Type host: Pseudacris strecker Wright and Wright, 1933, Strecker's chorus frog.

Other hosts: Pseudacris illinoensis Smith, 1951, Illinois chorus frog.

Type locality: NORTH AMERICA: U.S.A., Texas, Dallas County.

Geographic distribution: NORTH AMERICA: U.S.A., Arkansas, Texas.

Description of oocyst: Oocyst shape: spheroidal, rarely subspheroidal; number of walls: 1; wall thickness: ~0.6; wall characteristics: smooth; L x W: 15.8 x 15.7 (13-17 x 13-17); L/W ratio: 1.0 (1.0-1.1); M: absent; OR: absent; PG: absent. Distinctive features of oocyst: none.

Description of sporocysts and sporozoite: Sporocyst shape: spindle-shaped and pointed at both ends; L x W: 13.5 x 8.0 (11-15 x 7-10); L/W ratio: 1.7 (1.5-1.8); SB: present as a large thickening at 1 pointed end; SSB: absent; PSB: not described, although the end opposite of the SB tapers markedly; SR: present; SR characteristics: numerous coarse granules scattered among the SZ; SZ: elongate, 11.9 x 2.4 (10-14 x 2-3) in situ, each with 2 RBs; anterior RB spheroidal, 1.8 (1-2); posterior RB slightly larger, also spheroidal, 2.0 (1-3); N indistinct, located between the 2 RBs. Distinctive features of sporocysts: distinct spindle-shape, pointed at both ends, resembling the oocysts of Monocystis species from earthworms.

Prevalence: 5 of 34 (15%) in type host; 1 of 8 (12.5%) in adult P. illinoensis.

Sporulation: Presumably exogenous.

Prepatent and patent periods: Unknown.

Site of infection: Unknown, but see Remarks.

Endogenous development: Unknown.

Materials deposited: None.

Remarks: Only I. wenyoni has oocysts that are similar in size to those of this species. They differ, however, in that those of I. delicatus are more spheroidal and have larger sporocysts. Also, no other species of Isospora from an anuran has such spindle-shaped sporocysts. Although Upton and McAllister (1988) reported the site of infection for this species as the intestine, the oocysts were recovered from the feces and no attempt was made to check what organs were infected with I. delicatus; therefore, the site of infection of this species is unknown.