scholarly journals Miticidal Activity of Fenazaquin and Fenpyroximate Against Varroa destr uctor, an Ectoparasite of Apis mellifera

2022 ◽  
Author(s):  
Rassol Bahreini ◽  
Medhat Nasr ◽  
Cassandra Docherty ◽  
Samantha Muirhead ◽  
Olivia Herdt ◽  
...  
Keyword(s):  
Author(s):  
Maria Anna Pabst

In addition to the compound eyes, honeybees have three dorsal ocelli on the vertex of the head. Each ocellus has about 800 elongated photoreceptor cells. They are paired and the distal segment of each pair bears densely packed microvilli forming together a platelike fused rhabdom. Beneath a common cuticular lens a single layer of corneagenous cells is present.Ultrastructural studies were made of the retina of praepupae, different pupal stages and adult worker bees by thin sections and freeze-etch preparations. In praepupae the ocellar anlage consists of a conical group of epidermal cells that differentiate to photoreceptor cells, glial cells and corneagenous cells. Some photoreceptor cells are already paired and show disarrayed microvilli with circularly ordered filaments inside. In ocelli of 2-day-old pupae, when a retinogenous and a lentinogenous cell layer can be clearly distinguished, cell membranes of the distal part of two photoreceptor cells begin to interdigitate with each other and so start to form the definitive microvilli. At the beginning the microvilli often occupy the whole width of the developing rhabdom (Fig. 1).


2016 ◽  
Vol 51 (2) ◽  
pp. 156-171
Author(s):  
А.В. СПРЫГИН ◽  
◽  
Ю.Ю. БАБИН ◽  
Е.М. ХАНБЕКОВА ◽  
Л.Е. РУБЦОВА ◽  
...  

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