ENTOMOPHTHOREAE OF THE UNITED STATES. 171 



Hosts. Lepidoptera : imagines of geometrid moths {PetrojjJiora, Eujyithecia, Thera, 

 etc.). 



Habitat. Kittery, Maine. 



This species was found during the month of September (1886) attacking geometrid 

 moths of several species in or near pine woods, a favorite habitat of these insects. It is 

 usually the habit of the host to i-est with the abdomen curved upwards and, at one point 

 of the under surface, resting on whatever object the moth may have lighted upon, usu- 

 ally a pine needle. At this point of contact, and, as far as I have observed, nowhere else, 

 the rhizoids are produced in a tuft which thus fastens the insect by its abdomen. The 

 rhizoids appear before death and I have found a small Eupithecia fluttering violently in 

 its efforts to free itself from a pine needle to which the rhizoids had already become firmly 

 attached (fig. 173). Although the specimens collected were found for the most part on 

 the borders of pine (P. strohus) woods, several were noticed in other situations, as for in- 

 stance, in a room used by me for collecting night moths by means of a lamp. Here sev- 

 eral specimens of Ewpitliecla, thus atti'acted, were found fastened to the walls and win- 

 dow panes. The species was not studied while fresh and none of the dried specimens 

 were in the proper condition for showing clearly the method by which the i-esting spores 

 are formed. As far as could be seen, however, the process is similar to that described 

 in E. spliaerosperma. 



The conidia are peculiar and may be at once recognized by their short, thick form, 

 which readily distinguishes them from those of the closely allied E. sphaerosperma. 



Empusa (Entomophtbora) occidentalis nov. sp. 

 PI. 17, figs. 179-199. 



Conidia of the sphaerosperma type, sometimes slightly fusiform, often tajjeiing strong- 

 ly towards the apex, with a broad, rounded, papillate base. Average measurements 

 35 X 10/i, maximum 4.5 X 12 ji. Contents usually finely granular, sometimes Avith larger 

 fatty bodies. Conidiophores irregularly digitate, coalescing in a white or slightly yel- 

 lowish mass. Cystidla slender, slightly tapering. Secondary conidia like the primary, 

 or long almond-shaped and borne obliquely on capillary conidiophores. Resting spores, 

 azygospores or zygospores (?), borne laterally or terminally by budding from the hyphae; 

 colorless, spherical, 20-35// in diameter. Host attached to substratum by numerous 

 rhizoids. 



Hosts. Hemiptera : aphides on Betula poptd/ifolia. 



Habitat. Maine, Massachusetts. 



This is a well marked species of the sphaerosperma type, and occurs ver}- commonly 

 on the aphides which usually infest the common white birch in late August and in Sep- 

 tember. It generally is associated with the much rarer E. lageniformis which attacks 

 the same host, and it may be found, in my expei-ience, in almost any locality where the 

 white birch grows. The conidia are chiefly noticeable fi'om such foi-ms as are repre- 

 sented by figs. 183 and 184 which strike the eye at once in examining a preparation. 

 The contents of the conidia are usually finely granular with a central nuclear body (figs. 



