INNOXIOUS INSECTS FREQUENTING THE ORANGE. 193 



INNOXIOUS INSECTS. 



CASE-BEAIiERS ON ORANGE. 



The trunks of orange trees are favorite feeding-grounds for the larvae 

 of several small moths of the family Tineida% whieli protect their bodies 

 with cases formed of fragments of their food material. In the case of 

 those species which are met with upon orange-tree trunks the food con- 

 sists of lichens or other minute cryptogams found growing upon the 

 bark. 



A very common species belongs apparently to the genus Coleophora. 

 Its case is dull white, about the size and somewhat the shape of a grain 

 of oats; it is rather smooth outside, and seems to be formed of finely 

 comminuted bark. 



THE ORANGE CASE-BEARING TINEID. 



(Coleotechnites citriella Chambers.) 



This species was first made known in the Report of the Commissioner 

 of Agriculture for 1879, which contains the following account of its 

 habits. Mr. Chambers' descriptions of the genus and species will be 

 found in the same report, page 20G : 



"At Manatee, Fla., in the latter part of April, I found upon the trunk 

 of an orange tree the case of a Tineid larva. This case was rather slen- 

 der, llmm (43 inch) long, and rather pointed at the hinder extremity. 

 It was dark gray in color, resembling the bark upon which it was found, 

 and was apparently composed of small bits of lichens and excremental 

 pellets, with much gray silk. The moth issued March 6, and upon be- 

 ing referred to Mr. Chambers i) roved to be a new species representing 

 a new genus." 



BARK CLEANERIS. 



Among the host of harmless insects that from time to time make their 

 appearance upon the orange tree, there is a group of scavengers that 

 frequent the trunks and assist in cleansing the bark, by devouring the 

 fungi, molds, or excreta of other insects that befoul its surface. Of 

 these the most conspicuous examples are certain nerve-veined insects 

 (Neuroptera) belonging to the genus Psocus. 



Psocus VENOsus Burui. 



The adult of this species is smoky-brown ; head dark bronze ; an- 

 tennai dusky, lighter at the base, densely hairy in the male; thorax mar- 

 gined with yellow ; fore-wings almost black, the three basal veins yellow, 



