1920] ECONOMIC ZOOLOGY — ENTOMOLOGY. 257 



the sponnaforyte and hocoiiics applied to the nucleus of the spermatid like a rap. 

 The existence of a deeply stained rod of unknown origin and fate in the growing 

 oocyte and of a posterior mass of stained granules in the mature egg is shortly 

 referred to. Tlie egg nucleus undergoes two polar divisions, and fertilization 

 appears to be essential if the egg is to develop. 



"Breeding experiments did not confirm Hindle's observation that broods con- 

 sisting only of males or only of females are frequent. Some broods with great 

 preponderance of one or the other sex were obtained." 



The pea moth: How to control it, C. L. Fluke, jr. {Wisconsin Sta. Bui. 310 

 (1920), pp. 12, figs. 9). — A pea moth which feeds within the pods on ripening 

 peas and appears to be a species distinct from the European pea moth (Laspcy- 

 resia niyricana Steph.) occurs in the northeastern counties of Wisconsin and 

 threatens the pea industry of the State. This insect is said to have been one 

 of the principal pests of peas in Canada since 1893, having been introduced from 

 Europe about that time, and has been reported from Michigan, but is not known 

 to occur in any other State. The date of its introduction into AVisconsin is not 

 known, but most of the Door County farmers seem to agree that they first ob- 

 servetl the insect about 14 years ago. 



The percentage of infested pods ranged from 2 to 21. The infestation of the 

 previous year, however, was much heavier, counts showing that 10 to 50 per cent 

 were attacked. It attacks all varieties of both garden and field peas, but no 

 other host than peas is known. Late varieties of peas are more susceptible to 

 attack than the earlier maturing forms, due entirely to the time of appearance of 

 the moth and not to any varietal resistance of the peas. 



Ten months of the year are spent by the pest in its winter cocoon, the other two 

 months in activity near or on the pea plant. On reaching maturity in the fall 

 the worms leave the pea pods, make their way a short distance into the soil, and 

 construct a strong cocoon composed of soil particles, webbing and gluing them 

 together, and then lining the interior with fine silky threads. Here they remain 

 until late spring, when they change to pupJR, later coming out as adult moths. The 

 moths begin to appear shortly after the pea vines start to bloom, the first moth 

 in the field having been taken on July 14, the largest number on July 18, and the 

 last one July 30. 



The eggs are usually laid singly iipon the pods (seldom upon very young pods), 

 the leaves, the stems of the pea vines, or even on the stems and leaves of grasses 

 or weeds growing in the pea fields. The first eggs were laid July 17, and a maxi- 

 mum was reached within 2 or 3 days, very few having been oviix^sited after the 

 first of August. The incubation of the eggs varied from 7 to 10 days, depending 

 unon the temperature. Tlie first egg hatched July 23, and hatching continued 

 until August 13. 



When first hatched, the larva are pale, with the head and thoracic shield 

 almost black. The full-grown worms are about one-half inch long, yellowish 

 white in color, and with the .spots on the sides of the body rather inconspicu- 

 ous. The head and thorax are not so dark as when the larvte are young. The 

 few hairs that appear on the body are short, and pale in color. Upon hatching 

 out, the young larvic enter the growing or ripened pea pod through tiny holes 

 which are hard to find after the frass is rubbed or blown off. Here they feed 

 upon the peas, completing their growth in 16 to 26 days. From one to all the 

 peas in the pods attacked by the larvie are injured. When partly grown, 

 the young worm forms a cocoon within the pods next to the peas, the peas 

 forming one side of the cocoon, which is made up of accumulated frass webbed 

 together. The larva then continues feeding, making irregular holes and often 

 devouring as much as half of each pea. 



