355 



direction. A spray rod with an upturned nozzle at an angle of 45° 

 attached to a 10 U.S. gal. capacity hand spray pump is sufficient 

 for garden purposes. 



McDaniel (E.). The Silver Fish {Lepisma spp.). The Habits and 

 Control of this troublesome Household Pest. — Qtrly. Bull. 

 Michigan Agric. Expt. Sta., East Lansing, iv, no. 2, November 

 1921, pp. 62-64, 1 fig. [Received 3rd May 1922.] 



The two species of " silver fish " common in the north-eastern 

 United States are Lepisma saccharina and L. domestica. The former 

 feeds on starches and sugar ; the latter has been observed damaging 

 glue and leather. Both multiply rapidly in houses closed for the 

 summer, and chiefly infest attics, drawers, boxes or bookshelves 

 that are undisturbed for long periods. A paste of starch poisoned 

 with white arsenic spread on pieces of paper has often been used to 

 kill these insects, and dusting with powdered pyrethrum, borax or 

 sodium fluoride will destroy many. P3n:ethrum quickly loses its 

 efficacy, and borax is apt to stain materials when left for some time ; 

 sodium fluoride is on the whole the most successful, but it is poisonous 

 to human beings and domestic animals. 



HoRTON (J. R.). U.S. Bur. Ent. A Swallow-tail Butterfly injurious 

 to California Orange Trees {Papilio zolocaon, Boisd.). — Mthly. 



Bull. Cat. Dept. Agric, Sacramento, xi, no. 4, April 1922, pp. 

 377-387, 4 figs. 



Though not a major pest, Papilio zolocaon, Boisd., occurs throughout 

 the California citrus belt from Vancouver to Arizona and east to 

 Colorado, and does a varying amount of injury to young orange trees. 

 The damage is chiefly caused by the larvae of the first generation ; 

 they feed on the young foliage, the favourite food-plant besides orange 

 being garden parsley. Wild umbelliferous plants appear to be the 

 main food-plants outside the orange belt. On Citrus the eggs are 

 invariably deposited on new growth. The duration of the different 

 stages varies greatly at different periods of the season. The average 

 incubation period was 9-2 days, with extremes of 4 and 19 days. The 

 larvae occurring from March to May and from November to January 

 live almost twice as long as those occurring from May to Octobei, 

 but as they are less numerous and require less food, they also do less 

 damage. The average life of the larvae was 46 -6 days, with 25 days 

 as the shortest and 114 as the longest period. Though the belated 

 individuals apparently require very little food, they cannot survive 

 more than a month wdthout an}'. Pupation lasts from 7 to 42 days, 

 with an average of 13-2 days during the months of May to October, 

 but about 15 per cent, of those that pupated in May did not transform 

 into adults until April of the following year, averaging 318 days in 

 the pupal stage. The average period for pupation between October 

 and Januar}^ was 164 days. There are three full generations and a 

 partial fourth each season. True hibernation does not occur in the 

 citrus belt, the development of the stages being merely slowed down as 

 the weather becomes colder. Eggs and adults occur as late as 2nd 

 November, and occasionally larvae may pupate as late as 22nd January. 



The adults appear in the spring from the end of February to the 

 first week in May, arising from individuals that pupated during the 



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