308 ANNUAL REPORT OF THE Off. Doc. 



according to the standard formula. It was readily proven that it 

 was not necessary to go to the trouble of digging ditches and pit- 

 falls, or other contrivances, to destroy the army worm. Spraying 

 was satisfactory in results for those who watched and did it in 

 time. 



The most remarkable piece of practical work in economic entomol- 

 ogy during the year, was the successful artificial introduction of the 

 enemies of the San Jose scale, now commonly known as the scale 

 parasites, into scale-infested orchards in certain parts of Pennsyl- 

 vania, as well as in other states. The natural way of suppressing 

 all pests is by their parasites, and the Economic Zoologist succeeded 

 in finding tlie parasites in great numbers and in rearing and dis- 

 seminating them, so that the}'^ were eiTective in destroying the scale 

 in orchards to which they were thus introduced. As a result, trees 

 which previously bore fruit entirely unfit to be seen or used, pro- 

 duced this past season as fine fruit as was ever grown anywhere. 

 There are specific cases where such fruit was borne on trees that had 

 previously been infested with San Jose scale, but never had been 

 sprayed for this pest, and which were cleaned up entirely and solely 

 by the parasites. 



An account of this successful introduction of parasites was pre- 

 sented recently by the writer to the American Association of 

 Economic Entomologists, meeting with the American Association 

 for the Advancement of Science, at Philadelphia, and from the scores 

 of professional entomologists assembled, there was no dissenting nor 

 criticizing word. 



The following is an example of many reports that have been re- 

 ceived, stating the results of this beneficial distribution of scale 

 parasites: Within the past few days difl'erent states and countries, 

 even as far away as Australia, have made requests for shipments of 

 parasites in the hope of suppressing the San Jose scale in their 

 orchards as effectively as they have done in those of Pennsylvania. 

 When this subject was first mentioned a few years ago, it was 

 thought to be a hoax, but it now proves the cause of the disappear- 

 ance of the San Jose scale over vast areas, embracing several coun- 

 ties in Pennsylvania. But to the brief time of but fifteen minutes 

 allotted to us for this report, mention of certain other important 

 pests can not here be made, but we should not close without refer- 

 ence to the pests of the household and livestock. 



It appears that the roach bug or Croton bug frequently occurs in 

 houses and is quite annoying. A Franklin county correspondent 

 wrote to us that he was having indescribable trouble with this pest. 

 I recommend dusting fresh powdered borax in abundance around the 

 floors and cracks, and especially pumps and sinks, in the pantry, on 

 shelves, etc. He tried this, and within a few days replied that the 

 effect was as if magical. He could see manj'' dead roach bugs, but 

 no live ones were left. 



Pigs often remain thin and stunted, the hair becomes long, and 

 ears droop, the animals loose appetite, are inactive, and spend much 

 of the time rubbing themselves, and finally may get the "thumps" 

 and die. A careful examination would reveal great numbers of hog 

 lice on them, which could have been killed by the application of 

 equal parts of kerosene and grease, such as old lard. Insect pests 

 and mites in poultry houses have been destroyed by spraying thor- 



