amplitude sway. With Orxines macklottii the body roughly traces out the curved surface of a cylinder so that, if the cylinder touches the ground, the insect makes a thumping sound! 43:11 LARGER GENE POOLS WITHOUT LARGER CULTURES7 by Michael and Frances (No. 3) This can perhaps be achieved by arranging for the culture to be continually replenished and die by having all-year-round hatchings. Any given adult will then be able when young to mate with old adults (of the opposite sex) and later to mate with other adults as they mature. The number of sticks an adult can mate with throughout its life (which determines the size of the gene pool) is then greater than the number it can mate with at any one time (which determines the size of the culture). Of course, you can't increase your gene pool beyond what you start with, but this method could better conserve what genes you have. However, Phil Bragg (No. 445) points out that, with long-lived quick-hatching sticks, this method is likely to result in some parent-offspring mating, which reduces the gene pool - an effect known as genetic drift or inbreeding. This effect becomes more serious the closer the relationship and is likely to be even worse with parent-offspring than with brother-sister breeding. The effect is less important with larger populations (over 100 individuals) and after about eight generations. LIGHT DISTURBS STICKS by Michael and Frances (No. 3) We keep our adult Anisomorpha buprestoides in a semi-translucent plastic box. About half of one wall used to be exposed to our living-room light, although we ensured that the rest of the cage was covered up around dusk time. From the end of January we made sure that the whole of the cage was covered at dusk, and the average number of eggs laid per female per 24 hours increased from 1.27 to 2.01 (averaged over 10 days for 18-19 pairs). The increased covering barely increased the temperature. DROWNING STICK INSECTS by Michael and Frances (No. 3) Since sticks breathe through holes (called spiracles) along the sides of their bodies, one should be far more alarmed at a stick with its body under water than its head. SORTING OVA FROM FRASS by Stan Pack (No. 99) From Newsletter 12, page 6 I have tried putting the ova and frass into warm water. The droppings disin tegrate and, if you use a fine mesh plastic sieve to soak them for a short time, you can gently swish them around and give a final rinse with warm water to leave the ova. Put the ova on absorbent paper to dry them. I have tried this with three types of small ova and they do not seem to be affected. CAGES FOR NEWLY HATCHED NYMPHS by Michael and Frances (No. 3) Any newly hatched nymphs should clearly soon be transferred to a suitable cage containing foodplant(s). Such cages need not be so large as those for adults and can easily be made using plastic sheet rolled up into a cylinder and fixed with staples (easier to adjust) or glued together. A search round the house should yield a choice of sizes in pairs of lids for the top and bottom of the cylinder. Plastic lids (for example from coffee jars, or flower pot saucers, but not tapering) are better than metal lids because they do not go rusty. Ventilation can be provided by pin holes in the plastic cylinder or red-hot needle holes in the lid. These can also eliminate the risk of drowning from too much condensation. Don't forget the standard rule that cages should be at least three times as tall as the longest stick you intend to keep in them, to give the sticks a reasonable chance of being able to shed without touching the floor. In general, small nymphs which fall to the bottom of the cage should not have a long climb back to reach their food. So the taller water jars are unsuitable and should be replaced by, for example, pill boxes or small plastic food storage contain ers with a hole or holes drilled in the lid for the foodplant stems. It is easier to prevent nymphs falling into the water with such jars, but they need topping up more frequently and this can be fiddly. 43:12 FEEDING RHAPHIDERUS SCABROSUS - IVY by Fred Giles (No. 401) Some time ago I had a lot of eggs hatch but had a job to get the nymphs feeding. I put them on rhododendron and bramble, and did not have much success; I then tried rose and got some feeding on that. As they grew larger I managed to get them feeding on bramble and they grew to adults, mating and laying eggs (though one of the problems was leaves being nipped off at the stems and ending up on the bottom of the cage). |bur two Eurycantha species are terrors at doing this! - Eds! As usual, after some time the males died, and some time later the females started to go as well. I then put the ones that were left on to ivy and this seems a lot better - they have gone some time now without another female dying and they eat the leaves right down without their falling off. Ivy seems to be a much