The Life Cycle of Butterflies and Moths

All members of the order Lepidoptera, the butterflies and moths, progress through a four-stage life cycle, or complete metamorphosis. Each stage—egg, larva, pupa, and adult—serves a purpose in the insects development and life. Egg (Embryonic Stage) Once she has mated with a male of the same species, a female butterfly or moth will deposit her fertilized eggs, usually on plants that will serve as food for her offspring. This marks the beginning of the life cycle. Some, like the monarch butterfly, deposit eggs singly, scattering their progeny among the host plants. Others, such as the eastern tent caterpillar, lay their eggs in groups or clusters, so the offspring remain together for at least the early part of their lives. The length of time required for the egg to hatch is dependent on the species, as well as environmental factors. Some species lay winter-hardy eggs in the fall, which hatch the following spring or summer. Larva (Larval Stage) Once development within the egg is completed, a larva hatches from the egg. In butterflies and moths, we also call the larvae (plural of larva) by another name—caterpillars. In most cases, the first meal the caterpillar eats will be its own eggshell, from which it gains essential nutrients. From then on, the caterpillar feeds on its host plant. The newly hatched larva is said to be in its first instar. Once it grows too big for its cuticle, it must shed or molt. The caterpillar may take a break from eating as it prepares to molt. Once it does, it has reached its second instar. Often, it will consume its old cuticle, recycling the protein and other nutrients back into its body. Some caterpillars look just the same, only bigger, each time they reach a new instar. In other species, the change in appearance is dramatic, and the caterpillar may seem to be an entirely different kind. The larva continues this cycle—eat, poop, molt, eat, poop, molt—until the caterpillar reaches its final instar and prepares to pupate. Caterpillars readying for pupation often wander from their host plants, in search of a safe place for the next stage of their lives. Once a suitable site is found, the caterpillar forms a pupal skin, which is thick and strong, and sheds its final larval cuticle. Pupa (Pupal Stage) During the pupal stage, the most dramatic transformation occurs. Traditionally, this stage has been referred to as a resting stage, but the insect is far from at rest, in truth. The pupa does not feed during this time, nor can it move, though a gentle touch from a finger may yield an occasional wiggle from some species. Butterflies in this stage are chrysalides and moths in this stage are cocoons. Within the pupal case, most of the caterpillar body breaks down through a process called histolysis. Special groups of transformative cells, which remained hidden and inert during the larval stage, now become the directors of the bodys reconstruction. These cell groups, called histoblasts, initiate biochemical processes which transform the deconstructed caterpillar into a viable butterfly or moth. This process is called histogenesis, from the Latin words histo, meaning tissue, and genesis, meaning origin or beginning. Once the metamorphosis within the pupal case is completed, the butterfly or moth may remain at rest until the appropriate trigger signals the time to emerge. Changes in light or temperature, chemical signals, or even hormonal triggers may initiate the adults emergence from the chrysalis or cocoon. Adult (Imaginal Stage) The adult, also called the imago, emerges from its pupal cuticle with a swollen abdomen and shriveled wings. For the first few hours of its adult life, the butterfly or moth will pump hemolymph into the veins in its wings to expand them. The waste products of metamorphosis, a reddish liquid called meconium, will be discharged from the anus. Once its wings are fully dried and expanded, the adult butterfly or moth can fly in search of a mate. Mated females lay their fertilized eggs on appropriate host plants, beginning the life cycle anew.

Substance Abuse in the Elderly, Disabled, and LBGT...

The purpose of this paper is to explore the multicultural reaches of substance abuse by examining populations that are often overlooked in addiction studies. Over the past several decades, many general studies have been done about the prevalence and effects of addiction. These studies often focus on risk factors, daily use and/or treatment, and information is gathered through polls and observations. Most of these studies, however, are nonspecific regarding social and cultural factors. I will focus on how addiction affects three vulnerable populations: the elderly, disabled, and gay/lesbian/bisexual/transgendered populations. One population that is often overlooked when examining addiction is the elderly. In reality, alcoholism†¦show more content†¦The Royal College of Psychologists warns that even normal amounts of alcohol can be a danger to the elderly because of balance issues; alcohol can exacerbate unsteadiness and increase the risk of falling Although more elderly people seek treatment for alcohol abuse, it is not the most commonly abused substance among this population. Compared to adolescents and younger adults, illegal drug use among older adults is rare, however prescription drug abuse is common. Over 1/3 of all prescription medication sold in the United States is used by elder individuals, and most of the prescribed drugs have high abuse potential (Doweiko, p. 256). Consequently, more people over the age of 65 abuse prescription drugs than any other substance. Because of age-related medical problems, undiagnosed mood disorders (such as chronic depression, often magnified by social factors such as loss of peers or a spouse), and changed body chemistry, this population is particularly vulnerable to the effects of and the abusive properties of pharmaceuticals. These factors combined with the fact that many elderly adults have multiple prescriptions that can interact with each other and compound the risk for addic tion. Out of all the drugs prescribed to older adults, sedatives and benzodiazepines potentially cause the greatest concern. Benzodiazepines are prescribed to older adults more than any other age group. According to the Center for Substance Abuse

