Potential inter-guild interactions to enhance biological control of Bactericera cockerelli on tomatoes: a laboratory and cage study

The tomato–potato psyllid (TPP) Bactericera cockerelli, is a serious pest of solanaceous crops. Some populations are becoming pesticide-resistant, increasing the need for alternatives such as biological control (BC). This approach may be improved by combining different species of BC agents. We conducted three separate experiments to test four BC agents, either alone or combined with others: (1) A laboratory assay to test the effect of buckwheat (Fagopyrum esculentum) and alyssum (Lobularia maritima) flowers on the longevity of females of the parasitic wasp Tamarixia triozae; (2) A no-choice laboratory assay to investigate the consumption of B. cockerelli life stages by the predatory bug Engytatus nicotianae; (3) A cage experiment in a greenhouse to assess four natural enemy species against B. cockerelli on tomatoes: these were the predators Cleobora mellyi, Amblydromalus limonicus, E. nicotianae, and T. triozae. Access to buckwheat flowers allowed female T. triozae to live for an average of 10.9 days compared to 2.1 days with alyssum and 1.4 day with water but did not improve the BC of B. cockerelli. Adult E. nicotianae preyed on all offered B. cockerelli stages. In experiment 3, combinations of T. triozae with A. limonicus or E. nicotianae were not significantly better than single natural enemy species, except for the reduction of nymphal populations when A. limonicus and T. triozae were combined. Although there were few significant reductions in numbers of TPP when using natural enemy species combinations, some species showed good potential when used alone. We suggest testing earlier release of combinations of natural enemy for evaluate its impact on TPP.

     

Breakdown in classical biological control of Argentine stem weevil: a matter of time

Earlier study at a national scale has shown that insect pests in agriculture can develop resistance to natural enemies following ongoing expansion and simplification of agricultural systems. Here, we used 25 years of field-sampling data segmented into three distinct ecoregions in New Zealand to show that parasitism rate of a key pasture pest (Listronotus bonariensis, Argentine stem weevil) by the introduced parasitoid Microctonus hyperodae has significantly declined. However, this decline has not happened simultaneously in all three ecoregions but with a one year time-lag. The variation in parasitism rate trends might be attributed to subsets of the weevil populations that became resistant to their biocontrol agent once having been exposed to seven years selection pressure (ca. 14 generations) since the parasitoid releases. This result supports the hypothesis that adaptation leading to resistance might have similarly occurred in different parts of the country indicating that the genetic variation needed for the acquisition of resistance was equally present everywhere.     

RPS19 and TYMS SNPs and Prevalent High Risk Human Papilloma Virus Infection in Nigerian Women

High risk HPV (hrHPV) infection is a necessary cause of cervical cancer but the host genetic determinants of infection are poorly understood. We enrolled 267 women who presented to our cervical cancer screening program in Abuja, Nigeria between April 2012 and August 2012. We collected information on demographic characteristics, risk factors of cervical cancer and obtained samples of blood and cervical exfoliated cells from all participants. We used Roche Linear Array HPV Genotyping Test® to characterize the prevalent HPV according to manufacturer''s instruction; Sequenom Mass Array to test 21 SNPs in genes/regions previously associated with hrHPV and regression models to examine independent factors associated with HPV infection. We considered a p<0.05 as significant because this is a replication study. There were 65 women with and 202 women without hrHPV infection. Under the allelic model, we found significant association between two SNPs, rs2305809 on RPS19 and rs2342700 on TYMS, and prevalent hrHPV infection. Multivariate analysis of hrHPV risk adjusted for age, body mass index, smoking, age of menarche, age at sexual debut, lifetime total number of sexual partners and the total number of pregnancies as covariates, yielded a p-value of 0.071 and 0.010 for rs2305809 and rs2342700, respectively. Our findings in this unique population suggest that a number of genetic risk variants for hrHPV are shared with other population groups. Definitive studies with larger sample sizes and using genome wide approaches are needed to understand the genetic architecture of hrHPV risk in multiple populations.     

