MEXICAN rnNCHl'KLA IN wk-tkk.\ TEXAS IX 1905. li 



TACHINID PARASITES. 



A species of the very useful family Tachinidae, Gymnosoma fuli- 

 ginosa Desv., has boon reared from adult- of the conchuela. The 

 victims of this parasitic fly are distinguished by the yellowish-white 



esfir or effffshell which remain- attached to the thorax of the host 

 unless it happened to have been attached to a nymph in the fifth 

 ihstar, which afterwards molted. On August 11 and 12 only three 

 parasitized specimens were discovered, two in the fifth nymphal 

 instar and one an adult. An adult of this species of Tachinidae was 

 bred from one of these bugs. On September 12 parasitism by these 

 tachinids was found to be more common than at the time of the 

 previous visit. Of 24 adults examined at that time. 4 were found 

 to he parasitized. On October 13, of IS adults and 31 nymphs in 

 the fifth nymphal instar. '2 only had been parasitized, both nymph-. 

 While these parasites are decidedly beneficial and may be more useful 

 tinder some conditions, they were not sufficiently abundant at liar-tow 

 in 1005 to explain the rapid decimation of the numbers of the con- 

 chuela which has been described under the subject of seasonal history. 



PREDACE< US EN E M IKS. 



Although no observations on the subject of predaceous enemies 

 were made at Barstow, it seems important to refer briefly to the 

 records of observations by others along this line, in order that it be 

 not inferred that because pentatomids in general are characterized 

 by their ability to produce an offensive odor they are immune to the 

 attack- of insectivorous birds and of toads. On the contrary the 

 crow" is believed to be especially fond of bugs of this group, and 

 many other birds, 6 as well as the common toad.-.' seem to find them 

 unobjectionable as food. If we accept the evidence of definite reports 

 and observations during three successive seasons as indicative of the 

 usual seasonal history of the conchuela, the period of maximum abun- 

 dance is followed closely by a marked reduction in the numbers of 

 the pest. In this it is not unlikely that birds will prove to be an 

 important if not the leading factor. 



METHODS OF CONTROL. 



Under some conditions farm practices, such as the destruction of 

 weeds in the fall and otherwise hindering the sucessful hibernation of 

 the conchuelas, would be of unquestioned value in control, but under 



a Bui. 6, Div. Orn. and Mam.. U. S. Dept Agric, p. 63, 



& Buls. 13, Biol. sun.. Dept Agric., t\ s.. pp. 25, 62, 70; 15, p. 23; 21, p. 13; 

 i , : > >. p. 26. Yearbook U. s. Dept Agric. for 1895, pp. M7. 123, 129; Yearbook 

 t\ s. Dept Agric. for 1900, p. 414. Plates L. LI. 



<■ Bui. 4G. Hatch (Mass.) Exp. Sta., p. 26, Bui. 91, Ky, Exp. Sta., pp. 62, 64. 



