^O PSYCHE [February 



35. Chauliodes rastricorfiis Rambur. Larvae of this species are found occa- 

 sionally under button-bush trunks that are lying in the edge of the water, and I 

 found one pupa that had ensconced itself neatly in the pith cavity of a stub of large 

 size that projected from the open water. This pupa I reared, the imago issuing 

 on the 31st of May. 



AcARiNA. 36. An undetermined mite of very small size makes a felted gall 

 .on the leaves of the most vigorous shoots. The mites live on the under side of the 

 leaf between the veins in the midst of the reddened hypertrophied plant hairs which 

 fill the concavity that quickly develops. Frequently the gall becomes distinctly 

 sacculate, rising to a considerable iieight from the upper side of the leaf, and 

 becoming almost a mantle gall. It is of irregular shaj^e, with warty surface, and is 

 reddish in color, or green, tinged with redcli:>h. 



Besides the foregoing, there were at least four other species of insects that 

 certainly belong to the button-bush population, but which I have been able neither 

 to find out about, nor to name. These are a j.issid whose nymphs were common, 

 feeding on the leaves in June, but which I did not breed. A number of jassid 

 imagos might be swept from the foliage in midsummer, but whether they were there 

 by accident was uncertain ; an undetermined coleopterous larva that I took to be 

 one of the Oedemeridae which I found repeatedly under the bark of dead stems; 

 and two species of ants undetermined that were taken often about the colonies of 

 Aphis and Eulecanium. 



H ARM'S . 



The ecological relations of the members of this assemblage of insects are not 

 without interest. A number live in the dead stems only. Of these, four live in the 

 pith cavities of broken stems: two (nos. i and 7) in the dry tops, and two (in the 

 pupal stage only, nos. 32 and 35) in the wet stubs. Five live under the bark, three 

 (nos. I, 3 and 32) as pupae only, and two (nos. 23 and n) feeding as well as 

 transforming there ; twoof these live only in wet stems (nos. 23 and 32). Nine of 

 our list (nos. 4, 5, 24-30) are merely flower visitors. Two feed on the green stems 

 and these (nos. 15 and 16) are among the most important enemies of the button- 

 bush. Ten are leaf feeders (nos. 2, 6, 13, 14, 17-21, and 36, the last being the 

 only gall maker observed) and among these only one (no. 2) seemed of much 

 importance to the plant. Of the three prime depredators, therefore, the moth 

 larva (no. 2) and the scale insect (no. 16) have their internal parasites of the usual 

 sort, and the aphid (no. 15) has its predatory larval dipterous (no. 22) and coleop- 

 terous (no. 31) foes. Three aquatic insects of our list (nos. 24, 34. and 35) are 



