Monoctenus species male

Conifer Sawfly
Monoctenus species males

Conifer Sawfly Monoctenus species male. May 10, 2017. Leamington, Ontario.
Conifer Sawfly Monoctenus species male. May 10, 2017. Leamington, Ontario.

Sawflies in the genus Monoctenus feed on Red Cedar, Northern White and Eastern White Cedar Thuja and Common Juniper Juniperus. Flight time is late April to May. The females insert eggs into the tips of new shoots. Larva feed and mature in 4 to 6 weeks, then drop to the ground, dig into the soil and form a cocoon until the next spring. Very little damage is done to the trees. Larvae are parasitized by the Chalcid Wasp Perilampus hyalinus.

Three species in Ontario: Monoctenus fulvus, M. melliceps and M. suffusus. All have the same feeding patterns, flight time and life cycle.

Conifer Sawfly Monoctenus species male, close-up of pectinate antenna. May 10, 2017. Leamington, Ontario.
Conifer Sawfly Monoctenus species male, close-up of pectinate antenna. May 10, 2017. Leamington, Ontario.

Scientific literature indicate that none of the males have been described.

Monoctenus species males differ from other Conifer Sawfly males in that their feathered (pectinate) antenna are of uniform size. In Diprion and Neodiprion the feathers taper off nearer the tip.

Conifer Sawfly Monoctenus species male on my finger. May 10, 2017. Leamington, Ontario.
Conifer Sawfly Monoctenus species male on my finger. May 10, 2017. Leamington, Ontario.

Size: 5 to 6 mm long.

Synonyms: Lophirus

References:
Transactions of the American Entomological Society, 1872-73, Vol. 4, by Norton, pg. 86.
Transactions of the American Entomological Society, 1880, Vol. 8 by Cresson, pg. 26.
Canadian Entomologist, 1894, Vol. 26, by MacGillivray, pg. 328.
Bulletin of the Connecticut Geological and Natural History Survey, 1916 Pt. 3, by Viereck, pg. 108.
Canadian Entomologist, 1963, Supplemental #30: Catalogue of Nearctic Chalcidoidea by Peck, pg. 961.
United States Agriculture, 1985, Miscellaneous #1426: Insects of Eastern Forests by Drooz, pg. 384.
Canadian Entomologist, 1986, Vol. 118: Larvae by Wong & Szlabey, pp. 577 to 587.

 

 

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