The Proceedings of the Royal Entomological Society of London
The Royal Entomological Society of London
FOURTH instar larval characters of American BOMBIDAE (BREMIDAE) were described by Ritcher (1933) for nine species of Bombus (Bremus) and one species of Psithyrus. These two genera were separated on the shape of the mandibles. An attempt was made to separate the species of Bombus (Bremus) on the characters of the mesothoracical spiracles and the pleural sutures. The shape of the spiracles and atrial spine and the width of the peritreme were the main spiracular characters used. In the present work fourth instar larvae of seven species of Bombus and one species of Psitliyrus have been studied.
Cumber, R. A., "Larval Specific Characters and Instars of English Bombidae" (1949). Co. Paper 26.
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