The pink boll worm, Pectinophora gossypiella (Saunders), is a lepidopterous insect that feeds within the fruiting parts of malvaceous plants.
Host plants include more than 45 species, of which cotton is the most important. Larvae of the pink bollworm enter the fruit of the cotton plant and feed on the contents of the bolls or fruiting buds (squares). Owen and Calhoun (1932) determined under field conditions that most of the eggs hatched 4.5 days after deposition at a mean temperature of 83.04°F.
They found that the total length of the developmental period for non-diapause larvae from egg deposition to moth emergence averaged 26 and 32 days for those reared from squares and bolls, respectively. Lukefahr and Griffin (1961) found that the rate of larval development was faster in squares than in bolls.
They also found that as the age of squares and bolls increased, larval development was faster. Lukefahr and Griffin (1957) determined that copulation in this species occurred between the hours of 2 and 5 A.M., with the peak of mating occurring about 3:30 A.M.
The peak of egg deposition occurred on the third night after emergence, with more than 50% of the eggs laid between 8 and 10 P.M. A light intensity of 0.02 ft-c or below appeared optimum for moth activity and oviposition; however, these activities were sharply reduced at temperatures below 70°F.
Due to the low temperature in November, it goes to the state of hibernation. The phase of pupae depends on high temperature. A moth that emerge early in May die due to the absence of cotton, later they cause damage to the cotton.
The breeding season of this Pink bollworm grows very fast in September and this is the time when tendons are more abundant on cotton plants and the attack on PB worm is also prominent.
Hibernation is a complex process that depends on high temperature, length of the day. When the cotton crop end there are many larvae in the bolls that did not open. The rains in August and September help the attack of PB worm
Pink bollworm is one of the most dangerous cotton pests found in almost all the cotton-producing countries in the world. This insect is more invasive in Asia and Africa than in the United States. In North Australia, the Pink bollworm caused major destruction.
The severe attack of Pink Bollworm occurs on cotton when flowers and stems were abundant. First, it enters the flower and closes the heads of its leaves with the saliva that comes out of its mouth. The infected flower does not open and PB worm eats it’s male and female parts, but when the crop becomes tender, it enters through the holes in the small soft tendons and keeps eating the seeds inside.
And the affected boll of cotton cannot be identified. The number of PB worm in cotton boll may be more than one. The affected boll does not fully open and the cotton fiber becomes weak and thin. It affects about 100 million bales every year, worth about one billion rupees.
As this worm spends its time inside the bolls and tendons, its chemical control is difficult.
PB Ropes
PB Rope is a thin tube of about 6 inches of fiber. In which the aroma of the pink bollworm substance is kept in a fine tube in the form of chemicals. These ropes are planted in a block of at least 25 acres 150 – 100 ropes per acre.
In the block of PB ropes, the aroma of the substance spreads so that the male cannot find the female, and because of the sexual disruption between the male and the female, the egg that gives the egg does not fertilize. The number of Pink bollworms does not increase and the crop is protected from the attack of Pink bollworm for at least 90 days.
How to use PB ropes
1: Apply at least 25 acres in PB form
2: Apply a twist to the PB form with the trunk of the plant
3: Be careful that PB ropes do not touch the ground.
4: Apply PB ropes in all acres of the block.
Chemical control
Use the following poison in case of an excessive attack of pink bollworm.
1: Indoxacarb
2: Leufenuron
3: Trizophos
Authors: Faheem Shoukat, Alamdar Hussain, Shakeel Ahmad
Department of Entomology, MNS University of Agriculture Multan