448 



PSYCHE. 



[May 1S93. 



appendages. Fig. z,f to n inclusive 

 represent the right wing cover, showing 

 the great variation in size {f and^) and 

 in coloration^ to ?i inclusive). The 

 wing covers from which_/" and g were 

 drawn measure 1.2 mm. and 2 mm. 

 respectively, so that the smallest beetles 

 are scarcely more than one-half as large 

 as the largest. The wing covers were 

 all drawn with a camera lucida using 

 the same power of the microscope in 

 each case. No attempt was made to 

 represent the pubescence or striae. I 

 simply desired to bring out the gradual 

 change from a wing cover which is of 

 a plain rufous color as at ^to one which 

 has the rufous color almost entirely re- 

 placed by black with small whitish 

 spots as at n. A longer series might 

 have been taken in which the encroach- 

 ment of the black upon the rufous would 

 have been more gradual, but the eight 

 forms shown will serve the purpose. In 

 fact, every gradation exists in nature 

 between^ and n. Forms similar to / 

 and ?n are the most numerous. 



Soon after receiving the beetles I be- 

 gan experiments to study their habits 

 and life history. Many beetles were con- 

 fined among dry peas, beans, and corn. 

 Egg laying soon began on all the seeds. 

 The egg, figure 2, b, is oval in shape 

 with flattened base, and is of a bright 

 shining lemon yellow color. It is .6 

 mm. in length, .4 mm. wide, and .2 

 mm. thick. Each egg is firmly glued 

 to the outside of the seed (not deposited 

 in the seed as stated in "Insect life") 

 by a thin sheet of transparent substance 

 which extends beyond the egg as 

 shown in the figure. Sometimes fif- 



teen or twenty eggs are laid on a single 

 seed, and I have seen a pea from which 

 as many beetles have emerged. 



The eggs hatched at this season in 

 from thirteen to twenty days. Several 

 days before hatching the brown heads 

 of the larva can be distinctly seen through 

 the shell, and the whole egg assumes an 

 opaque creamish white color. In es- 

 caping from the egg, the larva invaria- 

 bly eats a round hole through one end 

 of the shell where it is in contact with 

 the seed, leaving the visible portion of 

 the shell intact. Figure 2, c represents 

 the basal aspect of an egg, showing the 

 manner of escape of the larva. The 

 larvae bore directly from the egg into 

 the seed. 



The newly hatched larva resembles 

 somewhat that of obtectus shown in 

 fig. 1, c, but more closely that of fiisi 

 figured in "Insect life," v, 205. It 

 differs in the form of its thoracic arma- 

 ture from either, and its legs (fig. 2, d) 

 are one-third shorter than those of obtec- 

 tus and resemble those of pisi in form. 

 Soon after entering the seed the larvae 

 moult and lose their legs, hairs, and 

 thoracic shield. When mature the lar- 

 vae are very similar to those of obtectus 

 (fig. 1, d) in size, shape, and color. 

 Larvae in all stages after the first may 

 be easily separated from those of obtec- 

 tus, however, by a glance at the cepha- 

 lic margin of the front of the head. 

 The front is of a dark brown color for 

 a considerable distance caudad as shown 

 ate, fig. 2 (compare fig. 1, c of obtectus). 

 Larvae are at present feeding in the 

 seeds of peas, corn, and beans. 



In December, 1S92, I confined sev- 



