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Show 126 Utah Academy of Sciences, Arts and Letters [Vol. XIV, by means of. its pro-tho.racic tarsi it freed the dead victim from the stylets and dropped It to the soil below. In the majority of cases under observation the. tenellus victims di? not escape after the stylets of the predator pierced their body and a considerable number of the victims struggled very little if at all. Field and laboratory observations indicate that Geocoris feeds readily upon adult and nymphal beet leafhoppers wherever they are readily available. Un der desert breeding conditions, tenellus often are present in greater abundance than was the case in most of the cage tests set up. During late summer upon short Russian thistle, it is not unusual for tenellus to constitute from' 90 to 98 per cent of the insect fauna taken in sweepings, with Geocoris making up a conspicuous portion of the balance. The cage data (Table 4) indicate that Geocoris is effective in reducing beet leafhopper populations when it occurs with appreciable numbers of tenellus. In early spring, from one to three Geocoris per square foot often have been found upon various northern Utah breeding areas. Lizard Predators The Northern Brown-Shouldered U ta.- The very common little brown shouldered uta, Uta stansburiana stansburiana (Baird and Girard), has been studied extensively relative to its importance as a predator of the beet leaf hopper in various parts of Utah. The following study was made in the Tirnpie Dolomite-Flux-Grantsville area of Tooele County. 1. A microscopic examination of the stomach contents of the first 1392 of these lizards, collected among or near to Russian thistle, Salsola pestifer, in the above area, showed that a large number had fed upon the beet leaf hopper, as well as upon other insects. A brief summary of the recognizable material in the stomachs showed: 3 Thysanura; 71 Collembola in 31 stom achs; 82 Orthoptera, of which 22 were adult and 50 nymphal grasshoppers in 65 stomachs, 2 field crickets, and 2 mantids; 27 adult Isoptera in 1 stomach; 14 Neuroptera, 5 being larval and 4 adult Chrysopidae in 9 stomachs, and 2 larval Myrmelionidae; 62 Odonata, 31 of which were damsel flies; 10 Thysan optera in 9 stomachs; 5953 Hemiptera, of which 1946 were adults and 1815 nymphal Geocoris, 580 adult and 75 nymphal false chinch bugs or Nysius ericae, 28 adult and 8 nymphal Pentatomidae, 12 adult and 1 nymphal Nabis ferus and N. alternata, 12 Miridae, 10 being Lygus elisus and L. hesperus; 6862 Homoptera, including 4006 adult and 2671 nymphal Euiettis ienellus in 1026 stomachs, 8 Agallia sanguinolenta, besides 47 adult and 17 nymphal leaf hoppers of other species, 8 Membracidae, 81 aphids, 1 nymphal cicada, and 5 Coccidae : 460 Coleoptera, including 4 Coccinellidae, 16 Chrysomelidae in 12 stomachs: 181 Carabidae in 94 stomachs, 1 Elateridae, 1 Buprestidae, 5 Tene brionidae, 5 Scarabaeidae, and 9 Curculionidae; 430 Lepidoptera in 249 stom achs, including 111 caterpillars; 693 Diptera including 4 Tabanide, 1 Strati Sar omyiidae, 2 Anthomyiidae, 13 Calliphoridae, 2 !ipulidae, 7 Syrphidae, 3 12 lrval cophagidae, 3 Muscidae, 4 Culcidae or m?s.qUltoes, .208 .dult and 228 midges Pipunculidae 16 Chloropisca glabra, 5 Tachinidae, 3 Simuliidae, and 13 in 71 stomahs; 1502 Hymenoptera including 1014 ants in 355 stomachs, 15 21 Vespidae stomachs, 111, 1,1 I? Sphecidae in 10 stomachs, Chalciddae .in stomachs, 2 Braconidae, 11 Ichneumomdae 111 10 stomachs? Imature DrY111I dae (in abdomens of ingested beet leafhoppers), 9 Chryl?ldae 111 8 stachs, addition to 12 Andrenidae in 11 stomachs, 1 Apidae and 1 Megachilidae. In foun were the insects and large amounts of unidentified insect 111 15 stomachs, mites 18 5 sowbugs; scorpions (in as many stomachs);. some 152 spiders in 119 stomachs; a few plant fragments; fragments pseudo-scorpions; |
