Mateeials, Their Taxonomy and Natural History 43 



Juvenile Stages. 



Eggs: Yellow, rarely lemon-yellow or yellowish white, laid on lower surface 

 of leaves, in bunches of 5 to 200. Length, 1.75 to 2.5 mm.; breadth, 0.75 to 

 1.35 mm. Concave on ventral side and attached to leaf by a stalk of greater or 

 less length composed of a coagulated gelatinous material which is extruded 

 ahead of eggs at laying. Development requires from 5 to 12 days, depending 

 upon external conditions. 



First larval stage : Head, pronotum, and legs black ; body yellow, with color- 

 pattern shown in plate 7, figure 10a. Tergal spots all with one or more spines. 

 Length at hatching, 2.25 mm. 



Second larval stage: Head, pronotum, and legs black; body yellow, with 

 single row of black spiracula spots (plate 7, fig. 10 &). Length, 4 to 7.5 mm. 



Third larval stage : Head, pronotum, and legs black ; body yellow, with two 

 rows of spots on pleurum, spiracula, and baso-pleural ; inner, middle, and outer 

 tergal spots present; more or less fused lateralward; frequently fused with 

 spiracula spots ; inner tergal always fused antero-posteriorly on each segment 

 (plate 7, fig. 10c). Length, 10 to 19 mm. Length of larval period varies with 

 meterological conditions, food, and the local race ; may be passed over in 15 

 days or prolonged to 40 or 50. In nature and in cultures it averages about 25 

 days. 



Pupa: Pupates in ground at foot of plant, from 0.5 to 5 inches deep, depend- 

 ing upon soil hardness, moisture, and air-supply. Pupal stage lasts from 10 to 

 30 days ; average 15 days. Of this period 25 per cent is passed in prepupal stage, 

 60 per cent as pupa, and 15 per cent as imago. Length of ontogeny from egg 

 laying to adult averages 40 days ; range 28 to 70 days. 



Geogbaphical Distribution. 

 (Plate 3.) 



Mexico, Stal, 1859, 1862 ; Gemminger et Harold, 1874 ; Jacoby, 1883 ; Tower, 

 1906. Eecorded from Izuca, Puebla, State of Puebla (Salle; Jacoby, 1883) ; 

 Cuernavaca, State of Morelos ; Aurula, Xucamanatlan, State of Guerrero (H. H. 

 Smith; Jacoby, 1883); Alarcon, Cuanutla, Jojutla, State of Morelos; Mata- 

 moros de Izucas, Atlixco, Tatetla, State of Puebla (Tower, 1896). 



The habitat of this species is confined to the upper portion of the eastern 

 and northern branches of the Rio Balsas, and in the main lives close to the foot 

 of the great Mexican escarpment (plate 23). I have not found it to extend 

 northwestward beyond the Rio Balsas Valley, eastward beyond the Rio Coetzala 

 Valley; neither does it reach an altitude of over 6000 feet, rarely above 5500 

 or below 4000. It is narrowly limited in range, and is also still more restricted 

 in its ecological relations. 



Source of Material. 



Of this species my chief source has been from localities near Cuernavaca, 

 Morelos, Mexico: (a) Rancho Basoco colony: Stock No. 418, obtained July 

 1903; No. 419, May 1904. (6) Quauhtemotzin colony: Stock No, 417, 

 obtained July 1903. (c) San Antonio colony: Stock No. 420, obtained May 

 1904; No. 421, July 1905 ; No. 422, June 1906. Other material has been used 

 at different times from near Atlixco and Matamoros in Puebla. The chief stock 

 location has been that at Rancho Basoco. 



