Mycetophylax strigatus

A nest of this species was discovered under the bark of a decaying tree.

Identification
See the description section below.

Distribution
Southeastern Brazil, from Rio Grande do Sul to Rio de Janeiro States.

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Biology
Kempf (1964) - According to Moeller (1941) this species resembles Cyphomyrmex auritus as regards the nest side and shape, and the cataleptic behavior of workers upon being disturbed. The fungus garden, however, is of a different aspect, consisting in an irregular agglomerate of small pellets of substrate, loosely heaped one upon another, as in Apterostigma wasmanni (=Apterostigma auriculatum) For. The mycelium shows the bromatia or gongylidia better differentiated than in that of auritus (cf. Moeller's figures 25 and 26). Yet auritus workers in artificial nests freely fed on strigatus fungus and viceversa. The sporophore of the fungus is not known, but seems to be a basidiomycete.

Luederwaldt (1926) discovered a nest under the bark of a decaying tree. The cavity was rounded-elongate, the fungus mass dirty yellowish and irregular in aspect. The colony consisted of approximately 30 workers.

Nomenclature

 *  strigatus. Cyphomyrmex strigatus Mayr, 1887: 558 (w.) BRAZIL. Forel, 1893e: 606 (q.m.); Wheeler, G.C. 1949: 669 (l.). See also: Kempf, 1964d: 14.

Worker
Kempf (1964) - Total length 2.9-3.7 mm; head length 0.75-0.89 mm; head width 0.67-0.80 mm; thorax length 0.91-1.17 mm; hind femur length 0.72-0.98 mm. Yellowish brown to dark ferruginous. Integument, including antennal scrobe, indistinctly granulate and opaque. Differs from auritus as follows 1. Smaller in size. Body more compact. Hind femur distinctly shorter than thorax length. 2. Auriculate occipital lobes (fig 6, 44) much less protruding, usually shorter than their maximum diameter. Supraocular tooth blunt and obtuse, lacking a distinct ridge between its base and the inferior occipital angle. Funicular segments 2-8 not longer than broad. 3. Lateral pronotal tubercles blunt and stout. Mesonotal armature (fig 18) relatively low, consisting of blunt tubercles. Longitudinal ridges on basal face of epinotum blunt, without a prominent tooth on posterior corner. Femora feebly marginate on flexor face. Hind femora gently and gradually thickening from base to basal third, where they form an obtuse, at most weakly carinate, angle on flexor face. 4. Petiolar node subquadrate, occasionally somewhat transverse, its anterior corners in dorsal view rounded; longitudinal crests on dorsum only vestigial. Postpetiole with anterior face moderately raised in vertical direction, anterior dorsal tubercles feeble, sides convex, somewhat constricted to slightly diverging behind: in dorsal view little to somewhat transverse. 5. Appressed hairs on frontal lobes, borders of frontal carinae, frontal and vertical ridges, thoracic tubercles, pedicelar tubercles and ridges, gaster, scapes and legs conspicuous and scale-like.

Queen
Kempf (1964) - Total length 4.0-4.3 mm; head length 0.93-0.96 mm; head width 0.83-0.91 mm; thorax length 1.23-1.36 mm; hind femur length 0.91-1.07 mm. Characters as given for the worker, with the same differences from auritus. Note the following: Lateral pronotal tubercles blunt and stout. Scutum and scutellum with shallower depressions and very low and blunt tuberosities. Epinotal tooth tubercular, small to vestigial. Scale-like hairs especially conspicuous on scutum and scutellum.

Type Material
Kempf (1964) - Worker, in the Mayr collection at the "Naturhistorisches Museum, Wien". Not seen.