To celebrate Halloween, bug of the week features four stylish bugs dressed in orange and black. Our first bug, the orangestriped oakworm, is more of a trickster than a treater. This leaf-eating caterpillar has a real appetite for oak although maple, birch, and hickory are also on its menu. The adults of this insect, moths, deposit eggs on the under surface of leaves during June and July. Eggs hatch and small greenish-yellow caterpillars munch leaves. As they grow their bodies turn charcoal black with orange lines that run from head to tail. Two long, devilish horns adorn the first body segment just behind their head. Oakworms often feed in large clusters. They can be very abundant and damage trees along streets. If you find a gaggle of oakworms, you can easily put an end to their shenanigans by simply pruning or picking them out of the tree.
This harlequin bug was causing severe damage to Pam's tomatoes.
Harlequin bugs also sport an exoskeleton of black and orange. This harlequin bug was in the process of devouring some tomatoes when captured in September. Like our friend the assassin bug (see It's the wheel thing, the wheel bug, Arilus cristatus, November 23, 2009 ), the harlequin bug has sucking mouthparts that pierce plant tissue. These little vegetarian vampires suck the life out of plants. Heavily infested plants turn brown, wilt, and may die. Sometimes large acreages of agricultural crops are ruined by harlequin bugs. In addition to tomatoes the harlequin bug is a common pest of cabbage, cauliflower, Brussels sprouts, radish, potato, eggplant, beans, asparagus and many other fruits and vegetables. Eggs of the harlequin bug look like tiny black and white barrels laid in clusters. If only a few harlequin bugs are found causing damage, they can be removed by hand, but when abundant, insecticides may be needed to prevent damage to plants.
Milkweed bugs gain protection from toxic chemicals found in the milkweed plant.
The large milkweed bug belongs to a family of sucking insects known as seed bugs. In the wild this bug is commonly found on the developing seed heads of milkweed plants in late summer and autumn. During her lifetime, the female milkweed bug may lay up to 2000 eggs. Small orange and black nymphs hatch from the eggs and eat seeds of the milkweed. Like other milkweed feeders such as the monarch butterfly (Bug of the week August 8), the large milkweed bug obtains poisonous compounds from the milkweed plant that are used in its own defense. The bright orange and black coloration warns predators such as birds to stay away and leave it alone.
Milkweed tussock moth caterpillars are another orange and black denizen of the milkweed plant.
The final member of the orange and black quartet is the larva of the milkweed tussock moth. These hairy orange and black larvae bear a striking resemblance to Cousin It. Sometimes a dozen or more of these hairy monsters can be found on a single milkweed plant devouring the leaves. Like the monarch caterpillar and milkweed bug, poisonous chemicals in the milkweed plants likely protect this leaf eater from its predators.
References
For many insects dressing right is the key to survival and to avoid an attack, they don orange and black. Happy Halloween, and below are links to more information about this week's featured bugs:
http://www.mda.state.md.us/plants-pests/forest_pest_mgmt/gypsy_moth/
md_hardwood_defoliators/orange_striped_oakworm.php
http://creatures.ifas.ufl.edu/veg/leaf/harlequin_bug.htm
http://www.life.uiuc.edu/ib/109/Insect%20rearing/milkweedbug.html
http://booksandnature.homestead.com/moth94.html