Susan E. Halbert

THE RELATIVE IMPORTANCE OF SHORT- AND LONG-RANGE MOVEMENT OF FLYING APHIDS

1. Aphids are notorious pests of world agriculture. Even so, uncertainty persists as to their capacity for successful aerial dispersal. Evidence exists that, under some conditions, aphids can be wind‐borne over long distances, i.e. hundreds of kilometers over desert or sea. It has been argued, in the recent past, that this phenomenon may be part of a strategy to locate fresh host plants in new distant areas. However, the proportion of these insects successfully colonizing new hosts is unknown.

A Guide to Separating Aphis glycines Matsumura and Morphologically Similar Species That Share Its Hosts

Abstract Aphis glycines Matsumura shares its hosts with two other aphid species, Aphis nasturtii Kaltenbach and Aphis gossypii Glover. Tables of characters and photographs are provided to assist in the separation of these three species. A photographic plate showing a gynopara, male, ovipara, and late summer apterous vivipara of A. glycines is included.

Domyzus (nectarosiphon) species other thanm persicae pose a threat to the idaho potato crop

Green peach aphids (Myzus persicae (Sulzer) ) pose a threat to the Idaho potato (Solanum tuberosum L.) crop primarily because they transmit potato leafroll virus (PLRV). Only colonizing vectors are epidemiologically significant because PLRV is persistently transmitted. Additionally, Idaho winters are severe enough that most permanently anholocyclic aphid species do not establish. It is now accepted that the taxon that has been known asMyzus (Nectarosiphon)persicae (Sulzer) is in fact at least three species (M. persicae, Myzus nicotianae Blackman andMyzus antirrhinii (Macchiati) ). It was not known whether the newly designated species had the potential to damage the Idaho potato crop. The objectives of our research were to determine whetherMyzus (Nectarosiphon) spp. other thanM. persicae occurred naturally in Idaho, whether they could colonize potato and transmit PLRV, and whether they were potentially holocyclic.NoMyzus (Nectarosiphon) spp. other thanM. persicae were found in Idaho in trap nurseries; howeverMyzus ascalonicus Doncaster recently has been found on stored bulbs and in suction trap collections in north Idaho. Laboratory bioassays for PLRV vector potential usingPhysalis floridana Rydb. indicator plants show thatM. nicotianae can transmit PLRV as efficiently asM. persicae. Similarly,M. nicotianae colonized potato as well asM. persicae in a replicated laboratory experiment comparing two clones ofM. nicotianae and one clone ofM. persicae. Our observations indicate that North AmericanM. nicotianae may be capable of a limited facultative holocycle. Thus, in laboratory experiments,M. nicotianae is as damaging asM. persicae with respect to PLRV vector potential; however,M. nicotianae may not occur naturally in areas like Idaho that have no tobacco production. A summary of allMyzus (Nectarosiphon) spp. with respect to PLRV epidemiology is provided.CompendioLos áfidos verdes del melocotonero [Myzuspersicae (Sulzer) ] representan un problema para el cultivo de papa (Solanum tuberosum L.) de Idaho debido principalmente a que ellos transmiten el virus del enrollamiento de la hoja de la papa (PLRV). Sólo los vectores que constituyen colonias son epidemiológicamente significativos debido a que elPLRV es persistentemente transmitido. Adicionalmente, los inviernos de Idaho son suficientemente severos de manera a que la mayoría de las especies de áfidos permanentemente anholocíclicas no se establecen. Se acepta ahora que el taxon que fuera conocido comoMyzus (Nectarosiphon)persicae (Sulzer) representa por lo menos tres especies [M. persicae, Myzus nicotianae Blackman yMyzus antirrhinii (Macchiati) ]. No se conocía si las especies designadas recientemente tenían el potencial para dañar el cultivo de papa en Idaho. Los objetivos de la investigación fueron determinar si las especies deMyzus (Nectarosiphon) diferentes aMyzus persicae ocurren naturalmente en Idaho, si ellas pueden colonizar a la papa y transmitir el PLRV y si eran potencialmente holocíclicas.No se encontraron en los semilleros trampa, en Idaho, especies deMyzus (Nectarosiphon) diferentes alMyzus persicae, sin embargo, se ha encontrado recientemente en el norte de Idaho alMyzus ascalonicus Doncaster en bulbos almacenados y recolecciones en trampas de succión. Bioensayos de laboratorio para determinar el potencial de los vectores del PLRV, utilizandoPhysalis floridana Rydb. como planta indicadora, muestran queM. nicotianae puede transmitir el PLRV tan eficientemente como elM. persicae. Similarmente,M. nicotianae colonizó a la papa tan bien como elM. persicae en un experimento de laboratorio con repeticiones en el que se compararon dos clones deM nicotianae con un clon deM. persicae. Las observaciones indican que elM. nicotianae norteamericano puede ser capaz de un holociclo facultativo limitado. Así, an experimentos de laboratorio, elM. nicotianae es tan dañino como elM. persicae en relación al potencial como vector del PLRV; sin embargo,M. nicotianae puede no ocurrir naturalmente en zonas como Idaho en donde no se produce tabaco. Se presenta un resumen de todas las especies deMyzus (Nectarosiphon) en relación a la epidemiología del PLRV

A New Species of Neophyllaphis (Hemiptera: Aphididae: Neophyllaphidinae) with Keys to Species on Podocarpus (Pinales: Podocarpaceae)

Abstract. An adventive, previously undescribed species, Neophyllaphis varicolor Miller and Halbert, n. sp., is described and illustrated. A modified key to Neophyllaphis found on Podocarpus spp. (Podocarpaceae) and a key to Neophyllaphis in the USA are provided.

An Update to the Adventive Aphids (Hemiptera: Aphidoidea) of America North of Mexico, with Notes on Intercepted Species

Abstract. Two hundred and sixty-two adventive aphids (Hemiptera: Aphidoidea) have been previously reported in North America north of Mexico. We update this to include 25 previously unrecorded species, and include information on the location and date of first discovery, biogeographic origin, and economically important North American hosts for these species. The number of adventive species introduced per year has decreased overall since 1930.We discuss aphids intercepted at United States ports of entry and identified by the Systematic Entomology Laboratory from 2000–2016 and comment on how the composition of species intercepted may affect the adventive species that become established.

Range and in-flight densities of barley thrips in the northwest United States.

The barley thrips, Limothrips denticornis, is a new pest in Idaho. Because of economic crop losses attributed to barley thrips in 1990 and 1991, a study was begun in 1992 to determine its biology and life history in eastern Idaho. Suction traps were used to determine in-flight densities of barley thrips during the barley growing season. An extensive tri-state suction trap system was used to delineate its range in Idaho, Washington and Oregon. A suction trap at the Univ. of Idaho, Tetonia Res. and Ext. Ctr., was located within the original area of economic crop damage. Sampling results from this trap were used to monitor the early spring and late summer migration flights of adult females into and out of winter wheat and spring barley. The distribution of barley thrips within the tri-state area included locations where economic losses had not been reported and resulted in new collection records for northern Idaho and Washington. The trap record for northern Idaho was later confirmed in the field.