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期已有了分化，由4类组成，即胚(E)、纤(F)、泡状(B)和吸收(R)。

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,昆虫中肠羧的活性及同功的差异是这种选择麻醉作用的重要机制。