Butterflies (order Lepidoptera; Spanish: Mariposas)
There are four stages in the life cycle of the butterfly; simple egg, larval caterpillar, inactive pupa or chrysalis and spectacular adult or imago. Females lay their eggs with a special glue on plants that are specific for each species; some butterflies only lay eggs on a single species, others use a range of plants. The caterpillar larva that emerge are eating machines who molt through several stages called instars. Many of the host plants for larva contain toxic substances that caterpillars can sequester within their bodies making them poisonous to birds. Fully grown larva stop eating and search for a location, often the underside of a leaf, to molt a final time forming a chrysalis or pupa. Butterflies later emerge from these hardened pupa, hang to dry their wings, and fly off to repeat their purpose in life, reproduction. The life span of the adult butterfly ranges from one week to months, but on average the imago life span is 2-3 weeks.
The kaleidoscope of butterfly colors are a result of pigments in scales or prism- like structures that bend light and absorb and reflect different wavelengths of light.
Butterflies eat during the day, tasting with their feet, sipping nectar and moisture from flowers with a siphoning mouth part coiled under its head. Some butterflies use this proboscis to suck tree sap and juice from fermenting fruits. Mouth parts are undeveloped or absent in some species of butterflies, so other than their time as larva they do not eat.
Several species common to Playa Blanca are described below.
White Morpho Butterfly (genus Morpho; Spanish: Mariposa)
There are over 80 species of the genus Morpho. They are neotropical butterflies found mostly in South America as well as Mexico and Central America. Many Morpho butterflies are colored in metallic, shimmering shades of blue and green. These colors are not a result of pigmentation but are an example of iridescence: the extremely fine lamellated scales covering the Morpho's wings reflect incident light repeatedly at successive layers, leading to interference effects that depend on both wavelength and angle of incidence/observance. Thus the colors produced vary with viewing angle, however they are actually surprisingly uniform, perhaps due to the tetrahedral (diamond-like) structural arrangement of the scales or diffraction from overlying cell layers. The lamellate structure of their wing scales has been studied as a model in the development of fabrics, dye-free paints, and anti-counterfeit technology used in currency. The lamellae reflect up to 70% of light falling on them, including any UV. The eyes of Morpho butterflies are thought to be highly sensitive to UV light and therefore the males are able to see each other from great distances. In most species only the males are colorful, supporting the theory that the coloration is used for intrasexual communication between males. Some South American species are reportedly visible by the human eye up to one kilometer away.
There also exist a number of white Morpho species, one of which frequents Playa Blanca. It is a spectacularly large butterfly with a wing span of eight inches or more, and it flutters somewhat haphazardly earning it the nickname of the Kleenex butterfly.
Morpho butterflies are forest dwellers but will venture into sunny clearings to warm themselves. Males are territorial and will chase any rivals. They feed on the juices of fermenting fruit with which they may also be lured. The inebriated butterflies wobble in flight and are easy to catch. Morphos will also feed on the bodily fluids of dead animals and on fungi. They may be important in dispersing fungal spores.
The entire life cycle of the Morpho butterfly, from egg to death, is approximately 137 days. The adults live for about a month. They have few predators as the adults are poisonous due to the feeding caterpillar sequestering poisonous compounds. The hairy brown caterpillars feed on a variety of leguminous plants. In some species the caterpillars are cannibalistic. If disturbed, some Morpho caterpillars will secrete a fluid smelling of rancid butter. The tufts of hair decorating the caterpillars have been recorded to irritate human skin. The commoner (Blue) Morphos are reared en masse in commercial breeding programs. The iridescent wings are used in the manufacture of jewelery and as inlay in woodworking.
Grey Cracker Butterfly (Hamadryas februa; Spanish: Mariposa )
These butterflies are mottled grey, cream and brown, with a wing span of approximately three inches. Their characteristic position is with their wings spread open on tree trunks with their head downward. Early in the morning and before dark, you can see groups of adults on a single tree. Males make a cracking sound as they dart out at people and insects. The larvae build resting platforms out of dung pellets. These butterflies eat sap and rotting fruit.
