TWENTY-NINTH FRUIT-GROWERS' CONVENTION. 



147 



destroys the scale it attacks before the scale reproduces, it can not long 

 remain in injurious numbers. 



The " brown apricot scale " (Lecanium armeniacum) was a very filthy 

 pest on prune, apricot, peach, and plum trees, owing to the great 

 amount of honey dew exuded by the insects. The leaves and fruit 

 were consequently badly attacked by black smut. Since its parasite, 

 Comys fnsca, became established in infested orchards, it is not so trouble- 

 some. It takes two years to thoroughly stock an orchard when 90 to 

 98 per cent of the scales are killed by its parasite. There is but one 

 generation of this scale and its parasite, so its work is not as effective 

 or expeditious as other internal parasites, still it is a valuable enemy 

 of this scale. We send out colonies of this parasite during the end of 

 May and early in June. 



Twenty years ago, the large green "katydid" did much damage to 

 the blossom twigs of orange trees in the southern counties. It is very 

 rare now, owing to a very interesting parasite that attacks its eggs. 

 This parasite, Enpelmus viirabilis, lays but a single egg in each katydid 

 egg. The latter is very flat, and the mature parasite has the same 

 character of body. If the katydid eggs are perfect they assume a convex 

 shape just before hatching, but if they are parasitized they remain flat, 

 and the parasite in issuing cuts a small round hole through the upper 

 side of its host. The katydids are large and voracious feeders and 

 would be destructive pests were it not for the work of our friendly 

 Eupelmus. 



Numerous other friendly insects could be mentioned, but a brief 

 review of what has been accomplished by the South African parasite of 

 the " black scale," Scutellista cyanea, will be interesting. This parasite 

 was introduced through the kindness of Prof. Charles P. Lounsbury, 

 Government Entomologist of Cape Colony, two years ago. Several 

 colonies were sent by Professor Lounsbury to Mr. E. M. Ehrhorn, Hor- 

 ticultural Commissioner and Entomologist of Santa Clara County. He 

 bred a colony in confinement, but did not succeed in establishing them 

 out of doors. On October 1, 1901, Professor Lounsbury wrote me that 

 he would send me, on the following day, two boxes containing para- 

 sites. The packages took thirty days to reach us, and we bred seventeen 

 Scutellista cyanea and a few secondary parasites; the latter we destroyed. 

 Only four of the true parasites were females, and unfortunately one of 

 those was killed by a small spider, leaving but three with which to stock 

 the State. On February 7, 1902, the Scutellista began to issue from the 

 scales, and the descendants of those three have increased to millions and 

 wonderful work has been accomplished by them in this short time. During 

 July I made an extended tour of the southern counties, and reported my 

 observations of the work of the Scutellista to State Commissioner of 

 Horticulture Cooper. Since then we have had most encouraging reports 



