Kansas State University

–by Frannie Miller

Snowy tree cricket – The image is of a snowy tree cricket. They are members of the order Orthoptera, which makes them more closely related to a grasshopper. They are sometimes referred to as “thermometer crickets” because you can estimate the temperature by counting the number of chirps for 15 seconds and adding 40.

–by Dr. Raymond Cloyd

For those of you that have been waiting patiently by reading another book or counting your stockpile of toilet paper, or for some…impatiently, it is time to look for bagworms. Although the cool weather we have experienced this spring will slow development, and consequently larvae hatching from eggs, bagworm caterpillars will eventually be present throughout Kansas feeding on broadleaf and evergreen trees and shrubs. Therefore, be prepared to act against bagworms once observed on plants. Bagworms are primarily a pest of conifers; however, they feed on a wide-range of host plants including a number of broadleaf plants, such as; rose, honey locust, hackberry, and flowering plum. It is important to apply insecticides when bagworms are less than 1/4 inch long to maximize effectiveness of insecticide applications and subsequently reduce plant damage.

Several insecticides are labeled for use against bagworms including those with the following active ingredients: acephate, Bacillus thuringiensis subsp. kurstaki, cyfluthrin, lambda-cyhalothrin, trichlorfon, indoxacarb, chlorantraniliprole, and spinosad. Most of these active ingredients are commercially available and sold under various trade names or as generic products. However, several insecticides, however, may not be directly available to homeowners.

The key to managing bagworms with insecticides at this time of year is to apply insecticides early and frequently enough to kill the highly susceptible young caterpillars feeding on plant foliage (Figures 1 and 2). Applying insecticides weekly for four to five weeks when bagworms are first noticed will reduce problems with bagworms later in the year. The bacterium, Bacillus thuringiensis subsp. kurstaki, which sold under various trade names, is only active on young caterpillars and must be consumed or ingested to be

Fig 1. Young Bagworm Larva Or Caterpillar Feeding On Conifer (Auth–Raymond Cloyd, KSU)

Fig 2. Young Bagworm Larva Or Caterpillar Feeding On Plant Foliage (Auth–Raymond Cloyd, KSU)

effective. Therefore, thorough coverage of all plant parts and frequent applications are required. The insecticide is sensitive to ultra-violet light degradation and rainfall, which can reduce residual activity (persistence). Spinosad is the active ingredient in several homeowner products, including: Borer, Bagworm, Tent Caterpillar, and Leafminer Spray; Captain Jack’s DeadBug Brew; and Monterey Garden Insect Spray. The insecticide works by contact and ingestion; however, activity is greatest when ingested by bagworms.

Cyfluthrin, lambda-cyhalothrin, trichlorfon, chlorantraniliprole, and indoxacarb can also be used against young caterpillars. Again, thorough coverage of all plant parts, especially the tops of trees and shrubs, where bagworms commonly start feeding, and frequent applications are essential in achieving sufficient suppression of bagworm populations. The reason multiple applications are needed is that bagworm larvae do not hatch from eggs simultaneously, but hatch over time depending on temperature. In addition, young bagworms can ‘blow in’ (called ‘ballooning’) from neighboring plants on silken threads. If left unchecked, bagworms can cause significant damage and ruin the aesthetic quality of plants. In addition, bagworms may kill plants, especially newly transplanted small evergreens, since evergreens do not usually produce another flush of growth after being fed upon or defoliated by bagworms

If you have any questions on how to manage bagworms in your garden or landscape, contact your county horticultural agent, or university-based or state extension entomologist. You can also read the new extension publication on bagworms:

Cloyd, R. A. 2019. Bagworm: insect pest of trees and shrubs. Kansas State University

Agricultural Experiment Station and Cooperative Extension Service. Kansas State University; Manhattan, KS. MF3474. 4 pgs.

http://www.bookstore.ksre.ksu.edu/pubs/MF3474.pdf

–by Frannie Miller

–by Frannie Miller

Robber Fly– This is an example of a robber fly. They are great predators and feed on a wide variety of arthropods, such as wasps, bees, grasshoppers etc. Robber flies have bristled, strong legs to help aid in catching prey.

–by Frannie Miller

–by Dr. Raymond Cloyd

We are seeing damage on elm (Ulmus spp.) trees caused by the larvae and adults of the European elm flea weevil (Orchestes alni). Larvae are cream-colored, legless (Figure 1), and located in the mines of leaves. Adults are 3 mm (0.11 inches) in length, red-brown, with black spots or markings on the abdomen or wing covers (Figure 2).

Fig 1. European elm flea weevil larva (Auth–Raymond Cloyd, KSU)

Fig 2. Adult European elm flea weevil (Auth–Raymond Cloyd, KSU)

The mouthpart is shaped-like a snout (Figure 3)

Fig 3. European elm flea weevil adult (note the snout-like mouth) (Auth–Raymond Cloyd, KSU)

since they are weevils and the hind legs are thickened and enlarged, which allows the adults to jump when disturbed. Adults are initially active in May, and after mating, females lay eggs in the large mid-veins of new leaves. Larvae hatch from eggs and tunnel through the leaf as they feed, creating serpentine-like mines that enlarge as larvae mature (Figure 4).

Fig 4. Serpentine mines created by European elm flea weevil larvae (Auth–Raymond Cloyd, KSU)

Larvae eventually transition into a pupal stage, and then adults emerge in May through June. Adults primarily feed on leaf undersides creating small holes on young leaves (Figure 5).

Fig 5. Feeding damage caused by European elm flea weevil adult (Auth–Raymond Cloyd, KSU)

Feeding damage caused by larvae and adults will not kill an elm tree; however, extensive feeding damage may ruin the aesthetic appearance. Adults overwinter under loose bark and in leaf litter located under previously infested trees. There is one generation per year in Kansas. Nearly all elm species are susceptible to feeding by the European elm flea weevil; especially Siberian elms (Ulmus pumila) and certain elm hybrids with Asian parentage.

                Management of European elm flea weevil involves maintaining tree health by implementing proper watering, mulching, pruning, and fertilizing practices Insecticides can be used to minimize damage; however, insecticides are difficult to apply to large trees. Contact insecticides must be applied May through June to suppress adult populations. Be sure to read the insecticide label carefully to ensure that “weevils” are listed. Thorough coverage of leaf undersides is important because adults tend to feed on the undersides of leaves. If damage is not extensive, especially on large trees, then there is no reason to apply insecticides. 

–by Frannie Miller

–by Frannie Miller

Allium – This is an allium. Allium is a genus of plants, which include cultivated onions, garlic, shallots, and leeks etc. This version is cultivated as a flowering plant and will produce a purple, globe-shaped flower. Alliums also attract bees and butterflies to your spring garden.