Combination of Methoprene and Controlled Aeration to Manage Insects in Stored Wheat.

A commercial formulation of the insect growth regulator methoprene was applied to wheat stored in small bins either alone or in combination with controlled aeration of the bins, to lower grain temperature for insect pest management of stored wheat. Grain temperatures were monitored and modified by a computer-controlled thermocouple system that also activated the aeration system at programmed set-points to move cool ambient air through the grain mass to lower grain temperature. Results from sampling insect populations in experimental storage bins along with laboratory mortality bioassays of insects placed on wheat taken from the bins over the course of the storage period showed that methoprene was very effective in controlling infestation by the externally-feeding stored grain insects Plodia interpunctella (Hübner), the Indian meal moth Tribolium castaneum (Herbst), the red flour beetle, Cryptolestes ferrugineus (Stephens), the rusty grain beetle, and also for the internal-feeding pest Rhyzopertha dominica( Fauvel), the lesser grain borer. Methoprene did not give good control of the internal-feeding pest Sitophilus oryzae (L.), the rice weevil. Aeration alone was somewhat effective in suppressing insect population development, while methoprene alone or when combined with aeration greatly enhanced insect control. Commercial grain grading for industry quality standards at the end of the storage period confirmed the impact of insect suppression on maintaining high quality of the stored wheat. This field experiment shows that methoprene combined with aeration to cool grain can be effective for pest management of stored wheat in the southern plains of the United States of America.

Oxygenated Phosphine Fumigation for Control of Light Brown Apple Moth (Lepidoptera: Tortricidae) Eggs on Cut-Flowers.

Light brown apple moth, Epiphyas postvittana (Walker), eggs were subjected to oxygenated phosphine fumigation treatments under 70% oxygen on cut flowers to determine efficacy and safety. Five cut flower species: roses, lilies, tulips, gerbera daisy, and pompon chrysanthemums, were fumigated in separate groups with 2,500 ppm phosphine for 72 h at 5°C. Egg mortality and postharvest quality of cut flowers were determined after fumigation. Egg mortalities of 99.7-100% were achieved among the cut flower species. The treatment was safe to all cut flowers except gerbera daisy. A 96-h fumigation treatment with 2,200 ppm phosphine of eggs on chrysanthemums cut flowers also did not achieve complete control of light brown apple moth eggs. A simulation of fumigation in hermetically sealed fumigation chambers with gerbera daisy showed significant accumulations of carbon dioxide and ethylene by the end of 72-h sealing. However, oxygenated phosphine fumigations with carbon dioxide and ethylene absorbents did not reduce the injury to gerbera daisy, indicating that it is likely that phosphine may directly cause the injury to gerbera daisy cut flowers. The study demonstrated that oxygenated phosphine fumigation is effective against light brown apple moth eggs. However, it may not be able to achieve the probit9 quarantine level of control and the treatment was safe to most of the cut flower species.

Oxygenated phosphine fumigation for control of Epiphyas postvittana (Lepidoptera: Tortricidae) eggs on lettuce.

Light brown apple moth, Epiphyas postvittana (Walker), is a quarantined pest in most countries. Its establishment in California and potential spread to other parts of the state and beyond make it urgent to develop effective postharvest treatments to control the pest on fresh commodities. Fumigation with cylindered phosphine at low temperature has emerged to be a practical methyl bromide alternative treatment for postharvest pest control on fresh commodities. However, its use to control E. postvittana eggs on sensitive commodities such as lettuce is problematic. E. postvittana eggs are tolerant of phosphine and long phosphine treatment also injures lettuce. In the current study, E. postvittana eggs were subjected to oxygenated phosphine fumigations to develop an effective treatment at a low storage temperature of 2 degrees C. In addition, soda lime as a CO2 absorbent was tested to determine its effects in reducing and preventing injuries to lettuce associated with phosphine fumigations. Three-day fumigation with 1,000 ppm phosphine under 60% O2 achieved 100% mortality of E. postvittana eggs in small-scale laboratory tests. In the presence of the CO2 absorbent, a 3-d large-scale fumigation of lettuce with 1,700 ppm phosphine under 60% O2 resulted in a relative egg mortality of 99.96% without any negative effect on lettuce quality. The 3-d fumigation treatment without the CO2 absorbent, however, resulted in significant injuries to lettuce and consequential quality reductions. The study demonstrated that oxygenated phosphine fumigation has the potential to control E. postvittana eggs and the CO2 absorbent has the potential to prevent injuries and quality reductions of lettuce associated with long-term oxygenated phosphine fumigation.

Effects of phosphine fumigation on survivorship of Epiphyas postvittana (Lepidoptera: Tortricidae) eggs.

Light brown apple moth, Epiphyas postvittana (Walker), eggs were subjected to phosphine fumigations under normal atmospheric and elevated oxygen levels in laboratory-scale chamber experiments to compare their susceptibilities to the two different fumigation methods. In fumigations conducted under atmospheric oxygen at 5 and 10 degrees C, egg survivorship decreased with increase in phosphine concentration but then increased at a concentration of 3,000 ppm; this increase was significant at 10 degrees C. Based on egg survivorship data, phosphine fumigations conducted in a 60% oxygen atmosphere were significantly more effective than those conducted under atmospheric oxygen conditions. Oxygenated phosphine fumigations at 5 and 10 degrees C killed all 1,998 and 2,213 E. postvittana eggs treated, respectively, after 72 h of exposure. These results indicate the great potential of oxygenated phosphine fumigation for the control of E. postvittana eggs.

