Keep Eyes And Ears Open For Corn Wireworms

Photo by Lyle Buss
Photo by Lyle Buss

Crops Affected

The corn wireworm (Melanotus communis) is a major pest of corn, sugarcane, potatoes, and sweet potatoes. It also may attack carrots, cucurbits, beans, peppers, and celery, as well as various grasses and flowers.

Identification

Wireworms attack mostly seeds, roots, shoots, and crowns of plants below the soil surface. In corn, damage appears in the form of hollowed out corn kernels, leaving only the seed coat. In later stages, larvae also may cut off small roots or tunnel into underground portions of the root or stems of young corn plants. The damage can be recognized in a field by the presence of gaps in rows or stunted or wilted plants with whorl leaves wilting first.

In potatoes, corn wireworms destroy planted seeds, tunnel into plant stems, and bore into roots and crown tissues. They feed on the seed pieces, causing weak stands. But the major yield losses are due to tunneling into tubers, leading to rotting.

The adults are commonly known as “click beetles.” The larvae are hard-bodied and darker colored than most maggots or grubs. They are glossy and yellow-brown, with a wire-like hard, cylindrical, jointed body ranging from 0.51 to 1.5 inches. First-instar larvae are pale yellow and change to reddish brown in later stages. First-year larvae do not cause significant damage.

Survival And Spread

Overwintering adult beetles are nocturnal and emerge from soil in late March or early April. They are most numerous in Florida during April to August, with peak oviposition in May.
Mated females prefer weedy or grassy fields for egg laying. The eggs are tiny and are usually laid in batches of 50 to 130. The larvae develop throughout the summer and overwinter as second-instar larvae in the soil. Most continue to develop over the next five years and undergo molting once or twice each year, but some larvae develop fully in three years. The larvae pupate in the soil for two weeks before emerging as adults. This is the only stage of wireworms that is found above ground.

Management Methods

Scouting of wireworms is very important for its management and it can be achieved by using bait traps. Fields with high wireworm densities in the past tend to retain populations over the years. Low-lying areas and high organic matter also promote wireworm populations.
Few predators and parasitoids are reported for biological control of wireworms. Pre-plant disking and summer plowing of fallow fields might reduce populations but does not prevent Melanotus communis from reaching economically damaging levels. Planting rice or fallow field flooding may eliminate the need to use a soil insecticide the following season.

No insecticides are available for wireworm control once the crop is planted. Preplant broadcasting and furrow application of soil insecticides are commonly used as a preventative measure. Newer insecticides provide effective wireworm control with less environmental impact and fewer potential human safety concerns compared to organophosphates. Consult UF/IFAS recommendations for currently labeled insecticides for wireworm control in Florida vegetables.

