. Beginners' Zoology . acedin each box to keep out the insect pests which infest col-lections. Captured insects which, in either the larval or the per-fect stage, are injurious to vegetation, should always bekilled after studying their actions and external features,even if the internal structure is not to be studied. Bene-ficial insects, such as ladybugs, ichneumon flies, bees,mantis (devils horse), dragon-flies, etc., should be setfree uninjured. Anatomy and General Characteristics of the Class Insecta The body of an insect is divided by means of two markednarrowings into three parts: the hea
. Beginners' Zoology . acedin each box to keep out the insect pests which infest col-lections. Captured insects which, in either the larval or the per-fect stage, are injurious to vegetation, should always bekilled after studying their actions and external features,even if the internal structure is not to be studied. Bene-ficial insects, such as ladybugs, ichneumon flies, bees,mantis (devils horse), dragon-flies, etc., should be setfree uninjured. Anatomy and General Characteristics of the Class Insecta The body of an insect is divided by means of two markednarrowings into three parts: the head, the chest, and theabdomen. The head is a freely movable cap-sule bearing four pairs of append-ages. Hence it is regarded ashaving been formed by the unionof four rings, since the ancestor ofthe insects is believed to have con-sisted of similar nngs, each ringbearing a pair of unspecialized legs. The typical mouth parts of aninsect (Fig, 123) named in orderfrom above, are (i) an upper lip (labrum, <?/), (2) a pair. Fig. 122. —Yellow FeverMosquito, showing head,thorax, abdomen. 74 BEGINNERS ZOOLOGY
Size: 1523px × 1640px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, bookidbeginnerszoo, bookyear1922
