Scolopendromorph Centipedes Research Articles

WATER AND TEMPERATURE RELATIONS, AND DIURNAL RHYTHMS OF SCOLOPENDROMORPH CENTIPEDES

Water is lost by transpiration at relative humidities (R.H.) as high as 98% at 27° C and there is no evidence of the uptake of moisture through the integument from unsaturated air or moist surfaces. Water‐loss through transpiration is directly related to saturation deficiency and there is no ‘critical’ transitional temperature at which the cuticle becomes porous. Nevertheless, water is retained more efficiently in Scolopendra than it is in Lithobius, suggesting an adaptation to hot‐dry environments. The mean supercooling point of large specimens conditioned in an insectary is —3.1 ± 0.48° and a single supercooling can be injurious or fatal. This indicates that cold winter weather must be avoided by burrowing deeply. Aktograph experiments show that these centipedes are nocturnal. The rhythm persists in darkness at constant temperature, but is quickly lost in constant light.RésuméRÉACTIONS À L'HUMIDITÉ ET À LA TEMPÉRATURE ET RYTHME JOURNALIER CHEZ DES MYRIAPODES SCOLOPENDROMORPHESLes Myriapodes étudiés montrent une perte d'eau par évaporation lorsqu'ils sont placés dans une ambiance à 27° et dont l'humidité relative est de 98%; il n'y a aucune indication permettant de penser que ces arthropodes peuvent se rehydrater à partir des surfaces mouillées ou de l'humidité atmosphérique, par prélèvement à travers leur tégument. La perte d'eau par transpiration est directement en rapport avec la déficience de saturation de l'air et il n'y a aucune température critique de transition pour laquelle la cuticule deviendrait perméable à l'eau. Néanmoins l'eau est retenue plus efficacement par Scolopendra que par Lithobius, ce qui suggère chez le premier genre une adaptation aux milieux chauds et secs.Le point de surfusion mesuré pour de grands spécimens maintenus en insectarium, est en moyenne de —3,1 ± 0,48° et un seul choc à cette température de surfusion peut être préjudiciable ou même fatal. Cela indique que ces arthropodes doivent éviter les froids de l'hiver en creusant plus profondément les galeries.Des expériences utilisant un actographe montrent que ces Myriapodes ont une activité nocturne. Le rythme naturel d'activité persiste à l'obscurité et à une température constante, mais il est rapidement perdu par exposition à un éclairement continu.

Scolopendromorph and geophilomorph centipedes from Eritrea

Summary A collection of scolopendromorph and geophilomorph centipedes from Eritrea is described and comparisons are made with an earlier collection described by Brolemann. It is suggested that Rhysida lithobioides abessynica Attems may not merit distinction from R. l. paucidens Pocock and that centipedes from Eritrea determined as Cryptops (?) bottegii Silvestri by Brolemann may prove to be C. niloticus Lewis. Mesocanthus albus minutus is redescribed and the use of prefemoral ratios in separating species of Trachycormocephalus is shown to be unreliable. The distribution and affinities of the fauna are discussed.

The scolopendromorph centipedes of the Sudan with remarks on taxonomic characters in the Scolopendridae

SUMMARY A study has been made of scolopendromorph centipedes recently collected in the Sudan and information from the literature and collections in the British Museum (Natural History) has been incorporated. Ten species are recorded from the Sudan, two of these (Cryptops spp.) being new to science. It is suggested that previous records of Scolopendra morsitans are, in fact, of S. amazonica and as a result of the examination of Sudanese material Scolopendra valida valida and S. v. simonyi are synonymized as are Asanada sokotrana sokotrana and A. s. kalaharina. The Sudanese Asanada is recognized as a new subspecies A. s. attemsi. The material is examined in some detail, this being necessitated by the individual variability of scolopendrids, and compared with previous descriptions. The value of a number of characters including colour in taxonomic discrimination in the Scolopendridae is discussed.