Zebra Butterfly (Heliconia charithonia; Spanish: Mariposa )
Present throughout the year, these butterflies have long, narrow black wings with yellow stripes. The males patrol aggressively for females for mating opportunities. Males are known to wait for the female to emerge from the chrysalids and then mates with her as she emerges. After mating, the male leaves a chemical that repels other males. Adult butterflies can be seen around many flowering plants but are particularly fond of lantana. Eggs are laid on a number of different passiflora plants. The passiflora is the host plant for the larvae.
Cloudless Sulphur Butterfly (Phoebis sennae; Spanish: Mariposa )
These are found throughout the year hovering for nectar around bougainvillea, hibiscus, cassias, lantana and morning glory. It is a large lemon yellow butterfly with irreggular black borders. Males patrol for females with a rapid flight. Eggs are particularly difficult to find as they are laid singularly on plants. Various cassias serve as the host plant for the larva.
Great Southern White Cabbage Butterfly (Ascia monuste; Spanish: Mariposa)
A 2 ½ to 3” white butterfly found in high numbers at Playa Blanca especially on the road along the beach. The caterpillars are numerous and are seen as pests to farms and gardeners. They feed in large groups and have many host plants including the mustard family, cabbage, lettuce, radish and plants in the caper family. The adults are nectar feeders and especially enjoy lantana, plumbago, hibiscus and bouganvilla.
Owl Butterflies (genus Caligo, family Nymphalidae; Spanish: Mariposa)
Owl butterflies, of which there are around 20 different species, are found in the rainforests and secondary forests of Mexico, Central and South America. The common name is derived from the presence of large "eyespots" (ocelli) on the underside of the hind wings. To a human observer of dead butterflies pinned up in a collection, owl butterflies' underwings resemble the head of an owl when the butterfly is held head down. It was speculated that the ocelli are "false eyes" to scare smaller birds that attempt to prey on the butterfly. Sadly not everything we learned in eighth grade science class is correct; there is no evidence that the function of the ocelli is to resemble an owl. The position in which the owl-like appearance occurs is not generally assumed by the butterfly in life. In its resting position, Caligo butterflies settle down with closed wings like most butterflies, showing only one of the eyespots and do not look remotely owl-like.
The actual significance of the ocelli remains elusive. In some butterflies, it has been shown that ocelli serve as a decoy, diverting bird attack away from the vulnerable body, and towards the outer part of the hind wings or the forewing tip. But decoy ocelli are almost always small and located near the margin of the wing, where the damage caused by a bird's beak would interfere little with the butterfly flying and going about its life. The position and size of the owl butterflies' ocelli makes them a decidedly suboptimal decoy, as they are far too close to the abdomen to ensure that no substantial damage is inflicted by a bird snapping at them.
Owl butterflies are very large, and fly only a few meters at a time, so avian predators have little difficulty in following them to their settling place. However, the butterflies usually fly around at dusk, when few avian predators are around Indeed their main predators are apparently small lizards such as Anolis. It has been suggested that the hind wing underside pattern actually resembles the head of a large Hyla tree frog, which prey on Anolis; but this theory has not been tested. It also is known that many small animals hesitate to go near patterns resembling eyes with a light-colored iris and a large pupil, which matches the appearance of the eyes of many predators that hunt by sight, so it is conceivable that the eye pattern is a generalized form of auto mimicry that would buy the butterfly time to escape from an approaching predator.
Leafcutter Ants (two genera—Atta and Acromyrmex; Spanish: Hormigas)
Leafcutter ants are social insects found in warmer regions of Central and South America. These unique ants have evolved an advanced agricultural system based on ant-fungus mutualism. They feed on special structures called gongylidia produced by a specialized fungus that grows only in the underground chambers of the ants' nest. So the ants harvest leaves, but they don’t eat them; they bring them into their nests and feed them to the fungus they cultivate there.
