Polyphagy and diversification in tussock moths: Support for the oscillation hypothesis from extreme generalists

Theory on plasticity driving speciation, as applied to insect–plant interactions (the oscillation hypothesis), predicts more species in clades with higher diversity of host use, all else being equal. Previous support comes mainly from specialized herbivores such as butterflies, and plasticity theory suggests that there may be an upper host range limit where host diversity no longer promotes diversification. The tussock moths (Erebidae: Lymantriinae) are known for extreme levels of polyphagy. We demonstrate that this system is also very different from butterflies in terms of phylogenetic signal for polyphagy and for use of specific host orders. Yet we found support for the generality of the oscillation hypothesis, in that clades with higher diversity of host use were found to contain more species. These clades also consistently contained the most polyphagous single species. Comparing host use in Lymantriinae with related taxa shows that the taxon indeed stands out in terms of the frequency of polyphagous species. Comparative evidence suggests that this is most probably due to its nonfeeding adults, with polyphagy being part of a resulting life history syndrome. Our results indicate that even high levels of plasticity can drive diversification, at least when the levels oscillate over time.</p

A global phylogeny of butterflies reveals their evolutionary history, ancestral hosts and biogeographic origins

Butterflies are a diverse and charismatic insect group that are thought to have evolved with plants and dispersed throughout the world in response to key geological events. However, these hypotheses have not been extensively tested because a comprehensive phylogenetic framework and datasets for butterfly larval hosts and global distributions are lacking. We sequenced 391 genes from nearly 2,300 butterfly species, sampled from 90 countries and 28 specimen collections, to reconstruct a new phylogenomic tree of butterflies representing 92% of all genera. Our phylogeny has strong support for nearly all nodes and demonstrates that at least 36 butterfly tribes require reclassification. Divergence time analyses imply an origin similar to 100 million years ago for butterflies and indicate that all but one family were present before the K/Pg extinction event. We aggregated larval host datasets and global distribution records and found that butterflies are likely to have first fed on Fabaceae and originated in what is now the Americas. Soon after the Cretaceous Thermal Maximum, butterflies crossed Beringia and diversified in the Palaeotropics. Our results also reveal that most butterfly species are specialists that feed on only one larval host plant family. However, generalist butterflies that consume two or more plant families usually feed on closely related plants

Euproctis montis Leech 1890

Euproctis montis (Leech, 1890) (Figs. 17–18, 36, 48) Artaxa monits Leech, 1890: 111. Nygmia montis: Swinhoe, 1922: 482. Euproctis montis: Strand, 1910: 137; Chao, 2003: 409. Diagnosis. Forewing length 14–20 mm. Forewing yellow, with two pale yellow median lines and a darker band from lower angle of cell oblique to middle of dorsum; hindwing slightly paler than the forewing. Male genitalia (Fig. 36): Uncus broad, with constricted sides; valva short and wide; costa strongly sclerotized, slightly protruded apically; saccus relatively large; aedeagus straight, vesica with irregular fields of spines. Female genitalia (Fig. 48): Apophysis anterioris longer than apophysis posterioris; sterigma inflated, sclerotized; ductus long, membranous; bursa with a transverse signum. Material examined. 23, 3 Ƥ, Nanling National Nature Reserve, Guangdong, 7.VIII. 2009. Distribution. China (Gansu, Jiangsu, Shanxi, Hubei, Zhejiang, Sichuan, Xizang, Jiangxi, Fujian, Hunan, Guangdong, Guangxi, Yunnan, Hainan). Remarks. The species is allied to E. collenettei Chao, 1994, but the latter is distinct in forewing with scattered black scales near middle of dorsum rather than a dark oblique band. Female genitalia are illustrated here for the first time.Published as part of Wang, Houshuai, Wang, Min & Fan, Xiaoling, 2011, Notes on the tribe Nygmiini (Lepidoptera: Erebidae: Lymantriinae) from Nanling National Nature Reserve, with description of a new species, pp. 57-68 in Zootaxa 2887 on pages 63-64, DOI: 10.5281/zenodo.20082

