86 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



are thrust through the egg membrane and all of the contents consumed, 

 usually from a single puncture. Ten or fifteen seconds is sufficient 

 time for an egg to be devoured. The contents of the spiders themselves 

 are similarly absorbed except that it requires a longer time, usually 

 from 4 to 7 minutes. One larva devoured 96 spiders in 16 days, 

 another a total of 226 spiders for its development from hatching to 

 pupation, or an average of 15 per day; another 136 spiders in 11 days 

 or 12 per day, and another 253 spiders for its entire larval period. 



When mature the larva selects a place on the under side of the leaf, 

 usually along the mid rib, for pupation. The cocoon consists of a 

 double layer of silk, an inner compact layer more or less oval in shape 

 and an outer flat, loosely woven web. Thirteen days are spent as a 

 pupa, when the familiar grayish white "dusky wing," which is about 

 8 mm. long, emerges. 



Oligota oviformis. This species of rove beetle (Staphylinidse) occurs 

 on citrus trees throughout the southern California section. The 

 egg is of a light orange color and is laid singly on the under surface of 

 the leaf. Hatching occurs in 7 to 9 days, and there appears a slender 

 larva which when full grown is 2 or 3 mm. long. With its sharp pointed 

 mandibles the larva punctures the spider about the center of the 

 body, and by a pump-like action the body contents are sucked out. 

 They, in the case of the common citrus spider, are of a red color and may 

 be distinctly observed passing out of the body of the spider and into 

 the alimentary canal of the more or less transparent larva of Oligota. 

 As most of the body juices of the spider are absorbed they are spewed 

 back again and the spider, which has been made transparent by the 

 removal of the contents, resumes its normal red color and rigidity. 

 This pumping back and forth is repeated two or three times before 

 the mouth parts finally release the victim. 



Records on the feeding of the larva of this beetle show that it will 

 consume about twenty spiders each day. This too includes a majority 

 of the more fully mature spiders, since they were transferred daily 

 and consequently the eggs and smaller spiders would be left. Twelve 

 to fifteen days represent the longest period we have been able to get 

 the larva to live, and in spite of repeated efforts, it appears to die just 

 before pupation. Counting the time that has actually been observed 

 the larva of this insect will consume upwards of two hundred or three 

 hundred spiders during its course of development. 



The adult beetle does not eat so many spiders each day as the larva, 

 but the longer life of the adult brings the total number consumed about 

 equal. The adults eat on an average ten spiders a day and the maxi- 

 mum adult life determined was 32 days, making a total of over 300 

 spiders. 



