11 



The parsnip butteHly was a common species in the plains region throughout the 

 State, and, to some extent, in the mountains late in May. The tomato worm ap- 

 peared June 1, feeding on the tomato and tobacco, iu i)articular. 



Practical directions are giveu for tbe use of various insecticides. 



Notes on insects (pp. 8-20). 



Currant measuring tcorm {Eufitchia ribcaria). — This caterpillar defoliated a large 

 planting of tlu; Houghton gooseberry, leaving untouched the Downing. 



European cahhatje caterpillar (Pitris rapcv). — This insect was very common this sea- 

 son over a large portion of Colorado, hovering over the cabbages in vast numbers. 

 Our first specimens ai)peared early in March, and toward midsummer it was one of 

 our most common species. /icHierftes: On July 15, andon the 2()th of thesamemonth, 

 we made separate trials of the kerosene emulsion and Ougarth's liquid tree protector 

 with success against cabbage worms. The latter was particularly effective, the worms 

 dying whenever struck by the liquid. 



Squash bu<j {Coreiis tristis). — This well-known insect appeared in this region in num- 

 bers for the first time this season, and proved a serious drawback to the culture of the 

 squash and pumpkia. Eernedies : The kerosene emulsion and Ougarth's Lquid tree pro- 

 tector kept them iu subjection. 



Codling motli {Car pocapsa pomonella). — The larva of this raoth is the chief pest of 

 our apple orchards in Colorado, as elsewhere. Remedies : We applied London purple 

 April 28, and again twelve days later, in the proportion of 1 i)ouud of the purple to 

 100 gallons of water, using the Field force-pump and tank mounted on the platform 

 of a two-wheeled cart. Everj alternate tree in a row of Duchess of Oldenburg was 

 thus treated. This was too strong, as it hurt the foliage considerably. * * * A 

 similar api>lication of Paris green in the same proportion was made in another orchard 

 April 28 and May 10. This proved to be satisfactory ; the foliage was uninjured, and 

 but few apples affected by the codling moth were found. Careful analysis of the calyx 

 of the fruit was made by Dr. O'Brine, chemist of the Station, and no trace of arsenic 

 was found — the usual winds and rains of the season secured its dispersion. The time 

 to make the first application is as soon as the fruit is formed and while erect on its 

 stem. 



Another good effect of the application of the arsenites at this season is the destruc- 

 tion of all other leaf-eating larvs, some of which are so injurious to the apple tree in 

 this region during the months of April and May. It is a great gain to fruit-growers 

 in this dry region to know that the arsenites may be safely applied to the foliage of 

 tbe apple tree without danger to human life when the fruit is fit for table use. 



Apple-leaf beetle (Graptodera foliacea). — This brassy-green apple insect has been in- 

 jurious to the foliage of apple grafts and small apple trees for several years in Col- 

 orado. It confines its work, however, mainly to the nursery, never working high 

 above the surface of the ground. It does not touch the pear, although working in 

 numbers on apple grafts, on either side of them. It shows, with us, a partiality for 

 some varieties over others, and is sometimes as destructive to the grape as to the 

 apple. It is a pest in every valley in the State where the apple is grown. It also 

 feeds in great abundance on the native species of the genus Gaura, so plentiful in 

 this region. Remedies : Fortunately it is easily overcome. We have to contend with 

 it annually, aiul find no difiiculty in getting rid of it with the arsenical preparation 

 already noted. 



Eight-spotted forester {Ahjpia octomacuJata). — The larva of this beautiful moth at- 

 tacks the foliage of the grape aunually, in some sections of the State, iu large num- 

 bers. There are two broods, the first moths appearing in May, and the second in 

 August. Remedies : I have always succeeded in destroying the larvie of the first brood 

 with a weak application of Paris green in water, iu June. For the second brood, if 

 the vines are in bearing, it will not do to apply the poison, but if the first attack 

 has been promptly met, there will not be much trouble from the second. 



