10 CIRCULAR 8 6 9. U. S. DEPARTMENT OF AGRICULTURE 



Many of these insects act as scavengers, eating dead bodies of the 

 cigarette beetle and the tobacco moth: others probably use the tobacco 

 as a temporary shelter. 



NATURAL ENEMIES OF STORED-TOBACCO INSECTS 



The cigarette beetle and the tobacco moth have a number of natural 

 enemies. The most important are Aplaswmorpha cat and me (How.). 

 a parasite on the larvae and pupae of the cigarette beetle, and Mic- 

 robracon hebetor (Say), a parasite on the larvae of the tobacco moth. 

 With the exception of certain mites, predators are of only incidental 

 importance. Xone of the natural enemies have been observed to reduce 

 appreciably the populations of their hosts. 



The little pteromalid wasp Aplastomorpha calandrae (How.) is 

 often found in abundance in connection with large populations of the 

 cigarette beetle, although unfortunately it is not of appreciable im- 

 portance in controlling its host. In tightly packed tobacco the female 

 wasps find difficulty in entering the feeding tunnels of the beetle 

 larvae. This parasite is also very susceptible to low temperatures, and 

 the adults seem particularly vulnerable to fumigants and space sprays. 



Other small wasps have been reared on larvae of the cigarette beetle 

 but have never been found in tobacco warehouses. Among them are 

 Cephalo?iomia gallicola (Ashm.), Lariophagus distingue ndus 

 ( Foerst) , and Choetospila elegans Westw. 



The predaceous mite Py emotes ventricosus (Newp.) has been noted 

 attacking cigarette beetle larvae, but it is of little value in controlling 

 this pest. Mites of Seiulus sp. and of MonezieUa sp. are also known 

 to feed on beetle eggs to a limited extent. 



The adults and larvae of the clerid beetle Thaneroelenis gerodi 

 Che v. prey on larvae and pupae of the cigarette beetle in Florida. The 

 cadelle (Tenebroides maur it aniens (L.)) and also TriboJium beetles 

 are sometimes predators on the inactive stages of both the cigarette 

 beetle and the tobacco moth. 



The braconid Microbracon hebetor (Say) parasitizes large larvae 

 (fig. 7) of the tobacco moth, but has never been observed in sufficient 

 numbers to give any appreciable control. Few adults of this parasite 

 are seen in tobacco warehouses until late in summer. 



Two ichneumonids, Mesostenus gracilis Cress, and Idecihis canescens 

 (Grav.). are at times fairly abundant in tobacco storages, where they 

 parasitize large larvae of the tobacco moth. 



Mites of a species of SeMus attack eggs and adults of the tobacco 

 moth, as do mites of the genus Laelaps. Gheyletus mites attack the 

 larvae. 



The egg-sucking bug Grins insidiosus (Say) sometimes enters ware- 

 houses and feeds on the eggs and young larvae of the tobacco moth. 



A number of spiders prey on the tobacco moth adults. Theridion 

 tepidariorwn (Koch) weaves extensive webs, which capture many 

 moths. The jumping spider SoUticus scenicus (L.) often destroys 

 many moths. Other spiders of the genera Pardosa. P< ttt ru s, Phidip- 

 pus. and Marpissa feed on the tobacco moth. However, none of these 

 spiders have ever been observed in sufficient numbers to indicate any 

 appreciable degree of control. 



