1899] PEAR-SHAPED WEEVILS. 25 



of M, Herpin, he mentions that his Clover was mown in full flower, 

 and in about ten or twelve days, or rather less, after housing the 

 Clover in the granary, a great quantity of Apions were perceived 

 moving in all directions upon the wall of the building, and making 

 their way towards the outside. The escape of these Apions continued 

 for eight or ten days.* 



These observations point to a good broadscale method of preventing 

 or forestalling recurrence of attack by mowing the Clover before the 

 flower-heads are sufficiently advanced to have become the nurseries of 

 any great quantities of maggots. The j)remature and partial maturity 

 of the florets in the flower-heads is one sign of presence of the maggots, 

 and mowing on the first symptoms of this being noticed is one measure 

 of prevention of a good proportion of coming mischief in the shape of 

 development of beetles, which would lay their eggs either, as the case 

 might be, in the flower-heads of the crop immediately following in 

 summer, or after hibernation in those of the first crop of the following 

 season. t 



Any measures, such as cutting, or feeding the crop off early, before 

 the heads have advanced to the condition at which they give shelter 

 to the weevils for egg- laying, are obviously beneficial ; and so likewise 

 (where there is any reason to apprehend that infestation is likely to 

 occur) is avoiding Clover crops remaining for more than two years in 

 succession on the same ground. 



Where the beetles are observed in the great numbers mentioned 

 at p. 24, as leaving the stack and making a regular advance in a semi- 

 circle, destroying the Clover leafage in their march, it would be well 

 worth while to experiment as to getting rid of them by the use of 

 some of the various insecticides which are now available. 



If circumstances allowed the space round the stack to be thoroughly 

 secured by hurdles or otherwise, so that there was no possibility of the 

 farm stock or ground game getting at the Clover, and there was no 

 reasonable probability of poultry flying over the fence, the use of 

 Paris-green would be exceedingly likely to be of service. The special 

 use of the application would be that it might be presumed that (as 

 in all other cases of application of this poison) the beetles would eat 

 the sprayed leafage and be killed. Kerosine emulsion or soft-soap wash 

 with parafiin mixed in it, or gas-lime applied as a dry dressing, would 

 not act so certainly, because, although any of them might very likely 

 protect the Clover plants on which they were thrown, they would have 

 no effect in preventing the Apions taking flight from the stack in which 

 they were developed. The Apion apricans have very powerful wings. 



* See ' Extrait des M^moires de la Soc. Eoy. et Centrale d'Agric' annde 1842. 

 t This treatment of course is not applicable where the Clover is being grown 

 for seed, 



