Zophobas atratus (Fabricius, 1775) – new genus and species of darkling beetles (Coleoptera, Tenebrionidae) for the fauna of Ukraine

Abstract

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.

The Superworm, Zophobas morio (Coleoptera:Tenebrionidae): A ‘Sleeping Giant’ in Nutrient Sources

“…In nature, it has been reported in association with fruit bat guano and organic litter ( Tschinkel and Willson 1971 ). It traces its origins in the tropical regions of Central and South America ( Marcuzzi 1984 , Tschinkel 1984 , Hagstrum and Subramanyam 2009 ); however, it has nowadays been also introduced to other regions in Europe and Asia ( Yuan et al 2012 , Fursov and Cherney 2018 ).…”

“…The eggs of Z. morio are oval with rounded edges, white and ~1.7 mm in length and 0.7 mm in width ( Fig. 2A ; Fursov and Cherney 2018 ). Each female can lay a high number of eggs (up to 2,200) during its lifespan, with the number of eggs being negatively correlated with female maternal age and positively correlated with adult density ( Tschinkel 1993 ).…”

“…The larvae are yellow with dark brown anterior and posterior ends ( Fig. 2B ; Fursov and Cherney 2018 ). They have a cylindrical, strongly sclerotized exoskeleton, conically narrowed from the base of the seventh to the ninth abdominal segment.…”

“…The duration of the pupal stage is 13–15 d at 25°C, depending on the pupal weight (adults emerging faster from small pupae) and temperature (faster adult eclosion at 29°C) ( Quennedey et al 1995 ). Similarly to other tenebrionid species, such as T. molitor ( Bhattacharya et al 1970 ) and A. diaperinus ( Esquivel et al 2012 ), individuals can easily be sexed at this life stage by noting two distinct projecting pygopods at the ninth abdominal segment of the female pupae close to the urogomphus, which are absent from the male ones ( Fursov and Cherney 2018 ).…”

“…The surface of the elytra is punctuated with nine rows of bristle-bearing punctures. Adults can live up to 6 mo ( Fursov and Cherney 2018 ).…”