better foodplant for the adults; whether it would be so for nymphs I don't know - I will have to try when I hatch some more out. [See also Newsletter 33, page 12. - Eds! I have also got nymphs of Heteropteryx dilatata, Creoxylus spinosus and Libethra regularis all eating some ivy, but not to the extent that R. scabrosus does. UNUSUAL BRAMBLE FOODPLANT FOR HAANIELLA ECHINATA ADULTS by Michael and Frances (No. 3) All the new bramble shoots up one branch were stripped off one February night - stick insects usually refuse these shoots. FOODPLANTS FOR BACULUM THAII by Les Fox (No. 50) From Newsletter 15, page 8 They eat, apart from bramble, rose, hawthorn, oak, primrose flowers, cage netting and newspaper! RUBBER PLANT AS FOOD by Kevin Hingley (non-member) From Newsletter 11, page 3 I have successfully fed my phasmids (Carausius morosus and Ctenomorphodes briareus) on Rubber Plant leaves for several weeks without adverse affects. RESULTS ON FEEDING APPLE SLICES TO VARIOUS PHASMIDS by Andrew Salter (ex No. 84) From Newsletter 11, page 3 I was recently told by a friend that his phasmids were eating apple (the fruit). I was surprised by this, so I decided to try it myself with my own insects. I cut the apple into thin (2 mm) slices and removed the skin. Then, in various places around the cages, I impaled the slices on to bramble thorns. The results were as follows: Carausius morosus - Only one small nymph was noticed on the apple, but I couldn't see if it was eating or just sucking the moisture from it. When the nymph had finished, there were no marks on the edge, so I came to the conclusion that it was just sucking. Sipyloidea sipylus - The adults and nymphs of this species were actually attracted to the apple. They ate large quantities of it (particularly the adults) and left the usual bite marks on the edges. Extatosoma tiaratum - As the adults seem to stay in one place most of the time, I offered a female a slice of apple from my fingers after spraying the foodplant (spraying seems to trigger off feeding). She took only small nibbles of the apple, while others just sucked. Eurycantha calcarata - Only one female was noticed eating the apple, almost as much as S. sipylus. I only give them apple occasionally as I am not too sure whether too much can harm them. Have any other members experimented with "different" foods? 43:13 FLOWER EATING AND DEFENCE IN SIPYLOIDEA SIPYLUS by Miguel Adams (ex No. 72) From Newsletter 15, page 2 I have found that both nymphs and adults of this species like to eat flowers, especially those of rose. I have found that it makes them live longer (possibly because of the nectar content?). Also, it makes them more productive (I have found up to seven eggs on a flower in one night). I have observed what could be a defence reaction: when there are a few individ uals in a cage, sometimes they hang together one on top of another forming a long chain, giving the appearance of a dried stick. Has anybody else experienced this? SIPYLOIDEA SIPYLUS DEFENSIVE REACTIONS by Michael and Frances (No. 3) From Newsletter 2, page 2 When disturbed they produce a strong smell like rotten vegetation. Other defensive reactions are wing "snap" and flutter (which may be a form of flash defence initially) or even exposing the pink wings as a coloration defence. THE STICK INSECT AND THE WASP by Alain Deschandol (No. 238) In the last issue of the French journal Imago (No. 37, October 1989, p. 14) Michel Chantraine reported a curious event. He was releasing some surplus Siplyoidea sipylus in his garden [illegal in the UK - Eds] when he saw a wasp on the back-of a sub-adult nymph. This wasp was stinging the stick insect's abdomen, and at the same time was biting through the abdomen! The nymph was cut in two, and the wasp flew away with part of its prey! The repellant smell of the S. sipylus was not effective on the wasp ... curious! COLOUR PREFERENCE OF SIPYLOIDEA SIPYLUS by Margaret Day (No. 635) In the classroom, pink-wings nearly always fly on to red (preferably) or pink pullovers. SIPYLOIDEA SIPYLUS MALE by Dave Grimwade (ex No. 12) From Newsletter 2, page 2 A male has arisen in my breeding stock, which is normally parthenogenetic (females only). As with most phasmids, he is somewhat slimmer than the females. He can achieve effective, if fluttery, sustained flight, covering large distances, and is the same colour as the females. ;=/ Wing showing pink veination Abdomen tip 43:14 PARTHENOGENESIS by David Robinson (No. 29) Abbreviated from Newsletter 12, page 5 In stick insects, unfertilised eggs produce only females. This is because the sex chromosome mechanism is of the XO (male) : XX (female) type. Unfertilised eggs are initially haploid - i.e. they have one sex chromosome per cell derived from the female. Subsequently, the chromosome number doubles by a method known as "blocked mitosis", so that each cell has two sex chromosomes, both