1034 DISEASES AND INSECTS 



DISEASES AND INSECTS 



CATALOGUE OF DISEASES, continued. 

 Rubus. See under Raspberry. 



Salix. RUST. Numerous species of the rust fungi produce red 

 rust spots on the leaves. 



Control. -Keep at a distance from species of conifers. 

 HEART- ROT (Trameles suaveolens). Enters through wounds. 



Control. Surgery methods. 



Salsify. MILDEW ( Albugo tragopogonis). Distortion and white 

 blisters on host. 



Control. Eradicate affected plants and grow on new soil 

 apart from wild and cultivated species of the Compositse. 

 Sambucus. CANKERS. See under Lonicera. 

 Sarracenia. BLIGHT. -See under Orchids. 



Saxifraga. RUST (Puccinia pazschkei and P. saxifrage). Dark 

 brown concentric circles of rust pustules on upper surface of 

 the leaves. 



Control. Burn affected leaves. 



Scilla. BULB-ROT (Sclerotinia bulborum). Yellow stripes and 

 blotches on leaves in early summer, with olive-brown mold 

 on them. Rots the bulb later. . 



Control. -Destroy affected plants. Spray with potassium 

 sulfid. Use new soil thereafter. 



Sedum. LEAF-SPOT (Septoria sedi). Dark circular blotches appear 

 on the leaves and defoliation occurs. 



Control. Destroy affected parts by burning. 



Sempervivum. RUST (Endophyllum sempervivi). Brown rust 

 pustules rupturing epidermis of leaf. 



Control. Destroy affected plants as the fungus lives over 

 from year to year in the same plant. 



Senecio. RUST (Coleosporium senecionis). Orange patches on 

 under surface of leaf. 



Control. Keep at a distance from species of Pinus. Burn 

 affected plants to protect neighboring pines. 

 Sequoia. BLIGHT. See under Pseudotsuga. 

 Silene. SMUT. See under Lychnis. 

 Solanum. See under Potato, Eggplant, etc. 

 Sorbus. BLIGHT. See under Pear. 



Spinach. ANTHRACNOSE (Colletotrichum spinacex). Spots on 

 leaves, at first minute and watery, gradually increasing in size 

 and becoming gray and dry. 



Control. Gather and destroy all diseased leaves. 

 MILDEW (Peronospora effusa).Gra.y, slightly violet, patches 

 of a velvety texture on under side of leaves. 



Control. As for Anthracnose, which see. 



Spiraea. RUST (Triphragmium ulmarix). Reddish yellow and 

 dark brown rust pustules on leaves. 



Control. Burn affected parts. 

 Squash. WILT. See under Cucurbita. 



Strawberry. LEAF-SPOT, or LEAF-BLIGHT (Mycosphxrella fra- 

 garix). Small purple or red spots appearing on leaves. Leaf 

 appears blotched. 



Control. Spray with bordeaux mixture, 4-^4-50, soon after 

 growth begins and make three or four additional sprayings 

 during season. 

 Sweet Pea. MILDEW. See under Pea. 



Sweet Potato. BLACK-ROT (Ceratocyslis fimbriata). Black shank 

 and a black rot of tuber. 



Control. Never use sprouts from affected potatoes. Steam 

 sterilize hotbeds. 



ROTS. The sweet potato is susceptible to a large number of 

 rots, soft, dry, hard, white, etc. 



Control. Use soil which has not grown diseased sweet 

 potatoes heretofore. 



Syrir.ga. MILDEW (Microsphxra alni). White powdery mildew on 

 upper surface of leaves. 



Control. Dust with sulfur. 



TWIG and BUD DISEASE (Phytophthora syringx). Tips of twigs 

 killed. 



Control. Prune off twigs. 



Thalictrum. RED-SPOT (Synchytrium anemones). Red eruptions 

 on stem, leaf and flower. Causing at times swelling and 

 crumpling of the organ. 



Control. Burn affected parts. 

 Thuja. ROOT-ROT (Polyporus schweinitzii). Diseased wood 



yellowish, cheesy, brittle when dry. 



HEART-ROT (Fames carneus). Causes pockets in the affected 

 wood. 



Control. Remove all affected wood, using surgery methods. 

 Tilia. LEAF-SPOT (Cercospora microsora). Causes spotting and 

 defoliation. 



Control. Two sprayings in Massachusetts resulted in 

 longer retention of the leaves. 



Tomato. LEAF-SPOT (Septoria lycopersica). At first small spots 

 appear, which spread until the whole leaf is consumed. Fruit 

 may be attacked. 