Topics: , ,

Leave a Reply

Crop Protection Stories
Crown gall on a trunk of French hybrid ‘Chancellor’ before and after bark is stripped away. Galls appear in spring as white callous tissue, most often at the base of the trunk, gradually turning green/brown and finally dying to turn into dark brown/black corky tissue. (Photo credit: Penn State University)
Cold Protection
June 15, 2016
Several Severe Winters Causing Crown Gall Concerns
Although this past winter may be considered more mild, severe cold the two winters prior in the Midwest and Northeast Read More
A new robotic weeder has been developed by France-based Naïo Technologies and is making its debut four years after the launch of the company’s autonomous weeding robot for small farmers, called Oz. The new robot, Dino, however, is designed for vegetable farms with 24 acres or more, and is now available worldwide.
Crop Protection
June 15, 2016
Robotic Weeder Makes Its Debut
Developed in France, the autonomous, electric-powered, lightweight machine doesn’t compact soil and operates for up to eight hours. Read More
cash money in hand
Citrus
June 14, 2016
Monsanto Rejects Second Bid From Bayer
Wall Street Journal reports Monsanto seeks bid increase from Bayer. Read More
Photo credit: USDA
Fruits
June 14, 2016
Stink Bug Pressure Could Be High This Year
Low overwintering mortality means growers should be trapping and monitoring. Read More
Closeup of Q-biotype or B-biotype whitefly
Cucurbits
June 14, 2016
Worry Spreading In Florida Over Exotic Whitefly
UF/IFAS expert warns species likely to cause problems for growers. Read More
Hull rot of almond causes spur and limb dieback, potentially reducing future crops. (Photo credit: University of California Cooperative Extension.)
Disease Control
June 7, 2016
Avoid Almond Hull Rot With Deficit Irrigation
As growers approach almond harvest later this summer, strategies to reduce the likelihood of hull rot should be a top Read More
Satellite image of Hurricane Katrina
Crop Protection
June 6, 2016
Bayer Teams Up With Aerospace Company To Provide Satellite Images
Collaboration with Planetary Resources is designed to arm growers with information to save water, etc. Read More
The Latest
Crop Protection
June 23, 2016
Scientists Selected To Work On Healthy H…
The four-year, $1 million program has a goal of improving the health of honeybee colonies. Read More
Crop Protection
June 15, 2016
Robotic Weeder Makes Its Debut
Developed in France, the autonomous, electric-powered, lightweight machine doesn’t compact soil and operates for up to eight hours. Read More
Citrus
June 14, 2016
Monsanto Rejects Second Bid From Bayer
Wall Street Journal reports Monsanto seeks bid increase from Bayer. Read More
Crop Protection
June 6, 2016
Bayer Teams Up With Aerospace Company To…
Collaboration with Planetary Resources is designed to arm growers with information to save water, etc. Read More
Crop Protection
June 6, 2016
Tessenderlo Kerley Opens Research And In…
Farm will allow company’s Crop Vitality division to try out materials under real world conditions. Read More
Crop Protection
June 5, 2016
How To Manage Consperse Stink Bug In Tom…
Tips to control the pest include pheromone traps, sanitation, and site selection. Read More
Crop Protection
June 3, 2016
Stockton Group Puts Stock In Crop Protec…
Industry veteran hired to help bolster global biopesticide business. Read More
Citrus
June 1, 2016
Groups Make Push To Challenge DuPont, Do…
Letter from industry organizations say proposed merger could hinder innovation, raise prices, and reduce choices. Read More
Crop Protection
June 1, 2016
5 Major GMO Myths Debunked
Disproving the myths associated with the technology and highlighting lesser-known truths may help improve public reception. Read More
Crop Protection
May 31, 2016
Study: Honeybees Collect Urban Pesticide…
Purdue research indicates pollen is consistently contaminated with not only agricultural, but urban pesticides. Read More
Crop Protection
May 31, 2016
A Preventive Approach Reduces Infection …
Conditions favoring disease development and spread have led to the establishment of early warning or forecast programs for late blight and early blight. Read More
Crop Protection
May 31, 2016
Radish Cover Crop Suppresses Weeds, Boos…
In trials conducted at the University of New Hampshire, the cover crop was consistently among the highest biomass-producing treatments in the fall. Read More
Crop Protection
May 25, 2016
More Apps Help Growers Identify Insects …
Berries, apples, pears, and cherries now rolled into new app series from Clemson University. Read More
Citrus
May 25, 2016
Monsanto Says Bayer Bid ‘Financially Ina…
Proposal cited as undervalued, not able to address financial, regulatory risks. Read More
Citrus
May 23, 2016
World Health Organization Experts: Glyph…
Risk unlikely when consuming crops treated with herbicide. Read More
Citrus
May 19, 2016
Bayer Makes Bid For Monsanto
Monsanto says proposal is being reviewed by board of directors as well as legal and financial advisors. Read More
Crop Protection
May 16, 2016
New Fungicide For Lettuce And Strawberry…
The product from Summit Agro USA is for use to control botrytis gray mold in strawberries and Sclerotinia drop in lettuce. Read More
Citrus
May 10, 2016
Survey: Beekeepers Lost 44% Of Bees Last…
Responses indicate summer losses rival winter losses for second year in a row. Read More
[gravityform id="62" title="false" description="false"]