. Cooperative economic insect report. Beneficial insects; Insect pests. - 92 - Hosts: Beets (Beta cicla, B. vulgaris maritima, B. sacchariera) . Life History and. Habits: The biology of the pest as recorded in Italy is as fol- lows: The adults first appear during early May and fly about quickly in search of young plants to deposit their eggs. Larvae, upon hatching, begin feeding on the succulent growth, excavating galleries in the midribs, leaf stalks and the roots. Often, a black, rotting mass is clearly visible on the infested plants due to mold development on the excreta, feeding residue an
. Cooperative economic insect report. Beneficial insects; Insect pests. - 92 - Hosts: Beets (Beta cicla, B. vulgaris maritima, B. sacchariera) . Life History and. Habits: The biology of the pest as recorded in Italy is as fol- lows: The adults first appear during early May and fly about quickly in search of young plants to deposit their eggs. Larvae, upon hatching, begin feeding on the succulent growth, excavating galleries in the midribs, leaf stalks and the roots. Often, a black, rotting mass is clearly visible on the infested plants due to mold development on the excreta, feeding residue and foreign bodies which are trapped in the silk threads spun by the larvae. Pupation takes place in silken cocoons, which may be rolled-up in the ends of the outer leaves, in chambers made from the central leaves which are tied together, or in feeding galleries. Duration of the life cycle, as well as the number of generations, varies consider- ably according to climatic conditions. In the northern area, the life cycle lasts 28-30 days and there are 2 generations, but in the central and southern areas, the cycle is completed in 20-23 days and 3-4 generations develop. The various gener- ations overlap, however, and adults, larvae and pupae can be found together in August, September and October. Description: ADULT - Body about 5 mm. long; wing expanse 13-14 ram. Forewings basically gray-brown or gray pale-yellow with small black, more or less distinct, spots surrounded by a light ring. Hind wings gray pale-yellow, with fringe of hairs a little lighter in color. Antennae with a series of yellowish-gray scales around the base and with another series of brown or black scales situated near the extremity. LARVA - Yoiing larvae are more or less light green, changing color as they mature. The changes are as follows: The dorsal region becomes reddish and some rosy longitudinal lines are more or less distinctly expressed, while the ventral region takes on a straw-yellow color. The head, pro
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Keywords: ., bookcentury1900, booksubjectbeneficialinsects, booksubjectinsect
