Identification of the Klambothrips myopori (Thysanoptera: Phlaeothripidae) Predator Complex in California

To identify the predator complex of the invasive thrips, Klambothrips myopori, on its ornamental host plant Myoporum laetum, field surveys were conducted at three sites in southern California over the period of 1 y. Five insect orders and five spider families were represented in the survey. Although the most abundant groups differed among collection sites, syrphid larvae, anthocorids, Chrysoperla spp., Franklinothrips orizabensis Johansen (Thysanoptera: Aeolothripidae), and one spider family (Salticidae) were all collected at each site. Based on the field surveys, Orius spp. and Chrysoperla spp. were identified as possible key natural enemies of K. myopori. Laboratory studies were then conducted to determine the consumption rates of Orius insidiosus Say (Hemiptera: Anthocoridae) and Chrysoperla rufilabris Burmeister (Neuroptera: Chrysopidae) at constant densities of K. myopori and to define the functional responses of the predators. Both predators consumed more second-instar larvae than other prey stages. Orius insidious displayed a type II functional response, while C. rufilabris displayed both type II and type III depending on prey stage. Generally speaking, O. insidiosus and C. rufilabris consumed a higher proportion of prey at lower pest densities, implying that in an augmentative control program using these commercially available natural enemies, predators could be released early in the year when host plants begin to flush and thrips populations are low to suppress population growth.

Laboratory Hybridization Between the Green Lacewings Chrysoperla comanche (Neuroptera: Chrysopidae) and Chrysoperla rufilabris, Predators of the Asian Citrus Psyllid

Chrysoperla comanche (Banks) and its sibling species Chrysoperla rufilabris (Burmeister) are voracious predators of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), an invasive pest that vectors a bacterium responsible for the lethal and incurable citrus greening disease. The Comanche lacewing naturally occurs in Southern California, whereas C. rufilabris is currently one of only two commercially available green lacewing in the United States. These sister species can be separated by larval morphological traits, by differences in courtship songs, and possibly by three nuclear genes wingless, PepCK, ATPase, yet they are not distinguishable based on the mitochondrial barcode gene (COI). Releasing in a new area a biological control agent capable of hybridizing with a resident species may pose risks that range from local displacement to irreversible loss of genetic identity. Therefore, we performed no-choice laboratory crosses to assess pre- and postzygotic isolation. We show that fertile and viable hybrid progeny could be readily obtained in interspecific crosses and backcrosses and, although there is a trend toward lower hybrid fitness, postzygotic isolation is overall weak and might not prevent loss of genetic identity under natural conditions. It remains to be determined if differences in courtship songs will prevent hybridization in the wild, as shown for other green lacewings. We also report a low prevalence of Rickettsia infection in both species.

Green Lacewings and Water Sprays for Azalea Lace Bug Control1

The azalea lace bug, Stephanitis pyrioides, is a serious pest of azaleas and rhododendrons which is often controlled by systemic insecticides. However, the efficacy of softer approaches such as biological control and water sprays against this pest on rhododendrons is unknown. Therefore, we tested the commercially available green lacewing predator, Chrysoperla rufilabris, and water sprays on lace bug infestation in one laboratory and four field trials. First, 2nd instar predator larvae were confirmed to consume lace bug nymphs and sometimes adults. Second, tapping predator larvae from hexcel units over dry leaves of potted rhododendrons and shaking loose eggs over wet leaves were reliable application methods. Third, predator larvae released onto potted rhododendrons lowered lace bug counts for two weeks. Fourth, after four bi-weekly applications, plants receiving egg cards or water-sprays had reduced lace bug counts and fewer damaged leaves than control plants. Fifth, landscape plants receiving the sequential combination of water spray followed by predator egg releases had 44 to 90% lower lace bug abundance and fewer damaged leaves than the control. After lace bugs were initially dislodged, hatching predators might have consumed hatching lace bugs. Index words: biological control, Chrysoperla rufilabris (Burmeister), mechanical control, rhododendron, Stephanitis pyrioides (Scott) Species used in this study: Azalea lace bug (Stephanitis pyrioides Scott), green lacewing (Chrysoperla rufilabris Burmeister), Rhododendron (Rhododendron spp.)