Online vs Offline Bookings free essay sample

Online versus offline bookings The upcoming decade for travel agencies The number of travel agents has declined sharply during the last decade. According to an article of RockCheetah (www. rockcheetah. com, viewed on 12 May 2013) 30 per cent of all travel agents have had to close down since 2000. The reason of the major decline seem clear. The internet is infinitely popular and beholds many advantages over the rather old fashioned travel agents. The online booking of holidays is preferred by many people because of several reasons. The best rates are just few clicks away while various organisations and tour operators are compared simultaneously. Moreover, no additional charges have to be paid to a travel agent. Complementary, cars and traffic jams are avoided because it is no longer necessary to get in the car. All can be arranged from the comfort of a own home. Questioned is whether travel agencies still have any purpose in todays society and if they will last for another decade. Booking a trip online has considerable disadvantages. The internet is open for all to post anything on it. Companies often claim the best rates, accommodations, photos and reviews. There is a great possibility that this not reflects the truth and therefore comes across as deceiving. An overload of unreliable information is the result, which makes the search of a holiday much longer than intended. Kate Springer of TIME news feeds states that the average person spends more than two hours to search and book a trip online (www. time . com, viewed on 12 May 2013) The same article of TIME claims that the IBM Institute for Business Value 20 per cent of them took more than five hours to find the proper holiday. Besides, the freedom to post anything causes the internet to be a less safe place. Cybercriminals have many opportunities to create websites offering false products, to steal real money. After listing all apparent advantages booking online trips, it might be slightly difficult to opt for a travel agents. However, against expectations, travel agents have many advantages. Travel agents filter out the overload of information and provide the customer with detailed information about destinations and accommodations which is not available for the big public. This information also includes advice regarding to visa. Many agents have much travelling experience themselves, which exclusive information to the customer. Furthermore, a travel agent often saves much money. This is due to large quantity in purchases made of accommodation, tickets and excursions. When these are bought in larger quantities, travel agents often arrange attractive discounts, doing their best to get the best deal for the customer. Furthermore, many customers have additional requests regarding their trip. The overload of possibly false information causes difficulties to find the proper product for the customer. Much stress is saved when assembling a tailor made product is done by a travel agent. A travel agent has the knowledge and the resources to do so. It can be stated that the demand for travel agents along with the overflow of information on the internet is rising. No guarantees are given on the existence of travel agents for the upcoming decade. However, the prospects are optimistic.

