Scientific Name: Pectinophora gossypiella Saunders
Stages of Pink Bollworm
Pink bollworm has 4 stages that is egg, larvae, pupa and adult.
Eggs are elongating and oval having 0.1mm length and 0.5mm width. Newly laid eggs are slightly greenish in colour but at maturity they turned reddish.
The larvae are white with a dark head at initial stage. The full-grown larvae are 10 to 12 mm long and are white with a double red band on the upper portion of each segment.
The pupa is almost 8 to 10 mm long, reddish brown; posterior end pointed and terminating in a short, no long setae, spines or hooks, except on last joint. At maturity, the pupa becomes much darker; the adult’s eyes can be seen prominently under the gena of the pupal skin, and the segmentation of the adult antennae and legs becomes discernible.
Dr. Faisal Hafeez, Ayesha Iftikhar, Muhammad Sohaib.
Ayub Agricultural Research Institute (AARI) Faisalabad.
They are brown with a wingspan of 15 to 20 mm.
The adults are dark-brown moths measuring about 12 to 20 mm across the wings. The head is reddish brown with pale, scales. Antennae are brown and the basal segment bears a pecten of five or six long hair-like scales. The have scaled proboscis.
Forewings are elongating and oval, pointed at the tips and bearing a wide fringe. The hind wings are broader than the fore wings, and silvery gray in colour with a darker, iridescent hind margin.
Host preference of pink bollworm larvae:
Cotton bolls were collected from cotton sticks placed at field area of Entomological Research Institute, (AARI) Faisalabad. Cotton bolls were brought into Biological Control Laboratory. The larvae were separated from cotton bolls into a petri dish (6cm×0.5 inches). Further these larvae were used to check the host preference. The environmental conditions were 25 ± 30 % RH and 55 ± 65 ®C Temperature.
Three Choice Bioassay:
A glass petri dish (15 cm× 2.5 cm) was used having weight of 218.39 grams. Three hosts including okra, Abelmoschusesculentus, cotton, Gossypiumhirsutumand tomato, Solanum lycopersicum after weighing themthose were placed in petri dish at different positions. okra (3 g), cotton (2.53 g), tomato (5.81g). It was observed that larvae moved towards cotton boll after 6 minutes and started feeding.However, it reached on okra after 10 minutes. This showed that larvae preferred cotton as compared to other hosts.
Two Choice Bioassay:
In the presence of okra and tomato, it preferred okra but didn’t feed as good as on cotton. Similarly, in case of cotton +tomato and okra +tomato, it preferred cotton and tomato respectively.
Free Choice Bioassay:
In free choice assay, above three hosts were placed in separate petri dishes and larvae was released at centre and stop watch was on. It was observed that towards cotton boll larvae moved within 4 minutes and start feeding, while it moved towards okra after 8 minutes and didn’t feed well and it reached on tomato almost after 15 minutesbut didn’t feed at all.