Pericnemis melansoni sp. nov., a new damselfly (Odonata: Coenagrionidae) from Compostela Valley Province, Mindanao Island, Philippines

Villanueva (2012) reviewed the Philippine members of the genus Amphicnemis. All species were transferred to three newly established genera, or moved into the genus Pericnemis. In the present sense, five named species are currently recognized as members of the genus Pericnemis in the Philippine archipelago. The island of Mindanao has one known species of Pericnemis, Pericnemis lestoides (Brauer, 1868). In addition, nearly a dozen species are still to be described from the island. During a short biodiversity survey in Cabalian Creek, Nabunturan, Compostela Valley Province conducted by the second and third authors, specimens of Pericnemis were collected. Voucher specimens were given to the first author who confirmed they represented a species new to science. Due to the urgency of establishing the known habitat of the present species as a protected area, it is described here in advance of a complete treatment of the Philippine Pericnemis. Materials and Methods All material was collected by the second and third authors. Measurements were made using calipers and on the left side of the specimen. Terminology generally follows Westfall & May (1996). The holotype and paratypes are all deposited in Father Melanson’s Museum of Natural History, Assumption College of Nabunturan, Nabunturan, Compostela Valley province, Mindanao Island, Philippines (ACN).

reviewed the Philippine members of the genus Amphicnemis.All species were transferred to three newly established genera, or moved into the genus Pericnemis.In the present sense, five named species are currently recognized as members of the genus Pericnemis in the Philippine archipelago.
The island of Mindanao has one known species of Pericnemis, Pericnemis lestoides (Brauer, 1868).In addition, nearly a dozen species are still to be described from the island.During a short biodiversity survey in Cabalian Creek, Nabunturan, Compostela Valley Province conducted by the second and third authors, specimens of Pericnemis were collected.Voucher specimens were given to the first author who confirmed they represented a species new to science.Due to the urgency of establishing the known habitat of the present species as a protected area, it is described here in advance of a complete treatment of the Philippine Pericnemis.

Materials and Methods
All material was collected by the second and third authors.Measurements were made using calipers and on the left side of the specimen.Terminology generally follows Westfall & May (1996) Paratypes: 6 males, 1 female, same data as holotype, ACN-2012-Odo-Coe-X001-6m/1f.

Diagnosis
This species is closest to Pericnemis lestoides among its known congeners in the Philippines.The male differs from that species in having a simple posterior lobe of the pronotum without a pointed middle portion, and in having the lower branches of the cerci longer than the upper branches; in P. lestoides both branches of the cerci are of similar length.The posterior pronotal lobe of the

Description of male
Labium and mandibles pale, a little darker on the apices of mandibles.Remainder of head black except for pale streaks as follows; around outer margin of the labrum; across anteclypeus; transverse streak across frons a little narrowed in the midline, around borders of genae and along anterior portion of scape and pedicle.
Thorax: Prothorax metallic green.Anterior lobe short and erect.Median lobe broad and dome shaped with broad shallow groove running across the lateral aspect.Posterior lobe (Figs.3-4) short and simple, its free margin rounded with unspecialized lateral corners.
Synthorax metallic green and pale laterally.Mesepisternum entirely metallic green.Mesinfraepisternum mostly metallic green.Mesepimeron metallic green except for pale posterior margin.Metepisternum pale except for metallic green patch adjacent to wing base.Metepimeron pale.Legs pale except for black spines, black streaks on extensor surface of femur, around joint of femur and tibia and on extensor surface of tibia.
Wings hyaline with black veins.Venation as for the genus, with 14 and 12 postnodals (Px) in fore wing and hind wing, respectively.R4 at subnodus.R3 situated just off subnodus, IR3 at Px8 and Px6 in forewing and hind wing, respectively.Pterostigma brown with pale margins, squarish with costal side a little shorter than subcostal side.

Female
Similar to male except for broad brownish streak on the outer margin of labrum and whitish streak along eye margins.Prothorax brown, blackish streaks on median pronotal lobe.Posterior pronotal lobe (Figs.5-6) sub-rectangular with middle part clearly separated from triangular lateral part.Synthorax tri-colored, mesepisternum dark metallic green, mesepimeron and posterior margin of mesepisternum orange, except for black streak on mesepimeron.Remainder of synthorax yellowish.Abdomen with S3-S6 black.
Variation: No notable variation evident except for the size of male paratypes which range from hind wing (mm): 24-28 and abdomen: 40-48.

Discussion
This species differs from most other Philippine Pericnemis, as yet undescribed by having a slender tubercle on the first segment of its genital ligula.This character is shared only with P. lestoides (see Villanueva 2012).
Pericnemis melansoni sp.nov. is the second described species of Pericnemis on the island of Mindanao.It is distinguished from its close relative P. lestoides (also found in Mindanao) in lacking an elongate posterior lobe of prothorax.In the present species, the lower branches of the cerci are longer than the upper branches whereas in P. lestoides the branches are of equal length.Lieftinck (1957) illustrated the female of P. lestoides which differs from the female of the present species by having more distinct middle and lateral parts on the posterior lobe of the prothorax.

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The holotype and paratypes are all deposited in Father Melanson's Museum of Natural History, Assumption College of Nabunturan, Nabunturan, Compostela Valley province, Mindanao Island, Philippines (ACN).