Omicron aridum Carpenter and Genaro, 2011

Genaro, Julio A., 2011, Vespidae (Insecta: Hymenoptera) of Puerto Rico, West Indies, Insecta Mundi 2011 (202), pp. 1-35 : 9-10

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Omicron aridum Carpenter and Genaro

new species

Omicron aridum Carpenter and Genaro , new species

( Fig. 43 View Figure 41-43 , 44A View Figures 44 �H)

DIAGNOSIS. The new species fails at couplet 29 of Giordani Soika’s (1978) key, coming closest to O. procellosum (Zavattari) , which is known from Colombia and Venezuela. The male has the last anten� nal article robust, with the apex reaching base of article 11 when folded, as in O. procellosum , not as in O. furiosum Giordani Soika , which keys as the alternative. The female has the clypeus moderately emarginate, with the emargination deeper than in O. procellosum , however it is not as broad as the width of the interantennal space. The emargination in O. furiosum is shallower than in O. procellosum .

DESCRIPTION. Female: holotype forewing length 7 mm. Structure � punctation of frons and mesosoma dense; vertex and tempora smooth; clypeus about as long as wide, moderately emarginate, with punc� tures small, superficial, sparse; pronotum with punctation largely absent just behind carina; scutum and lower part of mesepisternum regularly convex, with punctation uniform; scutellum weakly convex, with median impressed longitudinal line, coarsely punctate; metanotum with punctation more superfi� cial than that of scutellum; metasomal terga I�II and sternum II smooth, shiny, with small, scattered, nearly invisible punctures; tergum I narrow, more than three times as long as wide apically; tergum II conspicuously convex.

Color � black with yellow and reddish markings; yellow are two obscure spots dorsally on clypeus, interanntennal spot, spots in ocular emarginations, tempora, anterior and posterior borders of pronotum, dorsal spots on mesepisternum, parategula, anterior border of scutellum, metanotum, propodeum later� ally, apical fascia on metasomal terga I�II and partly developed on sternum II; pronotum, mesepister� num and propodeum tinged with reddish, tergum and sternum I extensively reddish; scape, pedicel and base of flagellum reddish brown; mandibles dark reddish brown apically; legs and metasoma becoming brownish apically; tegula brown; wings hyaline, forewing infuscate anteriorly, veins and pterostigma dark brown ( Fig. 43 View Figure 41-43 ).

Vestiture � short, silvery setae, longer on propodeum, dense tomentum dorsolaterally on clypeus, frons, gena, mespisternum and coxae, sparser tomentum on metasoma.

Male: last antennal article large, thick, not strongly arcuate, apex sharply pointed ventrally, reach� ing base of article 11 when antennal hook folded; clypeus yellow along dorsal margin.

Variation: many females have the clypeus entirely black, without yellow spots. Some of them have most of the clypeus covered with dense tomentum, indicating that the holotype has the clypeus rubbed. Some males have yellow spots on the femora and tibia.

DISTRIBUTION. Known only from Puerto Rico, occurring in the arid areas of the south.

TYPE MATERIAL. ♀ holotype Puerto Rico: Boquerón , 18°02’09”N 67°10’31”W, 28 Nov. 2008, 12 m (J. Carpenter & A. Davidson) [deposited in AMNH]. Paratypes: ♀ ♂ paratypes same label data GoogleMaps ; 5 ♀♀ 6 ♂♂ Guayanilla, Ventana , 6 Aug. 2005 (J. A. Genaro) ; 3 ♀♀ 3 ♂♂ same locality, Aug. 2005 (J. A. Genaro and A. Pérez-Asso) ; ♂ same locality, 7 June 2007 (Amador López) ; ♀ same locality, 10 Nov. 2007 (J. A. Genaro) ; ♀ ♂ Ponce, Central Mercedita , 6 Aug. 2005 (J. A. Genaro) ; ♀ Ponce, Guayanilla, May 2006 (J. A. Genaro) ; ♀ Coto Laurel, Real Anan, Carretera 511 Km 9.5, Ponce, May 2008 (J. A. Genaro) ; 2 ♂ Boquerón, near Punta Melones , 1 Nov. 2008 (J. A. Genaro) ; 2 ♀♀ 13 ♂♂ Guánica, Rta. 333, 17°56’55”N 66°52’36”W, 22-28 Nov. 2008, 50 m (J. Carpenter & A. Davidson) GoogleMaps ; 6 ♀♀ 9 ♂♂ La Parguera, 17°58’41”N 67°03’06”W, 24 Nov. 2008, 17 m (J. Carpenter & A. Davidson); 2 ♂♂ Guayanilla, Boca , 17°58’00”N 66°48’34”W, 25 Nov. 2008, 1 m (J. Carpenter & A. Davidson) GoogleMaps ; ♀ 6 ♂♂ Peñones de Melones , 18°00’06”N 67°11’25”W, 29 Nov. 2008, 31 m (J. Carpenter & A. Davidson) GoogleMaps ; 4 ♀♀ 6 ♂♂ El Combate, Rta. 330, 17°58’46”N 67°11’37”W, 29 Nov. 2008, 5 m (J. Carpenter & A. Davidson) GoogleMaps ; Rta. 511 N Coto Laurel, 18°06’49”N 66°34’37”W, 2 Dec. 2008, 237 m (J. Carpenter & A. Davidson) [all AMNH] GoogleMaps .

Additional specimens, not paratypes: Guayanilla, Loma Ventana , 23 Apr. 2008 (J. A. Genaro) [ JAGA] ; ♀ Campo Santiago, Salinas, Aug. 2010 (A. Sánchez) [ JAGA] ; ♀ La Rita , Ponce, Nov. 2010 (J. A. Genaro) [ JAGA] ; ♀ ♂ Lajas, laguna de Cartajena, 18°0040.28’’N 67°06’10.23’’W, 10 m (Biol. 4446SN and N. Franz) [ UPRM] .

ETYMOLOGY. From the Spanish word for arid, dry.

NESTING BEHAVIOR AND ECOLOGY. Observations on nesting behavior were made in Ventana, Guayanilla (23 Apr. 2008; 24 Jan. 2009, 23 Feb. 2009); Real Anón, Coto Laurel, Ponce (5 Sept. 2010) and La Rita, Ponce (25 Nov. 2010).

The species was observed commonly in dry areas ( Fig. 44A and B View Figures 44 ). Females constructed the nests between 18� 63 cm above ground, consisting of one to three cells ( Fig. 44C, E View Figures 44 �H). Nests were attached to plant stems ( Fig. 44F View Figures 44 ), concealed among spines of the cactus Pilosocereus royenii (L.) Byles and Rowley ( Fig. 44E View Figures 44 ), or in altered habitats including the screen of a greenhouse ( Fig. 44G View Figures 44 ) and a PVC plastic tube for water consumption ( Fig. 44H View Figures 44 ). One columnar cactus had 13 nests attached to its spines. All cells were pear�shaped, and lacked partitions. Females provisioned with Microlepidoptera larvae ( Fig. 44D View Figures 44 ). Open cells contained prey and small larvae, while closed cells contained pupae. One nest contained a small wasp larva and eight larvae belonging to two unidentified Microlepidoptera species (mean length= 3.80 mm; SD= 0.64; range: 3.00�4.10 mm). Some prey showed slight movements.

Dimensions of 14 nests: length, 6.90�8.92 mm (x=7.51 mm, SD=0.62); greatest width, 4.31�5.0 mm (x=4.80 mm, SD=0.27).


American Museum of Natural History


University of Puerto Rico at Mayagueez, Rhizobium Culture Collection