276 OHIO EXPERIMENT STATION: BULLETIN 332 



Natural enemies. — Natural control agencies for the most part 

 hold this insect in check in Europe, but with its introduction into 

 America, these native foes were left behind and this fact accounts 

 for the frightful damage it has been able to inflict. For some years 

 the Bureau of Entomology of the United States Department of Agri- 

 culture has been conducting an extensive and thorough-going cam- 

 paign for the introduction of these European insects, and the work 

 has been crowned with a satisfactory measure of success. A com- 

 prehensive report upon the work was published in 1911 by Howard 

 and Fisk (38). In this publication not only is a report made upon 

 the work of importations and colonization but a comprehensive dis- 

 cussion is included concerning the known parasites of this as well 

 as the brown-tail moth. The list of parasites is so long that the 

 writer will not attempt to enumerate them, let alone to discuss each, 

 but will refer the reader to the publication cited. 



Control. — The effective control of outbreaks of the gipsy moth 

 depends largely upon the early recognition of the species. The 

 reader who is not familiar with the pest in its different stages again 

 is referred to the illustrations of Plate XLIV. The writer suggests 

 that, whenever material is found of which the identity is not posi- 

 tively known, specimens be submitted to a competent entomologist. 

 If the plan as suggested is followed, outbreaks will be located in 

 their incipiency and the possibility of eradicating the colony greatly 

 enhanced. 



In handling small outbreaks the collection or destruction of the 

 over-wintering egg masses is one of the principal methods employed. 

 This is supplemented by banding the trees of the area with a sticky 

 substance, such as tanglefoot, or with bands of burlap. The object 

 in the banding is to collect the caterpillars or moths. A still further 

 aid is spraying with arsenicals after the foliage is well developed in 

 the spring in order to destroy the newly-hatched caterpillars. Since 

 the insect is one of the more resistant to the action of poisons the 

 dosage must be somewhat heavier than usual, from 10 to 12 pounds 

 of aresnate of lead paste being the usual amount used for 100 gal- 

 lons of water. 



In extensive operations, one of the more useful methods is the 

 destruction of the favored hosts where practicable. The larger 

 caterpillars feed with avidity upon conifers but the smaller cater- 

 pillars cannot subsist upon these hosts; hence one of the methods 

 of protecting conifers is to develop pure stands of them either by 

 planting or by cutting out susceptible deciduous species. 



