Studies on the histological changes of fat body and silk gland of bacterial infected silkworm Bombyx mori (L.) (Lepidoptera: Bombycidae) fed with antibiotic drug (Dicloxacillin) treated mulberry leaves

Mulberry silkworm, Bombyx mori is the preferred species for the production of silk cocoons. The quality of this species is generally affected by bacterial, viral, fungal and protozoan pathogens. Bacterial pathogens alone are responsible for causing cocoon loss to the extent of almost 70%. Antibiotics are widely and effectively used to control these pathogens affecting particularly Bombyx mori. The present study is aimed to find out the histological changes in the fat body, and silk gland of bacterial infected V instar larvae of silkworm fed with antibiotic drug (Dicloxacillin) treated V1 mulberry leaves. Silkworm fat body consisted of nucleus, cytoplasmic vacuole and granular substances. In bacterial infected silkworm’s silk gland showed necrosed columnor epithelium with disintegrated nucleus, vacuoles and the lumen contained low secretory substances, whereas in antibiotic drug (Dicloxacillin) treated V1 mulberry leaves fed V instar silkworm’s fat body and silk gland showed spectacular changes such as swollen nucleus, with more vacuoles in the fat body, whereas, the silk gland showed shrunken nucleus, vacuole in the epithelium, lumen contained more secretory substances suggested that the mobilization of to secretory substance from posterior silk gland to middle silk gland which enhance and to store more amount of secretory substance for spinning.