Control. Working lindane into the top 6 to 8 inches of soil just before
planting controls maggots but may impart an off-flavor to radishes. A
proprietary compound, Carco-X, combining creosote and benzene hexachloride, is sold for maggot control. Calomel has been used, with 1/2 cup
of mercurous chloride diluted 1 ounce to a gallon of water, poured
around each plant soon after setting out, or as a dust, 1 part calomel mixed
with 19 parts gypsum, talc, or lime.
CARROT RUST FLY (Psila rosae).
This maggot is injurious to carrots, parsnip, celeriac, and parsley in the Northeast and even more so in
the Pacific Northwest. Plants are stunted or entirely destroyed. The name
comes from the rusty color of larval excrement laid down in root tunnels.
Soft-rot bacteria often follow the maggots. The small fly is dark green
with yellow legs and head. Eggs laid about crown of host plants hatch
into yellow maggots. There are two broods, sometimes a third.
Control. Early planting helps to avoid trouble. Chlordane dust applied
in a 4-inch band along the row as soon as the plants come up is one
recommendation. Calomel, diluted as for cabbage maggots, can be sprinkled along the row.
ONION MAGGOT (Hylemya antiqua).
Small white maggots bore through
underground stems into bulbs, often mining out small onions
completely. This is a serious pest in wet springs, unimportant in a dry
Control. Moisten seeds with gum arabic and then coat with calomel,
using 2 parts by weight to 1 of seed, just before planting. Or use calomel
in solution along the row, 1 ounce in 5 gallons of water applied at the
rate of 1 gallon for each 25 feet of row.
SEED-CORN MAGGOT (Hylemya cilicrura).
Germinating seed of peas and
beans are more often injured than corn; cucurbit sprouts are sometimes killed. The maggots are yellow white, 1/4 inch long, with sharply
pointed heads. When they burrow in seed, it either fails to sprout or
produces a sickly plant. Beans sometimes become ballheads with no
foliage. The injury is increased in cold, wet seasons and on lands rich
in organic matter. The winter is spent in puparia in soil or as free maggots in manure. In May, gray flies start laying eggs in soil or on seed;
there are 3 to 5 generations.
Control. Avoid organic fertilizer in the seed row; plant after the soil
warms up. Soil treatment with lindane or chlordane before planting may
help. Reseed as soon as injury is discovered.
Various warm-blooded animals are, at times, garden pests.
Although they often mess up garden beds, cats seldom really injure plants. They do, of course, kill some birds and should be
belled or restrained during the nesting season.