“My roses are being devoured! What’s eating them?”
Like many gardeners in our part of Alabama, roses have a place in our hearts and yards. We may have a few bushes, or cover our property with as many plants as space allows. We look forward to the colors, fragrances, and impact of these bushes when they bloom in late spring and early summer.
But there is another creature that also watches our roses with hungry eyes, one that is up to no good. This critter can destroy a June bride’s dream of walking a path lined with beautiful flowers in the space of a weekend, leaving blooms shattered and leaves resembling grandma’s lace handkerchief!
The villain in this drama? Likely Popillia japonica, or Japanese beetle. This non-native member of the Scarabaeidae, or scarab beetle family, was inadvertently imported into New Jersey about 1916. From that point, the beetles spread west and south, leaving a trail of frustrated gardeners and farmers in their wake, as not only roses but grapes, Japanese maples, Hollyhocks, cherry, plum, and peach trees are favored by these eating machines.
If anyone living in the southeast isn’t familiar with this pest, glance at the pictures below, as once you’ve seen them in action, they are unforgettable.
So where do these infernal insects come from, and how can we reduce damage to our landscapes?
Starting in late May or early June depending on location, adults emerge from the ground and begin feeding during a 4 to 6 week frenzy, after which their numbers decline as adults die. But before dying, the mated females burrow a few inches into the ground in a suitable area, laying eggs near favorite food sources, so the next generation will have a readily available meal upon hatching! Adult beetles feed on plant leaves and flowers, while white grubs, the larval form of the insect, feed on the roots of our turfgrass – especially those turfgrass lawns that are irrigated on a regular basis!
How to Take Control
Controlling the beetle is a 2-pronged approach with one prong targeting adults, the other for white grub larvae.
Japanese beetles on roses (and other plants) attract more beetles, so removing a few of them before an entire crowd accumulates is helpful. Shake them off plants into a container of soapy water. Some more rabid gardeners substitute alcohol for soapy water – either works especially early in the morning when the beetles are sluggish.
For chemical control, there are several products labelled for adult Japanese beetles. Bayer, Ortho, Spectracide and other brands offer products that control beetle feeding for 2- 3 weeks. Read label instructions before using the product to ensure the most efficient control of the beetles and little or no damage to non-target species, such a honey bees.
A word of warning regarding Japanese beetle traps: some research indicates traps attract more beetles than they actually catch, which may mean you’ll have more damage ‘with’ than ‘without’ them.
Controlling white grubs necessitates proper timing of soil applications in areas associated with beetle populations. Products containing imidacloprid or halofenozide are applied to target areas i.e. lawns or orchards before eggs hatch. Extension ANR – 1250 “Japanese Beetles in Alabama” further explains the importance of timing during this process.
We won’t eliminate Japanese beetles from our landscapes, but we can reduce populations both in the current season and for next year!
Contact your county Extension office for additional information and advice.
By Sallie Lee, Urban Regional Extension Agent, Alabama Cooperative Extension System. Contact Sallie at firstname.lastname@example.org.
The Alabama Cooperative Extension System (ACES) operates as the primary outreach organization for the land-grant functions of Alabama A&M and Auburn Universities. ACES is committed to affirmative action, equal opportunity and the diversity of its workforce. Educational programs of ACES serve all people regardless of race, color, age, sex, religion, disability, sexual orientation, or national origin.