Fill tank with water containing 2 teaspoons household ammonia per quart, stir, and pump a little into hose and nozzle. Let stand
in sprayer at least 18 hours, drain and rinse at least twice, pumping
through hose and nozzle, with pure water. It is a lot better to have two
sprayers and to mark the weedkiller one with red paint. And for heaven's
sake don't open up your can of weedkiller and mix your spray in the
head house of your greenhouse or outdoors near your best bed of roses.
Weevils are beetles with head prolonged into a snout. If this snout is
long and curved, the insect is usually called a curculio. In many species
wing covers are fastened down so they cannot fly, and in some there seem
to be no males, females reproducing parthenogenetically. The boll weevil
is of course the most notorious and costly member of this tribe but as a
cotton pest is outside the scope of this garden book.
BLACK VINE WEEVIL (Brachyrhinus sulcatus),
also called taxus weevil and
cyclamen grub. This is an extremely important enemy of yew,
somewhat of a problem on rhododendrons, azaleas, and other broad-
leaved evergreens, and found in greenhouses on cyclamen, primrose, etc.
The damage is twofold, grubs eating all of small roots and the bark off
larger roots and adults feeding on foliage. Eggs or grubs are readily transported with evergreens sold balled and burlapped. If taxus does not start
new growth at the normal time in spring, looks sickly and off-color, you
should immediately examine the soil. Look for small, white legless grubs,
about half the size of Japanese beetle grubs, with brown heads, and
crescent shape. I have seen half a hundred plants in a new hedge die
within a month from grubs feeding on the roots. In late May thev change
to soft white pupae, free forms with appendages showing, and adults
usually come out in early June, feeding at night, hiding in the soil or
garden litter during the day. They are brownish to black, slightly corrugated and covered with fine yellow hairs, with a rather short snout (Fig-ure 63B). They chew off taxus needles and make notches in from the
margin of rhododendron, azalea, and laurel leaves. After feeding for 5
or 6 weeks, they usually lay eggs in or on the soil, and spend the winter
as partly grown larvae. In some cases the adult hibernates and lays her
eggs the next season.
Control. Kill the grubs by treating soil with chlordane emulsion (1
teaspoon of a 75% emulsion per gallon of water) or with 5% chlordane
dust, at rate of 5 pounds per 1000 square feet. Aldrin and dieldrin are
also coming into use as soil treatments. To control adults spray in late
June with DDT or aldrin, dieldrin, or heptachlor. An apple pomace
bait, sold as Go-West, has been long used to kill adults.