Euproctis flavotriangulata Gaede 1932

Euproctis flavotriangulata Gaede, 1932 (Figs. 25–26, 40, 52) Euproctis flavotriangulata Gaede, 1932: 104; Collenette, 1934: 115; Chao, 2003: 426. Diagnosis. Forewing length 15–18 mm. Forewing fuscous, with a yellow triangular patch near base of costa, and a smaller yellow patch at middle of dorsum, an irregular yellow marginal band, separated by fuscous scales from the middle of termen, apex with dark spots; hindwing fuscous with a yellow margin. Male genitalia (Fig. 40): Tegumen broad; uncus long, digitate; valva tongue-like, sacculus with a process at base. Juxta well developed. Female genitalia (Fig. 52): Papilla analis broad; apophysis anterioris longer than apophysis posterioris; ostium membranous; ductus short, Signum absent. Material examined. 43, 3 Ƥ, Nanling National Nature Reserve, Guangdong, 20.IV. 2009; 2 Ƥ, same locality, 7.V. 2009; Distribution. China (Beijing, Shanxi, Zhejiang, Sichuan, Fujian, Hunan, Yunnan, Guangdong). Remarks. Externally the female somewhat resembles those of E. piperita (Oberthur), but is separated from the latter by lacking a signum.Published as part of Wang, Houshuai, Wang, Min & Fan, Xiaoling, 2011, Notes on the tribe Nygmiini (Lepidoptera: Erebidae: Lymantriinae) from Nanling National Nature Reserve, with description of a new species, pp. 57-68 in Zootaxa 2887 on pages 66-67, DOI: 10.5281/zenodo.20082

Arna bipunctapex Hampson 1891

Arna bipunctapex (Hampson, 1891) (Figs. 1–2, 27, 41) Somena bipunctapex Hampson, 1891: 57. Artaxa bipunctapex: Kirby, 1892: 453. Aroa bipunctapex: Swinboe, 1892: 191. Euproctis bipunctapex: Hampson, 1892: 484; Holloway, 1976: 46; Chao, 2003: 423. Nygmia bipunctapex: Swinhoe, 1922: 483. Arna bipunctapex: Holloway, 1999: 48. Diagnosis. Forewing length 12–16 mm. Forewing brown, a yellow patch at the apex and tornus respectively, apical patch with two black spots; hindwing brown with a yellow margin and fringes. Male genitalia (Fig. 27): Uncus broad, apically divided in the dorso-ventral plane, acute at apex of dorsal part; valva narrowed from apex of sacculus to costa, costa protruded apically; saccus small, triangular; aedeagus small, slender. Female genitalia (Fig. 41): Ostium U-shaped; ductus short, sclerotized basally; bursa without signum. Material examined. 23, 1 Ƥ, Nanling National Nature Reserve, Guangdong, 13.VI. 2007. Distribution. China (Jiangsu, Henan, Shanxi, Shanghai, Zhejiang, Hubei, Sichuan, Xizang, Fujian, Jiangxi, Hunan, Guangdong, Guangxi, Yunnan, Hainan, Hong Kong, Taiwan), Japan, Thailand, Nepal, India, Malaysia, Indonesia. Remarks. Holloway (1999) reviewed this species and provided more detailed information.Published as part of Wang, Houshuai, Wang, Min & Fan, Xiaoling, 2011, Notes on the tribe Nygmiini (Lepidoptera: Erebidae: Lymantriinae) from Nanling National Nature Reserve, with description of a new species, pp. 57-68 in Zootaxa 2887 on pages 57-58, DOI: 10.5281/zenodo.20082