X, which gives a female. Very rarely, this doubling does not take place, and then an XO egg results, giving a male. In fertilised eggs, each cell has one sex chromosome from the male (either X or 0) and one from the female (either X or X), and there is no doubling of the chromosomes. EGG ACTIVATION AND PARTHENOGENESIS by David Robinson (No. 29) From Newsletter 15, page 6 Previously I wrote about parthenogenetic (asexual) stick insects. The eggs contain one sex chromosome initially, and this doubles by "blocked mitosis" to give an egg with two identical chromosomes. Such eggs always produce females. In stick insects that reproduce sexually, there is no doubling of the sex chromosomes, since the eggs are fertilised by the male. Now the interesting question is this: "In parthenogenetic eggs, what 'triggers' development of the embryo, since there is no fertilisation?". Most of our knowledge comes from experiments on Carausius morosus. Eggs take several months to develop within the female. About 6 days before oviposition, the sex chromosome prepares to divide, but is blocked for the next Sh days. So duplication does not actually occur within the female. Indeed, if you induce a female to retain ripe eggs, the eggs do not develop. From this we can deduce that development is triggered by an event occurring at, or just after, oviposition. However, if eggs are removed from a female by a "caesarian operation", they develop, so it is not the act of oviposition, in itself, that triggers development. If the female lays eggs directly into fluid, the eggs do not develop. If the eggs are exposed to air, even for a fraction of a minute, they develop normally. Eggs laid into an atmosphere of pure nitrogen do not develop. Thus we can conclude that oxygen from the air unblocks the chromosome doubling stage and allows embryonic development to proceed. This work is reviewed in a recent [in 1983 - Edsj paper by D. F. Went in the Biological Reviews of the Cambridge Philosophical Society. He concludes by saying: "It also remains to be clarified whether an activating mechanism as described for C. morosus triggers development in eggs of other parthenogenetic phasmids and possibly even of sexually reproducing phasmids." THE MECHANISM IN THE HATCHING OF THE WALKING STICK, DIAPHEROMERA FEMORATA SAY, BY HENRY P. SEVERIN AND HARRY C. SEVERIN Review by Michael and Frances (No. 3) This paper (Ann, ent. Soc. Amer., 4 (1911) 187-90) suggests that, in general in phasmid hatching, the operculum is pushed open by the expansion, due to an influx of blood, of the cervical ampulla membrane connecting the head and prothorax (the same mechanism starts the skin splitting in moulting). Also of importance in both moulting and hatching is a series of wave-like movements of the segments of the body starting from the end of the abdomen. The middle, front and rear legs are usually withdrawn in that order from both the egg and the old skin. The sudden increase in the length of a stick on or shortly after hatching (see Newsletter 31, page 12) may be because the insect is curled up in the egg, so folding the thorax a bit like a concertina, and these folds straighten out on hatching. DIE EIER EINIGER DIMORPHODES-ARTEN UND EINIGE BERMERKUNGEN ZUR SYSTEMATIK DIESES GENUS, BY BURGHARD HAUSLEITHNER i This paper (in German) in Nachr. ent. Ver. Apollo, Frankfurt (N.F. 10 (1989) (3) 253-62) describes and illustrates for the first time eggs of the genus Dimorphodes Westwood 1859 (eight species). That three of these eight may be only sub-species is one of the taxonomic changes suggested. 43:15 DIFFERENCES BETWEEN EGGS OF CLONOPSIS GALLICA AND BACILLUS ROSSIUS by John Sellick (No. 48) C. gallica Micropylar plate Lightly pitted short of rim operculum Surface pitted rather than patterned Variable pattern inside ring edian line extends to pole only Raised ring /on operculum Micropylar plate meets rim ghtly patterned surface Median line extends right round "egg to rim on other side The top two eggs are C. gallica; the bottom three B. rossius. Reference: Clark, J.T., The European species of Bacillus Latreille, Ent. mon. Mag., 112 (1977) 63-4. COLOUR VARIATION PROPORTIONS IN BACILLUS ROSSIUS ADULTS by Robert Lind (No. 513) I have successfully reared 45 B. rossius to adults: 15 were green and the other 30 brown. It would be interesting to see what colour ratios other members find. BACILLUS ROSSIUS COLOUR CHANGE by Michael and Frances (No. 3) From Newsletter 5, page 1 Our nymphs change from green to pink at all instars before adult, but most often change at about third instar, in at least some cases going through a marbled pink/green colour. We have also had large nymphs remain marbled for a week or more at high population densities. These sticks seem to be "waiting"- to turn pink, because, if a lot of sticks are removed (by posting out!), the marbled ones then readily turn pink. 