CHRYSANTHEMUM 
26 


cUTTING S§S 
een nen Wie (Gipee 
MITES 
Cyclamen mite and broad mite are often found on the same plants at the same time. Broad mite 
could pass through a complete generation in 4 to 5 days at 70 to 80 degrees while the Cyclamen 
mite will take 4 to 5 times longer. : 
INJURY. Infested leaves become deformed, curl from the outside inward, and wrinkle so that pockets 
and pit-like depressions are formed. When the infestation is severe, the mites collect about the 
buds, causing them to blight. 
CONTROL. Fumigating with Parathion is very effective and easy to apply. Wapotone containing 
HETP has given good control. Sodium Selenate is effective when applied in liquid form 4 gram 
per square foot after plants are well established. P40 used at the rate of 3 pounds per hundred 
square feet is another way to use sodium selenate. 
RED SPIDERS 
There are several species of red spiders that attack the chrysanthemum. They vary in color through 
yellow, orange and red. The body is oval in outline and bears eight well-developed legs. 
INJURY. Red spiders pierce the epidermis of the leaf and draw the liquid contents from the cells, 
causing the leaf to turn pale around the injured portion. They prefer to collect on the under 
surfaces of the leaves, which they cover with silken threads. 
CONTROL. Parathion or TEPP bombs are most effective and easiest to apply. HEPT or TEPP 
contained in insecticides such as Vapotone are by far the most effective on red spider. Moisture 
is detrimental to the development of the red spiders and frequent syringing washes them and 
their eggs off the plants. Sodium selenate is effective when applied in liquid form 4 gram per 
square foot or P40 at 3 pounds per 100 sq. ft. after plants are well established, especially de- 
sirable for cloth house operators, will also control foliar nematodes. 
SYMPHYLIDS 
Symphylids are small white creatures about Ys to ¥i6 inches long. About 40-60 days are necessary 
for the completion of the life cycle. 
INJURY. Symphylids destroy the fine root hairs and small rootlets, thus stunting the plants and often 
killing them outright. 
CONTROL. If possible construct raised bench. Steam sterilization has given fair control. Dowfume G 
or Dow MC2 when properly applied will give good control. Isotox (15% benzene hexachloride) or 
[5% wettable powder of Parathion has been used as follows with no apparent damage: Place 
3 ounces in 30 gallons of water and apply to 100 sq. ft. of bench space. Several applications 
2-3 weeks apart may be necessary for a complete clean-up. 
SOWBUGS 
INJURY. Sowbugs often become so plentiful in the greenhouse that they eat the newly planted 
cuttings at the base 
CONTROL. Any of the many poison baits will give partial control but a complete spraying with DDT 
under the benches has given excellent control. Deenate 50W will give complete control. 

Red Spider Injury Symphylids Enlarged 10x 