Control. Spray with bordeaux mixture, 4-4-50, making 

 the first application two weeks after the plants are set out 

 and repeating every two weeks throughout the season. 

 DOWNY MILDEW. See under Potato. Late Blight. 

 END-ROT. Due to lack of sufficient soil moisture. 



Control. Water soil in dry periods. 



Toxylon (Maclura). RUST (Physopella fid). Pale cinnamon- 

 brown rust pustules on under side of leaf. 



Control. Destroy by burning the affected leaves. 



CATALOGUE OF DISEASES, continued. 

 Tropaolum. See under Horse-Radish. 

 Tsuga. HEART- ROT (Trametes pini). Light brown decay pitted 



with small oblong cavities, which are white-lined. 

 SAP-ROT (Fames pinicola). Soft decay of sap-wood. 



Control. Surgery methods. 



Tulipa. MOLD (Sclerotinia parasitica). Olive-brown, velvety 

 patches formed on leaves, stem, and flowers; also, later, 

 small black lumps at base of stems. 



Control. Burn affected plants. 

 Turnip. CLUB-ROOT. See under Cabbage. Same disease. 



SOFT-ROT. See under Carrot. Same disease. 



Ulmus. TAR-SPOT (Gnomonia ulmea). Black spots on upper 

 surface of leaves. 



Control. Burn old leaves in fall or winter. 

 HEART-ROT (Pleurotus ulmarius). Soft rotting of wood. 



Control. Surgery methods. 



Vaccinium. LEAF-BLISTER (Exobasidium vaccinii). Large blisters 

 on leaves, petioles and stems, of a red or purple color. White 

 bloom beneath. 



Control. Remove and burn diseased parts. 



Verbena. MILDEW. (Erysiphe cichoracearum and others). Pow- 

 dery mildew growths on leaves. 



Control. Spray with any good fungicide or dust with 

 powdered sulfur. 



Veronica. LEAF-SPOT (Septoria veronicx). Well-defined spots on 

 leaves. 



Control. Pick off and burn affected leaves. 



Vinca. LEAF-SPOT (Sphxropsis vincx). Leaves disfigured by 

 spots which occur on the stem at times as well. 



Control. Destroy diseased parts of plants. 



Violet. ROOT-RQT (Thielavia basicola). Plants make poor growth; 

 roots rotted off. 



Control. Start in steam-sterilized soil, and transfer to 

 sterilized beds. 

 Vitis. See under Grape. 



Walnut. BLIGHT (Pseudomonas juglandis). Black spotting of 

 fruit and black cankers on the stems. Twigs and fruit-spurs 

 killed. 



Control. None known except such as mentioned under 

 Pear Blight. Grow immune varieties. 

 ANTHRACNOSE, or LEAF-BLIGHT (Marsonia juglandis). See 



under Hickory-Nut. Same disease. 

 Watermelon. MILDEW. See under Cucumber. 



WILT (Fusarium vasinfecta). Wilting of leaves and plant 

 dries up. 



Control. None recommended. Resistant varieties should 

 be grown. 



Yucca. LEAF-BLOTCH. See under Agave. 



Zea. See under Corn. 



Zinnia. WILT. See under Dahlia. 



DONALD KEDDICK. 



Insect enemies of plants. 



The animals which constitute the insect world 

 play an important part in most horticultural opera- 

 tions. The busy bee is an indispensable aid in the 

 production of many fruits, but the equally busy jaws 

 of canker-worms or other insects oftentimes seriously 

 interfere with man's plans for profitable crops. Horti- 

 culturists should become more intimately acquainted 

 with their little friends and foes in the insect world. 

 Not only from the economic standpoint is this knowl- 

 edge necessary in the business of growing plants, but 

 the striking peculiarities of form, coloring, structure, 

 habits, and the wonderful transformations of insects 

 afford one of the most interesting fields in nature. The 

 life-stories of many insects, if told in detail, would 

 rival in variety and interest many a famous fairy tale. 

 The science that treats of insects, or entomology, has 

 now reached the stage at which its devotees are no 

 longer looked upon with ridicule in most communities. 

 At the present time more than 350 trained men are 

 officially employed in entomological work in the United 

 States and Canada. 



What they are. An insect is an animal which, in 

 the adult stage, has its body divided into three distinct 

 regions: the head, the thorax and the abdomen (Fig. 

 1293). The head bears one pair of antenna?, and there 

 are always three pairs of legs and usually either one 

 or two pairs of wings attached to the thorax. By these 

 characteristics one can usually readily distinguish an 

 adult insect from any other animal. Among the near 

 relatives of insects in the animal world are the cray- 



