464 



L., harbours the Chrysomelid, Microrhopala viitata, F., which mines 

 the leaves. Heliopsis scabra (rough ox-eye) is the host of Agromyza vi- 

 rens, L., which mines the bases of the plants in large numbers. These 

 larvae have also been reared from the stem of the roadside thistle. 



Helianihus hirsutus (wild sunflower) is one of the host-plants of 

 Physonota unijmnctata. Say (sunflower tortoise beetle), which also 

 occurs on flowers of Crataegus, Monarda (horse mint) and Silphium 

 (rosin weed). The beetles are found eating the leaves and ovipositing at 

 the end of May, adults of the next generation emerging in early August ; 

 there is one brood in a year, hibernation occurring in the adult stage. 

 Several eggs were found to be parasitised by a new Chalcidoid, 

 A'prostectus whitmani, Gir. The Trypetid, Straussia longipennis, Wd. 

 (sunflower stem-borer) lays its eggs in June in the stem, the larvae 

 mining down the pith and in the roots ; there is one generation in a 

 year, winter being passed in the pupal stage in the stems. 

 Dichomeris {Trichotaphe) insermta, Wals. (sunflower leaf-roller), rolls 

 the terminal leaves together and eats the edges. 



Artemisia ludoviciana (white sage) is frequently infested by 

 Eucosma (Thiodia) artemisiana, Wals. (wormwood leaf-tier), the 

 terminal leaves being tied together by the larvae, which are active 

 in late May and June. Arctium lappa (burdock) is commonly infested 

 by the seed caterpillar, Metzneria lappella, L. 



Cirsium discolor (roadside thistle) harbours Agromyza virens, Lw., 

 the larvae mining in the stem ; there is one generation only, hibernation 

 being in the pupal stage. This species is also said to mine the roots of 

 clover. PlatyptiUa carduidactyla, Riley (roadside thistle plume moth), 

 attacks the terminal shoots ; there are apparently two generations, 

 adults emerging in early July and again in September. Larvae of 

 M'uscina stabidans were also found feeding on the terminal shoots. 

 Vanessa cardui, L. (painted lady) feeds on thistles, rolling the edges 

 of the leaves, and on many other host-plants, including mallow and 

 pigweed. 



Insects on Cirsium arvense (Canada thistle) include Trypeta ruficauda, 

 F. (thistle seed maggot), and Dasyneura gibsoni, Felt (Canada thistle 

 midge). These two species often destroy completely the seeds of this 

 weed. Lactuca scariola (prickly lettuce) is infested by the larvae of 

 Phalonia bunteana, Robinson, and Phorbia sp., which feed on the seeds. 



Babcock (0. G.). Minnesota BiW-Bugs.—Sixteenth Rept. Minnesota 

 State Entomologist for 1915 and 1916, St. Anthony Park, Ist 

 December 1916, pp. 153-159. [Received 7th August 1917.] 



Attacks from bill-bugs in Minnesota are confined almost exclusively 

 to river valleys and lake-shore lands, and occur when maize, wheat, 

 oats or timothy are planted near yellow nutgrass {Cyperus escidentus), 

 which is the native food-plant. The principal species found is 

 Sphenophorus venatus, which emerges in the spring and feeds upon 

 exposed, unsprouted maize and partly buried, sprouted maize. The 

 Hfe-cycle apparently occupies about 58 days. Eggs are never deposited 

 in the maize stalks, but always in sheaths of nutgrass. In the field, 

 the larval period extends from late June to September, hibernation in 

 all probabilit)' being in the larval or pupal stage. T^ ..le is only one 

 generation in a year. 



