Lasius talpa

Identification
Best distinguished by its very hairy, small-eyed worker caste.


 * Key to Palaearctic Lasius workers
 * Key to Lasius queens, males

Distribution based on Regional Taxon Lists
Oriental Region: India, Pakistan. Palaearctic Region: Democratic Peoples Republic of Korea, Japan, Republic of Korea.

It is also found in the Republic of Korea and China.

Biology
Dr. W. L. Brown has supplied me with field notes on his Chinese collection. Miao T'ai Tze is located in the Tsinling Shan at an elevation of over 6000 feet. The colony was situated in a small rotting stump on a steep slope in moist, mixed fir-hardwood forest (Liquidambar, Acer, and bamboos prominent) about 200 feet above the town. A large colony of Lasius flavus was found under a stone about 400 feet higher in a forest clearing. It is conceivable that Lasius talpa is the ecological equivalent of the North American species Lasius nearcticus in that it may tend to replace flavus in moister, more densely wooded situations. (Wilson 1955)

Nomenclature

 *  talpa. Lasius (Cautolasius) talpa Wilson, 1955a: 136 (w.q.m.) JAPAN. Imai, 1966: 119 (k.). See also: Yamauchi, 1997: 162; Collingwood, 1982: 291.

Worker
(1) Monomorphic to feebly polymorphic. Head shape similar to Lasius nearcticus, sub quadrate with widely spaced mandibles.

(2). Eyes very small, usually with only 6-12 ommatidia and a recorded maximum of 17 (Miao T'ai Tze).

(3) Numerous erect hairs on the scape along the plane of count standing out above the combined ground pubescence and subdecumbent to erect hairs of intermediate length. Standing hairs also abundant on the tibiae. Standing body pilosity in general denser than in other Cautolasius.

PW range 0.38-0.60 mm.; maximum intranidal PW range 0.38-0.51 mm. (Yasu) and 0.50-0.60 mm. (Hirooka III-8-1936). SI-HW regression zone high, at lower limit of northern Eurasian Lasius flavus zone (q.v.) and below that of nearcticus. Dentition similar in variation to that of flavus of comparable size; typically two basal teeth and occasionally a third intercalary one; the second intercalary tooth .often dropping out. Terminal segments of maxillary palp apparently varying as in Lasius fallax. The Hirooka III-8-1936 series contains some workers with VI equalling V and some with VI exceeding V, while all of the Yasu workers have VI exceeding V. Petiole always showing some degree of emargination, although this tends to be feeble in small specimens. Cephalic pubescence as dense as in extreme nearcticus. Body and appendages uniformly medium yellow.

Queen
(1) Best distinguished from other Cautolasius species by the presence of numerous standing hairs on the scape.

(2) Possibly averaging smaller than other Cautolasius species: three queens from the holotype nest series have HW's of 1.33, 1.35, and 1.35 mm. respectively.

(3) Body uniformly light brown, overall lighter than in other members of the subgenus.

Male
Lacking a dependable pilosity character; at most two or three erect hairs can be seen on the outer femoral surfaces, a condition probably overlapped by nearcticus. The mandibles may have a distinctive shape: the one perfect specimen I have examined, from the holotype nest series, had the masticatory border smooth, concave, and terminating in a sharply angular basal corner, which condition has been encountered elsewhere only in the highly variable flavus mandible.

Parameres and volsellae resembling those of other Cautolasius. Subgenital plate sub quadrate, with a single prominent posterior setiferous lobe; posterolateral flanges drawn out laterally and very thin and acute.

Type Material
HOLOTYPE. A worker in the Okamoto Collection selected from a series collected at Hirooka, Shikoku, on July 23, 1946, with associated queens and males (H. Okamoto leg.). Paranidotype workers, queen, and male in Okamoto Coll. and.