Spray Penetration and Natural Enemy Survival in Dense and Sparse Plant Canopies Treated with Carbaryl: Implications for Chemical and Biological Control1

Ornamental plant producers often rely on chemical control to manage insect pests. However, cultural practices, such as pruning, can influence plant architecture which may, in turn, affect pesticide penetration. Spray penetration was studied to determine the effect of canopy density on beneficial insect survival following insecticide application and to better understand the implications of canopy density on pest management. Regardless of canopy density or plant species, the interior position of the canopy received less than 8% spray coverage. The middle position of sparse canopies received 288 to 513% more coverage than the middle position of dense canopies. The middle and interior position of dense canopies protected greater than 50% of the convergent lady beetle (Hippodamia convergens (Guérin-Méneville) population while only the interior position of dense canopies protected greater than 50% of green lacewing (Chrysoperla rufilabris Burmeister) populations. Index words: beneficial insect, nursery crop, pesticide, plant architecture, woody ornamental. Species used in this study: China Girl® holly (Ilex ×meserveae ‘Mesog'); ‘Alice' Oakleaf hydrangea (Hydrangea quercifolia Bartr. ‘Alice'); convergent lady beetle [Hippodamia convergens (Guérin-Méneville)]; green lacewing [Chrysoperla rufilabris (Burmeister)]. Chemicals used in this study: carbaryl (1-naphthyl N-methylcarbamate, Sevin® SL, Bayer CropScience, Durham, NC).

Especies de Chrysopidae asociadas a Diaphorina citri kuwayama en cítricos y capacidad de depredación en Sinaloa, México

Los objetivos del estudio fueron determinar especies de Chrysopidae asociadas al psílido asiático de los cítricos Diaphorina citri Kuwayama, en huertas comerciales en el estado de Sinaloa, México, y evaluar la capacidad de depredación sobre huevo y ninfas de D. citri. Se identificaron cinco especies de Chrysopidae en huertas de naranja y limón mexicano en diferentes regiones del estado de Sinaloa; Chrysoperla comanche (Banks), Chrysoperla rufilabris (Burmeister), Chrysoperla carnea s. lat., Ceraeochrysa valida (Banks) y Ceraeochrysa claveri (Navás). Ch. comanche y Ceraechrysa valida fueron las especies más abundantes (p< 0.0004); Ch. comanche y Ch. rufilabris mostraron mayor capacidad de depredación de estados inmaduros: huevos, ninfas chicas (ninfa 1 y ninfa 2) y ninfas grandes (ninfa 4 y ninfa 5) de D. citri durante las primeras seis horas de exposición de las presas al depredador. Sin embargo, en la última lectura de depredación, a las 24 h, todas las especies de crisopa presentaron un consumo prácticamente similar (p> 0.05), de alrededor de 100 especímenes por depredador. El consumo de huevo y ninfa chica fue mayor que el de ninfas grandes. Estos resultados sustentan el empleo de Ch. comanche para el control biológico de D. citri en el estado de Sinaloa.

Enemigos naturales asociados al pulgón lanígero en huertos de manzano con diferente manejo de plagas

El pulgón lanígero (Eriosoma lanigerum Hausmann) es un fitófago que incide en huertos de manzano [Malus sylvestris (L.) Mill. var domestica (Borkh) Mansf.] establecidos en el estado de Chihuahua. Para su combate se ha privilegiado el uso de insecticidas convencionales, incurriendo en aplicaciones extemporáneas que posiblemente repercuten en la baja ocurrencia de enemigos naturales. Con base en lo anterior y la reducida información sobre enemigos naturales del pulgón lanígero del manzano en México, durante los años 2011 y 2012 se realizó el presente trabajo con la finalidad de identificar la incidencia de depredadores y parasitoides asociados a colonias de pulgón lanígero en huertos de manzano con diferente manejo de plagas. Por manejo del huerto, se detectaron 38 y 35 ejemplares para los huertos sin manejo y con manejo integrado de plagas, valores que fueron estadísticamente iguales entre sí y diferentes a los 12 ejemplares detectados en el huerto con manejo convencional. Las especies de depredadores asociadas a colonias de pulgón lanígero en Chihuahua fueron: Hippodamia convergens, Chrysopa nigricornis, Chrysopa oculata, Chrysoperla rufilabris, Chrysoperla comanche, Chrysopa spp., Allograpta obliqua, Sirphus sp. y Toxomerus sp., mientras que como parasitoides se detectó solo a Aphelinus mali.