82 INSECTS. RATS. DISEASES. AXD ENEMIES. 



A sporatic trouble or blight has recently made its appearance to annoy 

 aquaticulturists, it belongs to the order certosporae and is similar to the celery 

 blight. A few light-colored spots appear on the oldest leaves, which spread 

 rapidly, and the leaves soon after commence to rot where the spots appeared. 

 As the leaves are thus destroyed the plant is considerably weakened and noth- 

 ing like maturity can be obtained; the plant gets weaker and smaller, and 

 would ultimately die. Bordeaux mixture is the best remedy; the new mixture, 

 Potash Bordeaux, is preferable as it leaves no chalky or white-washed appear- 

 ance. Apply with a fine spray or dip the leaves where plants are in a portable 

 state. After treatment the leaves will, for a time, have the appearance of 

 having been whitewashed, but as new leaves quickly replace the others in a 

 healthy or vigorous plant, those that were affected can be taken off in the 

 course of a few days, but if more spots appear another application of the 

 fungicide will be necessary. 



There are several kinds of water snails, all more or less beneficial to the 

 cultivator, but one species, with a long black colored shell, is particularly fond 

 of the green leaves of Hydrocharis and Aponogeton, as well as of the decayed 

 leaves of other plants, confervfe, etc. Should the plants be found to be eaten 

 in this way, it is best to remove these plants to another tub or compartment by 

 themselves, and introduce a sunfish or two, which will clear off the snails and 

 their larvae in a remarkablj' short time. Sunfish will not only devour such snails 

 as are injurious, but will take all kinds, and as all snails are beneficial (even those 

 that eat Hydrocharis, etc., will not eat the leaves of the Ouvirandra), care 

 must be taken in this respect, and sunfish must be kept in their proper 

 place. It is questionable whether they should be kept at all in an artificial 

 pond, tank, or tub. Water snails have other enemies besides sunfish; the larvae 

 of the great dragon-fly will attack and destroy them, but as their season is 

 limited in duration, and the mature insect is more or less beneficial, and they 

 are difficult to exterminate, we must patiently bear this apparent injury, know- 

 ing they cannot do much, if any, injury indoors. 



Frogs and tadpoles are of great service and should be encouraged in and 

 around the ponds; these, too, have their enemies, the domestic cat should 

 never be allowed near the tanks, as pussy will surely find out the frogs as well 

 as the fishes, of which she is particularly fond. 



In the natural ponds, water snakes will put in an appearance, these reptiles 

 will devour both fish and frogs, and, until we are visited with a plague of the 

 latter, destroy all snakes possible. 



