JUN Do you have Japanese beetles? Adult beetles are hard to miss. They feed on roses, Virginia creeper and some 300 plants, | leaving holes and damaging leaves, flowers and fruit. Young grubs develop underground and JULY JULY typically eat grass roots. A softball-sized patch of brown grass is a sign of hungry grubs. Know your bug: Popillia japonica Lifespan: 1 year, though adults live about 30 to 45 days Reproduction: Females lay 40-60 eggs Threat: Feeds on 300 species of plants, | AUG loves watered lawns July: Adults mate. Females lay eggs in the ground no more than 3-inches deep LARVAL STAGE Eggs hatch after two weeks. | August: UNDER GROUND SEP Grubs feed on grass roots for 3-4 weeks Fall-winter: Grubs burrow 8-10 inches or Credit: Whitney Cranshaw, Colorado State University below frost line during winter | CSU Q&A: bit.ly/CSUJapBeetle OCT April-June: Grubs head back to surface but stay underground to feed on roots and CSU Extension: bit.ly/CSUjb pupate into an adult USDA guide: bit.ly/japbeetle | NOV Treatment Pros & Cons TIPS • Traps attract beetles from • Insecticides can kill adult » Hand-picking beetles off plants 1-2 miles away, not just beetles, but must be sprayed can be effective for gardeners. | your yard. directly. Read labels to see if it » Beetles are less active early or DEC • Milky spore bacteria is hurts beneficial insects. late in the day when tempera- spread on lawns and in- • Natural predators include birds, tures cool. gested by grubs, which die. racoons and skunks. Also: par- » Crushing them is okay, dead But CSU says the treatment asitic wasps (Tiphia vernalis, beetles don’t attract live ones. | JAN inconsistent and impacts a Tiphia popilliavora), parasitic » small population. flies (Istocheta aldrichi), mi- If treating plants or turf, timing crosporidian disease (Ovavesic- is critical. Late summer is more • Beneficial nematodes are effective than spring. parasitic organisms that ula popilliae). » | Switch to xeriscaping or FEB feed on insect’s larval or • Drying out lawn (Jun-Aug) pupal stage. Pick nema- makes turf inhospitable but choose plants beetles avoid todes in the genus Heteror- grubs in a neighbor’s lawn can » Deep watering lawn once a habditis. Also need water to fly to your garden as adults. week keeps grass alive and survive and are pricey. Grubs need moisture to survive. too dry for grubs | MAR Resistant Plants Susceptible Plants How Palisade beat the Japanese beetle 1. Ageratum 1. Hollyhock 2. Columbine 2. Dahlia • Discovered infestation early | APR 3. Dusty-miller 3. Hibiscus • Community united over peaches (economic 4. Begonia. 4. Common mallow motivation) 5. Lily-of-the-valley 5. Evening-primrose • All lawns in public areas plus 712 homes 6. Coreopsis 6. Soybean treated or dried out | • Under authority of Colorado’s only horticul- MAY 7. Larkspur 7. Penn. smartweed 8. Foxglove 8. Rose ture pest-control district so property owners 9. California poppy 9. Grape could be forced to participate 10. Coral-bells 10. Sweet corn • Read the story: bit.ly/palisadeJB Illustration: Dale Taylor, Special to The Colorado Sun Reported by Credit: Whitney Cranshaw, Colorado State University; Colo. Dept. of Agriculture; USDA .