Milk composition studies in transgenic goats expressing recombinant human butyrylcholinesterase in the mammary gland

The use of the mammary gland of transgenic goats as a bioreactor is a well established platform for the efficient production of recombinant proteins, especially for molecules that cannot be adequately produced in traditional systems using genetically engineered microorganisms and cells. However, the extraordinary demand placed on the secretory epithelium by the expression of large amounts of the recombinant protein, may result in a compromised mammary physiology. In this study, milk composition was compared between control and transgenic goats expressing high levels (1-5 g/l) of recombinant human butyrylcholinesterase in the milk. Casein concentration, as evaluated by acid precipitation, was significantly reduced in the transgenic compared with the control goats throughout lactation (P < 0.01). Milk fatty acid composition for transgenic goats, as determined by gas chromatography, was found to have significantly fewer short chain fatty acids (P < 0.01) and more saturated fatty acids (P < 0.05) compared to controls, suggesting an overall metabolic stress and/or decreased expression of key enzymes (e.g. fatty acid synthase, stearoyl-CoA desaturase). The concentration of Na(+), K(+), assessed by atomic absorption spectrophotometry, and serum albumin, determined by bromocresol green dye and scanning densitometry, were similar in transgenic and control goats during the first several weeks of lactation. However, as lactation progressed, a significant increase in Na and serum albumin concentrations and a decrease in K(+) concentration were found in the milk of transgenic goats, while control animals remained unchanged (P < 0.01). These findings suggest that: (a) high expression of recombinant proteins may be associated with a slow-down in other synthetic activities at the mammary epithelium, as evidenced by a reduced casein expression and a decreased de-novo synthesis of fatty acids; (b) the development of permeable tight junctions may be the main mechanism involved in the premature cessation of milk secretion observed in these transgenic goats.     

The food and feeding interrelationship of the fishes in the Lagos Lagoon

The food of 26 common fish species of the Lagos lagoon are given. It is shown that the food of the species covers a wide spectrum and most of the available invertebrates are being utilized as food by the fishes. The intra and interspecific relationship of the food and feeding habits of the various species are discussed.     

Influence of Spirituality and Modesty on Acceptance of Self-Sampling for Cervical Cancer Screening

Introduction

Whereas systematic screening programs have reduced the incidence of cervical cancer in developed countries, the incidence remains high in developing countries. Among several barriers to uptake of cervical cancer screening, the roles of religious and cultural factors such as modesty have been poorly studied. Knowledge about these factors is important because of the potential to overcome them using strategies such as self-collection of cervico-vaginal samples. In this study we evaluate the influence of spirituality and modesty on the acceptance of self-sampling for cervical cancer screening.

Methodology

We enrolled 600 participants in Nigeria between August and October 2014 and collected information on spirituality and modesty using two scales. We used principal component analysis to extract scores for spirituality and modesty and logistic regression models to evaluate the association between spirituality, modesty and preference for self-sampling. All analyses were performed using STATA 12 (Stata Corporation, College Station, Texas, USA).

Results

Some 581 (97%) women had complete data for analysis. Most (69%) were married, 50% were Christian and 44% were from the south western part of Nigeria. Overall, 19% (110/581) of the women preferred self-sampling to being sampled by a health care provider. Adjusting for age and socioeconomic status, spirituality, religious affiliation and geographic location were significantly associated with preference for self-sampling, while modesty was not significantly associated. The multivariable OR (95% CI, p-value) for association with self-sampling were 0.88 (0.78–0.99, 0.03) for spirituality, 1.69 (1.09–2.64, 0.02) for religious affiliation and 0.96 (0.86–1.08, 0.51) for modesty.

Conclusion

Our results show the importance of taking cultural and religious beliefs and practices into consideration in planning health interventions like cervical cancer screening. To succeed, public health interventions and the education to promote it must be related to the target population and its preferences.     

The food and feeding habits of the catfishes, Chrysichthys walkeri (Gunther), Chrysichthys filamentosus (Boulenger) and Chrysichthys nigrodigitatus (Lacépède) in theLekki Lagoon, Nigeria

A total of 1436 specimens were examined in the study of the food habits of the three Chrysichthys species in Lekki Lagoon. Certain differences were found in their food habits. Chrysichthys walkeri fed mostly on insects, Chrysichthys filamentosus on crustaceans and Chrysichthys nigrodigitatus on molluscs. It is suggested the observed diversity in feeding habits might be due to an active response to interspecific competition.     

The biology of the West African shad Ethmalosa fimbriata (Bowdich) in the Lagos Lagoon, Nigeria

The biology of the population of Ethmalosa fimbriata occurring in the Lagos lagoon was investigated. Three size groups, 35–69 mm (Yoyo), 70–169 mm (Efolo) and 170 mm and above (Agbodo) occur in the lagoon and the spatial distribution of these size groups and the length frequency distribution of the species is given. The relationship between length, weight, age and growth is discussed and the food and feeding intra-relationship of the size groups is shown. Information on the fecundity and possible spawning periods is discussed.