The infection begins with the corn borer piercing insect of corn plants at a height of about one meter, i.e. at the age of 40-50 days. Until it completely disappeared.
The infestation of this insect intensifies in crops, which are planted late in July and August, and the infestation increases gradually until the crop is cut off, where the infection rate reaches 100%.
The larvae begin to hibernate from early October to early May inside the tunnels in the stems, cobs, or male inflorescences. The larvae prefer the middle of the corn borer, as well as the corn cobs.
life cycle of the corn borer.
corn borer in the form of fully-grown larvae passes through the tunnels inside the corn stubble, and the butterflies begin to hibernate in mid-June.
The female lays eggs in the form of grafts superimposed on each other, such as fish scales, on the two surfaces of the upper and lower leaves.
The number of eggs in the mass is about 15 eggs, and the average number of eggs that the female lays is about 450 eggs, and the eggs hatch after 5-7 days and come out. Larvae feed on the inner surfaces of the leaf sheathing.
Then the larvae start digging the stems, starting from the third age and the larva has 4 + 5 larval ages. The growth of the single larval stage is completed within 2-3 weeks, and then the larva turns into a pupa inside a silk cocoon in the tunnel, leaving an open hole for the full insect to emerge from.
The European corn borer piercing insect has 4 generations per year from the beginning of July to October, and the larvae of the fifth and sixth generation enter the winter hibernation.
Appearance of corn borer piercing insect:
After hatching, the larvae feed for several days on the surface of the leaf near the place of their hatching, making small irregularly shaped holes on the blades, where the third and fourth instar larvae burrow into the stems, making tunnels along the stem penetrating the cuttings of plants and these tunnels are narrower and shorter than those made by the large cane worm Due to the smaller size of the larvae than the larvae of the large cane worm.
Holes appear on the stem from which the excrement of the larvae emerges. The appearance of the infection and the place of its feeding differ according to the stage of plant growth. At the age of 45 days.
the larvae usually attack the middle of the stem and at the end of the season, i.e. from September, October, and November, the insect can be present on the whole plant and enter The larvae of the cobs through the stalk holder as they enter into the male inflorescence holder and cause breakage of the male inflorescences and then the fall of the cobs.
Corn borer damage
corn borer damage
Piercing Insect Control:
1- Planting should be done at the recommended time from mid-May to mid-July.
2- Moderation in irrigation and nitrogen fertilization and disposal of corn stubble before the month of March.
3- Using items that can bear the injury.
4- Chemical control is carried out when the number of eggshells reaches 22-25% by spraying with one of the following pesticides:
* Stepban 48% EC pesticide at a rate of 1 liter/acre.
* Or Bichlorox 48% EC pesticide at a rate of 1.25 liters / feddan.
* Or chlorophyt 48% EC at a rate of 1.25 liters / feddan.
* Or Halban 48% EC at a rate of 1 liter/acre.
And when spraying pesticides, the plants must be completely covered, any washing of the plants, whether the surface of the upper leaves or the surface of the upper leaves.