ADJUSTMENT TO NEW HOSTS. 



67 



striking about the nature of the record that ^Ir. Cushman was sent 

 immediately to Victoria to study the surroundings of this field and 

 report upon the possible reasons for the high percentage of parasitism. 

 Mr. Cushman reported after considerable study that there were 

 only two factors which, it seemed to him, might have an influence 

 upon the parasites of the boll weevil. The first factor was the com- 

 plete lack of fruit upon the huisache trees (VacTiellia farnesiana) 

 which is the normal food of Laria sallxi. The second factor noticed 

 was the absence of flowers on the CallirrJioe involucrata, the host of 

 Anthonomus fulvus. !Mr. Cushman reasoned that the point would be 

 proven if we should rear from the boll weevil some of the character- 

 istic parasites of either this or the other species. As a result of 

 rearings from the material coflected in this field, the principal par- 

 asite was Microhracon mellitor, the typical boU weevil parasite, but a 



v5b4^0/U4Z /?0TAT/0JV (Dr hosts by CaTOL/^CCUS HUNTER! CpAWFORD. 



JANUARV FEBRUARY MARC» APRIL 



JULY AUGUST SEPTEMBER OCTOBER NOVEMBER DECEMBER 



/l/vrHO/JpMus s/Gi\/ATus Say 



/1/vmO' 



VOMUS AE/'eOtUS ffOMEMA/V 



T^CHyPTEREL LUS Q 7ADR/C IBBL S SAY 



Af\n-HONOI WS GRAM >/S BOHEf^, 4/V 



An. 



'HONOMUS 



GRAAJDIS BoF/EMa 



/ ^ATMOA/OMC 'S ALBOP/L OSUS O/l 



Smicraui 



TVBEP-:ULATUS P/ERCt 



'/ETfZ 

 OTHEC/ 

 ICRAU, 



VrHONO MUS METE/?ontECAE /• 



Sm/CRAULAK TukERClJLATjB P/ERCE 



Seasonal rotat/gaj of hosts by Cerambycob/us cyan/ceps Ashmead. 



Anthono 



^aS GRAN 0/S BOHEM. W 



l/XUS SCR OB /COLL 



•ICHOBAR/S TEXA.VA 



SM/CRAU/-AX TUBE^CUIATUS P/ERCE 



TACHyPT£RELU IS QUADRi 



IsCOA 'T£ 



SBOHEMAA/ 



S/BBUS S' IK 



Tyc/^us soRD/ous LeCcvte 



TP/C/iC BAR/S Cpyi PACTA CaSEY 



W/ 'THOA/OML 



A//Tt lONO/^US 



s GRAA/cis Schema A/ 



ALeOPILOS.'JS DiETZ 



Tp/chobar/s T£:>'AAJA 1£Go/\JT£ 



L/XUS SCPOB/COLLiS BOHETM AAA 



SaA/CI 'AULAX TV0ERCULATJS P/EfKl: 



Fig. 15.— Diagram Illustrating the seasonal rotation of hosts of Catdlaccus hunteri and Ceramhycohius 



cyaniceps. (Original.) 



species which is also a typical parasite of Anthonomus fulvus. It 

 is probable that the latter species furnished some of the Micro- 

 bracons for this infestation. The next most important species was 

 Ceramhycohius cuslimani, a typical parasite of Laria sallsei and of 

 Arxcerus fasciculatus which breeds in the fruit of the chinaberry tree 

 ( Melia azederach) . In addition to this species, this same field yielded 

 3 other new parasites of the boll weevil, 2 of which are known to 

 be parasites of the Laria. These were Eurytoma sp., Spilochalcis sp., 

 and Lariophagus texanus. 



To iUustrate the divergence of habits among parasites the host 

 relations of Catolaccus incertus may be cited. This parasite attacks 

 several species of Laria (Bruclius) which are internal seed eaters and 

 pupate in their feeding cells; such weevils as Zygoharis xanthoxyli and 

 Auleutes tenuipes, which are seed or bud feeders and pupate in the 



