Eleventh Report of the State Entomologist 255 



branches, would show signs of weakness. The number of plants thus 

 affected in December was so large that the trouble was apparently due to 

 some agency other than weakness of the plants, improper conditions of 

 the soil, or similar causes. 



The dying of mdividual carnations is by no means new to the 

 grower of these plants. They are usually reset without further thought, 

 and the loss attributed to the weakness of the plants or some other cause, 

 and nothing more thought of the matter. In some cases it may be due 

 to malnutrition, but in the present instance there appears to be a well- 

 defined cause, and the same may prove true in other places. 



An examination of a number of the affected plants showed several 

 large burrows in most of them at or near the surface of the ground, and 

 in these cavities, numerous small white mites, apparently a species 

 of Tyroglyphus, were found. In most of the stems examined, the mites 

 were very abundant — in many places they formed a distinct whitish- 

 appearing layer over portions of the affected parts. A limited number 

 of eel-worms, Aiiguilhdidce, were associated with the mites. Several 

 much larger, active, reddish mites were also seen in the course of the 

 examination; these, however, are predaceous, and belong to a species of 

 Gamasus — probably undescribed. 



Notes on Life-History and Habits. 

 These mites can live and multiply rapidly on the decaying carnation 

 roots, provided moisture is present. A number of them were placed in 

 tightly corked vials with bits of the roots. The vials were kept moist and 

 in a warm room from the last of December, 1895, till into February, 1896. 

 While the vials were kept moderately moist, the mites multiplied very 

 rapidly. During the latter part of the time that they were under observa- 

 tion, a black, smutty fungus developed upon the decaying carnation roots 

 and the mites were observed feeding upon it; not only were they seen 

 feeding on the fungus, but the black spores were within their semi- 

 transparent bodies. One mite was observed moving slowly through the 

 accumulated moisture in the bottom of the vial, and turning from side 

 to side, apparently seeking to capture the infusoria with which the fluid 

 abounded. From the above it is seen that these mites feed on decay- 

 ing carnation roots, on fungi, and probably on infusoria. It is also more 

 than likely that they injure the living tissue of the carnation. 



The drying up of the carnation roots was followed by many of the 

 mites deserting them and betaking themselves to the sides of the vial, where 

 they became fixed and remained motionless for some time. A few days 



