Grubby details

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first_imgBy Mike IsbellUniversity of GeorgiaThe rear end of a white grub isn’t a pretty sight. But if you’regoing to identify the grubs that are damaging your lawn,somebody’s got to look.That somebody is going to have to use a magnifying glass, too,which makes the grub’s rear end look even bigger.Lately, I’ve had a lot of calls about crows and even wild turkeysdigging up turf grass looking for stuff to eat. In a lot of thesecases, the birds are digging for grubs in the soil.Moles, skunks, raccoons and armadillos, as well as birds, all canroot up the turf hunting for grubs. And even if animals aren’tdigging, the grubs themselves can damage turf grasses.Damage symptomsMost grubs feed on grass roots, cutting the plants off from waterand nutrients. Damage from grubs appears as yellowing or browningof the leaves, signs of drought stress even when there’smoisture, and loose turf that pulls easily from the soil.A typical phone caller will say something like, “Mike, I was outmowing my lawn and my mower just tore up the grass by the roots.”Sounds like grub damage to me.Grubs feed most actively and are easiest to control during latesummer and early fall. But they may be active in warm periodsthroughout the winter.Main culpritsMore than a dozen species may damage turf in the Southeast, butthe main ones we have are green June beetles, chafers, Japanesebeetles and May beetles or June beetles.While white grubs in general are among the hardest turf pests tocontrol, the green June beetle grub is one of the easiest.Because they come to the surface at night, green June beetlegrubs come in contact with insecticides more readily than theother grubs that remain deeper in the ground.To check for white grubs, cut three sides of a square foot ofturf with a shovel. Then fold the sod flap back and look forgrubs in the top 2 or 3 inches of soil and roots.Some species can damage turf with just four grubs per squarefoot. Others can have 10 to 20 per square foot and still notdamage turf.Which grubs?If you find white grubs in your soil, how do you know which oneit is? Well, if it crawls on its back, with its legs sticking upin the air, it’s a green June beetle. I’m not making this up –they do crawl on their backs.If they don’t crawl on their backs, that’s when you use yourmagnifying glass. But you have to be willing to get close, andyou have to know what you’re looking for. It’s not for thesqueamish.With an identification key available from the Extension Service,you can identify the grubs you find. If you can identify them,your county agent can tell you what to use to control them.You don’t have to be an entomologist to identify a grub. But aproctologist? Maybe.(Mike Isbell is the Heard County Extension Coordinator withthe University of Georgia College of Agricultural andEnvironmental Sciences.)last_img

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