Sunday Express News
GARDENING, ETC.
Sunday, July 20, 2003

San Antonio has been fortunate in experiencing adequate amounts of rainfall thus far, even though, in our neck of the woods the phrase “dog days of summer” is usually appropriate. This week Extension will share two topics of interest with you. We have a July garden checklist of items needing your attention. Taking care of these chores now will benefit your garden in the fall. Hopefully the milder temps we have been experiencing will provide you with the incentive to get the job done! Secondly, those “dog days of summer” bring an unwelcome visitor – the grasshopper. If this problem pest is invading your space, we have some information that will help keep their numbers down.

First of all, let’s look at the garden checklist.

• Don’t allow plants with green fruit or berries to suffer from lack of moisture. Hollies will frequently drop their fruit under drought conditions.

• Prune dead or diseased wood from trees and shrubs. Hold off on major pruning from now until mid-winter. Severe pruning now will only stimulate tender new growth prior to frost. op their fruit under drought conditions.

• It is time to divide spring flowering plants such as irises, Shasta daisies, ox-eye daisies, gaillardias, cannas, daylilies, violets, liriopes, and ajugas.

• Make your selections and place your orders for spring flowering bulbs to arrive in time for planting in October and November.

• Mid-summer pruning of rose bushes can be beneficial. Prune out dead canes and any weak, brushy-type growth. Cut back tall, vigorous bushes to about 30 inches. After pruning, apply a complete fertilizer, and water thoroughly. If a preventive disease-control program has been maintained, your rose bushes should be ready to provide an excellent crop of flowers this fall.

• Establish a new compost pile for the fall leaf accumulation.

• Picking flowers frequently encourages most annuals and perennials to flower even more abundantly.

• It is not too late to set out another planting of many warm-season annuals such as marigolds, zinnias, and periwinkles. They will require extra attention for the first few weeks but should provide fall color in September, October and November.

• Plant bluebonnet seeds in August. This winter annual must germinate in late summer or early fall, develop a good root system, and be ready to grow in spring when the weather warms. Plant the seeds in well prepared soil, ½ inch deep, and water thoroughly.

• In August, sow seeds of snapdragons, dianthus, pansies, calendulas, and other winter flowers in flats for planting outside in mid- to late fall.

Grasshoppers

Consecutive years of hot, dry summers and warm, dry autumns favor grasshopper survival and reproduction. Warm, dry fall weather allows grasshoppers more time to feed and lay eggs. The large numbers of grasshoppers present last fall left many eggs in the soil which hatched this spring. Also, rains in the spring when eggs are hatching, drown young hoppers. Thus, dry weather in the spring favors their survival.

Grasshopper eggs are deposited in the soil ½ – 2 inches deep in weedy areas, fence rows, ditches and hay fields. The eggs hatch in the spring and early summer. Eggs of different grasshopper species hatch out at different times, so young grasshoppers can be seen throughout the spring and early summer. Young grasshoppers, called nymphs, feed for about six weeks. Once nymphs reach the adult stage, they can fly. As weedy plants are consumed or dry up in the summer heat, adult grasshoppers fly from weedy areas and pastures to more succulent crops and landscapes. Grasshoppers persist until late fall when old adults begin to die or when a killing frost occurs.

Reduce grasshopper numbers by eliminating weeds which starves young hoppers and later discourages adults from laying eggs in the area. Destroying weeds infested with large numbers of grasshoppers can force the hungry grasshoppers to move to nearby crops or landscapes. Control the grasshoppers in the weedy area first with insecticides or be ready to protect nearby crops if they become infested. Grasshoppers deposit their eggs in undisturbed soil, as in fallow fields, road banks, and fence rows. Shallow tillage of ;the soil in late summer may be of some benefit in discouraging them to lay eggs.

Grasshoppers are susceptible to many insecticides. However, insecticides typically do not persist more than a few days and grasshoppers may soon re-invade the treated area. The length of control will depend on the residual activity of the insecticides and the frequency of re-treatment. Controlling grasshoppers over a large area will reduce the numbers present which can re-infest a treated area. Dimilin 2L provides a long residual protection against young grasshoppers but is not effective against adults.

The best time to apply insecticides is to treat threatening infestations while grasshopper are still small, and before they move into crops and landscapes. Immature grasshoppers (without wings) are more susceptible to insectides than adults.

There are some biological controls available to kill grasshoppers. They are called Nolo Bait, Grasshopper Attack, and others containing similar ingredients.

These products contain spores of a protozoan call Nosema locustae, formulated in a bait. Grasshoppers consuming the bait become infected by the Nosema organism. Some immature grasshoppers die while adults often survive, but females lay fewer eggs. Nosema baits act too slowly and kill too few grasshoppers to be much value when the need for control is immediate.

Some insecticides for controlling grasshoppers in the home landscape at present (2003) include:

Cylfuthrin – The active ingredient in Bayer Advanced Home and Garden Spray.
Bifenthrin – Active ingredient in Ortho Ready-to-Use Houseplant and Garden Insect Killer.
Permethrin – Active ingredient in Spectracide and other products.
Acephate-Active ingredient in Orthene (at present, but product is being phased out).

For the landscape, several products may be used including those containing bifenthrin, lambda-cyhalothrin, diazinon, dimethoate, malathion, acephate and carbaryl (2003).

For more information, Extension fact sheet L-5201, Grasshoppers and Their Control is available. Send a self-addressed, stamped envelope to Texas Cooperative Extension: Grasshoppers, 3355 Cherry Ridge Ste 212, San Antonio, TX 78230.

Content for this article was reprinted from “Horticulture Update-July,” an online Extension newsletter, and edited by Nathan Riggs, EA-IPM.