A mite very often met with by bulb growers is the bulb-mite (_Rhizoglyphus hyacinthi_), now found in most parts of the world. Although this mite may possibly be able to attack practically all tubers or bulbs, it is commonly found infesting narcissus, hyacinth, tulip, crocus, and Easter lily; it is especially abundant in bulbs with loose scales, and has been found to be capable of attacking healthy tissue. The life-history of this species is complicated at times by the development of additional stages; one of these--the hypopus--is of particular interest, as it shows more activity than the others, and attaches itself to the bodies of insects, and is so transported. The mite develops from egg to adult within a period of nine days under favourable conditions, or as long as six weeks at other times. All stages of the bulb-mite occur at the same time in infested bulbs, which become soft and rotten. The adult mites (Fig. 13, 10) are smooth, yellowish-white, tinged with pink, and have legs and mouth-parts reddish. Symptoms of their presence are to be found in stunted growth and yellowing leaves, failure of flower development, reddish spots on bulb scales, or a softening of the bulbs. All seriously-infested bulbs should be destroyed, and the ground where they were grown treated with calcium cyanide. For the treatment of bulbs, they should be immersed for ten minutes in a two per cent. solution of formalin heated to 122 deg. Fahr., or simply in water at a temperature of 131 deg. Fahr. [Illustration: FIG. 13. (1) Five stages in mite development: (1) Egg, (2) larva, (3) nymph, (4) older nymph, (5) adult mite. (6) European red mite and (7) egg of same. (8) Brown mite. (9) Common red spider. (10) Bulb mite. (11) Pear-leaf blister mite. (12) Common woodlouse. (13) Garden millepede. (14) Garden slug. (15) Garden snail. (16) Bulb eelworm. (17) and (18) Immature and mature beet eelworm. (19) and (20) Immature and mature root knot eelworm.]