THE CITRUS THRIPS. 27 



reason it does not attack the citrus thrips, although the close asso- 

 ciation of this thrips with the bean thrips on orange trees seems to 

 be a good reason why it should do so, and it is quite possible, seem- 

 ingly, that the citrus thrips may in the future become one of its hosts. 



SPIDERS. 



A large number of spiders, representing three or four families, 

 capture the citrus thrips as a part of their food. The most im- 

 portant of these in the matter of destroying citrus thrips is a small 

 gray spider belonging to the family Dictynidae, genus Dictynus. 1 

 The Dictynidae are tubeweavers, and this particular species commonly 

 spins a thin sheet of web irregularly across an orange leaf, in a 

 single one of which adult and larval citrus thrips have often been 

 counted to the number of 50 or more. It is rare to find a web of one 

 of these young spiders with less than from 

 5 to 10 thrips entangled in its meshes. The 

 little spiders have several times been seen 

 with the thrips in their jaws. 



The second most important Arachnid 

 enemy of the citrus thrips is one of the 

 jumping spiders (Fam. Salticidae), known 

 as Thiodina puerperis. This spider is very 



,■ • • •, i • i •, Fig. 9. — Young spider, Mis- 



active in seizing its prey, which it pounces umessus gp>f which preys 

 upon cat fashion. From 4 to 10 or more upon the citrus thrips. 

 thrips will be eaten in succession by one of 



these young spiders. The spider drains the juice from the body 

 of its victim and casts the skeleton aside. 



Another spider (fig. 9), belonging to the genus Misumessus, has 

 often been taken in its immature stages with the citrus thrips in its 

 possession. This spider is a yellowish, very active creature belong- 

 ing to the family of so-called crab spiders (Thomisidae). It is com- 

 monly found, solitary, upon orange leaves. It does not spin a web. 



A small black spider (Erigone sp.), less common on orange trees 

 than any of the foregoing, is sometimes seen with adult citrus thrips 

 in its possession. As is the case with all the foregoing thrips enemies, 

 insects and spiders alike, except the 6-spotted thrips, this spider feeds 

 upon thrips when it is young, but confines itself mostly to larger 

 insects after it has become mature. The young, actually about one- 

 twentieth inch long, is shown greatly magnified in figure 10. 



FUNGUS GROWTH ATTACKING THRIPS. 



The spores of an unidentified fungus have occasionally been seen 

 about the bodies of citrus thrips which have died in captivity, but it 

 seems probable that either this fungus attached the insects after 



1 All spiders referred to herein have been identified by Nathan Banks. 



