midgut

The midgut gland cell differentiation occurs at Z2, There are 4 types of cells, i. e., embryonic cell (E-cell), fibrillar cell (F-cell), blister cell (B-cell) and resorptive cell(R-cell).

中肠腺小管上皮在Z2期细已有了分化，由4类细，即胚细(E细)、纤维细(F细)、泡状细(B细)和吸收细(R细)。

The results of biochemical analysis indicated that the difference of the activity of carboxylesterase and esterase isozymes in the larval midguts were the main mechanism of this selective toxicity.

化分析结果进一步指出,昆虫中肠羧酸酯活性及酯同差异是这种选择麻醉作用重要机制。