Insect Pests of Pulse Crops and their Management in Neolithic Europe.

Insect pests affecting standing and stored crops can cause severe damage and reduce yields considerably. Was this also the case in Neolithic Europe? Did early farming populations take a certain amount of harvest loss into account? Did they decide to change crops or rotate them when they became too infested? Did they obtain new crops from neighbouring communities as part of this process? Or did they actively fight against pests? This paper focuses on pulse crop pests, presenting the earliest evidence of fava beans displaying boreholes and of the presence of pea weevil in two different archaeological sites: Can Sadurní (in a phase dated to ca. 4800-4500 cal BC), located in the NE Iberian Peninsula and Zürich-Parkhaus Opéra (in a phase dated to ca. 3160 BC), located in Central Switzerland. Evidence suggests that early farmers were aware of the damages produced by pests and we propose different strategies for their management, including potential evidence for the use of repellent or trap plants in the plots.

A Non-Invasive Approach in the Assessment of Stress Phenomena and Impairment Values in Pea Seeds Caused by Pea Weevil.

Pea (Pisum sativum L.) is an important leguminous plant worldwide, in which pests trigger significant damage every year. One of the most important pest is pea weevil (Bruchus pisorum, L) which causes covert damage in crops. In the present study, our aim was to obtain precise information pertaining to the extent and the nature of damage in pea caused by B. pisorum by means of non-invasive imaging methods. The infested pea samples were analysed by an infrared thermometer and a bioluminescence plant imaging system as well as a computer tomograph under laboratory conditions. The calculated weight of organic matter destroyed by the developing larvae was 36.46%. The changing of RGB (red, blue, green) codes obtained through thermal imaging and the CPS (counts per second) values originating from bioluminescence imaging in infested samples were statistically verifiable. According to our CT assay, the damage caused by B. pisorum changed the tissue density, volume and shape of the pea seeds by the end of the development of the pest. The results of thermal and bioluminescence imaging contribute to a better understanding of the internal chemical processes and the CT analysis helps to understand the alteration trends of the inner structure of seeds caused by this pest.

Occupational airborne contact urticaria, anaphylaxis and asthma in farmers and agronomists due to Bruchus pisorum.

BACKGROUND: Occupational contact urticaria due to inhalation of legume pest allergens has rarely been described. OBJECTIVE: To determine the cause of an outbreak of airborne contact urticaria, asthma, and anaphylaxis in farmers and agronomists studying the disinsectization of dried peas. Peas were treated with aluminum phosphide (EPA). METHODS: Extracts prepared from Bruchus lentis and Bruchus pisorum bodies and from healthy legumes, EPA-treated legumes, and infested legumes, were used for in vivo tests (skin prick testing, oral, and specific bronchial challenge for the diagnosis of asthma and anaphylaxis) in affected patients and in five control patients with severe legume hypersensitivity. Open application, patch testing with the most common legume insecticides, molecular analysis, and IgE immunoblotting were undertaken. RESULTS: We found positive responses (prick, provocation, immune detection) to parasitic pea extracts and B. pisorum. A 25 kDa band was detected in the western blot of all patients who worked with infested EPA-treated peas. Bands from B. pisorum extract were detected in all patients. No responses to pea allergens were found in any patient, unlike in legume allergy controls. Oral provocation tests were negative. CONCLUSION: B. pisorum is a cause of contact urticaria and may cause occupational hives, anaphylaxis, and asthma. The allergen may enter by inhalation or puncture of setae released by B. pisorum.

Flower and Pod Source Influence on Pea Weevil (Bruchus pisorum) Oviposition Capacity and Preference.

