554 TRANS. ST. LOUIS ACAD. SCIENCE. 



become rudimentaiy and the body takes on more fully the clumsy 

 aspect of the typical Lamellicorn larva, for which reason I desig- 

 nate this as the Scarabceidoid stage of the second larva. 



Another six or seven days elapse and the scarabaeidoid skin is 

 rent and shed with but slight modification in the form and char- 

 acters of the animal.* In this, the Ultimate stage of the second 

 larva (PL V., Fig. 5) the creature grows apace, its head being 

 constantly bathed in the rich juices of the locust eggs, which it 

 now rapidly sucks or more or less completely devours. The color 

 is more yellowish than it was before, and the power to stretch 

 and travel on the venter on an even surface is still retained. In 

 another week it forsakes the remnants of the pabular mass, and, 

 by burrowing a short distance in the clear soil, avoids the deleteri- 

 ous decaying influences of these egg remnants. In the soil it forms 

 a smooth cavity, within which it lies stretched on one side, mo- 

 tionless and gradually contracting. The skin separates and 

 becomes loose at the end of the third or fourth day, when it splits 

 on the top of the head and thoracic joints and is worked toward 

 the extremity, but never fully shed. The mouth-parts and legs 

 are now quite rudimentary and tuberculous, the soft skin rapidly 

 becomes rigid and of a deeper yellow color, and we have what 

 has been called the semi-pupa (PI. V., Fig. 8). The term pseudo- 

 pupa given it by Fabre is more appropriate, and I should prefer 

 myself to call it the Coarctate Larva, for it is nothing but a rigid 

 and dormant larval stage, having its counterpart in the well- 

 known ''flaxseed" stage of the Hessian-fly larva and in the so-called 

 coarctate pupa of the Diptera generally. A similar dormant but 

 less rigid larval stage occurs with many Tenthredinidae in Fly- 

 menoptera, and, in fact, the summer dormancy of certain Lepi- 

 dopterous larvae and the winter dormancy of others is analogous. 

 We find something similar, therefore, in all the Orders undergo- 

 ing complete transformations, but in no insects is the change so 

 marked and exceptional or the freeing of the subsequent larva 

 from the coarctate larva so striking as in these Meloidae. The 



* None of the observers of Meloe or Sitaris mention the two molts which the second larva 

 undergoes, though these doubtless occur in those genera as they do in Epicauta- Only by 

 the most careful watching from day to day of a number of specimens have I been able to 

 observe these molts ; for the exuviae are generally devoured as soon as they are cast, and this 

 fact doubtless accounts for their not having been observed in the two genera first men- 

 tioned. 



