The influence of three rates of nitrogen (N) and fruit bagging on fruit peel and flesh mineral concentrations and fruit quality in `BC-2 Fuji' apple (Malus domestica Borkh.) trees on Malling 9 (M.9) was studied. Increasing N application decreased fruit peel red color, fruit N, iron (Fe), and manganese (Mn). Fruit from trees receiving 10.72 oz (303.9 g) N per year had higher evolved ethylene and respiration during poststorage ripening tests. Bagging of fruit reduced fruit peel red color, soluble solids concentrations (SSC), and dry weight as compared to nonbagged fruit. Bagged fruit had higher N, potassium (K), and copper (Cu) than nonbagged fruit. Fruit peel had a greater percentage of dry weight, and higher concentrations of all tested minerals compared to fruit flesh.

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Lygus hesperus Knight and L. lineolaris (Palisot) are important pests of numerous fruit, vegetable, fiber, tree, and seed crops in North America. We discovered Peristenus howardi n. sp., described in this article, parasitizing L. hesperus nymphs in alfalfa grown for seed in Idaho. Parasitism rates were surprisingly high,81% in generation I (1998), and 44-51%in generation II (1997 and 1998). This braconid wasp may be a practical biological control factor for alfalfa and other seed crops, and further research is warranted. We found that P. howarrh is a native species, is thelyotokous, has three generations per year, and produces some diapausing parasites in each generation. The geographic range of this species is not yet known. P. !toward{ readily parasitized the eastern L. lineolaris in laboratory tests, so it is also a potential biocontrol agent for this related mind species. KEY WORDS Lygus, Peristenus, alfalfa, biological control, parasites Two SPECIES OF Lygus are significant pests of numerous agricultural crops over large areas of the United States and Canada-Lygus lineolaris (Palisot) (Kelton 1975, 1982), which is most important east of the Rocky Mountains, and L. hesperus Knight, which is a major pest west of the Rockies (

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LARGERECTOPARASITES OF THE IDAHO GROUND SQIHRREL {SPERMOPHILUS BRUNNEUS)Eric YcnscMi', (jaisj; K. Baird-, aiitl I'aiil W. Shcniiair liSTKACT. -We sampled hiilli suhspeties oi the Idaho uroiiiid S(iiiini'l ISpcnnopliilti.s hrunncusj to tloemmiil die larger eetoparasites of tliis lare endemic. S'. /;. briinucuti was host (+ = new host record, * = new Idaho record) to 4 flea species {Neopsylla iiu)i)in(i + , Oropsi/lld i(lciisis + , O. tuhcrctilata, and Thrassis iHin(lorae + ), 1 X^iok (Ixodes sculptu.s + ), and an eyeworni (Nematoda: Hhalxliti.s ()rhitalis* + , also 1st records from Sciuridae); S. /;. ctulcmiciis was host to a louse species {Neohaematopimis la('iiiisciilii.s + ). 5 flea ta.\a (RJuidmopsijUu sp. + , (). t. tubcrculata, Tlirassis f. fr(incm + , T. f. b(irnesi + , and T. f. rockwoodi), and a mite {Aiidn)l(i('lai).s J(ilircnht)lzi + ). S))enni)pliilus hrimneus had fewer known ectoparasite species than other congeners. Although all of their parasites had many other hosts, S. h. endeinicus and S. h. bntnneiis shared only a single parasite species in common, whereas all but one of their eetoparasites also occurred on the closely related Townsend's ground squirrel (S. townsendii). The proportion of parasitized individuals and the parasite loads per individual were significantly lower in S. b. bninneus, which lives in small, isolated populations, than in S. b. cndemlcus, which has larger, less fragmented populations, suggesting a relationship between host population structure, parasite loads, and parasite species diversity. All but one of the flea species have been linked to plague transmission.