New Records of Leaf-Feeding for Adult \u3ci\u3eDiabrotica Barberi\u3c/i\u3e (Coleoptera: Chrysomelidae)

The first records of leaf-feeding on Iva xanthifolia (marsh elder) and Helianthus annuus (common sunflower) by adult Diabrotica barberi are reyorted. During September 1992, beetles were observed feeding on leaves 0 these plants, despite the availability of alternate flowering hosts. Beetles confined to clip cages in the laboratory fed readily on leaves of I. xanthifolia and H. annuus but not on those of Solidago missouriensis (goldenrod)

\u3ci\u3ePolistes Dominula\u3c/i\u3e (Christ) (Hymenoptera: Vespidae: Polistinae) Recorded from Nebraska

Polistes dominula (Christ), a Palearctic paper wasp that has established in various areas of North America, is reported for the first time from the state of Nebraska based on specimens from the city of Lincoln. Potential implications of its presence in Nebraska are discussed

Polistes dominula (Christ, 1791) (Hymenoptera: Vespidae: Polistinae) found in South Dakota, U.S.A.

Polistes dominula (Christ, 1791) (Hymenoptera: Vespidae: Polistinae), a Palearctic paper wasp established in North America, is reported for the first time from the state of South Dakota, U.S.A

Abundance of Rice Root Aphid Among Selected Plant Species and on Plants Grown With Different Soil-Surface Media

The rice root aphid, Rhopalosiphum rufiabdominalis (Sasaki), is distributed worldwide and colonizes a wide range of plants. However, relatively little is known about the suitability of different host plants, optimal rearing techniques, and the aphid’s impact on plant fitness. To improve understanding of these factors, laboratory experiments were conducted to compare the abundance of rice root aphid on plants grown using three different soil-surface media and among selected monocotyledonous and dicotyledonous plants. Rice root aphid was more abundant on plants grown with a sandy soil surface than a surface with fine wood chips or only bare non-sandy soil. Rice root aphid was more abundant on ‘Elbon’ rye than on ‘Bart 38,’ ‘Dart,’ ‘Fletcher’ and ‘Ramona 50’ wheat. More winged rice root aphids were produced on Elbon rye than on Dart wheat, but the number of winged aphids on Elbon rye did not differ from that on other wheat lines. Rice root aphid was more abundant on Elbon rye and ‘TAM 110’ wheat than on ‘Marmin,’ ‘Marshall’ and ‘Sharp’ wheat. Additional observations with monocotyledonous plants showed that abundance of rice root aphid on ‘Kivu 85’ triticale was comparable to that on Elbon rye. Rice root aphid did not reproduce on potato or soybean, although winged adults persisted up to 24 days on caged potato plants. The implications of differential abundance of rice root aphid on plants are discussed in regard to colony rearing, future experiments and possible pest management considerations

Phenomenological Aspects of F-theory

Stabilizing a heterotic string vacuum with a large expectation value of the dilaton and simultaneously breaking low-energy supersymmetry is a long-standing problem of string phenomenology. We reconsider these issues in light of the recent developments in F-theory.Comment: 11 pages, phyzzx macro