. Class book of economic entomology, with special reference to the economic insects of the northern United States and Canada. Beneficial insects; Insect pests; Insects; Insects. 26 ECONOMIC ENTOMOLOGY. Fig. 30.— Dorsal view of ali- mentary canal of the larva of the budmoth (Tmelocera ocellana). Ph., Pharynx; Oes., oesophagus; SM., suspensory muscles; Tr., vis- ceral tracheae of left side; MT., Malpighian tubules; Mes., mesen- teron; Inl., small intestine; In., intestinal nerve; rectum. directly into the stomach which is long. Further digestion occurs here through the action of secretions o
. Class book of economic entomology, with special reference to the economic insects of the northern United States and Canada. Beneficial insects; Insect pests; Insects; Insects. 26 ECONOMIC ENTOMOLOGY. Fig. 30.— Dorsal view of ali- mentary canal of the larva of the budmoth (Tmelocera ocellana). Ph., Pharynx; Oes., oesophagus; SM., suspensory muscles; Tr., vis- ceral tracheae of left side; MT., Malpighian tubules; Mes., mesen- teron; Inl., small intestine; In., intestinal nerve; rectum. directly into the stomach which is long. Further digestion occurs here through the action of secretions of the coecal tubes, often called the gastric coeca, which con- sist of glandular pouches emptying into the anterior end of the stomach. Most of the digested food is here absorbed and passes into the circulation. Pos- terior to the stomach is the intestine which consists of three parts—ileum, colon, and rectum. Into the ileum open the Malpighian tubes which are excretory in function, similar to the kidneys of higher animals. The undigested portions of food are expelled through the rectum and anus. Some variations may be noted. The oesophagus is long in those insects that suck their food, and short in herbivo- rous forms. In sucking insects the giz- zard may be absent, and the crop is often a side pocket of the oesophagus (Fig. 30). Structurally, the wall of the alimen- tary canal consists of: 1. An epithelial layer of cells which secrete the intima or lining layer. 2. The delicate basement membrane. 3. Circular muscles. 4. Longitudinal muscles, which aid in constricting and enlarging the canal (Fig. 31)- From an embr3'ological point of view the alimentary tract consists of three primary regions: 1. The Stomodceiim, embracing the fore part as far as the stomach. 2. The Mesenteron, or mid-intestine embracing the stomach, and. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of
Size: 852px × 2933px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectinsects, bookyear1919
