294 IOWA ACADEMY OF SCIENCE 



pear at the blossoming time of the strawberry. The slugs 

 mature in about a month, enter the soil, where they remain 

 until the next spring, pupating shortly before the adults emerge. 



GENERATIONS OF EMPRIA MACULATA. 



Here the situation is more complicated. In the literature 

 we have the definite statement by Riley that the insect has two 

 generations in Missouri, and the statements of F. M. Webster 

 (1888) and Pettit (1899) that larvae were found in abundance 

 in the fall in Indiana and Michigan. On the other hand, no 

 other writers have been able to discover a definite second gen- 

 eration. In fact, F. M. Webster (1894) determined a single 

 generation from larva? collected at La Porte, in northern In- 

 diana. 



The writer has bred this saw-fly in the insectary at Ames dur- 

 ing four years, and each year there was but a single generation. 

 According to these notes the life history in central Iowa is as 

 follows: The adults emerge in late April or early May and 

 deposit their eggs in the stems of strawberry plants. The larvae 

 hatch in late May and are present during June, mature and 

 enter the soil about a month after hatching. Larvae spend the 

 winter in the cocoons, pupating the next spring shortly before 

 the adults emerge. Adults reared in the insectary have been 

 identified by S. A. Rohwer as Em/pria maculata Norton. 



Eliminating references in the literature that clearly refer 

 to Empria fragariac, the following generalizations are offered: 



(1) Riley claimed two generations for Missouri. This may 

 be possible, since it has not been proved otherwise. 



(2) F. M. Webster determined only one generation from 

 larvaa from La Porte in northern Indiana, in 1894. 



(3) Only one generation is present in central Iowa, accord- 

 ing to notes hj the writer. 



(4) This does not dispose of the statements that this in- 

 sect has been seen in the fall in southern Indiana (Webster) 

 and Michigan (Pettit). 



(5) There still remains a possibility that there is a third 

 species of saw-fly, the larvae of which attack strawberry plants 

 in the fall, but which has not been recognized in the economic 

 literature as a separate species.* 



*Emphytus gillettei MacG. feeds on strawberry foliage in Colorado but 

 there is only one generation. The eggs are placed in the leaf tissue and 

 larvae appear in late May and early June. 



