Evolution of the Alimentary Canal in the Hemiptera

Evolutionary Trends in Heteroptera. Part II. Mouthpart-Structures and Feeding Strategies

“…On page 17, it was shown that barbed stylets are unlikely to aid in extracting sap from plant tissue. MILES ( 1972), following GOODCHILD ( 1966), considered ancestral Heteroptera to be litter-inhabiting, omnivores (the word 'omnivorous' can be interpreted in many ways, whereas I argue for a completely predatory ancestral life, a conclusion already emphasized in my 1968 book). CHINA (1933) stated that the primitive Heteroptera were undoubtedly phytophagous.…”

“…Some authors (SWEET, 1963;GOODCHILD, 1966;SCHLEE, 1969;MILES, 1972) recently have expressed the opinion that the ancestors of the Heteroptera were phytophagous and formed a salivary sheath. In 1968 (p. 376) I expressed the view 'that the archetypical hemipteran was a predominantly carnivorous insect'.…”

“…Gerromorpha probably deliver large amounts of saliva at one time mostly (and in Hydrometra, entirely) through the large, central maxillary canal (p. 67). To what extent the bladderlike, accessory, salivary lobe, which most probably serves for water excretion (GOODCHILD, 1966;MILES, 1972), contributes to normal salivation is not known. In Hebrus, a purely excretory function for the accessory lobe is strongly suggested (p. 83; Figs.…”

“…There is apparently no correlation between the presence of pharyngeal tendons and the oesophageal valve. The principal function of this valve is probably to prevent regurgitation of food (GOODCHILD, 1966).…”

The molecular correlates of organ loss: the case of insect Malpighian tubules

“…Malpighian tubules are near-universal in insects. Exceptionally, they are absent from the aphids (Aphidoidea), in which the gut comprises a tube without any discernible evaginations (figure 1a) [9,10]. Aphids are plant phloem sap-feeding insects of the order Hemiptera.…”