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类细组成，即胚细(E细)、纤维细(F细)、泡状细(B细)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.

化分析结果指出,昆虫中肠羧酸酯酶的活性及酯酶同功酶的差异是这种选择麻醉作用的重要机制。