RED FLOUR BEETLE joshi.pptx

Red flour beetle, Tribolium castaneum life cycle biology and flour conditioning

1. RED FLOUR BEETLE SS.PRAVEEN JOSHI 2022505017

2. Red flour beetle- Tribolium castaneum { Tenebrionidae Coleoptera } Its is one among the bran bugs which damages Broken grains/ mechanically damaged grains, germ portion and milled products. It feeds on cereals, flour, starchy material, fruit nuts, millets and prepared cereal foods. It usually feed on broken grains and results in dust formation. Worst pest of mill machinery Also important pest in commercial Corcyra production units COSMOPOLITION , origin is believed to be south A sia

3. Biology of RFB Egg : Freshly laid eggs were very small, whitish, cylindrical microscopic and often have bits of flour stuck to their surface and harden, making them difficult to see. The incubation period ranged from 4 to 7 days. Grub : Elateriform with urogomphi and minute hairs all over the body. 30 to 40 days { 6 instars} pupa: Exarate type .5-9 days 8 { male 6-7 days and female 7-9 days}

4. iology

5. Adult The adult red flour beetle is approximately 3-4 mm long with a flattish curved-sided body which is reddish-brown in colour. The head and upper part of the thorax are covered with minute punctures and the wing cases (elytra ) are ridged along their length . They can fly. Antenna have an abrupt 3 segmented club at distal end

6. Damage symptoms Adult and grubs causes damage . They highly prefer broken grains and flour and can damage some intact seeds. Eg ; sesame Adults constructs tunnels as they move through flour They produce quinine substances and thus the infected flour can be easily identified with acidous odour .

7. Gaseous quinines They produced compounds like 2-ethyl-1,4 benzoquinone 2-methyl 1,4 benzoquinone 2 methoxy 1,4 benzoquinone These compounds on inhaling continously causes several respiratory problems like bronchitis skin irritation , redness of eyes and when consumed causes abdominal pain, burning sensation. {International I abour Organization }

8. Flour conditioning and cannibalism in RFB As the beetles startes to feed , nutrition quality of flour reduces, flour is now filled with feacal matter , quinone derivatives ,and exuvia . This process is called flour conditioning. RFB exhibits cannibalism , active stage feeds on inactive stages

9. Effect of flour conditioning and cannibalism {Earlier findings } Flour conditioning is a result of depletion of nutrients and the build up of waste materials, pheromones, and ethylquinone , which is a repellent produced by the beetles ( Sonleitner 1961 ) Sonleitner (1961) showed that egg cannibalism in adult T. castaneum increased in conditioned flour compared with fresh flour. Cannibalism is directly proportional to flour conditioning

10. Later findings Adult male - cannibalism level was low Grub – cannibalism increased slightly as flour conditioning increased Female : cannibalism is inversely proportional to flour conditioning Since females didn’t prefer to dig the conditioned flour and quinines acts as repellent to females To conclude Conditioned flour acts as a ovipositional deterrent and protected existing beetle from unwanted visitors Females prefer to lay eggs on fresh flour

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