Among the 39 species, different species of leafcutters farm different species of fungus, but all the fungi are members of the Lepiotaceae family. The ants actively cultivate their fungus, feeding it with freshly-cut plant material and maintaining it free from pests and molds. This mutualist relationship is further augmented by another symbiotic partner, a bacterium that grows on the ants and secretes chemicals that protect the fungus- essentially the ants use portable antimicrobials. Leaf cutter ants are sensitive enough to adapt to the fungi's reaction to different plant material, apparently detecting chemical signals from the fungus. If a particular type of leaf is toxic to the fungus, the colony will no longer collect it.
A mature leafcutter colony can contain more than 8 million ants, and they can be major agricultural pests. Some species are capable of defoliating an entire citrus tree in less than 24 hours. Within a colony, the ants are divided into castes, based mostly on size, that perform different functions-- minims, minors, mediae and majors. Minims are the smallest workers and tend to the growing brood or care for the fungus gardens. Minors are slightly larger than minima workers and are present in large numbers in and around foraging columns. These ants are the first line of defense and continuously patrol the surrounding terrain and vigorously attack any enemies that threaten the foraging lines. Mediae are the generalized foragers, who cut leaves and bring the leaf fragments back to the nest. Majors, also known as soldiers or dinergates, are the largest worker ants and act as soldiers, defending the nest from intruders, although there is recent evidence that majors participate in other activities, such as clearing the main foraging trails of large debris and carrying bulky items back to the nest. The largest soldiers may have total body lengths up to 16 mm (.63 inches) and head widths of 7 mm (.28 inches).
Mosquito (family Culicidae; various species; Spanish: Mosquito)
We don’t think it is necessary to provide a physical description of these insects or chronicle their role as vectors in the spread of human diseases. Those are well known by almost everyone. But because you are likely to encounter at least one or two at Playa Blanca, we can point out a few things you may not know. For example, a mosquito can fly for 1 to 4 hours continuously at up to 1–2 km/hour, traveling up to 10 km in a night. Both male and female mosquitoes are nectar feeders, but the female of many species is also capable of haematophagy (drinking blood). It may be small consolation, but human blood meals are seldom the mosquito’s first or second choices; horses, cattle, dogs, smaller mammals or birds are preferred. The females do not require blood for survival, but they do need supplemental substances (like protein and iron) to develop eggs. Female mosquitoes hunt their blood host by detecting carbon dioxide (CO2) and 1-octen-3-ol from a distance. When they get closer they also pick up on the infrared heat being emitted which identifies the host as warm-blooded.
The Culex mosquito species usually lay their eggs at night over a period of time sticking them together to form a raft of from 100 to 300 eggs. A raft of eggs looks like a speck of soot floating on the water and is about 1/4 inch long and 1/8 inch wide. A female mosquito may lay a raft of eggs every third night during its life span.
Anopheles and many other mosquitoes lay their eggs singly on the water surface. Aedes and Ochlerotatus mosquitoes lay their eggs singly, usually on damp soil. Aedes and Ochlerotatus eggs are more resistant to drying out (some require complete drying out before the eggs will hatch) and hatch only when flooded with water (salt water high tides, irrigated pastures, tree holes flooded by rains, flooded stream bottoms). Anopheles , Culex and Mansonia eggs are susceptible to long periods of drying out.
Whatever the species, tiny mosquito larvae emerge from the eggs within 24 - 48 hours almost in unison. These "wigglers," live in water from 4 to 14 days depending on water temperature, and during that phase, they must come to the surface at frequent intervals to obtain oxygen through a breathing tube called a siphon. They are constantly feeding since maturation requires a huge amount of energy and food. They hang with their heads down with the brushes besides their mouths sweeping anything small enough to be eaten toward their mouths. They feed on algae, plankton, fungi and bacteria and other microorganisms. During growth, the larva molts (sheds its skin) four times. The stages between molts are called instars. At the 4th instar, the usual larva reaches a length of almost 1/2 inch and toward the end of this instar ceases feeding. When the 4th instar larva molts, it becomes a pupa.
