Can Isogroup Selection of Highly Zoophagous Lines of a Zoophytophagous Bug Improve Biocontrol of Spider Mites in Apple Orchards?

Zoophytophagous predators provide benefits in agroecosystems when feeding on pests, but they can also cause crop damage. Optimizing the use of zoophytophagous predators as biocontrol agents would require improving pest control and/or limiting damage. Populations of a zoophytophagous species can be composed of a mix of individuals diverging in their level of diet specialization. Consequently, depending on their level of zoophagy, individuals would vary widely in the benefits and risks they provide to pest management. We tested the hypothesis that manipulating the composition of the population of a zoophytophagous insect, the mullein bug, Campylomma verbasci (Hemiptera: Miridae), towards an increased zoophagy would increase their net benefit in an apple orchard. We compared the inherent benefits and risks of two different isogroup lines of mullein bug that genetically differed in their level of zoophagy. In spring, when damage occurs, both strains infrequently punctured apple fruit, which rarely lead to damage and therefore represented a low risk. During summer, only the highly-zoophagous line impacted the spider mite population, while the lowly-zoophagous line did not differ from the control treatments. We concluded that manipulating the composition of the zoophytophagous predator population provided extra net benefits that improved pest control.

New species and new records of Plant Bugs (Hemiptera: Heteroptera: Miridae) from Northwestern China

Two new species of Phylini, Glaucopterum alborubrum sp. nov. and Compsidolon schrenkianum sp. nov. are described from Xinjiang province of China. Illustrations of the male genitalia, tarsus and pretarsus, photographs of the dorsal habitus, known hosts, and distributional records are provided for each species. The following 13 species of Miridae are recorded for the first time from China: Anonychiella brevicornis (Reuter, 1879), Atomophora mongolica Konstantinov, 2000, Blepharidopterus angulatus (Fallén, 1807), Compsidolon eximium (Reuter, 1879), Dichrooscytus consobrinus Horváth, 1904, Dichrooscytus kerzhneri Josifov, 1974, Hallodapus montandoni Reuter, 1895, Orthotylus nassatus (Fabricius, 1787), Orthotylus (Melanotrichus) schoberiae Reuter, 1876, Phaeochiton ebulum Putshkov, 1977, Pilophorus confusus (Kirschbaum, 1856), Tuponia (Chlorotuponia) prasina (Fieber, 1864), Tuponia (Tuponia) soongorica Drapolyuk, 1980. Also, the following nine species of plant bugs are new records for Xinjiang Province: Atomoscelis onusta (Fieber, 1861), Blepharidopterus diaphanus (Kirschbaum, 1856), Campylomma verbasci (Meyer-Dür, 1843), Europiella alpina (Reuter, 1875), Lygocoris rugicollis (Fallén, 1807), Orthops mutans (Stål, 1858), Phaeochiton caraganae (Kerzhner, 1964), Pilophorus clavatus (Linnaeus, 1767), Psallopsis kirgisica (Becker, 1864). Distributional areas and distinctive features of Tuponia roseipennis (Reuter, 1878) and T. soongorica Drapolyuk, 1980 are briefly discussed.

Predators and parasitoids of Cacopsylla pyri (L.) (Hemiptera: Psyllidae) in Serbia

The presence of C. pyri and its natural enemies was studied in both treated and untreated pear orchards in Serbia from 2005 to 2009. Five parasitoid and 21 predator species were identified as present on a considerable number of sites. The following parasitoid species were found: Prionomitus mitratus (Dalman), Psyllaephagus procerus Marcet, Syrphophagus ariantes (Walker), Syrphophagus taeniatus (F?rster) and Tamarixia sp. In the study, the species Psyllaephagus procerus, Syrphophagus ariantes and Tamarixia sp. were for the first time identified as parasitoids of C. pyri and as new species in the Serbian fauna. Among the parasitoids determined, Prionomitus mitratus predominated. Of the predators, the following species in four orders were registered: Dermaptera [Forficula auricularia Linnaeus (Forficulidae)], Heteroptera [Anthocoris nemoralis (Fabricius), Anthocoris nemorum (Linnaeus), Orius (Heterorius) minutus (Linnaeus), Orius (Heterorius) niger Wolff (Anthocoridae), Campylomma verbasci (Mayer-D?r), Deraeocoris (Deraeocoris) ruber (Linnaeus) and Deraeocoris (Knightocarsus) lutescens (Schilling) (Miridae)], Neuroptera [Chrysopa pallens Rambur, Chrysoperla carnea (Stephens), Chrysopa sp. (Chrysopidae)], and Coleoptera [Coccinella septempunctata Linnaeus, Adalia bipunctata Linnaeus, Adalia decempunctata (Linnaeus), Hippodamia tredecimpunctata (Linnaeus), Hippodamia variegata (Goeze), Propylea quatuordecimpunctata (Linnaeus), Calvia (Anisocalvia) quatuordecimguttata (Linnaeus) (Coccinellidae), Cantharis rustica Fall?n, Rhagonycha fulva (Scopoli) and Rh. testacea (Linnaeus) (Cantharidae)]. Of the predators determined, 12 species were registered for the first time as predators of C. pyri in Serbia, while C. rustica, Rhagonycha fulva and Rh. testacea have so far been known neither in Serbia nor in the world as predators of pear suckers.

Impacts of seasonal kaolin particle films on apple pest management

The impact of multiple applications of the kaolin-based particle film M96-018 on the population density of selected pests of apple, Malus domestica (Borkh) (Rosaceae), and their natural enemy populations were measured in several Washington State orchards from 1997 to 1999. Densities of western tentiform leafminer, Phyllonorycter elmaella (Doganlar and Mutuura) (Lepidoptera: Gracillariidae), were significantly higher and percent parasitism was generally lower in treated plots than in untreated plots. The effect of M96-018 on green aphids (Aphis spp.) (Hemiptera: Aphididae) was variable between orchards; however, populations of rosy apple aphid, Dysaphis plantaginea Passerini (Hemiptera: Aphididae), were higher in treated plots than in untreated plots. M96-018 reduced the mean density of the white apple leafhopper, Typhlocyba pomaria (McAtee) (Hemiptera: Cicadellidae), and the density of spiders (Araneae) compared with untreated plots. Fruit injury by codling moth, Cydia pomonella (L.), and fruittree leafroller, Archips argyrospilus (Walker) (Lepidoptera: Tortricidae), was significantly reduced in the treated plots compared with the untreated plots. The effect of M96-018 on the mullein bug, Campylomma verbasci (Meyer) (Hemiptera: Miridae), was variable between orchards and years. Stink bug (Hemiptera: Pentatomidae) density and related fruit injury were unaffected by M96-018. Fruit infestation by San Jose scale, Quadraspidiotus perniciosus (Comstock) (Hemiptera: Diaspididae), was significantly higher in treated plots than in untreated plots. Discontinuing applications of M96-018 at mid-season reduced the number of aphid-infested leaves and increased fruit injury by leafroller compared with a full-season program. No differences in pest densities occurred in plots treated for one versus two consecutive years; however, the density of phytophagous mites (Acari: Tetranychidae) was significantly higher the subsequent year after plots were treated with M96-018. Further studies are needed to elucidate how these disruptive impacts of particle films can be minimized.