6/5/03M-DCC / PCB 2340C1 Costa Rican Butterflies Leah & Sefora

6/5/03M-DCC / PCB 2340C2 Life Cycle of the Butterfly~4 Stages

6/5/03M-DCC / PCB 2340C3 1. Egg- the embryonic stage; is the fertilized ovum of the female enclosed in a shell (chorion).  Contains a small pore in the top end (micropyle) where the sperm enters to fertilize the egg within the female.  Female deposits eggs on leaves or vegetative plants.  Eggs may be laid singly or in clusters.  This is a very vulnerable stage due to attack of parasitic insects.  ~Fun Fact~ The chorion (remember what that was?) is often the first meal a newly hatched caterpillar eats before starting life as a herbivore.

6/5/03M-DCC / PCB 2340C4 2. Larvae/Caterpillar- the feeding and growing stage.  Has 13 segments, a mouth with hard mandibles, and a long digestive tract.  Antennae at base of mandibles helps distinguish the larva’s food.  Silk spinning organs (located behind and to side of mandibles) secure larva while walking/escaping from predators and spinning for pupal attachment.  To grow, the larva molts it’s skin.  The stage between each molt is called  an “instar”.

6/5/03M-DCC / PCB 2340C5 Continuation….  The usual number of molts is 5, but can be as many as 7 in the Morpho.  During the final instar, the larva stops eating, voids its gut of food, and begins a wandering phase before pupation.  Feed either as solitary individuals or as groups.

6/5/03M-DCC / PCB 2340C6 3. Pupae or Chrysalis- The resting stage in which larval tissues are first broken down and differentiated to produce an adult.  Tissues of larva are biochemically broken down and reconstructed into an adult butterfly (metamorphosis).  In Costa Rican butterflies, the time of development of adult ranges from a week to a month or more.  Very susceptible to predation.  Majority of Costa Rican species pupate in groups.  Pupal stage is the least known in terms of general biology and ecology.

6/5/03M-DCC / PCB 2340C7 4. Adult butterfly- The sexually mature stage capable of flight.  Composed of 3 main parts: Head, Thorax & Abdomen  Contains the “proboscis” (the feeling organ) that, when not in use, is coiled like a spring.  Restricted to a diet of liquids, such as flower nectar.  Has 4 wings- a pair of forewings and a pair of hindwings, covered in scales.  Scales give the butterfly its characteristic patterns and colors.

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6/5/03M-DCC / PCB 2340C9 The Butterfly’s Enemies 1. Pathogens 2. Parasites 3. Parasitoids 4. Predators

6/5/03M-DCC / PCB 2340C10 1. Pathogens- cause diseases that eventually kill the butterfly host.  Highly contagious and rapidly kill the butterfly.  Attack and kill eggs, larvae, pupae, or adult insects.  Altered behavior is a characteristic of infected hosts.  Defenses against fungal pathogens are not known but may well exist.

6/5/03M-DCC / PCB 2340C11 2. Parasites- organisms that feed on portions of the host but do not directly cause death.  The parasite’s own fate is tied to the survival of the host.  Most common for Costa Rican butterflies are flies, commonly known as biting midges.

6/5/03M-DCC / PCB 2340C12 3. Parasitoids- devour the butterfly host slowly, from the inside, eventually killing it.  Usually applied to certain families of wasps and flies that lay their eggs on or in the early stages of butterflies, and whose larvae devour the internal tissues of the host.  Will wait beside a preapupal larva for a house, until the pupa is complete, and then will attack the still soft pupa.

6/5/03M-DCC / PCB 2340C13 4. Predators- kill their prey by devouring it.  Biggest invertebrate predators include spiders, mantids, ants, and beetles.  May suck the juices from their prey or consume all portions of their prey.  Biggest vertebrate predators are birds, lizards, and mammals.

6/5/03M-DCC / PCB 2340C14 Butterfly Defenses Against Enemies  Butterflies will use their appearance to deceive predators, like camouflage that makes the organism blend into its background.  The eggs are often laid in inconspicuous places on or off the host plant.  A bite taken by a predator from a butterfly wing where an eyespot is located may result in the predator getting a mouthful of wing while the butterfly escapes with its vital body parts intact.  Larvae contain spines to deflect the attack of predators.  Noxious chemicals are found in eggs, larvae, pupae, and adults.