BIOLOGICAL NOTES ON THE PARASITES. 



33 



to the total period passed as larva and pupa. The exact length of 

 the pupal period maybe denned as between the maximum period 

 from observation of the pupa to maturity and the minimum period 

 from observation of tho larva to maturity. 'Inns it will appear 

 from the following thai the total developmental period is over 

 twenty-three days, and the pupal stage lasts from six to nine days 

 during August and September. 



Table XX. Length of developmental periods in Microdontomerus anihonomi. 



Locality. 



Date. 



Collec- 

 tion to 

 maturity 



Larva to 



maturity. 



I'upa 

 to ma- 

 turity 



In 

 Hra- 

 con co- 

 coon 

 t<> ma- 

 turity. 



i levelopmenl . 





Maxi- 

 mum. 



Mini- 

 mum. 



Maxi- 

 mum. 



Ma si- 

 mum. 



Ma \i- 

 mum. 



Total. 



Larva • 

 pupa. 



i utpa. 



Cuoro. Tax ' 



1906. 



August 31 



8eptember3 



August 30 



August L's, •_*<). . . 



Days. 

 14 

 23 

 14 

 10 



Days. 



Days. 



Days. 



Days. 

 ' 9 

 19 



Days. 



Days. 



1>II IIS. 



Goliad, Tex 









23+ 







Hallettsville, Tex. .. 



9 



9 



9 



6 





6 



Waco. Tex 



9 5 



6 



















! 





23+ 



23 



6-9 













It was impossible with a lens to find any characters to distinguish 

 the larvae of this species from any of the other chalcidoids. as all of 

 the chalcidoid larvae concerned in this report are finely, transversely 

 lineolate and clad with a few hairs regularly placed in a line around 

 the middle of each segment. The pupa is nearest in appearance to 

 that of Cerambycobius. The female pupa is robust, brown until 

 almost mature, with no darker spots on the dorsal abdominal seg- 

 ments, but with three longitudinal white lines and a transverse 

 white line on each segment ; the ovipositor is appressed to the dorsum 

 and proportionately longer than in Cerambycobius. The exuvium 

 is easily recognized by the form of the ovipositor and its brown color. 

 (See figure of pupa and of chalcidoid larva, PI. I, figs. 4, 7.) 



A .most interesting point in the biology of this parasite is the 

 fact that a number of individuals were bred from Bracon cocoons. 

 This is one of those phenomena which are here designated as accidental 

 secondary parasitism — that is, where a natural primary parasite finds 

 its host consumed by another parasite and in order to retain its hold 

 on life is compelled to attack that parasite itself. 

 10292— Bui. 73-08 3 