Bruchus pisorum is an insect pest causing major damage to pea seeds worldwide. Control is difficult and limited resistance is available. In this work we studied the effects of pollen and pod source on insect fecundity and oviposition by comparing resistant and susceptible Pisum spp. accessions and non-host (Lathyrus sativus and Vicia faba) species. A first no-choice assay revealed that the source of flower offered to adults for feeding might retard oviposition (the case of V. faba), reduce fertility (Pisum sativum ssp. syriacum, P. fulvum, and V. faba) or increase adult mortality (V. faba and P. sativum ssp. syriacum). A second no-choice assay with all adults fed with pollen of the same pea cultivar showed significant effect of the source of pods offered. Oviposition was reduced on pods of some resistant Pisum accessions, but particularly low on pods of the non-hosts, being retarded if ever happening and coupled with high mortality of adults. This was confirmed in a third experiment consisting on dual-choice assays showing reduced egg laying in V. faba, L. sativus, P. fulvum, and P. sativum ssp. syriacum compared to the commercial variety pea used as a control (Messire).

Enhancing Neoplasm Expression in Field Pea (Pisum sativum) via Intercropping and Its Significance to Pea Weevil (Bruchus pisorum) Management.

Neoplasm formation, a non-meristematic tissue growth on young field pea (Pisum sativum L.) pods is triggered in the absence of UV light and/or in response to oviposition by pea weevil (Bruchus pisorum L.). This trait is expressed in some genotypes [neoplastic (Np) genotypes] of P. sativum and has the capacity to obstruct pea weevil larval entry into developing seeds. In the present study, 26% of the tested accessions depicted the trait when grown under greenhouse conditions. However, UV light inhibits full expression of this trait and subsequently it is inconspicuous at the field level. In order to investigate UV light impact on the expression of neoplasm, particular Np genotypes were subjected to UV lamp light exposure in the greenhouse and sunlight at the field level. Under these different growing conditions, the highest mean percentage of Np pods was in the control chamber in the greenhouse (36%) whereas in single and double UV lamp chambers, the percentage dropped to 10 and 15%, respectively. Furthermore, when the same Np genotypes were grown in the field, the percentage of Np pods dropped significantly (7%). In order to enhance Np expression at the field level, intercropping of Np genotypes with sorghum was investigated. As result, the percentage of Np pods was threefold in intercropped Np genotypes as compared to those without intercropping. Therefore, intercropping Np genotypes with other crops such as sorghum and maize can facilitate neoplasm formation, which in turn can minimize the success rate of pea weevil larvae entry into developing seeds. Greenhouse artificial infestation experiments showed that pea weevil damage in Np genotypes is lower in comparison to wild type genotypes. Therefore, promoting Np formation under field conditions via intercropping can serve as part of an integrated pea weevil management strategy especially for small scale farming systems.

Pea weevil damage and chemical characteristics of pea cultivars determining their resistance to Bruchus pisorum L.

Bruchus pisorum (L.) is one of the most intractable pest problems of cultivated pea in Europe. Development of resistant cultivars is very important to environmental protection and would solve this problem to a great extent. Therefore, the resistance of five spring pea cultivars was studied to B. pisorum: Glyans, Modus; Kamerton and Svit and Pleven 4 based on the weevil damage and chemical composition of seeds. The seeds were classified as three types: healthy seeds (type one), damaged seeds with parasitoid emergence holes (type two) and damaged seeds with bruchid emergence holes (type three). From visibly damaged pea seeds by pea weevil B. pisorum was isolated the parasitoid Triaspis thoracica Curtis (Hymenoptera, Braconidae). Modus, followed by Glyans was outlined as resistant cultivars against the pea weevil. They had the lowest total damaged seed degree, loss in weight of damaged seeds (type two and type three) and values of susceptibility coefficients. A strong negative relationship (r = -0.838) between the weight of type one seeds and the proportion of type three seeds was found. Cultivars with lower protein and phosphorus (P) content had a lower level of damage. The crude protein, crude fiber and P content in damaged seeds significantly or no significantly were increased as compared with the healthy seeds due to weevil damage. The P content had the highest significant influence on pea weevil infestation. Use of chemical markers for resistance to the creation of new pea cultivars can be effective method for defense and control against B. pisorum.