108 



or interfering with development. The parasitic egg is beheved to 

 hatch very shortly after the host's egg and the two larvae develop 

 together, that of C. meromyzae not maturing until after M. americana 

 pupates ; it then feeds voraciously and pupates within the pupal case 

 of the host. The j)upal stage of C. meromyzae is not more than 8 or 10 

 days in the laboratory, but probably lasts longer in the field. In the 

 spring adults of both parasite and host are found in the field together ; 

 in September C. merotnyzae appeared two or three weeks later than 

 M. americana. The indications are that there are two annual broods 

 of both parasite and host, but it appears probable that under favourable 

 conditions a third generation of M. americana occurs, in which case 

 there is also an extra generation of the parasite. M. americana has 

 been reported from nearly every State in North America, from Canada 

 to Texas, and the parasite evidently occurs wherever the host is found. 

 From observations in 1914 and 1915, the percentage of parasitism was 

 apparently not sufficient to control the host ; it is stated however that 

 this parasite is a sufficient control of the wheat bulb- worm in Illinois 

 and Iowa. This may be universally true, because in localities observed 

 there has not yet been a really serious outbreak of M. americana, 

 though it frequently does more or less damage to wheat. 



DoziER (H. L.). The Life-history of the Okra or Mallow Caterpillar 



{Cosmophila erosa. Htlbner). — Jl. Econ. Entom., Concord, N.H., x, 

 no. 6, December 1917, pp. 536-542, 2 plates. 



Anomis (Cosinophila) erosa, Hbn., is principally found in the southern 

 United States, but extends noilihwards to Massachusetts and Montreal, 

 westward to Kansas and southward through Mexico and the Antilles 

 to South America. The following food-plants in the order of damage 

 done at Gainesville, Florida, are recorded : — Flowering maple {Ahutilon 

 striatum), okra {Hibiscus esculentus), cotton rose {U. mutabilis), roselle 

 {H. sahdariffa), which is becoming an important commercial plant used 

 in jelly making, Chinese maUow {H. sinensis), cotton {Gossyjnum spp.), 

 swamp or rose maUow {H. moscheutos) and bell pepper {Pepperomia sp.). 

 Hibiscus plants, which are grown commercially, are frequently ruined, 

 and while the damage done to various species of cotton has as yet been 

 neghgible, this might not be the case under more favourable conditions. 



The eggs are deposited on either surface of the leaves, the lower for 

 preference, and hatch in about 4 days. The larval stage lasts about 

 24 days, and when mature the larva folds over the edge of a leaf and 

 pupates in the fold. The pupal stage averages six days in July, the 

 length of this stage increasing as the season advances. Pairing takes 

 place soon after emergence and oviposition follows within a few days, 

 the complete life-cycle thus requiring about 34 days. 



The most important enemies of A. erosa, are various predaceous 

 wasps, including Polistes americanus. A small Hymenopteron, Chalcis 

 ovata, is an occasional parasite. The larvae of the small ground beetle, 

 Callida decora, attack and devour the larvae. From eggs of A. erosa 

 collected on Ahutilon several Hymenopterous parasites, Trichogramma 

 minutum {pretiosum), emerged. Other important enemies are a Penta- 

 tomid, Euthrynchus floridanus, a Reduviid, Zelus bilobus, and other 

 Ehynchota, as well as insectivorous birds. 