43:16 BACILLUS ROSSIUS COLOUR CHANGES by Les Fox (No. 50) From Newsletter 15, pages 5-6 I have found that colour changes in this European stick may occur at any time in the insect's life cycle, as I have had all mine turn from green to brown in the space of 14 months. This includes insects from first instar right through to egg- laying adults. The fastest to change were the first-instar nymphs, and the slowest was an adult female which took a month to complete the change and still has three green patches under her abdomen. I feel that all these insects changing at one time must be due to the change in the quality of the bramble in January/February when the weather was very cold. I wonder if anyone has seen the reverse change at any time, i.e. brown to green? I have yet to see it. DORMANCY OF EGGS AND LIFE CYCLES by Les Fox (No. 50) From Newsletter 13, page 6 Stick insects appear to have three different life cycles, as follows: 1. One generation per year, the egg being dormant at the least hospitable time. If this happens to be winter, the egg can be said to hibernate, as in New Zealand species (their climate is much like Britain's), or, if dormant in summer, this is known as aestivation and occurs where plants dry up in the summer (owing to the heat of the sun). 2. Two generations per year, when both summer and winter are inhospitable to the adults and nymphs, for example Bacillus species. The species B. rossius, I find, has a different prominent colour in each generation: green in spring, brown/straw in autumn. This would coincide with the colour of grasses in the natural habitat at these times. 3. Some species, for example Baculum thaii, Carausius morosus and Sipyloidea sipylus, appear to be continuously brooded, i.e. in the natural state all stages will be present at any one time. With these species it would be advantageous if males from a particular female's offspring died before the females matured, thereby promoting cross fertilisation within the species. These species are characterised by fast growth and a short dormancy in the egg. WHY ARE NEWLY HATCHED PHYLLIUM NYMPHS RED? by Alain Deschandol (No. 238) In some Phyllium species (Ph. bioculatum, Ph. pulchrifolium, etc) the newly hatched nymphs are red in colour. Some days later, when they have fed, their colour turns brown, and after some weeks becomes light green. The green colour is provided by the chlorophyll contained in the vegetation eaten by the insects (Becquerel and Brongniart, La matiere verte chez les Phyllies, C. R. Acad. Sci., Paris, 118 (1894) 1299-1303). It is very curious that they hatch with such a colour while adults are green, looking like leaves! Colours are very important in the animal kingdom. Red, yellow and black are generally warning colours. Many animals (wasps, hornets, caterpillars, etc) with bright colours are dangerous or poisonous to predators. The latter have found this out, and after a bad try don't try again! Some animals who don't have this defence imitate those who do. This is called Batesian mimicry. Perhaps the young Phyllium nymphs use this ruse to escape their predators? On the other hand, it is possible the young nymphs look like small red leaves which exist in the wild. DARK RHAPHIDERUS SCABROSUS FEMALES by Saul Springett (No. 341) Instead of remaining their usual bright green colour, about half of my females darkened at about the last instar before adult to various shades of brown, from light to very dark. The dark ones also have yellow spots on them. They are all kept at about 20-23 C, sprayed once a day, and fed on rhododendron. Their cage is fairly dark. 43:17 LE MONDE DES PHASMES: SUMMARIES AND HIGHLIGHTS by Michael and Frances (No. 3) NUMBER 7 (March 1990) General information by P. E. Roubaud (page 2) The French PSG Revue is now entitled "Le Monde des Phasmes", and a Phyllium logo has been adopted. ~~~ Foodplants of Phyllium bioculatum Gray 1832 in the Seychelles Islands by Pat Matyot (pages 3-7) Lists scientific, Seychellois, French and English names of eight foodplants eaten by a female in captivity and five which she refused. Phenacephorus cornucervi by Burghard Hausleithner (translated from the German by Monique Vergne) (pages 8-11) This translation of the first description of the male (Ent. Zeit., 95 (1985), 21, 315-9) also describes variations in the female - the original references are omitted. Achrioptera madagascariensis by A. Danel (pages 12-13) Describes rearing a nymph to second instar on guava, at 22-25°C and moderate humidity (without spraying the foodplant). The nymph refused bramble, oak, hawthorn and pyracantha. "Language or not" by D. Parent (page 14) Is the sound sometimes made by Extatosoma tiaratum produced incidentally by some other means of communication? Breeders: take care with your species by A. Deschandol (page 15) New species may understandably lead to the giving up of long-cultured