Tuesday, July 16, 2013

UST GS Beware of the Spiny Caterpillar - Higad!

Beware of the Higad! (Tussock Moth Caterpillar)
Dr Abe V Rotor
Living with Nature - School on Blog
Paaralang Bayan sa Himpapawid (People's School-on-Air) with Ms Melly C Tenorio
738 DZRB AM Band, 8 to 9 evening class, Monday to Friday [www.pbs.gov.ph]

Adult of the tussock caterpillar is a gray moth with markings that serve as camouflage. It undergoes four stages.  The pupal stage is short, about a week. The caterpillar undergoes four or five moltings.
First aid: Train melted candle over embedded bristles, then carefully peel off. Apply vinegar on the affected area to dissolve remaining bristles. Do not rub.

Higad - caterpillar of Tussock Moth (Budo-budo Ilk).Tussock moth caterpillars in three stages (instars), pupa (left, scantily covered with cocoon thread), molted skin (lower left), and frass or waste. Snowy tussock moth mimic the color and pattern of its host tree, and growing lichens.

We call it samrid in Ilocano, higad in Tagalog and Pilipino. It is perhaps the most avoided insect next to the putakti or paper wasp. Unlike the latter, the injury one gets by contact with this spiny caterpillars is far reaching - it can spread to other parts of the body. Thus the rule is: Never rub - not even touch, the affected area. If feasible, light a candle, train the drops on the embedded spines, allow to solidify, then lift off. In this way the spines are pulled out without much damage. Apply vinegar to neutralize the alkaline chemical substance. Taking a bath without vinegar treatment will only spread the minute Neptune spear. There are people who are extremely allergic to higad that they need immediate medical treatment with antihistamine drug.
This species of Tussock Moth caterpillar belongs to Family Lymantiidae, Order Lepidoptera.  It is a commonly found on Fire Tree (Delonix regia) which blooms in summer. The colorful caterpillar, about an inch long in its last instar, dangles from the tree with spinneret and sways in the slightest breeze. It often lands on a passerby and causes extreme discomfort that needs immediate medical attention.  The rule is to remove the caterpillar immediately without rubbing the affected area. One who is  particularly sensitive to higad must get immediate help.
Tussock moth caterpillars are passive and tend to group together. Before they enter pupal stage they descend from their host tree, hide in crevices, and other suitable places where they will later emerge as moths.

Tussock moth - a master of camouflage. It can adjust to the color and pattern of its environment.
NOTE: Skin castings of higad can inflict considerable injury. Eliminate castings by burning or burying, just as caterpillars are disposed off. Higad may inflict the same injury on pets. Regular smudging (smoke emitted by burning dead leaves) can effectively reduced higad population. Household insecticide spray can help. Community control using chemicals needs expert's assistance. ~

Leo Carlo is the most sensitive in the family to allergy. At one time I rushed him to the nearest hospital for immediate shot of antihistamine. He stepped on the casting of higad, the caterpillar of the tussock moth. In his attempt to soap away the embedded bristles, he unknowingly caused it to spread all over his body. He stayed in the hospital until the swelling subsided.

Some years earlier Leo had a similar experience. The allergy came from the eggs of talakitok fish he ate. The swelling was so severe his eyes were virtually closed. Timely anti-allergy injection saved him.

Allergy runs in the family. Marlo, my oldest son is allergic to all kinds of crustaceans, from crabs to shrimps. I am allergic to tulingan fish.

But it is insect allergy that we are always on the guard. Insects are perhaps the most common causes of allergy in the world. Let me cite some findings and experiences.

• The popular image of insect allergies is its association with the bites and stings of venomous species like bees, ants, and wasps (injectant allergens). Over one-hundred deaths per year in the U.S. are attributed to fatal reactions to arthropod venoms. We don’t have any record in the Philippines on casualties from this cause.

