Larvae of sweetpotato weevil, Cylas formicarius (Fabricius). Figure 1. Larvae of sweetpotato weevil, Cylas formicarius (Fabricius). Photograph by James Castner . Brief summary. No one has contributed a brief summary to this page yet. Explore what EOL knows about Cylas formicarius. Add a brief summary to this page. C. formicarius adults feed on the epidermis of vines, scraping oval patches off young vines and petioles. Adults also feed on external surfaces of storage roots.
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Distribution of sweetpotato weevil in fields is aggregated.
Species Cylas formicarius – Sweet Potato Weevil –
International Potato Center, Dispersal rates of m per day have been observed, with dispersal more rapid in the absence of suitable hosts. Braun AR, Fliert Evan de, cyoas The distal antennal segment in the female is egg-shaped, only two-thirds the length of the flagellum.
Breeding sweet potato for weevil resistance. Among the three predators only Pheidole megacephala is reported to be an effective natural control agent of C. Journal of Root Crops Sweet Potato Management in Kenya: This was further confirmed in a related study where 1 to 8 week-old weevil-free plants were exposed to the weevil in the field. Z dodecenol E butenoate Food: Studies on some major pests of sweet potatoes and their control.
The usefulness of crop rotation with rice in controlling the weevil was investigated in two experiments, each lasting months in Taiwan Talekar, Thus, maintenance of moist soil with irrigation is helpful for weevil management. Crop rotation Rotations of crops, such as growing sweet potatoes in a field only once every 5 years TAC,avoiding planting of sweet potatoes in the same area for two successive years Ballou, ; Chittenden, ; Edwards, ; Holdaway, or planting rice between two sweet potato crops Franssen, have long been suggested.
When this species was first discovered in the new world, it was thought to be a new species and was named Cylas formicarius elegantulus. International Development Research Centre, The results obtained were variable dependent on the proximity of the source of weevil infection.
The sweet potato weevil. However, because they are active mostly at night, their dispersive abilities are probably underestimated.
In Penghu Island, Taiwan, Talekar et al. Comparison of single and multiple releases of Heterorhabditis bacteriophora Poinar Nematoda: Effect of a pentacyclic triterpene from sweet potato storage roots on oviposition by the sweetpotato weevil Coleoptera: Comportamiento de nuevos clones de boniato Ipomoea batatas en ciclo de dias y epoca de primavera. Identification of sex pheromone produced by female sweetpotato weevil, Cylas formicarius elegantulus Summers.
Temperature is the principal factor affecting larval development rate, with larval development not including the prepupal period occurring in about 10 and 35 forrmicarius at 30 o and 24 o C, respectively. The full-grown larva is 7. Conversely, a large number of volunteer plants grew in the non-flooded control plots, all of which were infested with weevils.
Sweet formiacrius weevil control was acceptable in a field planted away from a weevil-infested field, whereas the tubers were heavily infested when the fields were adjacent to each other. Report on the entomological section for the year ending 31st March The chemical control of Cylas formicarius Fab. Control of sweetpotato weevils and vine borer in Hawaii. Coleoptera Excepting Scotylidae and Platypodidae.
The basic colour of the insect is red Kemner,but this colour is usually masked, because the head is black, the elytra blue or bluish-green, sometimes black, and shining, the back of the thorax and sternites are usually dark bluish-green.
Therefore, the use of weevil-free sweet potato cuttings is often advised Ballou, ; Franssen, ; Tucker, ; Formicarihs, The full-grown apodous larva is 7.
Pheromone traps show great promise for monitoring of adult population density. However, because of its limited or almost non-existent flying activity, which implies that the insect is carried from place to place via movement of the plant material, host specificity to the genus Ipomoea, and characteristic mode of entry and damage to the plant, this pest is amenable to suppression by crop rotation, clean cultivation, mulching and similar simple cultural practices.
Go to distribution map Wild hosts of the sweetpotato weevil. The adult measures 5. Eulophidae have been formicariys from sweetpotato weevil larvae in the southeastern United States. An IPM approach for sweet potato weevil.
Biochemical changes due to weevil Cylas formicarius Fab. The use of pheromone traps in Kerala, India, was shown to be highly effective at mass trapping male weevils leading to a significant decline in population build-up and consequent yield increases. Chemical control of sweet potato insects in Hawaii. Field efficacy and persistence of entomopathogenic nematodes Rhabditida: Several natural enemies are known.
Planting weevil-resistant sweet potato cultivars also represents a potential cultural control method, however, a cultivar with a reliable level of resistance to the weevil is not yet available Talekar, b. Soon after emergence from the pupa, the adult stays in the pupal chamber and then cuts its way through the plant tissue. Gonzales in the Philippines reported that males cylaa days and females days.