species, which may then become scarce. Beginners can ensure the survival of easy species. The eggs of new species should be dispersed among several breeders to multiply the chances of success. Electronic thermostat by M. Chauche (pages 16-20) Includes circuit and layout diagrams and a parts list - a printed circuit board is used. A negative temperature coefficient resistance is used as the sensor (so avoiding the "sticking" with bimetallic strips) and this is isolated from the rest of the circuit by an optical coupler. The heater, which can be up to 500 W, is controlled by a triac (so avoiding any mechanical movement). Lists of phasmids in culture (pages 21-22) and Table of species for exchange (pages 23-24) Cover eggs, nymphs and adults from 17 and 56 GEP members respectively. Small ads (pages 25-26) Mainly wants. Answers to questions in Revue No. 6 (pages 27-28) P. E. Roubaud recommends a humidification system and controller described in earlier Revues. A. Deschandol points out that, when legs are shed, this is sometimes to escape predators or because of old age. Some species only rarely shed legs. X. Brettillon illustrates cases where an antenna is regenerated as part of a leg in Carausius morosus and Eurycantha calcarata - this is called heteromorphosis. A. Deschandol recommends, for eggs which are susceptible to mould, a fungicide or placing the eggs on an inert and well-ventilated support. In answer to another question, there should be no problems with rearing Libethra regularis at 23-25°C: this is a robust species. 43:18 PSG No. 31: CREOXYLUS SPINOSUS Updated from Report by Alan Gange (ex No. 17) in Newsletter 16 Main drawings by Frank Deschandol, son of Alain (No. 238) Classification: First described as Mantis spinosa by Fabricius, 1775 (274); a synonym is Phasma corniceps - Gray, 1835. Range: The Caribbean area (Guyana and Trinidad), also Colombia (Porto Cabello). Culture history: The original specimens were obtained in April 1980 on a collecting trip to Trinidad (possibly the Asa Wright Nature Centre, 7h miles north of Arima). ^J>4»'-^> Adults: This species exhibits sexual dimorphism, the main differences being that the male is winged and smaller than the female. The adults of both sexes resemble dead twigs in form and habits, hence their original common names "log insect" or "Trinidad log insect". Adult females reach about 70 mm long, with antennae some 30 mm in length. The insects range in colour from green through pale to dark fawns or browns: the colour seems to vary with the conditions the insects are kept in. The body is minutely roughened all over, and there are two large leaf-like spines on the back of the head and two rows, each of four spines, on the back of the thorax. When ready to lay eggs the female becomes very fat and the abdomen can reach a width of 10 mm. Paul Jennings (No. 80) points out that the female has a short "ovipositor tube" extending just beyond the tip of the abdomen. The ova can be seen in this tube prior to being laid. The angle at which the tube is held gives an unusual appearance to the tip of the abdomen. The tube appears to be made up of an extended genital operculum with a slightly rolled pointed flap on each side (see Paul's sketches). Paul has not seen this type of ovipositor in any other species. The female also has vestigial wings resembling just a tuck/ridge in the skin. The elytra resemble a small wing bud (somewhat as in an adult female Extatosoma tiaratum), roughly oval, 2 mm long by 1 mm wide. The elytra do not cover the vestigial wings as they do in other species with this type of wing (see Paul's right-hand sketch). The legs bear small spines along their lengths. Fore and hind legs measure about 30 mm with the mid legs about 20 mm. In 1990 Paul's adult females, but not his males, have body and leg lengths some 20 and 10% less respectively. 43:19 Tip of abdomen Dorsal (top) view of thorax Ventral (underside) view Lateral (side) view ?(x2) Elytron -Mid leg )u>k Vestigial wing "Ovipositor tube" A View along arrow The adult male is a more slender creature (maximum width 5 mm) reaching about 50 mm in length, with antennae slightly longer than the female's at about 35 mm. He has a well-developed pair of wings, grey in colour with bright red patches at the base. The body is also roughened all over and shows the same colour range as that of the female. The head also bears the leaf-like spines, but the thorax has only two spines, not eight. The leg lengths are also similar to those given for the female. Adult females are very inactive and often rest on the floor of the cage by day, hiding in leaf litter or a substitute such as brown paper. The males are generally inactive too, but can take flight with no warning and are capable of sustaining this at high temperatures. In Trinidad the adults occur in May-June. In culture they will live for 4-6 months or longer if kept cool. The