Can environmental dust from silo area allow the development of stored product insects?

Abstract

Dust derived from food processing can accumulate in places difficult to reach, where stored-product pests could thrive. The purpose of this work was to verify the development of Plodia interpunctella, Ephestia kuehniella, and Tribolium castaneum in dust collected on pipes and beams (15 m and 7.5 m) in a silo area of a pasta industry. Proximate analyses showed a higher metal content in the dust collected at the two different heights than semolina, including the presence of chrome, cobalt, arsenic, and lead. Particle size distribution analysis showed that in the two samples of dust the highest percentage was constituted by particle sizes smaller than 106 μm. The tests were carried out by using two quantities 4 g or 0.15 g of dust (corresponding to 3 mm and 0.1 mm), at controlled conditions. Fifty larvae, 0-24 hours old, of each species, were used for each dust, semolina, and thickness test. The number of emerged adults was assessed daily. T. castaneum developed on all the tested substrates, despite the high content of metals and the small particle size in the environmental dust. A significant interaction between diet and thickness of the layer was observed, but thickness had a stronger influence than diet. Moreover, light filth analysis detected a large number of fragments of Tribolium sp. in dust collected at a different height. Dust was unsuitable for the development of moths; only two E. kuehniella adults emerged from 3-mm-deep dust collected at 15 m, and development lasted more than 90 d.

Prevalence, Genetic Diversity, and Technological Functions of the Lactobacillus sanfranciscensis in Sourdough: A Review

“…Fruit flies have been proposed as a possible reservoir of this bacterium, as a strain of L. sanfranciscensis with 97% rDNA sequence similarity was reported in the gut of Drosophila simulans Stuvervant, a species of fruit fly closely related to Drosophila melanogaster (Groenewald et al, 2006). The presence of fruit fly in artisanal bakeries and plants corroborate this hypothesis (Locatelli, Savoldelli, Girgenti, Lucchini, & Limonta, 2017). A recent research showed the possibility that frass released by flies and grain beetles is a natural reservoir of this species, as L. sanfranciscensis was identified as a predominant species in fecal samples of Tribolium castaneum and Tribolium confusum larvae, the insects that infest stored cereal products, by sequencing 16S rRNA gene amplicons using the high-throughput Illumina MiSeq platform (Boiocchi et al, 2017).…”

Factors Affecting the Reproduction and Mass-Rearing of Sclerodermus brevicornis (Hymenoptera: Bethylidae), a Natural Enemy of Exotic Flat-Faced Longhorn Beetles (Coleoptera: Cerambycidae: Lamiinae)

“…As P. h. hilaris cultures are time-consuming to maintain, for assessment of the ability of the parasitoid to reproduce, we followed Abdi et al [ 65 ] and used C. cephalonica as factitious hosts. Larvae were reared on an artificial diet used to rear Lepidoptera associated with stored post-harvest products [ 83 ]. About two-hundred C. cephalonica eggs were added into a Petri dish (15 cm diameter × 2 cm height) half-filled with diet.…”

Insect frass in stored cereal products as a potential source ofLactobacillus sanfranciscensisfor sourdough ecosystem

“…), and insects are the most widespread poikilotherm animals (Bullock ), we have supposed that the origin of sourdough lactobacilli and yeasts could be attributed to a faecal contamination of insects infesting stored cereal products and the common fruit fly, which is sometimes observed in artisanal bakeries and plants (Locatelli et al . , personal communication).…”

“…The artificial diet for the feeding of larvae constituted of 23·4% (w/w) glycerol, 18·4% honey, 17·9% corn meal, 16·6% bran, 15·1% wheat meal, 4·7% wheat germ and 3·9% yeast extract (Locatelli et al . ). In addition to the artificial diet, larvae of P. interpunctella were reared on grains of Triticum aestivum .…”

“…The integrity of the eggs was controlled with a stereomicroscope (Stemi DRC, 10 X; Zeiss, Oberkochen, Germany) and then groups of 50 eggs were placed on sterile filter paper inside Petri dishes (⌀ = 15 cm; h = 2 cm) with an artificial diet. The artificial diet for the feeding of larvae constituted of 23Á4% (w/w) glycerol, 18Á4% honey, 17Á9% corn meal, 16Á6% bran, 15Á1% wheat meal, 4Á7% wheat germ and 3Á9% yeast extract (Locatelli et al 2017). In addition to the artificial diet, larvae of P. interpunctella were reared on grains of Triticum aestivum.…”