Supply and Demand The Case of Milk

Milk prices are soaring. Millions of consumers all over the world buy milk products on a daily basis and are not willing to give them up. Climate change, competition among biofuel producers, trade policies and other factors drive global milk prices and turn milk into one of the most expensive food products (Arnold, 2007). â€Å"Cows are fed with corn and as more corn is diverted to energy production, feed costs and dairy farmers in turn pass those costs up the food chain† (Doherty, 2007).Advertising We will write a custom essay sample on Supply and Demand: The Case of Milk specifically for you for only $16.05 $11/page Learn More Simultaneously, international milk producers fail to cope with the growing demand for milk. The demand for milk products is at all-time high (Arnold, 2007). The roaring global economy and rising incomes in India, China, and Latin America make the task of producing enough milk extremely challenging and virtually unachievabl e (Arnold, 2007). Milk products are similar to gasoline: consumers cannot give them up even when the price grows unbearable (Doherty, 2007). Financial experts predict that, as the price of milk increases, the demand for milk products is likely to remain unchanged (Doherty, 2007). Apparently, the elasticity of demand for milk and milk products is extremely low. Put simply, the global demand for milk and milk products is not responsive to changes in milk prices. It should be noted, that elasticity is the central measure of market responsiveness in microeconomics (Baumol Blinder, 2008). The main determinants of demand elasticity include the nature of the good, availability of substitutes, household budgets, and passage of time (Rittenberg Tregarthen, 2011). The nature of the good is directly related to demand elasticity: necessities like food products tend to have inelastic demand curves (Baumol Blinder, 2008). This is particularly the case of milk, since many consumers perceive mil k as the fundamental ingredient of their diets and large food manufacturers use milk in their products. Milk does not have close substitutes, and substitutability remains one of the main factors of demand elasticity in microeconomics (Baumol Blinder, 2008). Given that the demand for milk is highly inelastic, the demand curve for milk will look as follows: Advertising Looking for essay on business economics? Let's see if we can help you! Get your first paper with 15% OFF Learn More Fig.1. Inelastic demand for milk and milk products. Thousands of consumers spend their budgets on milk, because they believe it to be useful for their health. Consumers take the usefulness of milk for granted (Doherty, 2007). They treat milk as an excellent source of cheap proteins (Doherty, 2007). Therefore, if an advertising campaign spreads the message that milk helps to reduce weight, the quantity demanded will soar. Fig.2. Changes in quantity demanded and price after the advertising c ampaign. The price of milk in the short-term period will remain unchanged, as the growing demand for milk products does not reduce the costs of milk production. In short-term periods farmers will also experience the shortage of supply. In the long run, the price of milk will increase to create new market equilibrium. A mad cow disease epidemic will reduce the amount of milk in the market. The quantity demanded will drop, since customers will not be willing to purchase milk products and get infected. The supply curve will move to the left together with the demand curve. The price of milk will remain unchanged.Advertising We will write a custom essay sample on Supply and Demand: The Case of Milk specifically for you for only $16.05 $11/page Learn More Changes in the price of milk will cause no shifts in the demand curve. However, the quantity demanded will change. Consumers will want to purchase more milk at a lower price. An increase in the demand for mi lk products will manifest through movements along the demand curve. However, as the demand for milk increases, most farmers will fail to supply enough milk to the market, followed by the shortage of milk products. Consequentially, changes in the price of milk may move the supply curve to the left: possibly, milk manufacturers will have to adopt new technologies to meet the growing demand for milk. How the government price ceiling for milk affects the supply and demand of milk products depends on whether the ceiling price is below or above the market-determined equilibrium. Actually, the government price ceiling for agricultural products is a frequent object of microeconomic analysis. The government is believed to produce heavy influences on the stability and equilibrium in the milk market. The government-imposed price ceiling above the market-established equilibrium price will have no effects on either the supply or demand of milk. By contrast, the ceiling price below the market-est ablished equilibrium will cause profound effects on the supply and demand of milk. Farmers will not be able to charge the market price for milk. Some suppliers may choose to leave the milk market. Reduced supply will cause the shortage of milk products in the market. Consumers will fail to meet their demand for milk and milk products. Price control is one of the most controversial aspects of the market-government relationship. Government price ceilings reduce consumer prices, whereas price floors increase firms’ revenues and incomes (Economics Help, 2008). Consumers believe that government price ceilings limit suppliers’ ambitions and make goods and service affordable. Government price ceilings alter the market equilibrium in the agricultural market. Price controls are associated with numerous disadvantages. First, government price ceilings lead to the shortage of goods in the market (Economics Help, 2008).Advertising Looking for essay on business economics? Let's see if we can help you! Get your first paper with 15% OFF Learn More Second, government controls of minimum prices raise consumer prices and result in oversupply of products and production inefficiency (Economics Help, 2008). Given that milk does not have close substitutes and is considered a food necessity, its demand is inelastic. As a result, any increase in price for milk will inevitably lead to an increase in total revenues, as slight reductions in quantity demanded are a trifle, compared with the revenues earned from increased prices (Quick MBA, 2011). Conclusion Milk prices are soaring. More consumers are willing to have milk in their diets. Climate changes, new technologies, and increased consumer incomes make the task of producing enough milk virtually unachievable. The elasticity of demand for milk and milk products is extremely low. Put simply, the global demand for milk and milk products is not responsive to changes in milk prices. Many consumers perceive milk as the fundamental ingredient of their diets and large food manufacturers use m ilk in their products. Milk does not have close substitutes, and substitutability remains one of the main factors of demand elasticity in microeconomics. When an advertising campaign spreads the message that milk helps to reduce weight, the quantity demanded will soar. Changes in the price of milk will cause no shifts in the demand curve. Any increase in price for milk will inevitably lead to an increase in total revenues, as slight reductions in quantity demanded are a trifle compared with the revenues earned from increased prices. References Arnold, W. (2007). A thirst for milk bred by new wealth sends prices soaring. The New York Times. Web. Baumol, W. J. Blinder, A. S. (2008). Microeconomics: Principles and policy. Boston: Cengage Learning. Doherty, R. E. (2007). Milk demand stays strong despite high prices. Reuters. Web. Economics Help. (2008). Price controls – advantages and disadvantages. Economics Help. Web. Quick MBA. (2011). Price elasticity of demand. Quick MBA. W eb. Rittenberg, L. Tregarthen, T. (2011). Principles of microeconomics. Flatworld Knowledge. Web. This essay on Supply and Demand: The Case of Milk was written and submitted by user Leonard Hatfield to help you with your own studies. You are free to use it for research and reference purposes in order to write your own paper; however, you must cite it accordingly. You can donate your paper here.