Lawrence's poem is bursting with references to mosquito behavior and anatomy! Some are not completely accurate, some of them are perfectly accurate, and some of them are entirely metaphorical. Here I’ve pulled some quotes from the poem to discuss a little about mosquitoes’ anatomy and physiology.
Mosquitoes are order Diptera and family culicidae (Miller & Walton, 2014). Mosquitoes are relatively small, even in the insect world. In his poem Lawrence comments on the lightness of the mosquito: “weigh no more than air as you alight upon me, stand upon me weightless, you phantom” (Lawrence, 1920). He’s close – the mosquito isn’t completely weightless but the average mosquito only weighs about 2.5 milligrams or 0.000088 oz and is just over 1/8-3/4 inch or 0.3-2 cm long (National Geographic, n.d.). This “winged blood-drop” holds about 5 microliters or 5 millionths of a liter of blood after a blood meal (AMCA, n.d.). Mosquitoes
are holometabolous and have four life cycle stages: egg, larva, pupa, and
finally adult (Miller & Walton, 2014).
The lifespan of the mosquito seems incredibly condensed to us – the
entire cycle may take less than a month to cycle through all stages (CDC,
2012). Female mosquitoes lay 50-200 eggs
each time (called oviposition) and may lay eggs up to three times in her
lifespan (CDC, 2012). The mosquitoes
that have more than one blood meals are the mosquitoes that potentially
transmit malaria – if they are infected by the parasite in the first blood meal
they then transmit that during the second feeding (Plymouth, 2014). Eggs are laid in raft formations onto a wide
variety of water surfaces such as marshes, swamps, rice fields, streams,
buckets of water, puddles, even animal tracks if they’re filled with water. The eggs float in the water for a few days (or
longer depending on the weather) before hatching into larvae. The larvae continue to float on the surface
of the water source and feed on algae and bacteria (CDC, 2012). Larval development takes place over 2-3 days
of 4 stages (also called instars), molting their exoskeleton in each instar
(CDC, 2012; Plymouth,
2014). The larval stage usually takes
10-14 days, depending on temperatures, before the pupa splits open and the
adult form of the mosquito emerges (CDC, 2012).
The adult mosquito generally lives for about two weeks, although they
might be able to live as long as 2-3 months without the weather taking its toll
or predation from birds, dragonflies, and spiders (Rutgers,
2011).
Lawrence observes the mosquito “turn your head towards your tail, and smile.” Like most insects, a mosquito’s body itself is composed of three parts: the head, the thorax, and the abdomen. The mosquito’s eyes, as well as antenna and proboscis, are located on the head (“Mosquito anatomy,” n.d.). Lawrence accuses the mosquito of “eying me sideways” and “having read my thoughts.” Their eyesight is not what we would find useful, but it is quite good for their purposes. However, a mosquito’s eyesight pales at its other senses. When it comes to finding a blood meal, mosquitoes are capable of sensing their victims in several ways: seeing movement, sensing the infrared heat given off by our warmth, lactic acid in sweat, or carbon dioxide in our exhalations (AMCA, n.d.). The mosquito’s thorax is made up of three segments. The single set of wings originate from the center section of the thorax and the mosquito have one set of legs on each of its three sections of its thorax. Lawrence referred to the mosquito’s legs several times in the poem: “queer with your thin wings and your streaming legs,” “long thin shanks,” “what do you stand on such high legs for?” and “length of shredded shank.” Addressing the mosquito’s buzzing (his “hateful bugle”), Lawrence asks “why do you do it? Surely it is bad policy.” A mosquito beats its wings 300-600 times per second, creating the acoustic effect we hear as high-pitched buzzing. However, it’s too quiet to hear at a distance so we only hear the mosquito at close range (Hadley, n.d.). Although anyone who has ever been outside in the summer would be surprised to hear this, mosquitoes do not mainly feed on human blood. Males do not bite humans or other animals and are exclusively nectar feeders (Miller & Walton, 2014). Female mosquitoes only bite and suck blood when they need protein from blood in order to produce eggs (Hadley, n.d.). We always refer to mosquitoes as biting insects, but it’s not really a biting motion – the proboscis stabs into the skin like a very fine, serrated needle (Marks, 2011). The proboscis is made of two tubes – saliva travels from the mosquito to prey through one (as do any mosquito-borne diseases) and blood flows from prey to mosquito through the other (“Mosquito anatomy,” n.d.). In the poem, Lawrence is frustrated with the mosquito’s perceived “anesthetic power to deaden my attention in your direction.” While it hasn’t been identified conclusively, there may actually be an anesthetic component of the mosquito’s saliva to help prevent its prey from noticing the tiny mosquito sucking its blood (Ribeiro & Charlab & Valenzuela, 2001). The itchy red bump left on skin after a mosquito bite is an allergic reaction to the mosquito’s saliva. Specifically, an anti-coagulant in the mosquito’s saliva that helps her suck your blood more efficiently causes the allergic reaction that leaves the characteristic welt (Rutgers, 2011; Zielinski, 2011). |