Antkey

ID guide | introduced ants

Pheidole parva

General description: 

Pheidole parva is a very small dark species that is thus far restricted to Asia, a few localities in Arabia, and the islands of the Indian Ocean and the Pacific Ocean. The minor workers are completely covered in punctate sculpture and are difficult to differentiate from those of the Neotropical P. flavens complex. The similarity is entirely convergent, as these lineages are distantly related. The major workers are characterized by a defined and moderately depressed antennal scrobe and a thick network of reticulated rugulae on the posterior lobes. Little is known about the biology of P. parva, but it does appear to be expanding its range and is worth monitoring for in the future as it exhibits a high tolerance for disturbance. Eguchi (2008) observed that the species seems to inhabit open lands and forest edges, and has probably expanded its range in some part as the result of human commerce. Pheidole parva was one of the most commonly collected ants in a study myrmecological study of agricultural fields in Vietnam, and was found co-occurring with many non-native species (Anh et al. 2010). A recent study of 18 structure invading pest ants of healthcare facilities in Singapore found P. parva the most frequently encountered species (Man and Lee 2012). Pheidole parva and Pheidole megacephala were the two most common ant species encountered and together accounted for over 50% of the total collection (25.9% and 25.2%, respectively). 

  • Anh LN, Ogata K,  Hosoishi S (2010) Ants of Agricultural Fields in Vietnam (Hymenoptera: Formicinae). Bulletin of the Institute of Tropical Agriculture Kyushu University 33: 1-1 
  • Eguchi K (2008) A revision of Northern Vietnamese species of the ant genus Pheidole (Insecta: Hymenoptera: Formicidae: Myrmicinae). Zootaxa 1902: 1-118
  • Man LS,  Lee CY (2012) Structure-invading pest ants in healthcare facilities in Singapore. 59: 241-249
Diagnostic description: 

Diagnosis among introduced Pheidole. Yellowish brown to dark brown. Major | HW 0.85–0.92, HL 0.96–1.07, SL 0.41–0.45, CI 85–92, SI 45–51 (n=11, Eguchi et al. 2007). Head rectangular. Posterolateral lobes, including posterior head margin, covered in rugoreticulum. Antennal scrobes indistinct to moderately impressed, but frontal carinae always forming a border capable of accepting the antennal scape. Promesonotum in profile forming a single dome, lacking a distinct mound or prominence on the posterior slope. Promesonotum in dorsal view transverse with strongly projecting shoulders. Promesonotal dorsum rugoreticulate with distinct long longitudinal striae in addition to shorter sections of transverse and intersecting striae. Postpetiole not swollen relative to petiole. Minor | HW 0.39–0.50, HL 0.43–0.54, SL 0.38–0.46, CI 88–94, SI 84–102 (n=17, Eguchi et al. 2007). Posterior portion of head with many short to medium length segments of striae distinctly interlaced among punctate ground sculpture. Antennal scapes with erect to suberect hairs; scapes do not surpass posterior head margin. Promesonotum in profile forming a single dome, lacking a distinct mound or prominence on the posterior slope . Pronotal humeri angular. Hairs on mesosoma fine, flexuous, of unequal length and not arranged in pairs. Postpetiole not swollen relative to petiole; postpetiole narrow in dorsal view, only slightly broader than petiole.

Distribution: 

Pheidole parva is considered here as native to the Indo-Malay region. The species is recorded from the Asian mainland from India east to China. We consider the records from Indonesia, Borneo, the Philippines and Taiwan to be native, but much of this distribution could represent a more recent anthropogenic expansion.

The species is certainly introduced in the Seychelles and Mauritius. A population has become established in Saudi Arabia where it was collected in date tree orchards and banana plantations. We consider the records from the Okinawa and Kagoshima prefectures of Japan to be introduced along with the records from Palau to represent introduced populations, but it is difficult to know whether the species arrived in these islands before, with or after the arrival of humans.

Pheidole parva was also collected from hothouses in Austria and Germany.  

Taxonomic name: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith