Antheromorpha festiva ( Broelemann , 1896)

Likhitrakarn, Natdanai, I. Golovatch, Sergei, Semenyuk, Irina & Panha, Somsak, 2019, A new species and a new record of the Southeast Asian millipede genus Antheromorpha Jeekel, 1968 (Polydesmida, Paradoxosomatidae) from Vietnam, ZooKeys 832, pp. 77-89 : 79

Antheromorpha festiva ( Broelemann, 1896) Fig. 1

Orthomorpha festiva Brölemann, 1896: 1 (D).

Orthomorpha festiva : Attems 1898: 339 (M); 1914: 194 (D); 1930: 131 (D); Brölemann 1904: 4 (D, R).

Orthomorpha (Orthomorpha) festiva : Attems 1936: 199 (M); 1937: 60 (D).

" Orthomorpha " festiva Jeekel, 1963: 269 (M).

Antheromorpha festiva Jeekel, 1968: 57 (M); 1980: 85 (M); Golovatch 1983: 181 (M); Enghoff et al. 2004: 37 (M); Enghoff 2005: 95 (R); Nguyen and Sierwald 2013: 1234 (M); Likhitrakarn et al. 2016: 45 (D); Nguyen et al. 2018: 98 (D, R).

Material examined.

3 ♂ (ZMUM), Vietnam, Dong Nai Province, Cat Tien National Park, 11°25'37"N, 107°25'39"E, 140 m a.s.l., secondary monsoon lowland forest with dominating Lagerstroemia calyculata , on forest floor, 10.V.2015; 1 ♂ (ZMUM), same locality, on ground road in grasslands, 11°24'20"N, 107°24'17"E, 120 m a.s.l., 14.XI.2014, all leg. I Semenyuk.

Remarks.

The new specimens fully agree with the detailed and beautifully illustrated redescriptions of the species as given by Brölemann (1904) and Likhitrakarn et al. (2016). This is the first formal record of A. festiva in Cat Tien National Park. In that park, A. festiva shows a pronounced seasonal rhythm. According to several years of observation by one of us (IS), juveniles of different stages (from the 4th to the last instar) start swarming in the autumn, just before the dry season. Swarms contain hundreds of millipedes slowly moving around and feeding. One swarm patch usually contains mainly same-age individuals (Fig. 1). Even though swarms of different instars may appear next to each other, they normally do not mix. Patches of swarming are usually localized in secondary forest with dominating bamboo and in grasslands. Swarms of individuals of the latest instars are looser than those of earlier stages. Adults appear during the same season, but do not swarm. In the dry season, the abundance of A. festiva abruptly declines and then, in the early rainy season in summer, it gradually grows again to abruptly stop in the middle of the rainy season.