The citrus red mite (Paratetranychus citri) is injurious to
citrus fruits in California, also in Florida where it is called purple
mite. Leaves have a silvery, speckled effect and may drop; fruits turn
gray or yellow. The six-spotted mite (Tetranychus sexmaculatus) is more
important in Florida and the Gulf States than California. The mites form
colonies and webs in depressed areas on underside of leaves, the upper
surface appearing swollen, shiny, and yellow. Oil sprays or DN dusts
control these mites. The citrus rust mite (Phyllocoptruta oleivora) is important in the Gulf States on orange, grapefruit, lemon, and lime. Orange
skins are russeted, lemons silvered. Sulfur dust or a wettable sulfur spray
gives better control than oil sprays for this rust mite.
CYCLAMEN MITE (Tarsonemus pallidus).
This is a very important house
and garden enemy, almost inevitable on delphinium, common on
monkshood, occasional on snapdragon, chrysanthemum, and petunia outdoors, and deforming cyclamen, African violet, geranium, begonia, fuch-
sia, etc., indoors. The mites are only 1/50 inch long, too small to see
without a lens, white to green when young, brown as adults. Plants are
stunted with leaves greatly distorted, thickened, with purple-black areas;
flowers turn black in the bud stage or are streaked and blotchy (Figure
39). Stems on African violets are twisted. This mite flourishes in cool
weather, with a generation every 2 weeks.
Control. Space pot plants so foliage does not touch; keep suspected
plants well isolated; wash hands with soap and water before handling
healthy plants. Parathion aerosols are used in greenhouses. For African
violets at home you can place a capsule of sodium selenate (sold as Kapsulate) on the soil and fill the pot to the rim with water, one treatment
lasting 4 to 6 months. In buying delphinium refuse any plants showing
the slightest trace of abnormal foliage or stunting. If mites are already
established in the garden, spray with Dimite (1 teaspoon to a gallon of
water) starting early in spring and repeating weekly until hot weather,!
resuming treatment when nights get cool in late summer.
EUROPEw RED MITE (Paratetranychus pilosus).
This important fruit pest,
on apple, plum, pear, is most destructive where DDT is used in]
the spray schedule. The foliage is sickly, looking as if covered with dust,
leaves drop, fruit is not formed or very poor. Bright red or orange eggsl
winter on twigs and hatch just before apples bloom. Adults are bright to|
brownish red, very, very small. There are 4 to 8 generations a year.
Control. Spraying with a 2 to 3% dormant oil emulsion kills over-
wintering eggs, but a miticide, such as parathion, may be needed in later