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The potato tuberworm, Phthorimaea operculella (Zeller), is one of the most important pests of potato, Solanum tuberosum L., worldwide. We evaluated six Beauveria bassiana strains with potential for control of larvae. Strain SD was the most virulent, causing up to 98% mortality 10 days after inoculation of first instars. The other tested strains (HL, XJ, SC, JL and GZ) were only marginally virulent compared to the controls. In cage trials, SD strain applied to potato plants significantly reduced the survival of tuberworm larvae. Our results suggest that strain SD may be recommended for effective biological control of P. operculella. [ABSTRACT FROM AUTHOR]

Stratiolaelaos scimitusBerlese (Acari: Laelapidae) is an important soil-dwelling predatory mite used to control thrips and it is necessary to explore its potential predation capacity. In the present study, the functional response forS. scimituson the pupae ofFrankliniella occidentalisPergande was examined. In addition, the effects of releasedS. scimitusfor the control ofThrips tabaciLindeman andF. occidentalison greenhouse cucumber were evaluated, and compared with that of the common predatorNeoseiulus barkeriHughes (Acari: Phytoseiidae). The results showed thatS. scimitusexhibited a Holling type II functional response on thrips pupae. The greenhouse study indicated that the release ofN. barkeriandS. scimitusseparately at the density of 250 mites/m2suppressed the population growth of thrips. In comparison with control plots,N. barkeriandS. scimitusreduced the population ofT. tabaciby 76% and 64% in six weeks, respectively. Releases ofN. barkeriandS. scimitusled to a reduction inF. occidentalisby 41% and 43%, respectively. Significantly lower densities of both thrips species per leaf were recorded in treatments of individual releases ofN. barkeriorS. scimitusthan that in the control plots. The findings highlight the potential forutilising N. barkeriandS. scimitusas biological control agents ofT. tabaciandF. occidentalis, respectively. [ABSTRACT FROM AUTHOR]

Spatial and temporal patterns of insect damage in relation to aflatoxin contamination in a corn field with plants of uniform genetic background are not well understood. After previous examination of spatial patterns of insect damage and aflatoxin in pre-harvest corn fields, we further examined both spatial and temporal patterns of cob- and kernel-feeding insect damage, and aflatoxin level with two samplings at pre-harvest in 2008 and 2009. The feeding damage by each of the ear/kernel-feeding insects (i.e., corn earworm/fall armyworm damage on the silk/cob, and discoloration of corn kernels by stink bugs) and maize weevil population were assessed at each grid point with five ears. Sampling data showed a field edge effect in both insect damage and aflatoxin contamination in both years. Maize weevils tended toward an aggregated distribution more frequently than either corn earworm or stink bug damage in both years. The frequency of detecting aggregated distribution for aflatoxin level was less than any of the insect damage assessments. Stink bug damage and maize weevil number were more closely associated with aflatoxin level than was corn earworm damage. In addition, the indices of spatial-temporal association (χ) demonstrated that the number of maize weevils was associated between the first (4 weeks pre-harvest) and second (1 week pre-harvest) samplings in both years on all fields. In contrast, corn earworm damage between the first and second samplings from the field on the Belflower Farm, and aflatoxin level and corn earworm damage from the field on the Lang Farm were dissociated in 2009. [ABSTRACT FROM AUTHOR]

Among 28 isolates of Beauveria bassiana tested for virulence against F. occidentalis in laboratory bioassays, we found strain SZ-26 as the most potent, causing 96% mortality in adults at 1×107 mL−1conidia after 4 days. The effect of the strain SZ-26 on survival, longevity and fecundity of the predatory mite Neoseiulus (Amblyseius) barkeri Hughes were studied under laboratory conditions. The bioassay results showed that the corrected mortalities were less than 4 and 8% at 10 days following inoculation of the adult and the larvae of the predator, respectively, with 1×107 conidia mL−1 of SZ-26. Furthermore, no fungal hyphae were found in dead predators. The oviposition and postoviposition durations, longevity, and fecundity displayed no significant differences after inoculation with SZ-26 using first-instar larvae of F. occidentalis as prey in comparison with untreated predator. In contrast, the preoviposition durations were significantly longer. Observations with a scanning electron microscope, revealed that many conidia were attached to the cuticles of F. occidentalis at 2 h after treatment with germ tubes oriented toward cuticle at 24 h, penetration of the insect cuticle at 36 h, and finally, fungal colonization of the whole insect body at 60 h. In contrast, we never observed penetration of the predator's cuticle and conidia were shed gradually from the body, further demonstrating that B. bassiana strain SZ-26 show high toxicity against F. occidentalis but no pathogenicity to predatory mite. [ABSTRACT FROM AUTHOR]

