Acacus sp. "Sibayak"
(by Bruno Kneubuehler)
 

OrderPhasmatodea
 
SuborderVerophasmatodea 
InfraorderAnareolatae 
FamilyDiapheromeridae Kirby, 1904
SubfamilyNecrosciinaeBrunner v. Wattenwyl, 1893
TribeNecrosciini Brunner v. Wattenwyl, 1893
GenusAcacusBrunner v. Wattenwyl, 1893
SpeciesAcacus sp. "Sibayak"(not yet described)


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General Notes

  • the genus Acacus has been set up by Brunner v. Wattenwyl
  • the type species for this genus is Bacteria sarawaca  (= Acacus sarawacus) Westwood 1859
  • 2010 – first successful culture of this species by Bruno Kneubuehler
  • 2011 – a few starter cultures have been distributed to some of my friends
  • 2011 – this species is momentarily under taxonomical examination

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Origin

  • this species has been collected by Jimmy Gideon (Sumatra) in November 2010 on Mt. Sibayak near Brastagi (nothern Sumatra)

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Females

  • inconspicuous, typical phasmids
  • about 7 cm long
  • coloration is rather variable between amongst females
  • different brown shades
  • many small tubercles, especially on the dorsal thorax area
  • antennae longer than fore legs
  • small, faintly yellowish wing rudiments

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Males

  • thin phasmids
  • about 5.5 – 6 cm long
  • several small tubercles, especially on the dorsal thorax area
  • different brown shades
  • coloration is rather consistent amongst males
  • antennae longer than fore legs
  • small, faintly yellowish wing rudiments

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Nymphs

  • L1 nymphs are about 17 mm long
  • a light band near the antennae tips
  • antennae longer than fore legs
  • dark knees
  • it is possible to distinguish male and female nymphs by L3

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Eggs

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Food Plants

  • freshly hatched nymphs accept bramble (Rubus sp.) easily
  • also older nymphs and adults feed well on bramble (Rubus sp.)

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Behaviour

  • nymphs as well as adult specimens show no active defensive behaviour. When the feel threatened, then they just freeze and rely on their camouflage
  • thus it is a rather calm species
  • females start laying eggs about 3 weeks after their final moult
  • they lay about 8 – 10 eggs per week
  • females will stick some eggs into cracks (e.g. bark), most mostly they just let the eggs drop to the ground. Eggs were not stuck into sand
  • matings can be observed regularely during the night, they last for some hours at the most

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Developement

  • incubation time (HH-incubation method on slightly humid sand at 20 – 23°C) is about 5 months
  • hatching ratio in F1 was high (50+ %)
  • males will be adult after about 3 months (at 20 – 25°C), females after about 4 months

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Breeding Notes

  • an easy to keep species
  • incubation with the HH-incubation method (on slightly damp sand) yields good hatching ratios
  • spread some dry moss over the eggs, this will make it much easier for the nymphs to hatch properly
  • 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
  • nymphs can be kept in a Faunabox (or similar cages)
  • move nymphs to a bigger cage as they grow bigger
  • I have never sprayed nymphs or adults with water
  • make shure 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

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References

  • Phasmida Species Files  (www.phasmida.orthoptera.org)



 

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direct link to category: sp. (Sumatra, Mount Sibayak)