233 



found upon fruit trees, it is usually preying upon Ladybugs 

 \vhich in turn were preying upon Aphis or Scale Insects, hence 

 ill this case Zelus should most certainly be considered an in- 

 ijurious insect. It also feeds upon Ladybugs and other bene- 

 ficial insects in cane-fields, to some extent ; but the number of 

 Icaf-hoppers consumed by it more than offsets the injury done 

 by its eating an occasional Ladybug. 



The nymphs of Zelus, when they hatch in a favorable place on 

 the sheltered and secluded underside of a cane leaf, where 

 young leaf-hoppers congregate, are in the habit of remaining in 

 such place till they are grown to maturity, not seeking other 

 locations unless their food supply of young leaf-hoppers be- 

 comes exhausted. I have often observed this in the cane at the 

 Experiment Station. 



An example of their voracity is shown by the following ob- 

 servation : 17 adult leaf-hoppers were confined with an adult fe- 

 male Zelus, and within 24 hours she had eaten 14 of them. 

 This same female ate files of various species ; ladybugs, young 

 and adult ; spiders ; nymphs of her own species ; and, in fact, one 

 day ate the adult m'ale which was confined with her; in another 

 instance a full grown nymph ate an adult which had just molted 

 and was still soft and unprotected. 



Life History. 



Eggs are cylindrical, a little more than i mm. in length. They 

 are laid in columnar masses of 20 to 40 eggs. (PI. X\T, fig. 2) 

 They are brown in color and covered with a sticky substance, 

 the tops whitish with a depression in the center and a raised 

 fringe at the periphery. During her life a female must lay 

 several hundred eggs. Below is the record of one captured in 

 the sugar cane at the Experiment Station, and fed in confine- 

 ment till she died 39 days later. 



May 29th, 42 eggs, hatdhed June 8th. 



June 4th, 19 eggs, hatched June 13th. 



June 1 2th, 34 eggs, hatched June 20th. 



June 2 1 St, 18 eggs, hatched June 30th. 



June 23rd, 31 eggs, hatched July 3rd. 



June 26t'h, 42 eggs, hatc'hed July 6th. 



June 29th, 44 eggs, hatched July 9th. 



July 3rd. 39 eggs, hatched July 12th. 

 269 eggs. 



July 7th, she died. 