Artaxa digramma Boisduval 1844

Artaxa digramma (Boisduval, 1844) (Figs. 12, 33) Bombyx digramma Boisduval, 1844: 508. Artaxa sastra Moore, 1859: 351. Euproctis digramma: Hampson, 1892: 477; Chao, 2003: 406. Nygmia digramma: Swinhoe, 1922: 484. Artaxa digramma: Holloway, 1999: 60. Diagnosis. Forewing length 16 mm. Forewing yellow with two pale transverse lines medially, shaded grayish at middle of dorsum,apex with black spots; hindwing paler than the forewing. Male genitalia (Fig. 33): Uncus short, rather triangular, with a pair of acute processes on the lateral side; valva simple, tapering, slightly rounded apically; saccus triangular; aedeagus short, straight, with an unadorned vesica. Material examined. 13, Nanling National Nature Reserve, Guangdong, 31.IV. 2006. Distribution. China (Jiangxi, Guangdong, Guangxi, Hainan), Burma, India, Malaysia, Indonesia. Remarks: The species was reviewed by Holloway (1999).Published as part of Wang, Houshuai, Wang, Min & Fan, Xiaoling, 2011, Notes on the tribe Nygmiini (Lepidoptera: Erebidae: Lymantriinae) from Nanling National Nature Reserve, with description of a new species, pp. 57-68 in Zootaxa 2887 on pages 62-63, DOI: 10.5281/zenodo.20082

Somena scintillans Walker 1856

Somena scintillans Walker, 1856 (Figs. 5–6, 29, 43) Somena scintillans Walker, 1856: 1734. Artaxa scintillans: Butler, 1881: 52. Euproctis scintillans: Hampson, 1892: 483. Nygmia scintillans: Swinhoe, 1923: 49. Prothesia scintillans: Strand, 1933: 333. [Porthesia kurosawai: Chao 2003: 317.] Misidentification Diagnosis. Forewing length 12–17 mm. Forewing reddish brown with a yellow irregular border in male, and a yellow patch at apex, central termen and dorsum respectively in female. Male genitalia (Fig. 29): Uncus broad, weakly bifid. valva divided in the distal half, the dorsal arm broad, the ventral arm slender, acute apically; saccus triangular; aedeagus simple, vesica unadorned. Female genitalia (Fig. 43): Papilla analis small; ductus short, cylindrical, sclerotized; bursa long, sausage-shaped, with a bicornute signum. Material examined. 33, Nanling National Nature Reserve, Guangdong, 6.V. 2006; 1 Ƥ, same locality, 31.IV. 2008. Distribution. China (Hebei, Jiangsu, Anhui, Zhejiang, Hubei, Sichuan, Fujian, Hunan, Guangdong, Guangxi, Hainan, Taiwan), Korea, Japan, Nepal, India, Sri Lanka. Remarks. Strand (1933) regarded the species as typical of Porthesia Stephens. However, Porthesia has been confirmed by Maes (1984) as an invalid genus. P. k u ro s a w a i Inoue reported by Chao (2003) from Guangxi Province in China is actually Somena scintillans, based on the adults and male genitalia.Published as part of Wang, Houshuai, Wang, Min & Fan, Xiaoling, 2011, Notes on the tribe Nygmiini (Lepidoptera: Erebidae: Lymantriinae) from Nanling National Nature Reserve, with description of a new species, pp. 57-68 in Zootaxa 2887 on pages 58-59, DOI: 10.5281/zenodo.20082

Nygmia uniformis Moore 1879

Nygmia uniformis (Moore, 1879) (Figs. 15–16, 35, 47) Chaerotricha uniformis Moore, 1879: 49. Nygmia uniformis: Kirby, 1892: 449. Euproctis uniformis: Hampson, 1892: 483; Kishida, 1993: 85; Chao, 2003: 350. Diagnosis. Forewing length 19–29 mm. Forewing brown, with scattered black scales, fringes yellow; hindwing dark at basal half, yellow at apical half. Male genitalia (Fig. 35): Uncus broad basally, hooked apically; valva deeply bifid, dorsal part broader, somewhat rectangular, ventral part small, acute at apex; aedeagus with a L-shaped spur medially and a patch of spines in vesica. Female genitalia (Fig. 47): The eighth segment narrow; ostium relatively large; ductus long, sclerotized at base; signum with a longitudinal flange medially. Material examined. 2 Ƥ, Nanling National Nature Reserve, Guangdong, 25.III.2005. 13, same locality, 28.IV. 2009. Distribution. China (Guangdong, Yunnan, Hainan), India, Nepal. Remarks. The species is close to Nygmia poppaea Collenette and N. venata Collenette illustrated by Holloway (1999) in male genitalia characters, but it can be easily differentiated from the latter two by the forewing lacking the broken black fasciae and male genitalia with a smaller aedeagus vesica. It can also be separated from N. poppaea by the shorter ventral part of valva, and from N. venata by the dorsal part of valva without a protrusion at the apex. Female genitalia are illustrated here for the first time.Published as part of Wang, Houshuai, Wang, Min & Fan, Xiaoling, 2011, Notes on the tribe Nygmiini (Lepidoptera: Erebidae: Lymantriinae) from Nanling National Nature Reserve, with description of a new species, pp. 57-68 in Zootaxa 2887 on page 63, DOI: 10.5281/zenodo.20082