males mature first and die well before the females. Ova: The ovum is a small, slightly distorted ovoid about 2.5 mm long, 2 mm wide and 1.5 mm thick. It is light brown in colour and has a lightly pitted surface. The operculum is a flat, round sepia cover at the top of the ovum. The micropylar plate is a small oval, lighter brown than the general colour and situated on the swollen side of the egg. The egg is relatively large for the size of the insect and consequently the number laid is fairly low (about two per night). When laid the egg is wet and sticky and will adhere to the foodplant or cracks in the cage. It soon dries but will become sticky again if re-wetted. They may be dropped haphazardly but it seems that a soft, irregular surface is preferred: peat is a favourite. Bert Charman (ex No. 141) finds that floor carpet provides an ideal surface and is better than soil or silver sand. The ova are all laid operculum upwards, with the bottom quarter in the substrate, rather like the eggs in the mother ship in the film "Alien"! (Peter Curry, ex No. 91). Ova hatch in about 2-3 months if kept fairly humid at about 75 F. The time may be reduced by up to one month with an increase in tempera ture of 10 F. Nymphs: The newly hatched nymphs are a light greyish brown colour, with the legs banded in yellow and brown. They should not be overcrowded or allowed to become too dry or too wet. As they grow up they show a range in colours similar to the adults'. They reach adulthood in about 8 months or less. Defence: This is both active and passive. At all stages the nymphs are extremely inactive and play dead if touched. They hide away by day and begin to move only at night. The adult female is the same, especially at low temperatures of around 50-60 F. At higher temperatures she becomes slightly more responsive. The adult male also plays dead, but he 43:20 exhibits flash coloration, using the red patches at the base of the wings. The male will also open up his wings like sails, as does Ctenomorphodes briareus, and will sit or run along with them in this position - a likely defence against bird predation. Michael and Frances (No. 3) also say that the male will make stinging movements with his tail - possibly a defence against smaller predators or parasites. Foodplants: Bramble is the best and most reliable. The insects will also take ivy but, according to Bert, will only accept the high-level lance-shaped leaves surrounding the berries and not the five-lobed sort. They will also eat oak, hawthorn, raspberry, rose and skimmia. Paul Brock (No. 26) writes in Newsletter 17 (page 4) that, in the wild, they are said to occur on several species of plants; most often on a herbaceous plant resembling a Polygonum species (Polygonaceae) which grows along roadsides in the northern range of mountains in Trinidad, but also on ivy and firethorn (Pyracantha coccinea). Comments: This is an easy species to keep. They are very hardy and will tolerate a wide range in temperature and humidity. It is likely that most cultures here are not kept as hot or humid as their natural environ ment; however a temperature of 70-75°F with a light daily mist spray and good ventilation appears to provide optimum conditions. It is an interesting species to keep, despite its inactivity, and does not require a large cage to maintain the culture. FORTHCOMING SPECIES REPORTS Libethra sp. (PSG 51) (postponed from this issue) Libethra regularis (PSG 32) (updated from Newsletter 18) Dares nolimetangere (PSG 99) Carausius sechellensis (PSG 16) Paraphasma rufipes (PSG 85) Carausius sp. (PSG 66) Please send all your information on all these species to the Editors (address below), to reach us by 15th July 1990 for the first three. NEXT NEWSLETTER Please send all other contributions to the Editors: Michael Lazenby and Frances Holloway, at 9 Oaklands Court, Nicoll Road, London NW10 9AU, to reach us by 1st August 1990, or preferably earlier. Up-to-the-minute items may be accepted up to 15th August. All contributions to the Newsletter will be deemed to be submitted also to the French GEP Le Monde des Phasmes for translation. BACK ISSUES OF THE NEWSLETTER These are now available again from David Robinson (No. 29) without the need to complete Copyright Forms, but Newsletters 1 to 8 and 11 to 15 are withdrawn (Newsletter 9/10 is reissued in a revised version). Newsletters 24, 26 and 32 are available without the drawings of Calynda sp. (PSG 52) and articles on a Scilly Isles expedition and some Malaysian sticks (since lost) respectively. Newsletters 16 to 19, 22 and 30 are available without their Species Reports, but it is hoped to update most of these Reports in current Newsletters. Later it is hoped to issue new Reports on Species 2, 3, 4, 5, 9, 12, 13 and 22, to replace some of those in the withdrawn Newsletters. For prices and Order Forms please consult David or Paul Brock (No. 26).