Orange dog (Papilio demodocus) belongs to the family Papilionidae and is found in citrus growing regions. It is usually a minor pest to the mature trees but severe attacks are common in nurseries and on young trees. These insect pests are most abundant during the rains. It is also called Citrus Swallowtail, Citrus butterfly or Christmas butterfly
The female lays eggs singly on the citrus tree leaves which hatch after about 4-6 days. The larvae, after several days of feeding, attach themselves to branches with silk and pupate. This process takes about 24hours.The pupal stage lasts for 2-3weeks and adults emerge.
Orange dog goes through approximately three generations in a year.
- Eggs– they are spherical, whitish in colour with smooth outer shell, about 1mm long.
- Larvae– the immature ones are black, yellow and whitish with spikes. Their colour variation gives an effective camouflage, because they look like bird droppings. The mature larvae are green with white or pinkish markings and eyespots. They are about 45mm long.
- When threatened by predators the larvae use their orange osmeteria (‘horns’ which they can display and then retract) which emit a strong smell acting as a discouragement to the predator.
- Pupae– they vary in colour from yellowish-green to brown and are about 3cm long. Are in cocoons.
- Adults– The butterflies have black and yellow markings with blue and red eyespots. The forewings are black and have no tails while the undersides are yellow. They have a wingspan of about 100-160mm. Females are larger than the males.
- They are usually found sucking nectar from flowers.
Feeding & Damage
The larval stage is the most destructive. Caterpillars (larvae) feed on the leaves of the citrus plants and can completely defoliate young trees and devastate citrus nurseries. In the mature trees, these caterpillars attack the young and tender leaves.
Management & Control
Considering the damages caused by this pest, early control before getting to threshold level is essential. Various methods are integrated for its control and management. These include;
Chemical Method– this involves the use of insecticides. The following are effective against this pest.
- Kingcode Elite 50EC 10ml/20l
- Pentagon 50EC 10ml/20l
- Escort 19EC 10ml/20l
- Lexus 247SC 8ml/20l
- Profile 440EC 30ml/20l
- Presento 200SP 5g/20l
- Sinophate 750SP 20g/20l
Biological Method bio pesticides are used. For instance;
- Baciguard 16000WDG 15g/20l
This acts by multiplying bacteria strains on the Orange dog thus eliminating it.
- Whenever spraying the product, it is advisable to mix it with Integra 3ML/20L. This improves on the efficacy of the product, as it acts as a spreader, sticker and penetrant
- In order to prevent the insect from developing resistance against any of the pesticides, it is recommended that the pesticides be alternated.
- Timely application of the pesticides is very important.
Other Control Measures– These majorly the cultural practices and include the following;
- Field sanitation
- Proper weed control
- Crop rotations with non-host plants
- Use of predators