Caterpillar sometimes called thistle butterfly. About 1 1/2 inches long, dull brown or black with yellow stripe down each side. Feeds on foliage and sometimes ties terminal leaves together. Prefers calendula, sunflower, lupine, and hollyhock.
Tiny but distinctive in appearance, with lacelike wings and hood. Sucks the sap of chrysanthemums, asters, scabiosa, and other garden plants, ruining them rapidly when attacking in large numbers. Spray or dust undersides of leaves with nicotine or pyrethrum.
Mainly a scourge of the vegetable garden, but also attacks many ornamental plants, including ageratum, abutilon, canna, carnation, amaranth, dahlia, chrysanthemum, geranium, gladiolus, hibiscus, mignonette, nasturtium, morningglory, poppy, phlox, rose, sunflower, and sweetpea. The corn earworm is a caterpillar, 1 1/2 inches long, changing from reddish brown to green with brown or green stripes as it becomes full grown. Feeds on leaves and tunnel stems and bores into buds. Spray with Paris green, cryolite. The use of mineral oil and dichloroethyl ether also is recommended. The oil alone is often effective, but the addition of the ether compound assures better success.
Citrus mealybug and long tailed mealybug most generally found of several species. Suck plant juices, cause colour loss, wilting, and dying. Are scarcely 1/4 inch long. Feed on a throng of plants, but are partial to the more succulent ones, such as ageratum, coleus, ferns, geraniums, heliotrope, lantanas, and salvia. Are usually found clustered on veins on underside of leaves. Spray weekly with nicotine sulphate and soap until the plague is eradicated. Also spraying the plants with water in as great force as they will stand is helpful.
A sucker of habits similar to its relatives, the mealybugs. Its special targets are chrysanthemum, coleus, heliotrope, lantana, periwinkle, petunia, salvia, and verbena. The female is brown or green and distinctive for its white fringe and white fluted egg sac. Is about 1/3 inch long. The treatment is the same as for mealybugs.
Principal offender among the caterpillar species which bore through stalks and stems of such thick-stemmed, fleshy plants as dahlia, aster, cosmos, delphinium, goldenglow, lily, phlox, peony, hollyhock, and zinnia, and usually the plants are at the wilting or breaking point before its work is discovered. About 1 inch long, brown with a purple or dark brown band around the middle and brown or purple lengthwise stripes, it makes a small hole in the stem and burrows in. Assist individual plants by splitting infected stems lengthwise, removing the borer, and binding the stem together.
Tarnished plant bug
Especially damaging to aster, calendula, cosmos, dahlia, and marigold. Stings young tips and causes buds, particularly of dahlias, to "blast" open and die. Also punctures leaves and seems to inject poisonous substance into the plant, killing the tissue surrounding the feeding area. Is a brassy brown, flat bug, about 1/4 inch long, with black and yellowish diagonal markings. Attack these active bugs early in the day, knocking them into a pan of water covered with kerosene.
European corn borer
Offends chiefly against corn but tunnels in stems of many garden plants, including aster, chrysanthemum, dahila, cosmos, gladiolus, geranium, hollyhock, and zinnia. Dahlia, particularly susceptible to attack, shows first signs of infestation by wilting of new foliage and flower buds. About an inch long and distinguished from stalk borer by absence of bands or stripes. The young caterpillars may be combated on dahlias, by spraying while they are still feeding on the surface of growing foliage, before they bore in. Use 2 ounces of derris of phenothiazine and a small amount of sodium lauryl sulfate in 3 gallons of water.
Fuller's rose beetle
A night feeder and a danger in all its stages. The larvae attack roots, the beetles attack foliage, buds, and leaves. Sometimes they feed so voraciously that they sever leaves. Their deposits of black excrement make plants unsightly. Azalea, camellia, canna, chrysanthemum, dracaena, deutzia, goldenglow, gardenia, lilies, hibiscus, palms, and roses are among the plants which they injure. If the infestation is not heavy, knock them into a pan of water and oil. If they are present in swarms, spray, or dust with barium fluosilicate or cryolite.
This invader from Japan is abundant in several
eastern states and attacks many plants, sometimes destroying flowers and
foliage completely. Among its usual victims are rose, hollyhocks, zinnia,
hibiscus, dahlia, Virginia creeper, and flowering quince, cherry, and
peach. It is a bright green bug, scarcely more than 1/4 inch long, with
copper coloured wing covers and white dots marking the sides and tip of
the abdomen. Especially numerous in July and August. Pyrethrum spray kills
the bugs it hits.
Red-Banded leaf roller
Most common in the East, this greenish caterpillar resembles the greenhouse leaf tier in its appearance and in the injury it inflicts. The treatment is also the same as for the greenhouse leaf tier. Principal objects of attack are chrysanthemum, geranium, hollyhock, honeysuckle, violet, rose, lobelia, and zinnia.
These pests constitute a large group of sucking insects protected by a scaly covering or a waxy body secretion. Among them are azalea scale, peony scale, camellia scale, San Jose scale, scurfy scale, oyster scale, tea scale, dogwood scale, soft scale, cottony maple scale, euonymus scale, oleander scale, and many others. Being suckers, their action is largely to weaken the plants, destroy their vigour, force them to produce undersized foliage. White-oil emulsion spraying is recommended against scale insects.
Common enemy of lilac but also attacks box, birch, rhododendron, willow, mountainash, poplar, and other trees and shrubs. Chews patches of bark off branches and stems, sometimes girdling them. Found only in the eastern states. About 1 inch long, hairy and with yellow-orange markings. Builds a dark, papery nest in tree hollows, between building rafters, and in ground holes. No way of stopping the bark attacks has been found and best control is to destroy the nests if they can be located.
Narcissus bulb fly is most important of the species that attack flowering bulbs. The maggots feed in the centre of the bulbs, from which either no growth develops or foliage turns yellow or is stunted. Among other bulbs attacked are tulip, iris, amaryllis, and hyacinth. Damage is usually well advanced before presence is discovered. Maggots of lesser species usually attack unhealthy bulbs. Dig up infected bulbs and soak them for 1 1/2 hours in water kept at temperature of 110 to 115 degrees. If you know how to handle calcium cyanide and its gas, you can fumigate the bulbs, keeping them for 4 hours in a fumigation chamber.
This long-legged, yellow-brown beetle, about a third of an inch long, eats holes in flowers and leaves. It offends chiefly against rose, iris, and peonies, but also attacks foxglove, dahlias, hollyhock, poppies, and many others. Appears in swarms in June or July, chiefly in areas with light, sandy soil. No really satisfactory treatment known, but spraying or dusting the beetles with pyrethrum is helpful. A good preventive is to cultivate sandy wastes, disturbing breeding grounds.
Tiny winged insects that feed on the tender parts of peonies, roses, and many other flowers, flecking and discolouring the petals, deforming the blooms, and frequently causing them not to open. The young are pale yellow, turning to brownish-yellow as they mature. Use tartar emitic spray twice weekly until controlled. The gladiolus thrip, brown with a white band at the wing bases, is the worst pest of this plant. It attacks corms in storage, silvering the leaves, drying out bud sheaths and bleaching flowers. Corms should be treated with naphthalene flakes, 1 ounce per 100 corms. Put them in paper bags, sprinkle the flakes on the corms, then close the bags. Remove the naphthalene after 4 or 6 weeks and store the corms in an insect-free place.