Pseudothyretes, DUFRANE, 1945

Przybyłowicz, Łukasz & Tarcz, Sebastian, 2015, Strong sexual dimorphism unraveled by DNA analysis - towards a better understanding of Pseudothyretes classification (Lepidoptera: Erebidae: Arctiinae), Zoological Journal of the Linnean Society 173 (1), pp. 22-54 : 28-29

PSEUDOTHYRETES DUFRANE, 1945

Type species: Pseudothyretes mariae Dufrane, 1945 (by original designation).

Diakonoffia Kiriakoff, 1953: 22 (synonymized by Przybyłowicz & Kühne, 2008: 154).

Type species: Apisa kivensis Dufrane, 1945 (by original designation).

Diagnosis

Pseudothyretes is a member of the metarctioid group (Ł. Przybyłowicz, unpubl. data). Along with Thyretes , this genus forms a separate clade characterized by the epiphysis almost as long as the fore tibia and the lack of retinaculum. Pseudothyretes differs from Thyretes in the rust-brown coloration with white markings and the minute teeth on the basoventral portion of the claw.

Redescription

Forewing 10–24 mm. Coloration uniformly pale or rusty brown to dark brown (coffee); with narrow, transverse black bands on abdomen (except P. mirus sp. nov.); semi-hyaline markings on wings (forewing, in discoid cell, between R 4 and CuA 1, in middle part of dorsal area; hindwing, medially); labial palpus moderately long, second segment at least three times as long as wide, third segment in males strongly reduced, spherical, in females usually atrophied; antenna pectinate in males, filiform in females; eye medium sized, naked; proboscis rudimentary; tymbal organs absent, tympanum directed ventrodistally; epiphysis almost as long as tibia; retinaculum absent; M 2 –M 3 of forewing and hindwing stalked basally.

Male genitalia

Relatively small; uncus diverse, divided into two long flattened processes, long, narrow, bifid, or pointed at apex; tegumen of same size as vinculum; the latter with short saccus; valva moderately long; cucullus elongate, gradually tapering terminally, pointed at apex; phallus shorter than valva, moderately sclerotized, straight; vesica short, wide, dorsobasal portion with or without numerous minute cornuti.

Female genitalia

Anal papillae relatively large; anterior and posterior apophyses of similar length; dorsal pheromone glands short, divided into several separate openings; ventral pheromone glands deep, wide, fused into a pouch; ostium sclerotized, rounded; ductus bursae short, straight, membranous, or sclerotized in anterior part; corpus bursae much smaller than sternite A7, membranous, without signum; ductus seminalis slender, arising from base of corpus bursae.

Biology

Almost nothing is known on the biology of the genus. The developmental stages and the host plants remain undiscovered. The imagoes indicate night activity, and can be collected throughout the year. The males are frequently attracted to light whereas the females are collected only rarely. The real proportion of sexes is unknown.

Specimens have been collected in different kinds of woodlands and on their edges, regardless of humidity and anthropogenic modification. Remarkably, the moths were never collected in the open, such as in habitats devoid of trees, like savannahs.

Distribution

The genus has diversified in tropical Africa. Its representatives are distributed from Western Equatorial Africa ( Guinea) east to central Kenya and Tanzania. North and south of the equator the genus only reaches 10° of latitude. The most common and most widely distributed species are P. perpusilla , P. carnea , and P. obscurus sp. nov. Pseudothyretes erubescens and P. nigrita constitute a pair of taxa restricted to areas around Lake Victoria and the Ruwenzori Mountains, respectively.

Molecular variation

The intraspecific haplotype diversity across specimens (N = 61) was Hd = 0.948, which indicates the great variability of the DNA fragment studied. Nucleotide diversity amounted to π = 0.0552. The nucleotide frequencies were A = 0.321, T = 0.382, C = 0.131, and G = 0.166, and revealed a high proportion of A–T pairs, which is typical of insect mitochondrial DNA. The mean divergence over all Pseudothyretes sequence pairs studied (N = 61) was 0.055 / 0.009 (distance/standard error). There were 44 variable positions across all specimens studied in the COI fragment, 36 of which were parsimony informative (25 with two variants, nine with three variants, and two with four variants). A total of 29 haplotypes were found among the specimens studied. The mean sequence divergence, haplotype, and nucleotide diversity for each of the Pseudothyretes species studied are presented in detail in Table 3.

Remarks

The male genitalia of the already known species ( P. carnea , P. erubescens , P. kamitugensis , P. nigrita , and P. perpusilla ) are not described here in detail. They are illustrated here and are briefly described in Przybyłowicz (2009).