618 



INSECTA. 



composed of fourteen joints; and the proboscis is long, porrected, filiform, inclosing a punctorial 

 sucker, composed of five setse, [according to Latreille, but in reality of six, exclusive of the palpi]. 

 They constitute the genus 



CuLEX, Linn. {Culicides, Latr.), — 

 And have the body and legs very long, the antennae very hairy, forming a thick pencil, in the males ; 

 the eyes large, convergent above ; the palpi porrected, filiform, villose, as long as the proboscis, and 

 5-jointed in the males, shorter and fewer-jointed in the females ; the proboscis is composed of a 

 membranous cylindrical tube, terminated by two lips, forming a kind of knob, and of a sucker consisting 

 of five [six] scaly filaments, producing the effect of a sting, the wings resting horizontally upon 

 the back, with small scales. 



These insects are very annoying, especially in damp situations, where they most abound. Thirsting 

 for our blood, they pursue us every where, entering our habitations, especially in the evening, 

 making a loud buzzing, and piercing our skins, which our clothes cannot even always protect, with 

 the delicate setae of their proboscis, which are denticulated at the tips. In proportion as they thrust 

 it into our flesh the sheath of the proboscis becomes elbowed towards the breast. They discharge a 

 venomous fluid into the wound, which is the cause of the pain felt. It is observed that we are only 

 attacked by the female gnats; [the males indeed have the mouth organs, fewer in number and 

 weaker]. The gnats are known in America under the names of Maringouins or Musquitoes. They 

 are only to be guarded against by enveloping the bed with a Musquito curtain. The Laplanders drive 

 them away by fire, and by coating the naked parts of the body with grease. The females deposit their 

 eggs on the surface of the water, crossing their bind legs near the anus, and by degrees extending 

 them as the eggs are discharged from the body, and which they place side by side, the entire mass 

 icsembling a small boat : each female deposits about 300 eggs in the course of the year. These 

 insects are able to withstand the strongest frosts. The larva; live in stagnant water, and are es- 

 pecially to be found in the spring. They suspend themselves at the surface of water, head downwards 

 for respiration ; they have a distinct rounded head, furnished with a pair of antennae, and of ciliated 

 organs, which serve by their continual motion to form a kind of current, which brings their food to the 

 mouth ; a thorax with bundles of hairs ; an elongated, nearly cylindric abdomen, much narrower tlian 

 the anterior part of the body, 10-jointed, the antepenultimate joint being furnished with a respiratory 

 organ on its back ; the terminal joint is also terminated by setae and by radiating pieces. These larvae 

 are very active, swimming with great agility, often descending, but quickly coming again to the 

 surface of the water. After having undergone several moultings, they are transformed into pupae, 

 which continue moveable with the assistance of their tails and two oar-like pieces at its extremity. 

 They also suspend themselves at the surface of the water, but in a contrary direction to that of the 

 larva ; the organs of respiration being now placed at the thorax, and consisting in a pair of tubular 

 horns. It is then also that the imago is developed, the exuviae of the pupa becoming a kind of raft 

 for it, which preserves it from submersion. All these changes are efi'ected [in the summer], in three 

 or four weeks, so that there are several generations in the course of the year. 



Culex proper, comprises those species which have 

 the male palpi longer than the proboscis, and very 

 short in the females. C. pipiens, Linn., the Common 

 Gnat. 



Anopheles, Meg., has the male palpi as long as 

 the proboscis. 



JFaIbs, Hoffm., has the palpi in both sexes very 

 short. Robineau Desvoidy, in his essay on this 

 family, has added three other genera. 



Sabethes, -with the palpi shorter than the probos- 

 cis, and the middle tibioe and tarsi dilated. 



Megarhina, with the proboscis long and recurved 

 ' at the tip ; the palpi short, with the basal joint 

 thick. 

 Psorophora, with the ocelli distinct ; the legs of the female ciliated, and two small appendages at the sides of 

 the prothorax. C. ciliatus, Fabr. 



-Culex pipiens, fen 



The other Nemocera have the proboscis either very short, and terminated by two large lips, or like 



