342 Insect Pests. 



over to another season in the ground. This accounts for the sawflies 

 often appearing every other year, instead of annually. 



Cameron (3) says the larva? feed on pear, plum and cherry trees, 

 also on the whitethorn, Mespilus and other rosaceous shrubs. 

 Colonies are frequently to be found on whitethorn in the hedgerows 

 in Kent. Dwarf trees seem to be especially subject to the attack 

 of these false caterpillars. For the last five years but few have 

 been noticed and no inquiries have been made by fruit-growers. 



XATURAL ENEMIES. 



There are three Ichneumon parasites on the larva? of P.Jiariventrix, 

 known as Option mercator, Gr., Ophion mixtn.s, Gr., and Tryplion- 

 armillatoriux, Gr. The two former lay their eggs in the nearly 

 full grown lame, just before they enter the earth to pupate. The 

 Ichneumon lame feed off the body of the sawfly grubs and then 

 pupate, hatching out in the late spring or early summer. 0. mercator 

 is black, the first abdominal segment being partly black and partly 

 red, the second and third segments red, and the last black ; the hind 

 feet are much longer than the fore feet and reddish to the knees, 

 which are black. 



These Ichneumons materially lessen the prevalence of this pest, 

 but attacking the larva? so late in life they do not do much good 

 in the particular year of the attack. 



TREATMENT. 



If the lame have been allowed to develop, the ground beneath 

 the trees upon which they have been feeding should be well dressed 

 with gas lime during the winter, the caustic substance being worked 

 into the soil by a prong hoe. As the larva? do not stray from their 

 dwelling they can easily be caught, the tent and its occupants being 

 cut off and put into a pail of hot lime. "When this is done great 

 care should be taken to hold some receptacle beneath the tent, as 

 the larva? readily fall to the ground, and hang suspended by a silken 

 cord when frightened, as they would be during the process of cutting 

 off the tent. This is by far the best way to cope with this pest. 

 When out of reach a good drenching with cold water or soft soap 

 emulsion, so as to thoroughly saturate the silken house, may do 

 a little good, but the destruction of the nest appears to be by far 

 the most successful method of coping with it. 



