Balaustium

Abstract: The Australian grains industry is dealing with a shifting complex of invertebrate pests due to evolving management practices and climate change as indicated by an assessment of pest reports over the last 20-30 years. Acomparisonofpestoutbreakreportsfromtheearly1980sto2006-07fromsouth-easternAustraliahighlightsadecreasein the importance of pea weevils and armyworms, while the lucerne flea, Balaustium mites, blue oat mites and Bryobia mites have increased in prominence. In Western Australia, where detailed outbreak records are available from the mid 1990s, the relative incidence of armyworms, aphids and vegetable weevils has recently decreased, while the incidence of pasture cockchafers,Balaustiummites,blueoatmites,redleggedearthmites,thelucerne fleaandsnailshasincreased.Thesechanges are the result of several possible drivers. Patterns of pesticide use, farm management responses and changing cropping patterns are likely to have contributed to these shifts. Drier conditions, exacerbated by climate change, have potentially reduced the build-up of migratory species from inland Australia and increased the adoption rate of minimum and no-tillage systems in order to retain soil moisture. The latter has been accompanied by increased pesticide use, accelerating selection pressures for resistance. Other control options will become available once there is an understanding of interactions between pests and beneficial species within a landscape context and a wider choice of 'softer' chemicals. Future climate change will directly and indirectly influence pest distributions and outbreaks as well as the potential effectiveness of endemic natural enemies.Geneticallymodifiedcropsprovidenewoptionsforcontrolbutalsopresentchallengesasnewpestspeciesarelikely to emerge.

Abstract: Balaustium putmani Smiley has been abundant in unsprayed fruit orchards of the Niagara Peninsula, Ontario, since 1959. The larva, like the nymph and adult, is a free-living predator of small soft-bodied arthropods on the trees; it was seen attacking all stages of the European red mite, Panonychus ulmi (Koch); all stages of the San Jose scale, Aspidiotus perniciosus Comstock; and the apple aphid, Aphis pomi De Geer, though aphids were not very suitable prey. B. putmani agrees with other Balaustium spp. in having free-living larvae; otherwise its development is typical of erythraeids in general, with apodous quiescent nymphs alternating with motile feeding stages. It has 2 generations per year.

Abstract: Haitlinger, R.: New records of mites (Acari: Prostigmata: Erythraeidae, Trombidiidae, Eutrombidiidae) from Croatia, with descriptions of three new species. Nat. Croat., Vol. 13, No. 2, 143–160, 2004, Zagreb. Hauptmannia pseudolongicollis, H. stanislavae, H. silesiacus, Grandjeanella multisetosa, Leptus josifovi, Erythraeus (Zaracarus) budapestensis, Charletonia bucephalia, C. dalegori, C. krendowskyi, Phanolophus oedipodarum, Balaustium nikae, Eutrombidium trigonum and E. robauxi are new to the fauna of Croatia. Erythraeus (Zaracarus) sibuljinicus n. sp. belongs to the group of species having basifemoral, setal formula 3-3-3, Charletonia zorani n. sp. belongs to the group of species with four setae between coxae II and III and Trombidium botovicus n. sp. belongs to the group of species with narrow and nude hypostomalae are described. Additional measurements for L. josifovi, E. (Z.) budapestensis, C. dalegori and P. oedipodarum are given.

Abstract: Generalist predators have the potential advantage to control more than one pest and to be more persistent than specialist predators because they can survive on different foods. Moreover, their population growth rate may be elevated when offered a mixture of prey species. We studied a generalist predatory mite Balaustium sp. that shows promise for biological control of thrips and whiteflies in protected rose cultures in Colombia. Although starting its life in the soil, this predator makes excursions onto plants where it feeds on various arthropods. We quantified life history parameters of the predator, offering high densities of three pest species: first-instar larvae of Frankliniella occidentalis, eggs of Trialeurodes vaporariorum and Tetranychus urticae, either alone or in combination. The predators completed their life cycle on each diet. The egg-to-egg period was c. 2 months. All eggs were laid in one batch in 1–2 days, indicating a pronounced semelparous reproduction pattern. In general, females reproduced earlier and laid more eggs on mixed diets, and these early reproducers consequently had higher population growth rates than late reproducers. The best diet in terms of egg-to-egg period and juvenile survival was the combination of eggs from whiteflies and spider mites. Spider mite eggs alone and western flower thrips larvae alone were the worst diets. It remains to be investigated whether mixed diets promote the population growth rate of Balaustium sufficiently for biocontrol of whiteflies and thrips in the presence of alternative prey, such as spider mites, to become effective.