Effects of reserpine on reproduction and serotonin immunoreactivity in the stable fly Stomoxys calcitrans (L.).

Biogenic amines are known to play critical roles in key insect behaviors such as feeding and reproduction. This study documents the effects of reserpine on mating and egg-laying behaviors of the stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), which is one of the most significant biting fly pests affecting cattle. Two sperm staining techniques were adapted successfully to reveal the morphology of stable fly sperm, for the first time, and determine successful mating in females through the assessment of sperm transfer. This approach was also applied to assess sperm transfer by males treated with different doses of reserpine. Mating or sperm transfer did not occur in flies during the first 3 days after emergence. Thereafter, the percentage of females that mated increased with age. Reserpine treatment of males reduced sperm transfer in a dose-dependent manner. Older males were more sensitive to reserpine treatment than younger flies. Reserpine treatment of 5 days old females reduced the number of eggs laid, but had no effect on egg-hatching rates. Results of immunoreactivity (IR) experiments indicated that serotonin in the neuronal processes innervating male testes was completely depleted by reserpine within 5h after treatment. This effect was transient as the serotonin immunoreactive signal was recovered in 33.3% of the males at 1 day post-treatment and in 94.4% of the flies at 3 days post-treatment. The results of this study concur with previous findings in other insect species and extend our knowledge of the critical roles biogenic amines play in mating and oviposition behaviors of the stable fly. The work could provide a foundation to further characterize the specific roles of individual biogenic amines and their receptors in stable fly reproduction.

Immunohistological localization of serotonin in the CNS and feeding system of the stable fly Stomoxys calcitrans L. (Diptera: Muscidae).

Serotonin, or 5-hydroxytryptamine (5-HT), plays critical roles as a neurotransmitter and neuromodulator that control or modulate many behaviors in insects, such as feeding. Neurons immunoreactive (IR) to 5-HT were detected in the central nervous system (CNS) of the larval and adult stages of the stable fly, Stomoxys calcitrans, using an immunohistological technique. The location and pattern of the 5-HT IR neurons are described and compared for these two different developmental stages. Anatomical features of the fly feeding system were analyzed in third instar larvae and adult flies using a combination of histological and immunohistological techniques. In third instar larvae, the cibarial dilator muscles were observed within the cibarial pump skeleton and innervated by 5-HT IR neurons in nerves arising from the brain. There were four pairs of nerves arising from the frontal surface of the larval brain that innervate the cibarial pump muscles, pharynx, and muscles controlling the mouth hooks. A strong serotoninergic innervation of the anterior stomatogastric system was observed, which suggests 5-HT may play a role in the coordination of different phases of food ingestion by larvae. Similarly, many 5-HT IR neurons were found in both the brain and the thoracico-abdominal ganglia in the adult, some of which innervate the cibarial pump dilator muscles and the stomatogastric muscles. This is tnhe first report describing neuromuscular structures of the stable fly feeding system. The results reported here suggest 5-HT may play a critical role in feeding behaviors of stable fly larvae and adults.

Using proteomic approach to identify tumor-associated proteins as biomarkers in human esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers in China. The lower survival rate of ESCC is attributed to late diagnosis and poor therapeutic efficacy; therefore, the identification of tumor-associated proteins as biomarkers for early diagnosis, and the discovery of novel targets for therapeutic intervention, seems very important for increasing the survival rate of ESCC. To identify tumor-associated proteins as biomarkers in ESCC, we have analyzed ESCC tissues and adjacent normal tissues by two-dimensional electrophoresis (2DE) and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) analysis. The results showed that a total of 104 protein spots with different expression levels were found on 2DE, and 47 proteins were eventually identified by MALDI-TOF MS. Among these identified proteins, 33 proteins including keratin 17 (KRT17), biliverdin reductase B (BLVRB), proteasome activator subunit 1 (PSME1), manganese superoxide dismutase (MnSOD), high-mobility group box-1(HMGB1), heat shock protein 70 (HSP70), peroxiredoxin (PRDX1), keratin 13 (KRT13), and so on were overexpressed, and 14 proteins including cystatin B (CSTB), tropomyosin 2 (TPM2), annexin 1 (ANX1), transgelin (TAGLN), keratin 19 (KRT19), stratifin (SFN), and so on were down-expressed in ESCC. Biological functions of these proteins are associated with cell proliferation, cell motility, protein folding, oxidative stress, and signal transduction. In the subsequent study using immunoassay on ESCC serum samples and tissue-array slides, two representative proteins, HSP70 and HMGB1, were selected as examples for the purpose of validation. The results showed that both HSP70 and HMGB1 can induce autoantibody response in ESCC sera and have higher expression in ESCC tissues. Especially, the frequency of antibodies to HSP70 in ESCC sera was significantly higher than that in normal human sera. The preliminary results suggest that some of these identified proteins might contribute to esophageal cell differentiation and carcinogenesis, certain proteins could be used as tumor-associated antigen (TAA) biomarkers in cancer diagnosis, and further studies on these identified proteins should provide more evidence of how these proteins are involved in carcinogenesis of ESCC.