The Chinch Bugs

Injury and Damage
Chinch bugs suck the sap from turf grasses, causing yellow patches that grow larger through the summer. Chinch bugs are quick to move into poorly tended lawns with compacted soil and thatch. To spot them, all you need to do is remove both ends of a tin can, push it into the ground and fill it with water. The chinch bugs will float to the surface. The larvae chew grass at the base of the stems, weakening the lawn and causing the most severely affected areas to die during hot days. The symptoms are similar to those of drought. In severe infestation, chinch bugs can destroy the whole lawn.

Description and Biological Cycle
The adult chinch bug (Blissus leucopterus hirtus) is a very small black insect ( 4 mm length); at rest, its white wings draw an X on its back. At immature stage or larvae, the body is red with back curved in distinctive white bands. Approaching adult stage, their coloring passes from orange to brown, then black. The larvae are deprived of wings. The adults pass winter in groups at the base of trees and shrubs or hidden under decaying materials, at the edge of the lawn or flower garden. Mating takes place in spring or the beginning of summer when the temperature reaches 20 °C. During the following month, the females deposit between 200 and 300 eggs on the underside of leaves or on the roots of grass. The eggs take 30 to 40 days for maturation. The larvae cause the most serious damage, usually in June. The young chinch bugs reach adult stage in July.

Gravity of infestations
The adult chinch bugs give off an unpleasant odor when crushed. If you smell this odor when walking on your lawn, be aware! Your lawn could be seriously infested. Pull aside the turf of grass and inspect the surface of the ground in order to detect the possible presence of red larvae or black adults.

How to proceed:

• Cut out the bottom of an empty box (metal) of coffee or juice and insert this box 5 cm in the ground. Fill the box with soapy water. Wait five to ten minutes. If your lawn is infested, you will see bugs floating on the surface. Repeat this operation in different corners of the lawn.
• If you find 5 to 10 bugs in your box, the infestation is sufficiently serious to damage your lawn. A healthy lawn will tolerate a population of 2 or 3 bugs per box. On the other hand, a low population can be harmful to poorly maintained lawn.

Preventive measures
The chinch bugs prefer poorly maintained lawns, full of vegetable debris and established on compacted, dry soil with high nitrogen content. A well-maintained lawn is less likely to be attacked and, in case of infestation, tolerates better the damage caused by the pest. The following practices can help prevent the infestations or mitigate the effects of them:

• If you redo a lawn, plant endophyte-enhanced varieties of grass. Chinch Bug does not like to feed on grasses infected with the fungus Acremonium.
• A thick thatch layer provides many sheltering sites for chinch bug, and improves their winter survival; reduce excess thatch through proper lawn care practices.
• Aerate the lawn in spring to reduce the compaction of the soil;
• Chinch Bugs thrive in hot dry conditions. Water droplets may seriously damage young nymphs. Water lawns regularly beginning in late May to reduce the pest population.
• Chinch Bug does not like to feed on grasses infected with the fungus Acremonium. Plant endophyte-enhanced varieties of grass.
• Chinch bugs prefer feeding on soft young grass. This type of growth is stimulated by applications of high nitrogen fertilizers. When you suspect you have a problem with this pest, modify your fertilizer application schedule.

Injury and Damage
Beetle grubs (larvae) feed on grass roots. As the roots are destroyed, the turf wilts and turns brown. As you walk across your lawn, the affected areas will feel soft and spongy. These spots can be lifted up with ease. If your lawn has yellow patches, try pulling the grass up in those areas. If it lifts up like a carpet, grubs may have severed the roots of the grass. If you see birds pecking away on your lawn, a skunk digging, or groundhogs burrowing, check for white grubs before chasing the animals away.

Description and Biological Cycle
The white worms most known are the larvae of the following insects:

• the Grub of Saint-Jean
• the European grub
• the Japanese beetle

The grubs are white or yellowish and have fleshy, wrinkled C-shaped bodies, with tan or brown heads and 6 spiny legs. They are quite small upon hatching, but at maturity can measure from 2 to 2.5 cm long, depending on the species.

Treatment
It is recommended to inspect the lawn at the end of the summer or the beginning of the autumn to detect the presence of grubs, before they have time to make considerable damage. Cut a piece of soil with a cheval and check for hiding white larvae. The maintenance of a good level of moisture in the lawn contributes to limit the damage of the white worms.

The Sod Webworms

Injury and Damage
The caterpillars (webworms) chew grass off at the base of the stems. As the larvae develop, the browned grass increase until complete destruction. The tufts of dead grass are torn off easily, revealing silk masses mixed with soil particles. In healthy lawn, the damage is less visible, but in seriously damaged or dormant zones you can expect to see pieces of lawn at ground level. At first sight, the damaged zones could resemble the remainder of the dormant lawn, but after the rain, the chewed zones will remain brown. The minor damage at the beginning of summer can worsen in august and september following the increase in the population. The presence of birds is also an indication of their activity.

Description and Biological Cycle
The webworms are caterpillars of the butterflies of the lawn that you often see circling around the house in the evening. Small night butterflies measuring between 0,6 and 1,2 cm length. The immature stages or caterpillars measure up to 2 cm length. They are of white-greyish color with a series of darker spots on the back.

Treatment
During the day, the caterpillars hide inside the tunnels. You can see them in the evening with a flashlight or if you sprinkle them with soapy water. Bacillus thuringiensis (B.t.) is very effective against the caterpillars. If you see butterflies, wait two weeks before treating with B.t. Apply more treatment the next spring. Try the soapy water treatment: 25 ml of pure liquid soap or 50 grams of toilet soap for 4 litres of water, once per week during a few weeks. A mixture of garlic juice with 4 ml of friction alcohol in 4 litres of water can also be used; the spreading of ash of wood, lime or rye flour on the caterpillars make them die by asphyxiation. The caterpillars like the presence of thatch. Plough and aerate the lawn. Sow the stripped places.

Wireworms and Click Beetles

Injury and Damage
The wireworm is the larva of the click beetle. Wireworms live in the soil and feed on roots, severing them at ground level. They thrive in poorly drained, moist compacted soil.

Description and Biological Cycle
Wireworms are the larval stage of click beetles. The adult beetles range in length from 10 to 16 mm, are hard bodied and brown or black. All wireworm larvae are similar in outward appearance. Newly hatched wireworms have three pairs of thoracic legs, are white and measure about 1.5 mm in length. Later, they become yellow or light brown, with a shiny smooth exterior. The larval body is elongate and nearly cylindrical, but somewhat flattened beneath and, at maturity; it measures up to 3 cm long.

Depending on the species, the life cycle ranges from 2 to 6 years, with 2 to 5 years being spent as actively feeding larvae. In chronically infested areas, all larval instars may be present at the same time during the growing season. Typically, mature larvae pupate in earthen cells in the soil in late summer or early fall and within three weeks develop into adults that over winter. The adults emerge from the soil the following spring or summer, and mate, after which the females burrow 2.5 to 15 cm into the ground, where they lay 50 to 300 eggs. The females are poor fliers, so the spread of infestations from field to field is slow. The egg stage lasts 3 to 4 weeks and the young larvae will feed on plant residue or the roots of many crops and weeds. Larvae move upward or downward in the soil, responding to moisture, temperature and the presence of food.

Treatment
Use the same treatment as for grubs, and remember to aerate the soil.