The effect of primary and processed plant products on red flour beetle Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) development and behaviour

Abstract

Tribolium castaneum (Herbst) is one of the most harmful species of storage pests. Every year it causes great economic losses in animal feed industry around the world, feeding on a large number of primary and processed plant products of the industry. Nine different primary and processed plant products (substrates), divided in three groups, were used in the experiments: protein-rich plant feed diets (sunflower meal, soybean concentrate and corn gluten), carbohydrate-rich plant feed diets (wheat bran, coarse wheat meal and corn feed flour) and feed products (compound feed for fattening pigs and compound feed for laying hens). The control diet was soft wheat flour type 500 with brewer’s yeast (5%) which is used for laboratory rearing of T. castaneum. In the first experiment we examined the effect of the initial population densities of 10, 25, 50 and 100 insects (undetermined sexes) on the first day of adults emergence, eclosion length, the number and body mass of progeny in 50g of tested substrates. In the second experiment in 10g of tested substrate we examined the influence of the initial population densities of 1, 2, 5, and 10 pairs of insects (determined sexes) on the duration of egg, larva, pupa stages, complete development cycle, the first day of adults emergence, the eclosion length, the number of progeny, the average productivity of females and progeny body mass. After development of progeny (10 pairs / 10g of substrate) in the substrates, the analysis of protein and starch content was conducted using the Kjeldahl apparatus and polarimeter. The analysis aimed to compare the substrates content before and after insects feeding and thus determine which nutrients the insects utilized during their development from the tested substrates. The data was statistically analyzed by repeated measures and one-way ANOVA and the means were separated by Fisher’s LSD test. Using olfactometer and preference test we examined the effect of volatiles of substrates rich in carbohydrates, compound feed for fattening pigs and laying hens and the standard substrate for laboratory rearing, on the behavior of T. castaneum. The substrates were used in uninfested and infested condition...

Tribolium castaneum (Herbst) jedna je od najštetnijih vrsta skladišnih insekata. Svake godine širom sveta nanosi velike ekonomske štete u industriji hrane za domaće životinje, hraneći se velikim brojem sirovina i proizvoda ove industrije. U eksperimentima je korišćeno 9 različitih biljnih sirovina i proizvoda (supstrata) podeljenih u 3 grupe: supstrati bogati proteinima (suncokretova sačma, sojino brašno i kukuruzni gluten), supstrati bogati ugljenim hidratima (pšenične mekinje, prekrupa i kukuruzno stočno brašno) i gotove smeše (hrana za svinje i koke nosilje), dok je kao kontrola korišćen standardni supstrat za laboratorijsko gajenje T. castaneum (brašno + 5% pivskog kvasca). U prvom eksperimentu je na 50g testiranih supstrata ispitan uticaj početne gustine populacije od 10, 25, 50 i 100 insekata sa neodređenim odnosom polova na: prvi dan pojave, dužinu trajanja perioda eklozije, brojnost i masu potomaka. U drugom eksperimentu na 10g testiranih supstrata ispitan je uticaj početne gustine populacije od 1, 2, 5 i 10 parova insekata određenih polova na dužinu trajanja stadijuma jajeta, larve, lutke, ukupnu dužinu ciklusa razvića, prvi dan pojave imaga, dužinu perioda eklozije, brojnost potomaka, prosečnu produktivnost ženke i masu potomaka. Nakon razvića potomaka (10 parova/10 g supstrata), urađena je analiza sadržaja proteina i skroba u supstratima pomoću Kjeldahl aparature i polarimetra kako bi se uporedio hemijski sastav supstrata pre i nakon ishrane insekata. Podaci su statistički obrađeni višefaktorijalnom analizom varijanse za ponovljena merenja i jednofaktorijalnom analizom varijanse, a srednje vrednosti poređene Fisher's LSD testom. Pomoću olfaktometra i testa izbora ispitan je uticaj mirisa supstrata bogatih ugljenim hidratima, gotovih smeša za ishranu svinja i koka nosilja kao i standardnog supstrata za laboratorijsko gajenje, na ponašanje T. castaneum. Supstrati su korišćeni u neinfestiranom i infestiranom stanju. Infestirani supstrati su dobijeni izlaganjem supstrata odraslim insektima T. castaneum u trajanju od 15 dana, nakon čega su insekti prosejavanjem eleminisani...