Artaxa angulata Matsumura 1927, comb. nov.

Artaxa angulata (Matsumura, 1927) comb. nov. (Figs. 9–10, 31, 45) Euproctis angulata Matsumura, 1927: 40; Chao, 2003: 402. Diagnosis. Forewing length 14–20 mm. Forewing yellow with two narrow, paler lines medially and forming a fuscous medial transverse band, the submarginal area with three black spots, two being at apex, and one near tornus. Male genitalia (Fig. 31): uncus short, with a pair of acute processes on the lateral side; valva simple, tapering, acute at apex; saccus triangular; aedeagus short, straight. Female genitalia (Fig. 45): Sterigma irregular, protruded at both sides; ductus and bursa relatively small, flimsy, the latter without signum. Material examined. 63, 2 Ƥ, Nanling National Nature Reserve, Guangdong, 29.VII.2008. 23, 1 Ƥ, same locality, 23.VI. 2009; Distribution. China (Zhejiang, Fujian, Hunan, Guangdong, Guangxi, Sichuan, Yunnan, Shanxi, Taiwan), Burma, India, Pakistan, Sri Lanka, Malaysia, Singapore, Indonesia. Remarks. The species is transferred to Artaxa Walker based on the uncus being flanked by a pair of acute processes, which is a typical feature of this genus. It is closely related to Euproctis sakaguchii Matsumura (Fig. 11, 32), but can be distinguished by the forewing with a black tornal spot and valva round apically.Published as part of Wang, Houshuai, Wang, Min & Fan, Xiaoling, 2011, Notes on the tribe Nygmiini (Lepidoptera: Erebidae: Lymantriinae) from Nanling National Nature Reserve, with description of a new species, pp. 57-68 in Zootaxa 2887 on pages 59-60, DOI: 10.5281/zenodo.20082

Toxoproctis croceola Strand 1918, comb. nov.

Toxoproctis croceola (Strand, 1918) comb. nov. (Figs. 13–14, 34, 46) Euproctis croceola Strand, 1918: 345; Matsumur, 1933: 125; Chao, 2003: 428. Euproctis crocea Wileman, 1910: 247. Diagnosis. Forewing length 14–17 mm. Forewing yellow with a dark spot at upper angle of cell, and one or two dark subapical spots and tornal spots, a dark oblique band between lower angle of cell and middle of dorsum. Male genitalia (Fig. 34): Uncus broad basally, apex slightly forked; valva rather square; juxta concave on dorsal margin; saccus moderate; aedeagus with a longitudinal bundle of spines. Female genitalia (Fig. 46): Apophysis anterioris longer than apophysis posterioris; sterigma sclerotized, M-shaped; ductus long, membranous; bursa pyriform, with a transverse flange-like signum. Material examined. 13, 1 Ƥ, Nanling National Nature Reserve, Guangdong, 7.VIII. 2006; 23, 4 Ƥ, same locality, 29.VII. 2008. Distribution. China (Guangdong, Yunnan, Taiwan). Remarks. The species was previously placed in the genus Euproctis Hübner. It is now assigned to the genus Toxoproctis Holloway according to the following genitalia characters: male with a broad uncus, valva rather square and juxta concave on dorsal margin; female with a transverse flange-like signum within bursa.Published as part of Wang, Houshuai, Wang, Min & Fan, Xiaoling, 2011, Notes on the tribe Nygmiini (Lepidoptera: Erebidae: Lymantriinae) from Nanling National Nature Reserve, with description of a new species, pp. 57-68 in Zootaxa 2887 on page 63, DOI: 10.5281/zenodo.20082