Be sure to scout your lawn for summer pests
Hot summer days and expected thundershowers are ideal for your lawn grass to grow and get healthy from winter injury or spring diseases, but don’t let your guard down just yet. They are also ideal conditions for lawn insects.
Chinch bugs
Chinch bugs love St. Augustinegrass lawns. The adults of this destructive insect are only about 1/5 of an inch long. They are black with what appears to be a white “X” across their backs where their wings fold over. The immature nymphs may be pink to orangey brown with a single white line across their backs.
An indication of an early infestation is a subtle yellowing of the leaf blades. This is quickly followed by a thinning of the canopy and eventual death of the turf. These insects are somewhat unique in that they prefer hot sunny areas of the lawn over shade so their injury symptoms generally appear in an open area first.
To scout for these tiny insects in your lawn you will need to part the turf canopy to the soil surface along a line where there is a change from damaged yellowing turf to healthy green turf. They move rather quickly, so keep an alert eye for their scurrying back into the turf.
Carbaryl (Sevin®), cyfluthrin (Bayer Advanced Powerforce® Multi-Insect Killer), lambda-cyhalothrin (Spectracide® Triazicide® Insect Killer Once & Done! http://www.spectracide.com/NR/exeres/270496F7-8D96-4A61-B795-D104A8553FF0.htm and permethrin are labeled insecticides for their control.
Mole crickets
Mole crickets are not nature's most beautiful insect specimens. Adults are odd-looking light brown crickets. The front legs are short, flat, and shaped like miniature shovels well equipped for digging in your yard. The immature insects, or nymphs, look the same as the adults, just smaller. Both, however, feed on the grass roots.
Walking across your grass may give you a hint to an infestation. The sod will have an unusual fluffiness to it. Closer examination will reveal holes in the ground about the size of a pencil. Small burrowing trails can also be seen.
However, we always want to confirm the presence of mole crickets. Mix two tablespoons of lemon liquid dishwashing soap in two gallons of water in a sprinkling can, and pour the solution onto a two by two foot section of affected turf. If two to four mole crickets emerge within four minutes after applying the soap solution, insecticide use may be justified.
For more information on how to treat for mole crickets, review a University of Florida online publication at http://edis.ifas.ufl.edu/lh039.
White grubs
White grubs are the larvae of several species of beetles. They feed below ground, pruning the roots and weakening our lawns. A sign of a grub infestation is the digging of raccoons or armadillos in the lawn.
A full-sized larva is about one inch long, has a brownish-yellow head, grayish-black posterior, three pairs of legs, and are usually found curled in a C-shape. These insects may go unnoticed until severe turf damage is done.
Scout for them by cutting several one to two foot-square samples about two inches deep into the turf and then lift or roll the sod back to search for the grubs.
Because grubs are much easier to control when small the best time for control is mid to late summer. It is often difficult to determine the threshold of grubs before treatment is necessary, but generally treatment is suggested if three to five grubs are found in a one-foot square sample.
For more information on grub treatment, review the online University of Florida publication at http://edis.ifas.ufl.edu/lh037.
Theresa Friday is the Residential Horticulture Extension Agent for Santa Rosa County. The use of trade names, if used in this article, is solely for the purpose of providing specific information. It is not a guarantee, warranty, or endorsement of the product name(s) and does not signify that they are approved to the exclusion of others.
For additional information about all of the county extension services and other articles of interest go to: http://santarosa.ifas.ufl.edu <http://santarosa.ifas.ufl.edu/> .
