Morphology and Morphometry of the Midgut in the Stingless Bee Friesella schrottkyi (Hymenoptera: Apidae)

Abstract

Friesella schrottkyi is a small stingless bee (3-mm long) important for agricultural and native forest pollination. This study describes the morphology and morphometry of the midgut in F. schrottkyi forager workers. The F. schrottkyi midgut presents a single-layered epithelium with digestive, regenerative and endocrine cells. The digestive cells are similar along the entire midgut length with a spherical nucleus, apex with long striated border, cytoplasmic granules in the apical region and well-developed basal labyrinth associated with mitochondria, suggesting they are multifunctional, synthesizing digestive enzymes and peritrophic matrix compounds and absorbing nutrients. Regenerative cells are located around the basal region organized in nests with some cells with a spherical nucleus. Phe-Met-Arg-Phe-NH2-amide (FMRFamide) positive endocrine cells are restricted to the posterior midgut region, suggesting a paracrine function in the midgut. This is the first morphological description of the F. schrottkyi midgut contributing to the comprehension of the digestive process of this bee.

Ultrastructural Changes in the Midgut of Brazilian Native Stingless Bee Melipona scutellaris Exposed to Fungicide Pyraclostrobin

“…Myelin figures and autophagic vacuoles, or autophagosomes, are common in the digestive cells of the bee midgut, which exhibit a high turnover level of intracellular compounds, such as membranes and organelles, due to their multiple functions [ 68 ]. These cells synthesize digestive enzymes [ 69 ], compounds of the peritrophic matrix [ 70 ], and membrane protein transporters for nutrient absorption in the midgut [ 40 ].…”

Midgut Cell Damage and Oxidative Stress in Partamona helleri (Hymenoptera: Apidae) Workers Caused by the Insecticide Lambda-Cyhalothrin

“…Upon entering the insect body, this compound disrupts the conduction of nerve stimuli and feeding processes, leading to a cascade of detrimental effects. These include the loss of muscle control, resulting in paralysis and ultimately culminating in the death of the insect [ 17 , 18 ]. The potent neurotoxic action of lambda-cyhalothrin has made it an effective tool for pest control in various agricultural and public health applications.…”