Feature Extraction of Stored-grain Insects Based on Ant Colony Optimization and Support Vector Machine Algorithm

[Objective] The aim was to study the feature extraction of stored-grain insects based on ant colony optimization and support vector machine algorithm, and to explore the feasibility of the feature extraction of stored-grain insects. [Method] Through the analysis of feature extraction in the image recognition of the stored-grain insects, the recognition accuracy of the cross-validation training model in support vector machine （SVM） algorithm was taken as an important factor of the evaluation principle of feature extraction of stored-grain insects. The ant colony optimization （ACO） algorithm was applied to the automatic feature extraction of stored-grain insects. [Result] The algorithm extracted the optimal feature subspace of seven features from the 17 morphological features, including area and perimeter. The ninety image samples of the stored-grain insects were automatically recognized by the optimized SVM classifier, and the recognition accuracy was over 95%. [Conclusion] The experiment shows that the application of ant colony optimization to the feature extraction of grain insects is practical and feasible.

Effectiveness of spinosad against seven major storedgrain insects on corn

In January 2005, the United States Environmental Protection Agency registered spinosad as a stored grain protectant. No referenced data on the efficacy of spinosad on corn in suppressing major stored-grain insects have been published. In this paper, we evaluated the efficacy of spinosad against seven major stored-grain insects on shelled corn in the laboratory. Insect species tested were the red flour beetle, Tribolium castaneum （Jacquelin duVal）; rusty grain beetle, Cryptolestesferrugineus （Stephens）; lesser grain borer, Rhyzopertha dominica （F.）; sawtoothed grain beetle, Oryzaephilus surinamensis （L.）; rice weevil, Sitophilus oryzae （L.）; maize weevil, Sitophilus zeamais （Motschulsky）; and Indian meal moth, Plodia interpunctella （Htibner）. Corn kernels were treated with spinosad at 0, 0. 1, 0.5, 1, and 2 active ingredient （a.i.） mg/kg for controlling the seven species. Beetle adults or P. interpunctella eggs were introduced into each container holding 100 g of untreated or insecticide-treated corn. The seven insect species survived well on the control treatment, produced 28 to 336 progeny, and caused significant kernel damage after 49 days. On spinosad-treated corn, adult mortality of C. ferrugineus, R. dominica, 0. surinamensis, S. oryzae, and S. zeamais was 〉 98% at 1 and 2 mg/kg after 12 days. Spinosad at≥ 0.5 mg/kg completely suppressed egg-to-larval survival after 21 days and egg-to-adult emergence of P. interpunctella after 49 days, whereas 16% T. castaneum adults survived at 1 mg/kg after 12 days. Spinosad at 1 or 2 mg/kg provided complete or near complete suppression of progeny production and kernel damage of all species after 49 days. Our results indicate that spinosad at the current labeled rate of 1 mg/kg is effective against the seven stored-grain insect pests on corn.

Effects of Artemisia herba-alba essential oils on survival stored cereal pests:Tribolium castaneum(Herbst)(Coleoptera,Tenebrionidae)and Trogoderma granarium(Everst)(Coleoptera,Dermestidae)

Objective:To assess the chemical components and toxicity of Artemisia herba-alba(A.herba-alba)essential oil against two major stored cereal pests,Tribolium castaneum(T.castaneum)and Trogoderma granarium(T.granarium).Methods:Two bioassay actions were tasted:repellent and fumigant actions against adult and larvae,respectively,to assess the effect of A.herba-alba essential oil.Results:Gas chromatography-mass spectrometer analyses of the essential oil contained β-thujone(12.50%),α-thujone(8.78%),sabinyl acetate(8.56%),terpinene-4-ol(8.51%),α-terpineol(3.35%),1,8-cineol(5.45%),γ-terpene(4.82%),camphor(4.52%),dimethylethylbenzene(3.93%)and α-terpinene(3.35%)as the major components.Fumigant toxicity tests showed that A.herba-alba oil was more toxic than T.granarium(LC_(50)=2.09 mg/mL,LC_(90)=4.12 mg/mL)and T.castaneum(LC_(50)=6.39 mg/mL,LC_(90)=10.10 mg/mL).Conclusions:This study has highlighted a bioinsecticide activity of A.herba-alba against two insect pests of stored foodstuffs(T.castaneum and T.granarium).The Artemisia essential oil offers an interesting potential insecticide that could be studied more deeply to isolate and identify the active substances,to study their physiological impact on other insects.