Luridiblatta, Fernandes, 1965

Bohn, Horst, 2022, Revision of the genus Luridiblatta (Blaberoidea, Ectobiidae, Ectobiinae), Zootaxa 5215 (1), pp. 1-72 : 26-27

Similarities of Luridiblatta with other Palearctic Ectobiinae

Looking for species or species groups possibly related to the genus Luridiblatta first the panteli -group of Phyllodromica has to be mentioned which is distributed in Southern Spain and North-Western Morocco ( Bohn 1993). The species of this group have glandular structures on T7 resembling those of Luridiblatta : a pair of large tubes anteriorly, and a pair of narrower tubules posteriorly. But, a proper pit is not developed, the larger tubes open either separately or via a short common atrium about at middle length of T7, not at the anterior border as in Luridiblatta . The tubules also open separately, shortly behind the opening(s) of the tubes. There are also strong differences in the histological structure of the glandular tubes: in the panteli -group they have a distinct cuticular lining which is, however, missing in Luridiblatta . Similarities with Luridiblatta can also be found in the structure of the genital hook: an acutely pointed velum and a partly broadened shaft. But the similarity in the latter character is rather weak and only present in the more derived species of the panteli- group. Thus, only the velum remains as a common character of both groups possibly pleading for close relationship. But the agreement in this character appears neglectable in view of the numerous characters in which they differ, as are the structures of male T6,7, S9 and phallomeres, female genital sclerites (in panteli -group symmetrical), and wings of both sexes. The most important differences are those concerning male S9 and phallomeres: Luridiblatta species have a specialised stylus, but no scale sclerite and thus belonging to “Ectobiinae Category I” ( Bohn 2019), while the species of the panteli - group have an unspecialised stylus and a scale sclerite showing their belonging to the “Ectobiinae Category II”.

Similarities with Luridiblatta are also found in the maculata -group of Phyllodromica ( Bohn & Chládek 2011) : a fairly strong excision of the posterior border of T7 which in some species is strengthened to an apparent splitting of T7. But strong differences in other structures (hindwings, male glandular pit, phallomeres, scale sclerite, and stylus, and female genital sclerites and ootheca) argue for an independent development of this character in both groups; the maculata -group also belongs to “Ectobiinae Category II”.

Asymmetries of the basivalvular sclerites as found in the female genital sclerites of Luridiblatta can also be observed in the erythronotus -group of Ectobius , though to a less strong degree: the right dorsal basivalvular sclerite is slightly longer and broader at its anterior end than the left (Bohn, unpublished results). Though the erythronotus - group fulfils the criteria for a membership in the “Ectobiinae Category I” (with specialised stylus, without scale sclerite), and though asymmetry in female genitals of Ectobiinae is relative seldom, the slight similarity mentioned is not sufficient to allow the assumption of a close relationship with Luridiblatta ; apart from the specialised stylus no other important character is known which is shared by both groups.

Biology

The developmental strategy of Luridiblatta species is unusual for European Ectobiinae. They are univoltine, overwintering as ootheca; the larvae hatch in spring and develop to imagines until late summer or autumn (August, September) of the same year—a kind of development which they share with the representatives of genus Capraiellu s ( Bohn & al. 2013), while most other European Ectobiinae have a bivoltine development with imagines appearing in spring. It appears astonishing, that the animals pass their main growth and developmental phases in the season with highest temperatures and strongest dryness (June to August). The distribution in Europe—only in the South of the Mediterranean countries—points to their preference of high temperatures.

The species of Luridiblatta are preferably found in tufts of dry grass, occasionally also among leaf litter of olive or eucalyptus trees. The handsome colouration—yellowish straw-coloured with dark longitudinal lines—can be seen as a cryptic adaptation to their environment.