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Journal/Book Title/Conference

Contributions in Science, Los Angeles County Museum



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In a greenhouse, each nest of Pseudomasaris edwardsii (Cresson) was constructed of nectar-moistened soil, was solitary and was placed in open but concealed niches attached to a variety of substrates. The wasp anchored her egg by its posterior tip to the bottom of the cell, deposited a jellylike cylindrical provision composed of Phacelia pollen and nectar and constructed a cell cap. Soil carried to the nest was attached to the post genal surfaces of the female's head, and the pollen and nectar were transported in her honey stomach. Cells were clustered and attached to each other and to the substrate along their lateral margins. Most nests were covered with separate layers of soil (surface ornamented in various ways) that camouflaged the nest against natural enemies and protected it against extreme temperatures. The larva, after consuming its provision, spun a cocoon which closely adhered to the inner surface of the cell, and then voided its feces across the bottom of the cell. The post-defecated larva subsequently migrated to the anterior limit of the cell where it firmly appressed against the cocoon as it assumed a strongly decurved, overwintering, prepupal position. Rearings in the laboratory indicated that the species is univoltine and nonproterandrous. The immature forms of P. edwardsii and Euparagia scutellaris Cresson are described and represent the first descriptions of the immatures within the family Masaridae. Relationship of these immatures is discussed and both are compared with the immature forms of other known vespoids.

Subject Area

Natural history

Taxonomic Grouping

Wasps and other insects

Included in

Entomology Commons