Grain was carefully removed to allow for study of the grains for eggs and larval development of S. zeamais. ‘Stress on chemical products’,”, A. Merville, A. Vallier, S. Venner et al., “Determining the instar of a weevil larva (Coleoptera: Curculionidae) using a parsimonious method,”, R. T. Arbogast, “Beetles: coleopteran,” in, M. Danho, C. Gaspar, and E. Haubruge, “The impact of grain quantity on the biology of. The developmental period of 3rd instar larvae on rice was significantly ( < 0.05, F = 3.75) longer (6.5 days) and shortest on millet (5.3 days), whereas it was significantly ( < 0.05, F = 44) longest on maize at 4th instar stage and shortest on rice and sorghum (4.7 days). Peng, W.K., Lin, H.C., Wang, C.H. Corn redirects here. J. Factors like food host conditions, type of insect species, geographical locations, and experimental conditions could play significant role in the developmental study of maize weevil. This provides the only visible evidence that the kernel is infested. Also, there was significant different ( < 0.05, F = 3.99, and DF = 3) adult longevity found among the cereals used; adult maize weevil significantly lived longest on maize and millet ( and d) than on rice and sorghum ( and .07 days), respectively (Table 1). grown,[2] including: Polynesia, Argentina, Brazil, Burma, Cambodia, Greece, Japan, Morocco, Spain, All data were analyzed using analysis of variance and descriptive statistics. 1973. The life cycle of a weevil is an interesting one. 2003. Continuing to use this site, you agree with this. She then deposits a small oval white egg, and covers the hole as the ovipositor is removed, with a waxy secretion that creates a plug. Adult females will start laying eggs almost immediately so once you have some activity in a structure, its sure to blossom into a problem which will need attention. The female chews through the surface of the grain, creating a hole. When the adults emerge, the females move to a high surface and release sex pheromones. Proctor, D.L. Sun, “Instar numbers, development, flight period, and fecundity of, J. Gómez, B. Y. Chávez, A. Castillo, F. J. Valle, and F. E. Vega, “The coffee berry borer (Coleoptera: Curculionidae): how many instars are there?”. The female… … Universalium, Sitophilus — Taxobox name = Sitophilus image width = 250px image caption = Sitophilus granarius regnum = Animalia phylum = Arthropoda classis = Insecta ordo = Coleoptera familia = Curculionidae subfamilia = Dryophthorinae genus = Sitophilus subdivision ranks … Wikipedia, Home stored product entomology — is most commonly used in lawsuits over the contamination or infestation of foods by insects, usually in the commercial sector. The food hosts significantly influenced emerging body measurements of adult maize weevil. The end of the body of the maize weevil is also more rounded that of the LGB and its head is elongated into a distinctive “beak-like snout? t-test for larval instar conformity to Dyar’s rule was carried out using vertex width measurement. Cf. ITA 306), sorghum (var. The significant variation in sizes between adult S. zeamais could be a result of the type of food crops used; also female maize weevil was observed to be bigger than their male counterpart regardless of the food host. Journal of Stored Products Research, 6: 351-352. When the adults emerge, the females move to a high surface and release sex pheromones. © 2020 Presto-X and subject to the conditions in the legal statement. A possible indication of infestation is grain, when placed in water, floating to the surface. from Sitophilus oryzae (L.) (Coleoptera: Cuculionidae). The common control methods for this pest are the use of chemical insecticides, biological control, and botanical insecticides [9–11] among others. A significant difference ( < 0.05, F = 1.45, and DF = 3) was observed from third instar larval onward, although, at 2nd instar stage, there were significant ( < 0.05, F = 1.99, and DF = 3) shortest developmental days on sorghum, rice, and millet (5.5 and 5.7 days), the longest developmental period recorded being on maize (6.5 days). Maceljski, M., Korunic, Z. We are committed to sharing findings related to COVID-19 as quickly as possible. No significant difference ( > 0.05, F = 0.56, and DF = 3; > 0.05, F = 0.17, and DF = 3) were observed in maize weevil oviposition and egg incubation period across the maize, rice, sorghum, and millet tested. Development is about 35 days under optimal cnmditions. However, the only reliable features to distinguish adults of both species are on the genitalia (see table below).