The onion thripsThrips tabaciis one of the most important pests of greenhouse and open-field broccoli, onion and other crops. However, the current strategy of using synthetic pesticides for its control is inadequate and unsustainable, leading to a growing interest in novel and effective biological control alternatives such as entomopathogenic fungi. Among 20 isolates ofBeauveria bassianatested for virulence againstT. tabaciin laboratory bioassays, we found strain SZ-26 as the most potent, causing 83–100% mortality in adults at 1×107mL−1conidia after 4–7 days. Further experiments in greenhouses showed the strain SZ-26 significantly lowered the numbers of adult and larval stages. [ABSTRACT FROM AUTHOR]

Orius sauteri (Poppius; Hemiptera: Anthocoridae) is an important predator of western flower thrips, Frankliniella occidentalis (Pergande; Thysanoptera: Thripidae). O. sauteri would be directly exposed to the entomopathogenic fungus Beauveria bassiana (Bals.) Vuillemin in the field should the fungus be used as a biopesticide. If the fungus were to negatively affect O. sauteri in agro-ecosystems, predation of F. occidentalis by O. sauteri may be limited. The present study was undertaken to evaluate the insecticidal activity of strain B.bassiana-RSB of B. bassiana, which is highly virulent to F. occidentalis, on the predator under laboratory conditions. Results showed that, regardless of the concentration applied to first instars, Bb-RSB was not insecticidal against O. sauteri, nor did direct applications affect the developmental rate of the predator. Significant differences in developmental rates and adult longevity were observed between O. sauteri that fed on Bb-RSB-infected F. occidentalis cadavers and those that fed on untreated thrips. Developmental time (from first instar to adult) increased from 0.3 to 0.7 days and adult longevity decreased by 0.8 to 1.2 days for predators fed thrips treated with low and high concentrations of strain Bb-RSB, respectively, compared with predators fed on untreated thrips. However, these differences were only 3–13% of mean values for the controls, suggesting that the effects of Bb-RSB on O. sauteri are relatively minor. These findings highlight the potential use of O. sauteri in combination with B. bassiana for the biocontrol of F. occidentalis, but field tests must be performed to confirm their compatible use. [ABSTRACT FROM AUTHOR]

Five Beauveria bassiana strains were evaluated for control of western flower thrips. Strain RSB was the most virulent, causing 69–96% mortality at concentrations of 1×104–1×107 conidia mL−1, 10 days after inoculation of first instars. In greenhouse trials, RSB applied to broccoli foliage significantly reduced adult and larval populations. [ABSTRACT FROM PUBLISHER]

Liriomyza huidobrensis, L. trifolii and L. sativae (Diptera: Agromyzidae) are serious horticultural pests. The three species are very similar and difficult to discriminate from each other. In this study, we report the mitochondrial genome of L. huidobrensis and compare with L. trifolii and L. sativae. The mitochondrial genome of L. huidobrensis is 16,239 bp long, and it contains 37 genes and one A + T-rich region as do the sequenced liriomyza species. The sequence and structure of H51-H100 region in srRNA is significantly different from that of L. trifolii and L. sativae. The greatest sequence differences among the three leafminers are located in the region including ND2, ND3, ND6, ATP6, ATP8, CYTb and A+T region, which can be considered as candidate regions for molecular identification or SNP markers. [ABSTRACT FROM AUTHOR]

The Western flower thrips, Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) is an invasive polyphagous pest with an expanding global range that damages a wide variety of crops. F. occidentalis was first reported in China from Yunnan province during 2000, and has rapidly expanded its range since then. It is currently distributed across at least 10 provinces in China and has become a particularly devastating pest, causing substantial damage and economic losses. At present, the still heavy reliance on frequent use of insecticides for control of F. occidentalis, has lead to a series of ecological problems stemming from insecticide resistance, interspecific displacement and non-target effects. Thus, integrated pest management (IPM) programmes, multiple complementary tactics, including preventive tactics, biological controls, and judicious use of insecticides will likely provide a viable IPM strategy for control of F. occidentalis in the near future. This review provides an overview for information gained during the 10+ years since the invasion of F. occidentalis into China, reviews lessons that have been learned enhancing our overall understanding of the biology and ecology of F. occidentalis and discusses IPM practices relative to this widespread invasive insect pest.