LEAF-K0LL1:RS ox ORAX(iK. 



1 ;>:] 



OI'W"''""**. 



-Trichogntmma minuta. 

 Rilev.) 



(After 



method younjj trees can without diffipiilty be licpl tree irom tlieir 

 attacks. 



Parasites — THchogramma pretinsa Riley. — Tliis minute Clialcid 

 fly, well known as the parasite which renders effective aid by destroy i:!g 

 the e,2:gs of the Cotton Worm, also infests the egg clusters of the Orange 

 Leaf-roller. The 'nother paiasite deposits a single egg in each cell like 

 igg of the Tortrix, and within this nar- 

 row cell the 3'oung parasite finds food 

 and domicile until it has coni])leted all 

 its changes. Then it eats its way out, 

 making a ragged hole in the shell, and 

 emerges as a perfect four- winged fly like 

 its parent. The fly is 0.3""" (-^^o inch) 

 long, clear yellow in color, with ruby 

 eyes and iridescent, hyaline wings, 

 which are delicately fringed with hairs. 

 It has been bred from the Tortrix eggs in March and also in September. 

 Fig. 72 represents Trichoc/ramma minuta, a closely-allied species, which 

 dilfers from Trlchoyramma pretiosa only in color and the form of the 

 su)all joints of the antennje. 



Miotropisplnfynot(eIlo^n.rdJ'^ — A slender hymenopterous fly has been 

 bred from the larva of the Orange Leaf- roller. It is honey-yellow; 

 head lemon-yellow, with dark eyes and anteuuie. The head is much 

 wider than long, and bears above three dark-colored, simple eyelets 

 (ocelli). The wings are hyaline. Three or four maggots of the parasite 

 are found living within a single caterpillar of the Tortrix, which is at 

 last almost completely devoured by them. The parasites form naked 

 ])up{e, loosely disposed within the tubular web of. the destroyed Leaf- 

 roller, and in about nine days change to adult flies by casting the thin, 

 transparent skin of the pupa. The tlies were obtained in September. 



Pohispltinvtd (ilhipes Cressou. — Cocoons of slightly yellowish, ooarse 

 silU, loosely spun, were found by Professor Comstockon an orange leaf, 

 a I Kock Ledge, Kla. The flies issued in February. They have been 

 described by Mr. Cresson in the Keport of the Commissioner for 1879, 

 1>. 208. The body is dull red, smooth and polished ; head black, with 

 white mandibles; wings hyaline, and legs white. Length 7'"'" d^y^y 

 inch). This insect is somewhat donbtfully considered a i)arasiteof Tor- 

 trix rout rami. 



fro»/oc?/A- n. sp.; '■' family Proctotrupida-. — A minute i)arasite is bred 

 from the caterpillar of the Leaf-roller. It has a shining, black body, 

 with yellow legs and antennje, an<l hyaline wings, with a dark-brown 

 stigmal spot. Length 2.5""" {^\ inch). Four or five of the i)arasites 

 are found in a single caterpillar. They spin oval cocoons of whitish 

 silk within the tubular web of the Tortrix. The parasites i.ssued Octo- 

 ber 1. 



