the cypress tree mealybug, planococcus vovae (nasonov) (hem., pseudococcidae) is one of the most important pests of cypress trees, especially cupressus semprevirens fastigiata l. in iran. a survey was carried out to determine the natural enemies of cypress tree mea-lybug in tehran province, during 2004-2005. as a result of this study, 17 species of preda-tors, parasitoids and hyperparasitoids b...

the pink hibiscus mealybug maconellicoccus hirsutus (green) (hemiptera: pseudococcidae) is a serious economic pest in tropical and subtropical regions and causes damage to many agricultural, forestry and greenhouse crops. in order to identify the natural enemies of this pest, bi-weekly samplings were done in infested areas of ahvaz, located at southwest iran during 2011-2012. samples were also ...

during a two-year (2004-2005) survey of alfalfa aphids and their natural enemies in isfahan, a total of four aphid species and 58 species of their natural enemies comprised of 45 predatory species, 11 parasitoid species and two species of parasitic mites were collected and identified. moreover, five hyperparasitoid species were collected. on each sampling date, six 20-sweep samples were taken u...

To study the effects of wheat-maize intercropping on the population dynamics of wheat aphids and their natural enemies, wheat-maize intercropping patterns were divided into four levels: 8:2, 6:2, and 4:2 intercropping, and monoculture wheat. The results showed that as the wheat coverage rate decreased, the quantities of immigrating winged aphids and their natural enemies significantly differed;...

the tomato leafminer, tuta absoluta (meyrick), is one of the most important pests of tomato, solanum lycopersicum l., in iran. in this research, natural enemies diversity of t. absoluta and proportion of predators or parasitoids density to moth eggs or larvae density on five tomato cultivars including super strain b, super chief, mobil, korral, and early urbana y were studied in an experimental...

Empirical research has not supported the prediction that populations of terrestrial herbivorous arthropods are regulated solely by their natural enemies. Instead, both natural enemies (top-down effects) and resources (bottom-up effects) may play important regulatory roles. This review evaluates the hypothesis that higher-order predators may constrain the top-down control of herbivore population...

Planting Bt cotton in China since 1997 has led to important changes in the natural enemy communities occurring in cotton, however their specific effect on suppressing the cotton aphids (being notorious in conventional cotton ecosystem) has not been fully documented yet. We observed strong evidence for top-down control of the aphid population, e.g. the control efficiency of natural enemies on co...

1049-9644/$ see front matter Published by Elsevier doi:10.1016/j.biocontrol.2009.05.008 * Corresponding author. Address: Biological Cont National Biological Control Laboratory, USDA-ARS, Mi Lee Road, Stoneville, MS 38776, USA. Fax: +1 662 312 We review aspects of the life histories of representative enemies of coccinellids (both entomophagous and phytophagous species) and expose both potential ...

The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is an economically important pest in the north central United States. In the state of Iowa, economically damaging populations occurred in seven of 11 growing seasons from 2001 to 2011. The high frequency and economic impact of the soybean aphid makes it an ideal candidate for management by using host plant resistance. We compar...

As growers switch to transgenic crops and selective insecticides that are less toxic to natural enemies, natural enemies can become more important in agricultural pest management. Current decision-making guides are generally based on pest abundance and do not address pest and natural enemy toxicity differences among insecticides or the impact of natural enemies on pest survival. A refined appro...