Phryganistria heusii yentuensis "Tay Yen Tu"

(by Bruno Kneubuehler)

General Notes

• Nov. 2014 - described by J. Bresseel and J. Constant as Phryganistria heusii yentuensis
• coloration of males of Ph. heusii yentuensis „Tay Yen Tu“ is considerably different from males of Ph. heusii (which originate from Cuc Phuong NP, Vietnam)
• the habitat of both subspecies are about 200 km apart
• further taxonomical informations → Phasmida Species Files
• in the past few years several Phryganistria species came new into culture

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Culture History

• 2014 - first successful culture by Bruno Kneubuehler
• 2014 – distributed to other breeders as Phryganistria heusii ssp. „Tay Yen Tu“
• 2014 - this culture is now called Phryganistria heusi yentuensis "Tay Yen Tu"

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Origin

• Tay Yen Tu Nature Parc (Vietnam)

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Females

• very big phasmids
• body length about 26 - 29 cm
• one of the wild-caught females was had a body lenght of 32 cm
• coloration quite consistent amonst females
• dorsal coloration is brown-green (head, thorax) and green with dark mottling (abdomen)
• many small, almost white dots dorsally
• dorsal coloration is green, abdomen dark mottled
• many spines on the legs
• antennae shorter than forelegs
• subgenital plate reaches more or less to the end of the abdomen
• praeopercular organ (the structure at the ventral end of the 7th abdominal segment, which serves as an anchorage for the male during mating) is very well developed

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Males

• very long and thin phasmids
• body length about 20 – 22 cm
• coloration is rather consistent amongst males
• dorsal coloration mainly light brown
• ventral coloration green, brown – with a dark middle stripe
• hairy, almost black antennae shorter than forelegs
• many spines on the legs
• mid- and hindlegs have 2 big, black at the ventral-distal end of their femur

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Nymphs

• lenght (L1) about 30 mm
• short, dark antennae
• dark forelegs, green-brown ringed mid- and hindlegs
• green head and body
• by L3 it is quite easy to draw a distinction between ♀♂ (by the naked eye)
• examples on how to differentiate between male and female nymphs

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Eggs

• about 6 x 4 mm
• brown
• often black mottled
• oval
• surface smooth and slightly glossy
• a distinct capitulum present on the operculum (lid)
• micropylar plate arrow-shaped

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Food Plants

• it is very much recommended to cut away the edges of the leaves for nymphs in L1
• regularly change the plants and the water in which they stand
   
• bramble (Rubus spp.)
  is very well accepted by nymphs and adults
• hazelnut (Corylus avellana)
  is very well accepted by nymphs and adults

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Behaviour

• nymphs as well as adult are passive during the day and out and about feeding at night
• nymphs react quite frantically when they feel threatened (like when they are touched). Then they often let themselves fall backwards through the twigs with all legs closely folded foreward ! In this pose they fall like an arrow through the twigs, with would not be possible with their long legs streched out. Out in nature, this behaviour is definitly great for escaping
• just after their fall they just stand still
• they also quite easily drop legs (autotomy). Thus they have to be handled carefully
• adults do also try to escape when they feel threatened, but usually by crawling away
• mating are frequent during the night, males do not stay with the same female for a long time
• a defensive spray has not been observed
• females fling the eggs away - with a swing of the abodmen and they just drop to the ground

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Developement

• incubation time (HH-incubation on slightly damp sand at 20 - 23 °C) is about 5 – 6 months
• please note, that for phasmids it is not uncommon that some nymphs hatch a few or many months after the first nymphs hatched
• spread some moss over the eggs - this will make it much easier for the nymphs to hatch unscathed and it also reduces mould growth to some extend
• males will be adult after about 4.5 months (at 20 – 23°C), females after about 5 months
• females start laying eggs after about 2 – 3 weeks
• about 25 – 30 eggs per female and week
• adults can live for several months

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Breeding Notes

• my general notes on how to breed phasmids are an integral part of this care sheet …
• it is recommend to keep this species in a seperate cage. The culture is much more likely to be successful than in an multi-species cage which are all too often badly crowed
• degree of difficulty =  2                (1= very easy / 5 = very difficult)
• as the freshly hatched nymphs are already very big, therefore the incubation container must be big enough too
• keep nymphs seperate from the adults. This makes it much easier to monitor their developement and they are protected from being disturbed or even harmed by the much bigger adults (like during their moults)
• keep the nymphs in a cage with good ventilation, but take care that the humidity does not drop too low
• a constantly wet paper towel on the floor of the cage helps raising humidity
• a humidity level of about 60+ % rH (for adults) and 75+ %  rH (for nymphs) seems to be fine
• small nymphs can be kept in a Faunabox (or similar cages like Faunarium)
• move nymphs to a bigger cage as they grow bigger
• a cage of at least 60 x 60 x 90 cm height should be provided for 3 adult couples
• at least 2 (-3) cages are needed to breed this species – one cage for the small nymph, maybe another one for the older nymphs and one cage for the adults
• spray smaller nymphs with water 2 – 3 times a week (do not used chlorinated tap water). This water should dry up within a few hours, therefore an airy cage is needed
• it is not needed to spray older nymphs and adults
• make sure that nymphs, which are about to undergo their adult moult, do not find places in the cage which would not offer them enough space beneath to moult successfully