No. 8/July 29, 2020

Chinch Bugs
There are two species of chinch bugs that can cause damage to turfgrass in Illinois, the common chinch bug in southern and central Illinois and the hairy chinch bug in northern Illinois. Both species feed on Kentucky bluegrass, fescues, ryegrass, bentgrass and zoysiagrass. Common chinch bug also feeds on corn, wheat and sorghum.

Fall Webworm
Fall webworms (Hyphantria cunea) are communal caterpillars that spin silk into a tent-like structure at the tip of branches. These webs are often built around leaves they feed on. Fall webworms feed on a wide range of deciduous trees and shrubs, including, but not limited to, crabapple, redbud, sweetgum, maple and oak. As the caterpillars consume the leaves within the web, they will expand the web every week or so to include more leaves. The web of mature caterpillars can be 2 to 3 feet long.

Aphid Lions
Green lacewing larvae are out in force, eating aphids. These larvae are called aphid lions,  but more like little alligators than lions. They have large, curved and hollow mandibles which they use to inject a paralyzing venom and extract the juices of the aphid. After feeding, they throw the carcass down on the ground. One aphid lion can eat 600 aphids in 14 to 20 days. They also go for other small bodied invertebrates such as caterpillasr, beetles, scales, mealy bugs, leaf hoppers, thrips, and mites.

Crabgrass: Controlling This Season-Long Germinator
When there is an unknown weedy grass growing in a lawn, often crabgrass is quickly and inaccurately blamed. Further investigation typically reveals that the offending grass is often quackgrass or tall fescue. This week I saw the tables flip while some plant enthusiasts online were discussing the possible identification of a mystery seedling grass. Because it is late July, crabgrass was quickly ruled out and the fingers pointed instead towards quackgrass. Without any haste, control recommendations then moved that direction. When crabgrass is improperly blamed, I often think, “poor crabgrass” but this time found myself thinking, “poor quackgrass”.

Pear Trellis Rust
We’ve confirmed pear trellis rust (also known as European pear rust) on samples from Illinois a few times over the past several years. It is still a fairly rare rust disease in Illinois. Other gymnosporangium rusts diseases (cedar-apple, cedar-hawthorn, and cedar-quince) are still much more common and are found across the state. For more information about the common gymnosporangium rusts, please see this 2017 Home, Yard, and Garden Pest Newsletter article: So far, pear trellis rust has only been confirmed Illinois in northern counties.

Basil Downy Mildew
Basil downy mildew has been detected at several locations in northeast and east-central Illinois. This disease affects both homeowners growing a few basil plants for fresh harvest and commercial producers.

Choosing Grass Seed
How long does one take to purchase a new vehicle? It might take hours, maybe days or even months researching the features, comparing different brands, makes, models, engines, mileage, warranty, or test driving. The same thought and care should also be taken when choosing the seed for your lawn. Sounds crazy? It is not! This is the most critical investment in ensuring a high-quality turf that lasts.