Several of the books I ordered at the library last week have come today: one of them, 'Global Silk Industry' by Rajat K Datta and Mahesh Nanvaty, is a particularly interesting book, but one guaranteed to induce hypochondria -by-proxy in any silkworm farmer. The diseases, which all sound as though they could be describing an interesting French cuisine, are Pebrine, first identified by Louis Pasteur, which almost decimated French sericulture in the nineteenth century, and is spread by spores; Flacherie, a viral infection (symptoms are sluggishness, loss of appetite and vomiting); Grasserie, another viral disease (particularly nasty, the silkworm swells, the skin stretches and becomes yellow and leaks fluid); Muscardine, which is fungal and comes in four varieties (according to which colour it turns the silkie*) - white, yellow, green or brown.
The silkworm can also be afflicted with pests: ants, earwigs, wasps, crickets and praying mantis as well as the Uzi fly. These lay eggs on the silkworm which hatch and leave a black scar. The book provides a picture and when I looked at my silk worms just now I thought one had some of these scars so I have put him in isolation as a precautionary measure (you can see the offending black spot near his tail in the picture below).
He looks strong and is feeding well at the moment but I shall be monitoring him carefully over the next few days.
Who says silkworm husbandry isn't exciting? (His name, by the way, is Caradoc).
*Thanks to Jem for the terminology.