.2 E .2 5   A
Strawberry Insect Pests and Their Control
P. O. Ritcher
Insects are responsible for more reduction in strawberry yield than is
commonly realized. Too often poor growth of plants or delayed setting of runners
because of crown borer damage is blamed on dry weather. Also, poorly formed
berries are often blamed on frost damage or cold weather when plant bugs or
other insects are the real cause of the trouble. This past season damage from
either crown borer, plant bugs or the strawberry weevil was severe in many
Kentucky patches. Injury from plant bugs and strawberry weevil was evident
during harvest in the spring; crown borer injury did not show up until late in the
92222 Pmer
Injury. Plants are killed or stunted and runner formation is reduced. l
Crowns_of injured plants contain blackish tunnels made by the borer grubs
(Fig. 5). Injury is much worse in dry seasons.
Life history. The adult insect (Fig. 6) is a small brown and black snout '
beetle a—l;>*iE_l_/Tgxnch long, which overwinters in or near the strawberry patch ,
under litter or in the soil. Adults become active on warm days in February and
March and eat holes in the strawberry leaves from the underside. They lay {
eggs from l\/[arch on through the summer, either in the plant crowns or in holes `
gnawed in the bases of the leaves. Eggs hatch into small, whitish, legless
grubs which bore through the strawberry crowns and leave dark colored, winding,
frass-filled burrows behind them (Fig. 5). The oldest grubs become full grown
by early june and after a l_O—day pupal stage, new adults begin emerging late in A
june. Adults continue to emerge thru October. There is usually only one _  
generation a year and as a rule only mother plants are infested by the larvae.
Control, 1. Set new patches with plants that are free of borer. Use
plants from p-a-tches certified to be free from borer or use plants dug before
March ] and washed free of all soil or use plants fumigated with methyl bromide.
Z. Set new patches on land previously cultivated and that is not closer than 350
yards to old strawberry patches, patches of cinquefoil or wild strawberries all {
of which are often heavily infested with crown borer. 3. If necessary to set a i
new patch close to an old infested patch apply bait to crowns of newly set plants.
The best bait consists of dried, chopped, apple refuse coated with 3-l/Z percent Q
sodium fluosilicate or 2-1/2 percent lead arsenate. A half teaspoonful of bait  
should be applied to the crown of each plant. First application should be made
in March and again at lO day to 2 week intervals. 4. Burn over old strawberry
patches soon after harvest and plow them under. Don't leave old abandoned
patches over the farm since they are breeding grounds for crown borer and
other_ strawberry pests.