Wednesday, February 17, 2016

Backyard as Laboratory and Workshop Series 3: Bizarre creatures share our homes

Bagworm, looper or geometrid, giant African snail, balloon frog

Dr Abe V Rotor 
 Living with Nature School on Blog
Paaralang Bayan sa Himpapawid with Ms Melly C Tenorio
738 DZRB AM Band, 8-9 evening class, Monday to Friday

Looper or geometrid caterpillar moves by loop-and-stretch, and stands like a cobra on reaching a dead end. When threatened, it feigns dead and mimics its surroundings. Geometrids belong to Order Lepidoptera, Family Geometridae. (from Greek geo 'the earth' and metron 'measure' — refers to the larvae, or inchworms, which appear to "measure the earth" as they move in a looping fashion. 

 A very large family, it has around 35,000 species of moths. A well-known member is the Peppered Moth, Biston betularia, which has been subject of numerous studies in population genetics. Several other geometer moths are notorious pests. These include Chaisma, Selenia, Scopula and Tetracis Geometrid moths however have butterfly characteristics, like slender abdomen. Typical of moths, they are nocturnal, active at night time. Note specimen crawling on the author's arm.  Does the looper cause blister like the higad?

Pagoda Bagworm (Cryotothelea heckmeyeri). It is the larva of a moth belonging to Order Lepidoptera, Family Psychidae.  The caterpillar remains ensconced in its bag in its entire larval stage which takes five moultings before it becomes into a cocoon without leaving its bag.  The male soon emerges as a winged moth, then into adult.  The male moth leaves the bag to find a mate, while the female moth is wingless and has to remain in the bag, receives a mate, deposits her fertilized eggs inside, then falls off to the ground or waiting prey.  The bag grows by accretion, that is, the larva adds pieces of leaves on to the bag. 

 The pagoda is built by adding shingles over the bag, each shingle increases in size as the larva gets bigger. Which of these photos shows the correct position of the insect with its host plant? 

Another species of bagworm (Crypthothela fuscescens), builds its bag with dried twig of the uniform sizes.  The spent bag simply remains hanging in the plant. Right photo shows an exposed larvae purposely for study.

 Giant African snail (Achatina fulica) is the biggest land snail in the Philippines, introduced by the Japanese during WWII, either as supplemental food or biological agent of warfare. This mollusk has developed into a pest of garden and orchard crops. 

Can you locate the pair of eyes? You may use a magnifying glass over these photos,  or you may zoom in these photos in your computer. 

Globular or Balloon Frog (Tukak Bat'og Ilk which means fat bellied) 

Uperodon systoma is a small genus of microhylid frogs from South Asia. Their sister taxon is Ramanella of Class Amphibia, Order Anura. The common name of these frogs is globular frogs or balloon frogs in reference to their stout appearance. These medium-sized (maximum snout–vent length 64–76 mm (2.5–3 in) burrowing frogs eat ants and termites. This species is widespread in South Asia, Little is known about the population status of this species. This is a completely fossorial species that buries itself in loose, moist soil. 

Specimens have been observed in dry forest areas, plains, home gardens and low-intensity agricultural areas. The adults surface only during the summer monsoons; during the dry months they retreat into the soil. Termites are reportedly the main food of this species. Breeding takes place during the monsoon rains. Males call from the banks of torrents or paddy fields, and eggs are laid in masses which float on the water surface. 

The main threats are the loss of suitable habitat to increasing urbanization, and the pollution of both land and wetlands with agrochemicals. There are no reports of this species being utilized, except that it is caught for food like other edible frogs in some parts of the country. What triggers this frog to become enormously bloated like a balloon from which it got its name? 

Answer to Trivia:

1. Looper: The caterpillar is smooth and has no poisonous hairs like the higad (tussock moth caterpillar).

2. Pagoda bagworm - The normal position is upside down.  The bagworm hangs on the underside of the leaf for protection against direct sunlight and enemies.

3. Giant African snail: The eyes are mounted at the tip of each of the longer antennae like periscope. 

4. Balloon frog: It engulfs air until it become distended.  This is for self defense since it appears instantly big before its puzzled potential predator.  When threatened it wedges itself in its abode like a rock crevice where it is difficult to pry it out. By storing air it can stay under water, or afloat, and it can travel on moving water. Air increases the volume of the frog's mating call which can be heard far and wide.

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