94 Habits of the Tomato Moth 



(iii) Moth Trapping. 



The trapping of the moths is as essential as the spraying. It is 

 important that the escape of the moths to the outside should be pre- 

 vented as far as possible, as they are responsible for the spread of the 

 pest to neighbouring nurseries, and their offspring may re-enter the 

 houses when the plants are not protected by the spraying. Trapping 

 will not entirely prevent this escape but it must reduce it greatly. Apart 

 from this, immediate advantage follows. The moth is long lived and can 

 lay ten batches of eggs. As many of them may be caught soon after 

 they leave the pupae the laying of most, or in some cases all, of these 

 can be prevented. 



The moths show no reaction to any lights which have been tested 

 (candle flames, oil and acetylene lamps) and it is therefore necessary to 

 attract them by baits. These are best exposed in jars which are tolerably 

 deep in proportion to the width, have a pronounced shoulder, and a 

 mouth opening about 2 inches across. Glass fruit preserving jars were 

 found to answer well, the dimensions being, depth 8 ins., diameter 3 ins., 

 width of neck 2 ins. 



A fermenting mixture of crushed ripe tomato, water and yeast, was 

 first tested as a bait in the houses, and a few moths were caught by 

 this means. Five jars containing this mixture were hung on the wires 

 near the gutters, and five others, each containing about three ounces 

 of a mixture of ale and treacle, were placed in contrasting positions on 

 the other sides of the gutters. In two nights the latter caught 52 moths, 

 while the tomato traps caught only seven. Three jars of the following 

 baits were then prepared: (1) ale alone; (2) treacle, one part; water, two 

 parts; (3) treacle, one part; ale, two parts. One jar of each of these was 

 placed in each of three houses and exposed for a fortnight. The distance 

 between the traps was 100 feet, and their positions were interchanged 

 twice during the exposure to equalise the chance of each bait. The 

 numbers of moths caught were as follows: ale alone, 14; treacle and 

 water, 12; treacle and ale, 109. The last of these was thus proved to 

 be a very effective bait and was used in all subsequent trappings, a good 

 quality dark treacle (present retail price, 9d. a pound) and ordinary 

 cheap ale being employed. Waste beer was used in one set of traps but 

 was found to be less effective, as the debris floated and formed a platform 

 on which the moths could rest to feed, and escape. Even with the mixture 

 usually employed it was found that some of the moths escaped after 

 feeding, as a few were caught by hand in the houses and were found to 



