Synonyms and other taxonomic changes
Amyelois transitella (Walker)
Orig. Comb: Nephopterix transitella Walker 1863
Numbers
Monotypic genus in U.S. per Hodges (1983)
(1) and Nearctica.
Size
Adult length is 9.7 to 10.9 mm
(2)Identification
Larva - ½ to ¾ inch long, reddish orange when first hatched, changing to cream color after the first molt. Later, their color depends on the color of their food
Range
s. US, but mostly Calif. / Mex. / W. Indies -
Map (MPG)
Season
Adults fly in California from the end of March to the end of Oct
(2)Food
Polyphagous in Florida hosting on orange, grapefruit, peach, apple, dates, figs, Acacia, Cassia, Pithecellobium, Robinia, Sapindus, Yucca, and walnut.
(3)
The navel orangeworm is a critical pest in California of almonds, pistachios and walnuts, which cover more than 1.1 million acres and yield an annual farm gate value of more than $3 billion. Damage by navel orangeworm may also decrease quality, reducing the competitiveness of these products in the export market, valued at over $1.5 billion.
(4)Life Cycle
Creamy-white lustrous eggs are laid in small groups. During incubation, they change color to pink and reddish orange. Total egg production per female ranges from 3 to 244, with an average of 85. At 82° F the incubation period is 5 days. As the larvae feed, they produce abundant silken webbing, and the interiors of figs and dates that have been occupied by them are littered with coarse pellets of excreta. The larvae develop more rapidly when relative humidity is high. At 55 percent, they take 55 days to develop, but at 95 percent they require only 22 days. Pupation lasts for about a week. The pupae are dark brown. At 82° F, the egg-to-adult period is only 36 days at 95 percent relative humidity, but 69 days at 55 percent
(4)Remarks
NOW biological control agent: Chrysidoidea (Cuckoo Wasps and Allies) » Bethylidae » Epyrinae » Goniozus legneri:
first found in California in 1942 and spread widely by 1949.
Print References
Burks, C.S., & D.G. Brandl. 2004. Seasonal abundance of the navel orangeworm, Amyelois transitella, in figs and the effect of peripheral aerosol dispensers on sexual communication. J. Insect Science 4: 40.
Siegel, J., L.A. Lacey, R. Fritts, B.S. Higbee, & P. Noble. 2004. Use of steinernematid nematodes for post harvest control of navel orangeworm (Lepidoptera : Pyralidae, Amyelois transitella) in fallen pistachios. Biol. Control 30: 410-417.
Zalom, F.G., W.W. Barnett, & C.V. Weakley. 1984. Efficacy of Winter Sanitation for Managing the Navel Orangeworm, Paramyelois transitella (Walker), in California Almond Orchards. Prot. Ecol. 7: 37-41.
Internet References
USDA - INSECTS ON DRIED FRUITS - life cycle, larvae description
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