1G2 THE ENTOMOLOGIST. 



COBDYCEPS ENTOMOnilHIZA (Dickson), A VEGETABLE 

 ENEMY OF HEPIALUS LUFULINUS LAEVJ5. 



By F. V. Theobald, M.A., F.E.S. 



We are all well acquainted with the fungoid disease, Empusa 

 viiisca, that often causes such havoc amongst the abundant 

 house fly and other Diptera, but beyond this we do not often 

 come across vegetal parasitism in insects in this country, 

 although some seventeen insect fungi are recorded. It is only 

 when insects are present in very large and abnormal numbers 

 that these parasitic diseases, due to vegetable parasites, seem to 

 appear. Kecently there seems to have been a considerable 

 increase, anyhow in cultivated areas, of the larvie of the garden 

 swift moth {H. lajmUiius), especially in the south-east of England, 

 and notably in Kent. Not until recently, however, have I been 

 able to detect any natural enemies at work upon them, save a 

 single species of Anihocoris, which I have referred to before in 

 these pages, but which I am sorry to say has had no effect in 

 lessening their numbers, and so helping to allay the damage the 

 ravenous //. lupulinus larvfe occasion. During the latter part of 

 February, Mr. Kennard, of Linton, in Kent, sent me a number 

 of so-called " vegetable caterpillars," which he could not account 

 for, and which he had noticed in bis garden in certain areas on 

 and off for the last fifteen years. These turned out to be the 

 larvffi of 11. lupulinus that had been invaded by a parasitic 

 fungus of the genus Cordi/ccps. Although many of the speci- 

 mens differ very much in form from the previous figures, they 

 are undoubtedly those of the species entomorrldza described 

 by Dickson* in 1785, and subsequently noticed by Tulasne, 

 Saccardo, Currey, Cook, and others. 



Many of the larvae showed no signs of having been invaded 

 by a fungus, they simply remained in the soil as yellowish brown 

 shiny bodies, like " mummies " of Hepialus larviie. On cutting 

 these open, they were seen to be full of a solid white or creamy 

 mass of matter, which under the microscope was shown to be 

 composed of closely compacted fine mycelial threads. This 

 fungus completely invades the larva, and even destroys the 

 chitinous skin, yet retaios most perfectly every detail of the 

 larval structure. A number of the larvae were covered externally 

 by a white or dirty-yellow coarse mycelium, esijecially over the 

 anterior half of the body (figs. 1 & 2/>) ; this is also noted by Cook 

 in his * Vegetable Wasps and Plant Worms.' Others, and those 

 that are most interesting, have developed and proceeding from the 

 side or beneath near the head the large fruit-bearing body so 

 characteristic of the genus Cordyceps. This structure grows out 

 from the buried larva into the air. It is swollen at the free end, 

 and the stem in old specimens is deeply striated longitudinally 

 ■■'■■ riant. Crypt. Britt., p. -22, t. 3, fig. 3. Dickson, 1785. 