Mosquito pupae, commonly called "tumblers," live in water from 1 to 4 days, depending upon species and temperature. The pupa is lighter than water and floats at the surface. It takes its oxygen through two breathing tubes called "trumpets." The pupa does not eat, but it is not an inactive stage. When disturbed, it dives in a jerking, tumbling motion toward protection and then floats back to the surface.
The metamorphosis of the mosquito into an adult is completed within the pupal case. The adult mosquito splits the pupal case and emerges to the surface of the water where it rests until its body dries and hardens.
Dragonflies are natural predators of mosquitoes. They eat mosquitoes at all stages of development and are quite effective in controlling populations. Although bats and Purple Martins can be prodigious consumers of insects, many of which are pests, less than 1% of their diet typically consists of mosquitoes. Neither bats nor Purple Martins are known to control or even significantly reduce mosquito populations. For more proactive control, window screens, introduced in the 1880s, have been called "the most humane contribution the 19th century made to the preservation of sanity and good temper” and bed nets, particularly those dipped in permithrin, have proven excellent protection.
One of the most popular chemical treatments is N,N-diethyl-meta-toluamide, commonly known as DEET. Mosquitoes use carbon dioxide (CO2) and 1-octen-3-ol from human and animal breath and sweat as odor cues and DEET inhibits the detection of the latter in insects. It doesn’t kill the mosquitoes; it hides you from them. It has been used widely since its invention by the U.S. Department of Agriculture in 1945, but has occasionally been associated with some minor to moderate adverse reactions. Other repellants also have been shown to have some effectiveness, but by far DEET is the champion against mosquitoes. When using repellants, The American Mosquito Control Association makes the following recommendations:
• Wear long sleeve shirts and pants outdoors during peak mosquito activity time periods.
• Apply repellent sparingly only to exposed skin or clothing.
• Keep repellents away from eyes, nostrils and lips: do not inhale or ingest repellents or get them into the eyes.
• Avoid applying high-concentration (>30% DEET) products to the skin, particularly of children.
• Avoid applying repellents to portions of children's hands that are likely to have contact with eyes or mouth.
• Pregnant and nursing women should minimize use of repellents.
• Never use repellents on wounds or irritated skin.
• Use repellent sparingly; one application will last approximately 4-6 hours. Saturation does not increase efficacy.
• Wash repellent-treated skin after coming indoors.
Dragonflies (order Odonata suborder infraorder Anisoptera: Spanish: Libelula)
Dragonflies are familiar insects living in and near water where they perform their meritorious service as “mosquito hawks”. Females lay eggs in water, often on floating or emergent plants, and most of a dragonfly's life is spent in the larvae (naiad or nymph) form beneath the water's surface, using internal gills to breathe and using extendable jaws to catch other invertebrates or even vertebrates such as tadpoles and fish. The larval stage of large dragonflies may last as long as five years. In smaller species, this stage lasts between two months and three years. When the larva is ready to metamorphose into an adult, it climbs up a reed or other plant at night. Exposure to air causes the larvae to begin breathing. The skin splits at a weak spot behind the head; and the adult dragonfly crawls out of its old larval skin, waits for the sun to rise, pumps up its wings, and flies off. The adult stage of larger species of dragonflies can last as long as four months. Dragonflies feed on mosquitoes, midges and other small insects like flies, bees, and butterflies. They are therefore valued as predators, since they help control populations of harmful insects. They capture their prey by clasping them in legs studded with spikes. The prey cannot escape by diving because dragonflies always attack from below.