Swallowtail butterfly: Citrus Plant Pest

Swallowtail butterfly. Picture Source: Dave's Garden

Passionate gardeners often exhibit special affinity for the varieties of citrus plants to grow in their gardens, most common of which is a lemon tree. Citrus plants attract a variety of butterfly species to enter the gardens. These butterfly species’ larvae often are found to feed on these citrus plant leaves and foliage. One of the species known as “tent caterpillar” affects citrus plants but is not seem to be very harmful for lemon tree. While another very common butterfly species, swallowtail butterfly (papilio cresphontes cramer), whose larvae are very well known as lemon tree caterpillars or orangedogs caterpillars can drastically affect the foliage of a lemon tree or more precisely a growing shrub of a lemon tree.

Caterpillar of swallowtail butterfly
Picture Source: Pinterest

Identification of Orangedog caterpillars:
Orangedogs are easily identified as long worms of about 1 n half to about 2 inches with bodies blotched with brown or green coloured markings. In a quick eye view, they resemble the bird droppings and when feeling threatened, release slimy orange material with strong foul odour to protect themselves.

How to Control?
There are various solutions present ranging from chemical to biological control. For the application of chemical insecticides, gardeners must use selective targeted chemicals to prevent any harm to the plant as recommended by University of California.

• Mix insecticide soap in a water in a bucket. Hands pick the worms and throw them in bucket to kill them. Use the same mixture of insecticide soap and water and pour it in spray bottle and thoroughly spray the mixture over the plant in their nests. Apply this procedure every seven to ten days or otherwise specified on the insecticide soap label.

The highly recommended is the biological control, which University of California suggests, can be done using the bacterium sprays or species of wasps.

• Eco-friendly gardeners suggest the use of Bacillus thuringiensis (bacterium species commonly known as Bt) spray. Use the Bt spray in April when usually these caterpillars start to emerge on your plant. Always remember to thoroughly spray on all the leaves.
• Another biological control is by using species of wasps such as Hyposoter spp. and trichogramma. Spread the eggs of these wasps using cards, as much eggs as 40,000, in the branches of trees. Once these eggs sprout, they will start feeding on the larvae of these caterpillars.

Natural insecticides can also be prepared at home.

• Use 6 cloves of garlic, 1 tbsp of liquid detergent and red paper powder and 5 cups of water to create an insecticide mixture. Pour it in spray bottle and spray over the plant or tree. Cover all the foliage evenly. Orangedog larvae avoid leaves coated with this mixture. Apply the mixture every seven days.

Other ways might include use of sweet fennel as lemon tree caterpillars attract to the fennel. Simply spread the strips of fennel around your plant and mow it on regular basis. You can also hand pick the worms when spotted or simply see for their eggs on top of leaves and crush the eggs.

Warnings:

• Always read the instructions on the insecticide soap label thoroughly.
• Use gloves while applying either chemical or natural insecticide as it can cause irritation to skin it comes in contact with. Also try to cover the nose and eyes as it might be an irritant to your eyes.