• More common allergic reactions attributable to insects include those caused by contacting body parts or waste products (contactant allergens) or inhaling microscopic dust particles composed of pulverized carcasses, cast skins and excreta (inhalant allergens). Symptoms range from eczema and dermatitis, to rhinitis, congestion and bronchial asthma.

• Mites which are relatives of insects that infest cheese, bran, dried fruits, jams and sugars are known to cause transient dermatitis among workers when body fluids are re leased upon crushing. Similarly dust mites that inhabit our dwellings cause cold symptoms often diagnosed as such, or as asthma.

. There are people sensitive to mosquito bite. Usually it is accompanied by swelling of the affected area and itchiness, becoming dark afterward. It takes a week or more for the skin to return to its normal color. This symptom may be similarly manifested by the bite of flea (Siphonoptera).

• Nine orders of insects, and mites and spiders (Arachnids) were found to be the sources of the inhalant allergens. In the US a survey found out that allergy symptoms are due to direct or airborne exposure to Lepidopteran (moth and butterfly) scales - despite the use of exhaust hoods and protective masks and clothing. Case histories of asthma among Lepidoptera workers are numerous.

• Personally I discourage the use of butterflies released in wedding receptions, and other occasions for that matter. Scales of the butterfly (and moth and skippers as well) are made up of a very tough kind of protein known as chitin which can cause blindness other than allergy. Children are most vulnerable to this.

• Reactions to Orthoptera (grasshoppers, crickets, locusts, cock roaches, etc.) are also common in the form of rhinitis, itching skin, bronchitis and ultimately asthma in general sequence. A researcher suffered dyspnea (labored breathing) during a prolonged session of grinding crickets into meal to supplement chicken feed. There are also cases of anaphylactic shock involving orthopterans.

. Have you experienced waking up with swollen eyelid? One explanation is that, you must have been bitten by cockroach (Periplaneta or Blatta) while you were sleeping. Cockroaches eat on almost anything, including dried tears.

• Workers in grain warehouses exposed to the insect pest like weevils (Coleoptera) suffer from skin itching, hives, rhinitis, dyspnea, and bronchial asthma.

• Flies and midges (Diptera) as well as mayflies (Ephemeroptera) and caddis flies (Trichoptera) have likewise been implicated as allergy.

• Fortunately processing – from milling to cooking - largely diminish the potential threat of food allergies as compared with their reactivity in raw form. But this is no guarantee of eliminating the allergen. One may be allergic to the bean weevil that attacks mungbean, and when the bean is cooked the insect allergen is diminished. But the allergy to the bean itself is not. One school of thought suggests that insect allergens in food are deactivated by cooking, or deactivated in the highly acidic environment of the stomach.

. Red ants bite and sting, injecting formic acid in the process, which explains the extreme pain sensation. Because they attack by group, the amount of formic acid may reach a level that leads to anaphylaxis to sensitive people, and may cause death. Children are most vulnerable.

. The most dangerous sting comes from the wild African honeybee that hybridized with the domesticated honeybee since its entry to the US several years ago. Beekeepers have learn to deal with the crossbred because it produces more honey than the domesticated type. Except for hornets, they are perhaps the most dangerous bees in the world.

. We have a local counterpart of hornets - the paper wasp or putakti. They are however less dangerous because they attack only intruders or when they are disturbed.

. The tree ant, locally known as hantik, can cause extreme pain and discomfort to orchard growers and fruit pickers, intruders notwithstanding. There are people who are highly allergic to their poison.

. Relatives of insects that are harmful for their poison are
  • Black Widow spider (Most dangerous arachnid)
  • Scorpion
  • Centipede
  • Millipede (it exudes cyano gas when threatened)

• There is evidence for cross-reactivity among distantly related members of the Arthropoda suggesting the existence of common allergens within the phylum. So, if you are allergic to shellfish, you are likely to be allergic to say, camaro (fried mole cricket) a delicacy not only locally but in other parts of the world.

Beware of insects, especially those that cause allergy.


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