Histopathological changes in the midgut ofSpodoptera lituralarvae on ingestion ofBacillus thuringiensisdelta endotoxin

Histopathology of the larval midgut of Helicoverpa armigera (Hübner) fed on Bacillus thuringiensis crystals and Bt-tomato plants

“…Shrinkage of the nucleus and nuclear envelope destruction of nuclear sheath and chromatin clumping with accumulation of ribosomes were observed. These findings coincide with those of Salama and Sharaby [19], Ingle et al [5], Salama et al [21], Pandey et al [14], Griego et al [4], Endo and Nishiitsutsuji-Uwo [3], Percy and Fast [15], Abdel-Razek et al [2], Rashmi and Singh [16] working on other lepidopterous insects. In their investigations, the mitochondria and microvilli showed rapid swelling and the connections between the epithelial cells were loosened by the separation of cell membranes.…”

“…Studies on the ultrastructural changes of lepidopterous larvae fed Bt endotoxin received the attention of many workers [9], [19], [20], [5], [23], [13], [21], [8], [14]. In their investigations, the interaction between Bt toxins and the midgut of lepidopterous larvae using purified crystal toxins, was evaluated.…”

Impact of Bt cotton on the immune system and histology of the midgut of the fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

“…The Oriental leafworm, Spodoptera litura (Fabricius), ingesting Bt endotoxin respond with slight elongation of the epithelial cells (Pandey et al, 2009). Similar results in the abnormal growth of epithelial cells were observed with Baculovirus anticarsia (AgNPV) and commercial Bt toxin Dipel® for Anticarsia gemmatalis (Hübner) (Knaak & Fiuza, 2005).…”

“…This species displays drastic structural changes in the goblet and columnar cells and a significant reduction in the number of regenerative cells (Sousa et al, 2010;Castagnola et al, 2011) after eating approximately similar amounts of the same toxin (18.3 ± 0.07 ng of CrylAc). Pandey et al (2009) observed slight elongation of the epithelial cells the midgut of S. litura fed with Bt toxins. The changes observed in the midgut of caterpillars with fed Bt cotton could be associated with an increased number of regenerative cells that are directly related to the renewal of epithelial cells in the intestine (Hakim et al, 2010).…”

Larvicidal, growth inhibitory and biochemical effects of soil bacterium, Pseudomonas sp. EN4 against Spodoptera litura (Fab.) (Lepidoptera: Noctuidae)

“…Chitinases have been shown to damage the peritrophic membrane and impair digestion [ 58 ]. Delta endotoxin and Vip3Aa toxin of B. thuringiensis have been known to damage the epithelial and muscle layers of the gut of lepidopteran insects [ 59 – 61 ]. Similar histological alterations in the midgut have been documented in S. frugiperda , S. litura , and H. armigera larvae following exposure to P. akhurstii , K. pneumoniae , and P. paralactis [ 37 , 43 ].…”