August, '21] moznette; avocado insects 343 



With the approach of spring, various other insect activities appear. 

 Before the avocado tree produces new foHage, the blossom clusters 

 arise from the terminal twigs or from the base of the years' growth 

 The bloom as it appears is attacked by a blossom thrips {Frankliniella 

 cephalicus Craw.)- This blossom thrips is not the same which attacks 

 citrus in Florida or California. However, it does not differ material- 

 ly in general appearance from most thrips. It averages about a mil- 

 limeter in length and in general color is pale yellow. It was first re- 

 corded as taken from native acacia-like plants in the mountains of 

 Mexico and it is quite probable that it has found its way into Florida 

 from that country. The injury produced by this thrips is caused 

 by feeding of the young and adults on the individual flower parts. As 

 succeeding generations appear the adults deposit their eggs in great 

 numbers in the stems and pedicles which bear the floral panicles and 

 which eventually hold the fruits as they set to the terminal twigs. 

 The species does not attack the fruit. 



It is controlled by spraying with nicotine sulphate 40% solution 1 

 to 900 with the addition of 2 or 3 poimds of soap added to each 100 

 gallons of the diluted spray as a spreader. 



With the maturing of the bloom and the setting of the fruit, new 

 foliage commences to arise from the floral racemes. As the new growth 

 appears it is attacked by the avocado white fly {Trialeurodes floriden- 

 sts Q.). This white fly is unlike any species which attacks citrus in 

 Florida and California. The adults are small and average less than a 

 millimeter in length and possess pale yellow bodies. The adults which 

 appear at this time emerge from the pupae clustered in great numbers on 

 the lower surface of the older dormant foliage. The adults deposit 

 their eggs in great numbers on the new growth, the larvae which hatch 

 from the eggs pass their existence on the lower surface of the foliage. 

 As the new growth commences to harden, pupae are formed and the 

 adults which emerge later reinfest subsequent new growth put out by 

 the trees. There are three generations with a partial fourth in south- 

 em Florida during spring and summer. This species like practically 

 all species of white flies produces an abundance of honeydew in the 

 course of development. This honeydew accumulates on the upper 

 surface of the foliage and fruit. The soDty mold fungus develops in 

 this honeydew deposit eventually giving the avocado foliage and fruit 

 a decided dirty and blackened appearance. The sooty mold adheres 

 rather tightly to the fruit which must be cleaned before shipment, neces- 

 sitating considerable extra labor. By proper spraying this expense 

 is practically eliminated. 



