MORPHOLOGY OP THE ALEYRODIDiE. 3 



jugeai y vouloir faire scs oeufs; je marquai I'endroit de la feuille ou il etoit. 

 Je trouvai, le lendemain 26. le papillon dans la meme place; le 27. il n'en avoit 

 pas change, mais tout aui>res de lui il y avoit un petit espace k peu pres circu- 

 laire, aist; i distinguer du reste de la feuille; il 4toit poudr6 d'une poudre 

 blanche, de celle qui blanchit toutes les parties de ce papillon; li elle 6teiguoit 

 la vivacity du verd. Get espace avoit environ une ligne de diam^tre. Sur sa 

 circonfCrence j'observai trois petits corps que je crus etre des oeufs, & qui en 

 etoient reellement. P^nfin le 28. le papillon s'Stoit ^loigne d'un demi pouce au 

 plus de la place ofi je I'avois toiijours trouve pendant les jours precedeus. II 

 me fut plus ais6 alors d'observer sans crainte de I'inquieter, les petits corps 

 qui etoient arranges autour de la circonference du petit espace qu'il avoit 

 blanchi. Avec le secours d'une forte loupe, je reconnus que leur figure 6toit 

 asses semblable a celle des oeufs ordinaires, elle tenoit pourtaut plus de la 

 cylindrique. Ces oeufs sent oblongs, ce sont de petits cylindres dont les deux 

 bouts sont aruenes en pointes arrondies; leur plus grand diametre etoit a peu 

 pres dirige vers le centre de I'espace circulaire. 



In American literature Dr. Britton appears to have given the first 

 account in 1902, though Davis mentions it in Insect Life, Volume VII, 

 1804. In describing the habits of a species on lettuce. Dr. Britton 

 says : ^ 



The female first thrust her beak into the leaf and depositing an egg swung 

 about with her beak still inserted and serving as a pivot, continuing to deposit 

 eggs in a circle of about one millimeter in diameter. One of these circles con- 

 tained six, while another had nine eggs. 



The same habit was described and figured bv Dr. Back * for 

 Aleyrodes howardi Quaintance, and it has been described in connec- 

 tion with the description of species by the senior author and other 

 writers. Some species, however, use no definite arrangement but 

 scatter the eggs irregularly over the leaf almost exclusively upon 

 the underside. The number of eggs deposited seems to be fairly 

 large if the proper food conditions are found. Dr. Zehntner^ gives 

 150 to 200 eggs for Aleyrodes hergi Signoret, and Morrill and Back ** 

 have secured 211 from a female of Aleyrodes citii Riley & Howard. 



Dr. Morrill was the first to note parthenogenesis in this family '' 

 and we give therefore his original observations on the subject "^ 



Adult females hare been isolated on plants previously free from Aleyrodes in 

 any stage, for the purpose of determining the duration of adult life, the number 

 of eggs laid by each female, whether or not parthenogenesis occurs, and. if so, 

 its character. The females isolated for the purpose of these observations wero 

 seen to emerge from their pupa cases, and consequently there was no possibility 

 of their having been fertilized. The plants upon which these females were kepc 

 were growing in small pots covered with lantern chimneys, which were closed 

 at the top with cheesecloth. Four trials were made: 



1. April 3. 1902, an unfertilized female began egg laying, and on April 17, 

 three eggs were observed to have hatched. 



2. April 17, 1002, an unfertilize<l female began egg laying, and on April 29 

 several eggs had hatched. 



3. Dec. 8. 1902, a female emerge<l, was isolated on a tomato plant, and began 

 egg laying Dec. 12 (females usually begin egg laying on the second or third 



