scholarly journals Why does the Namib Desert tenebrionid Onymacris unguicularis (Coleoptera: Tenebrionidae) fog-bask?

2008 ◽  
Vol 105 (5) ◽  
pp. 829-838 ◽  
Author(s):  
Strinivasan G. NAIDU
Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 804
Author(s):  
Joh R. Henschel

Noy-Meir’s paradigm concerning desert populations being predictably tied to unpredictable productivity pulses was tested by examining abundance trends of 26 species of flightless detritivorous tenebrionid beetles (Coleoptera, Tenebrionidae) in the hyper-arid Namib Desert (MAP = 25 mm). Over 45 years, tenebrionids were continuously pitfall trapped on a gravel plain. Species were categorised according to how their populations increased after 22 effective rainfall events (>11 mm in a week), and declined with decreasing detritus reserves (97.7–0.2 g m−2), while sustained by nonrainfall moisture. Six patterns of population variation were recognised: (a) increases triggered by effective summer rainfalls, tracking detritus over time (five species, 41% abundance); (b) irrupting upon summer rainfalls, crashing a year later (three, 18%); (c) increasing gradually after series of heavy (>40 mm) rainfall years, declining over the next decade (eight, 15%); (d) triggered by winter rainfall, population fluctuating moderately (two, 20%); (e) increasing during dry years, declining during wet (one, 0.4%); (f) erratic range expansions following heavy rain (seven, 5%). All species experienced population bottlenecks during a decade of scant reserves, followed by the community cycling back to its earlier composition after 30 years. By responding selectively to alternative configurations of resources, Namib tenebrionids showed temporal patterns and magnitudes of population fluctuation more diverse than predicted by Noy-Meir’s original model, underpinning high species diversity.


2018 ◽  
Vol 14 (1) ◽  
pp. 10-24
Author(s):  
V. N. Fursov ◽  
L. S. Cherney

Darkling beetle Zophobas atratus (Coleoptera, Tenebrionidae) is recorded here for the first time as a new species for the fauna of Ukraine. Detailed study on morphology of preimaginal stages and biology of this species recently introduced to Ukraine, is given here. Zophobas atratus is an important species being easily reared in laboratory cultures and widely distributed in North and South America, Europe, and Asia. Detailed descriptions of all life stages, including egg, young and older larvae, pupa and adult of Z. atratus are required for further taxonomical study of the genus Zophobas, which isn’t yet definitively established. New identification keys for adults and larvae of the genera of tribe Tenebrionini are presented here, based on a comparative analysis of the taxonomic characters of adults and larvae of Z. atratus and species from the genera Tenebrio and Neatus. Comparative analysis of morphology of larva of Z. atratus and larvae of the tribe Cteniopodini of close subfamily Alleculinae was conducted here. The subfamily Alleculinae previously had the rank of family Alleculidae, but our analysis confirmed the reliability of its current taxonomic position as subfamily. The study of morphology of larvae of 1st and 2nd instars of Z. atratus revealed that they are characterized by special taxonomic structures that are not characteristic for oldest instars of larvae of Z. atratus. These characters include absence of spines on caudal segment, presence of a set of 4 setae at posterior margin of tergites of prothorax, metathorax, and 1st to 8th abdominal segments, strongly convex 2nd antennal segment and sensory zone in the form of an open ring on its apex, and etc. Moreover, structure of antenna of larvae of Z. atratus is similar to that of oldest larvae of most species of darkling beetles of the fauna of Ukraine. The most distinctive features of Z. atratus are: sexual dimorphism in structure of clypeus of adults; filiform sclerotized antenna of larva with a continuous sensory zone at apex of 2nd segment, weakly developed 3rd segment; fusion of sclerotized pleurites of 1st–8th abdominal segments with their tergites; sexual dimorphism in structure of 9th abdominal segment of pupa, and presence of two hooks on apex of its appendages. The data of original study of features of life cycle of Z. atratus are given. The pictures and photos of details of morphology of egg, larvae, pupa and adult of Z. atratus are presented. It was recored that life cycle of Z. atratus from laying of egg to the emergence of adult continues from 169 up to 181 days. Adults lived maximum up to 206 days. Maturation of eggs in female after copulation continues 10-11 days. Stage of egg continues 7 days, larva – up to 151 days, including pre-pupal period from 6 to 22 days, pupa – from 8 to 21 days. Twelve larval stages of Z. atratus were recorded in laboratory culture.


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