Explanation of Names
psyllo is Greek for a flea, probably referring to the small size; boreal is Greek for northern.
(1)Numbers
in our area:
P. vigintimaculata (Say 1824) - widely dist.
P. borealis Casey 1899 - west of the Rockies
P. plagiata Schaeffer 1908 - se AZ, w. TX
P. renifer Casey 1899 - mostly along Mexican border
P. parvinotata Casey 1899 - coastal se US
P. schwarzi Chapin 1957 - so. FL
P. nana Mulsant 1850 - s. FL
Size
Adults 1.5-3.5 mm; larvae up to twice as long
Identification
Key to species [adapted from
(2)]:
P. vigintimaculata, Twenty-spotted Lady Beetle - most of North America except coastal Southeast and Florida. Pronotum always has spots (may be light brown/yellow), elytra markings with various levels of coalescence, can include yellow and orange markings.
P. borealis - northern New Mexico west to Pacific, up to British Columbia and Alberta. Apical spot well separated from lateral spot behind middle; may also have lateral spot narrowly connected to discal spot.
P. nana - Florida. Common sutural spot on elytra apical third (completely joined at middle of back)
P. parvinotata - Florida and Gulf Coast states. Small elytral maculae, usually not confluent; sometimes with immaculate pronotum. (Name means "poorly marked.")
P. plagiata - southern Arizona. Elytral maculae reduced, with only subapical spot large; form broadly oval.
P. renifer - Louisiana, Southwest from TX to California, and up the CA Sierra to Tahoe; elytra markings always coalescent.
Larvae: Gray with black and sometimes orange markings, tubercles bearing many fine pale hairs (setae).
Range
Canada to Central America
Food
Plant mold, especially powdery mildew (uniquely in the family)