Micrallo minutus St Laurent & C. Mielke

St. Laurent, Ryan A. & Mielke, Carlos G. C., 2016, Three new genera of Neotropical Mimallonidae (Lepidoptera, Mimallonoidea, Mimallonidae) with descriptions of three new species, ZooKeys 566, pp. 117-143 : 136-138

Taxon classification Animalia Lepidoptera Mimallonidae

Micrallo minutus St Laurent & C. Mielke sp. n. Figs 20-21, 22, 23, 24, 25

Type material.

Holotype, ♂: BRASIL: PI [ Piauí], Oeiras. 200 m, 12.iv.1994, V.O. Becker Col/ Col. Becker 92248/ USNM-Mimal: 2376/ St. Laurent diss.: 10-21-15:1/ DZ 32.730/ HOLOTYPE male Micrallo minutus St Laurent and C. Mielke, 2016 [handwritten red label]/ (ex. USNM, to be deposited in DZUP). Type locality: Brazil: Piauí: Oeiras.

Paratype, 1 ♀: BRAZIL: Piauí: Oeiras, 200 m: 12.IV.1994, V.O. Becker Col., Col. Becker 92248, USNM-Mimal: 2377, St. Laurent diss.: 10-21-15:2 (USNM). Paratype with the following yellow label: PARATYPE female Micrallo minutus St Laurent and C. Mielke, 2016.

Diagnosis.

See genus diagnosis.

Description.

See genus description.

Distribution

(Fig. 25). The unique species in the genus Micrallo is so far known only from the type locality at Oeiras, Piauí, Brazil. This location is interesting because it lies on the edge of both Cerrado and Caatinga biomes ( IBGE 2004).

Etymology.

Micrallo minutus is named for its minute (minutus Latin) size, making it one of the smallest described species in the family.

Remarks.

Due to the interesting habitat at the type locality of Micrallo minutus , it is not surprising that this taxon represents a previously undescribed species in a new genus. Both Caatinga and Cerrado biomes are incredibly undersampled (C. G. Mielke & R. A. St. Laurent pers. obs.), with the latter biome recently proven to support many new and endemic Mimallonidae species ( Herbin and Mielke 2014). As of yet, no study has been published to determine the degree of Mimallonidae endemism to Caatinga.

The highly specialized genitalia in both sexes are unique among Mimallonidae . The complicated male genitalia bear two pouches on either side of the semi-membranous valves that contain many thick, specialized setae that are prone to falling out when the genitalia are examined. The female, likewise has rather complicated genitalia for female Mimallonidae , and also has specialized pouches, one on each lateral side of the papillae anales. In the single available female specimen, the right (when viewed ventrally) pouch contained an abundance of the same setae, the pouch was so completely filled that many of the setae are extending outside the pouch. See Fig. 23 for the genitalia before extension of the final abdominal segment. After extension (Fig. 24), most of the setae were expelled from the pouch. Close examination shows that the female genitalia are not asymmetrical, but that the second pouch was simply never filled with setae, or if it did contain setae at one time, they were completely lost before our examination. It is possible that these setae have characteristics pertinent to copulation, although we are unable to determine their exact purpose. It is interesting that only one pouch was filled, suggesting that females of Micrallo minutus are capable of mating two or more times. Perhaps even more intriguing is the fact that males may be able to fill only one female pouch at a time, despite possessing two complimentary pouches of their own on either side of the genital capsule.