118 



SCIENTIFIC AGRICULTURE 



March, 1921. 



Terminal abdominal segments of certain fruit-infesting- 

 insects: (1) Codling moth, (2) Tmetocera ocellana, (3) 

 Plodia interpunctella, (4) Mineola tricolorella. (5) Lesser 

 Apple Worm. (6) Anarsia lineatella. (Original micro-photo- 

 graphs by M. H. Ruhmann.) 



The next grou]i, the CEeophnridae, is so chwely re- 

 lated to the Gelechiidae tliat there is difficulty in dif- 

 ferentiating the larvae. The only species with which we 

 have to deal in this paper is EpicaUima dimidiella 

 which by reason of the fact that it is always taken under 

 bark and in places frequented by other fruit infesting 

 larvae may possibly be mistaken for tlie Codling Moth. 

 This species which appears to be very common in the 

 vicinity of Vernon, B.C. is a refuse feeder and has never 

 been observed to leave the crevices of the bark or to at- 

 tack fresh fruits. It is, therefore, except in the matter 

 of the confusion liable to arise in comparison with the 

 Codling Moth, easily recognized. Mature and partly- 

 grown larvae winter in cracks and crevices of apple tree 

 bark, much in the same way as does tlie Codling I\Ioth, 

 and emergence of the moths occurs from the middle of 

 May until July. The eggs have not been observed but 

 they are doubtless laid in bark crevices, for the reason 

 that young larvae may be seen in their typical habitat 

 during August. 



Larval characters. EpicaUima dimidiella. 



Mature larva 7.5 mm. in length. General colour dull 

 grey, with a snb-dorsal line on each side composed of 

 a series of small spots of a semi-transparent appear- 

 ance. These markings are absent on abdominal seg- 

 ments 9 and 10. The ventral surface of the body is 

 pale grey, almost white in colour. The head is pale 

 brown, shiny, with darker mouth parts ; lateral ocelli 



black. Thoracic shield dull grey-black divided by a 

 central longitudinal pale line, with five small well- 

 defined spots, semi-transparent, arranged in the form 

 of a crescent. Anal plate dull grey-black, bearing 

 eight pale yellow setae. 



The pupa measures slightly less than 5 mm. in 

 length and is of a straw colour with a dark brown 

 crema.ster. 



The only species of Geometridae to which our atten- 

 tion has been drawn is Rachela bniceafa. These larvae 

 may cause surface injury to fruit and on account of 

 their somewhat gregarious habits in tlieir earlier stages 

 may be mistaken for more important fruit-infesting 

 insects. They are, however, typical leaf feeders and 

 being possessed cf only two pairs of prolegs, whence 

 arises the name of 'measuring worms', they are dis- 

 tinctive larvae. 



It is with the various members of the sub-family Tor- 

 tricinae, mentioned in this report, that most confusion 

 is liable to arise in the matter of larval identity. 



Archips rosaceana may be readily separated from its 

 allies l)y reason of its green colour and the fact that the 

 larva dees not bore into fruit but produces a large rough 

 surface feeding-area, which causes malformation. 



Larval characters. Archips rosaceana. 



The mature larva measures 19 mm. in length. Gen- 

 eral colour dark velvety green, paler on the ventral 

 surface. Head variable in colour from black to dull- 

 brown ; mouth parts pale brown. Thoracic shield 

 concolorous with head, also variable in colour, divid- 

 ed by a narrow median line of pale green. Anal 

 plate slightly paler than the dorsum, mottled on the 

 anterior margin with five irregularly arranged grey 

 blotches and bordered laterall}' with a narrow band 

 of grey. Spiracles circular, ringed with dull brown. 

 Thoracic legs black, ringed at base on the anterior 

 margin with a dull brown plate. Tubercles slightly 

 paler than the general surface of the body with a cen- 

 tral spot of dull gre}^ 



The larva of A. argijrospila is so similar to the above 

 description that it is not necessary to draw attention to 

 its characters. 



Peronea (Acleris) trunimana has proved an interest- 

 ing insect attacking orchard trees in the Okanagan val- 

 ley, not so much from its economic importance, which is 

 slight, but from its identity and discover}-. The early 



alpha 

 gamma 

 eps ilon 



kappa 

 eta 



nu 



tau 

 omega 



Hypothetical Setal Map, after Fracker. 



S igma 



