20 REPORT ON INJURIOUS INSECTS FOR 1907. 



REPORT UPON INSECT PARASITES OF INSECTS. 



In this fascinating branch of Economic Biology much useful work 

 has been accomplished. 



Two species of Ichneumons (both probably new T to science) have 

 been bred from the Plum Aphis (Aphis pnini, Reaumur) and valuable 

 information has been collected as to their economic importance. 



An attempt was made to breed and distribute examples of Aphidius 

 silenes, Marshall, a small Ichneumon which parasitises the Pea Aphis 

 (Siphonophora pisi, Kalt), with most beneficial results. 



Various species of Hovering Flies (Syrphidae) and Ladybird Beetles 

 (Cocdnellidae) have been bred and distributed. 



There is undoubtedly a very important field for work on these lines 

 in the fruit-growing districts of the Midlands, and whilst I do not for 

 one moment think that we are ever likely to reap the results from native 

 parasites as accrue from the introduction of foreign species, yet they 

 undoubtedly exercise a control upon the numbers of this or that 

 particular pest, which is to the advantage of the fruit-grower. 



THE GOOSEBERRY GALL-MITE. 



Eriophycs grossulariac, Cllge. 



Early in the year an Evesham correspondent forwarded me some 

 Gooseberry cuttings on which all the present year's buds appeared dry 

 and shrivelled. All the outer leaves were quite dead, and in some cases 

 the bark was peeling off in long shreds. 



Careful examination for a fungus or some boring insect larva was 

 unrewarded by any success, so as a final resort I teased a bud, just as 

 one would do to find the Black Currant Gall- Mite, and I was very much 

 surprised to find a mite of the genus Eriophyes. 



Further examination showed that practically all the remaining buds 

 were infected. 



Growers noticing buds which appear dead or drying up on the 

 new wood should immediately cut it away, and destroy by burning. 



THE BULB MITE. 



Rhizoglyphus echinopus, F. & R. 



A somewhat serious attack of this mite was reported by a 

 Warwickshire correspondent ; tulips and hyacinths were the bulbs 

 attacked. 



The life-history is only imperfectly understood. The eggs give 

 rise to six-legged larvae ; which, later on develop into nymphs possess- 

 ing legs. These, after undergoing a couple of moults, become the 

 sexually mature adults. 



What is known as a hypopial stage may occur ; and it is in this 

 stage that the species is spread. The hypopus possesses on its under 



