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Common Rose Pests - Part 6: Grasshoppers and Leaf Cutter Bee

© Mark Whitelaw

It is appropriate we conclude our series on Common Rose Pests with a discussion of these two critters. Both will soon be emerging in your garden.

Grasshoppers

Description: There are more than 600 species found in North America alone. As a member of the Orthoptera Order of insects, they are characterized by large hind tibia used for jumping to scattered locations in our garden and feeding on a wide range of plants. Although most species are herbivores, some are omnivorous and even predatory of other insects. The order is divided into several families, but the two that concern most of us rosarians are the Long-horned Grasshoppers and the Short-horned Grasshoppers.

Note: Leafhoppers should not be confused with grasshoppers. The leafhopper that concerns us rosarians is the Rose Leafhopper (Typhlocyba rosae). Leafhoppers are a member of the Hemiptera Order of insects, suck juices from plant leaves rather than chew them, produce "honeydew" as an exudate, and as such are more closely related to the aphid, whitefly, and mealybug than the grasshoppers. Controls for the Rose Leafhopper are similar to those of its "cousins" and include the use of a parasite called Anagrus.

Biology: Most grasshoppers overwinter as eggs ready to hatch the following year. Eggs are laid during summer and fall in packets below the soil's surface. Eggs hatch into small nymphs in spring and early summer. Timing and quantity of the hatching depend on weather conditions.

Damage: Grasshoppers chew everything in sight! Their damage is most noticeable on leaves and at first glance resembles that of caterpillar damage. Although not the only indicator, commonly grasshopper damage is characterized by rough-edged holes in the leaf's center. Both leaf tissue and veins will be chewed away, although some species will commonly eat only the tissues.

Control: There are numerous controls of these pests. From "least toxic" to "most toxic" these include:

1. Hand removal - This can be a daunting task since grasshoppers can be quite mobile. As a "neighborhood kids' moneymaking project," however, your chief worry is whether the children will do more damage chasing after grasshoppers than the grasshoppers themselves.

2. Row Covers - As a home gardening remedy, these can be a bit difficult to manage and are included for those gardeners who need "least toxic" protection for special occasions or circumstances.

3. Innoculation with natural controls which include

a) Nosema locustae - a protozoan pathogen which targets grasshoppers and their locust "cousins." This bio-control takes time to work effectively, however, and may take a whole season to significantly reduce a pestiferous population. I receive frequent complaints about the length of time these products require to achieve control. This is because the pathogen is spread (depending on grasshopper species) either by cannibalism or the ingestion of feces.