370 



Leech and Chandler: Coleoptera 



Thus, Bagous can utilize the air-filled burrows behind 

 it for respiration. 



Presumably the adults are able to store air beneath 

 the elytra. Bagous americanus is reported by McGaha 

 to spend long periods on the underside of floating 

 leaves. The extent to which the Calendrinae are 

 aquatic is not known, but I took several species by 

 sweeping among aquatic vegetation which was mostly 

 submerged. This prompted me to place two of the 

 species on rush stems in a container half filled with 

 water, so that the tops of the stems were above the 

 surface. These specimens remained submerged more 

 than half the time for a weeii or more. They would 

 walk up or down the stems at will but were helpless 

 if separated from them. 



Life history. — According to McGaha, the adults of 

 Bagous feed and may even mate below the surface. 

 He never found more than six to eight eggs in the 

 females at any one time and only half of these were 

 mature. B. longirostris may insert its eggs into the 

 petioles of Nymphaea tuberosa as much as six feet 

 below the surface. The larvae burrow through the 

 petioles where - they also pupate in an air-filled cham- 

 ber. B. americanus mines the leaves of Nymphae 

 odorata for the first three larval instars and then 

 enters the pedioles where it pupates at their junction 

 with the leaves. 



Habitat and distribution. — Aquatic curculionids are 

 usually closely associated with their host plants. 

 My first contact with this group was while collecting 

 on the shore of Utah Lake in a shallow, temporary 

 pool in which vegetation was starting to grow. After 

 collecting the first three specimens of the type series 

 B. chandleri while sweeping the bottom, a closer look 

 was taken to see where they were coming from. They 

 were found walking about on the bottom of this shallow 

 pool. 



Tanner and McGaha record the following plant asso- 

 ciations: Lissorhoptrus simplex is a serious pest of 

 cultivated rice; Brachybamus electus on Sagittaria; 

 Endalus limatulus on Scirpus; Tanysphyrus lemnae on 

 Lemna; Onychylis nigrirostris on Sagittaria, Nymphaea 

 and adults on the flowers of Pontederia; Anchodemus 

 angustus on Sagittaria; Lixellus filiformis on Scirpus, 

 Ptilimnium, and Lepidum. Additional records for Ba- 

 gous are Carex, Eleocharis, Cyporus, and Po tamo ge ton. 

 Listronotus appendiculatus and Hyperodes sp. are 

 recorded by McGaha from Sagittaria, but no mention is 

 made as to whether this group is aquatic. 



Taxonomic characters. — Boving and Craighead set 

 up the subfamily Lissorhoptrinae for Lissorhoptrus 

 simplex, based largely on the specialized respiratory 

 structures of the larvae. Lissorhoptrus has usually 

 been placed with Bagous in the Hydronomi. The 

 respiratory structures of the latter are not at all 

 like those of Lissorhoptrus. 



Key to North American Genera of Curcullonidae 



Presumed to be Aquatic 



Adults 



1. Abdomen of male with an apparent extra segment at 

 tip, pygidium and anal segment separated by a suture; 



club of antennae usually annulated, sensitive, and 

 not shining. CURCULIONINAE: ERIRHININI, HYDRO- 

 NOMI 2 



— Abdomen similar in both sexes, pygidium not divided 

 by a suture as the anal segment of male is at least 

 partly free and retractile; club of antennae usually 

 with its basal segment enlarged or shining, or both, 

 without or with indistinct sutures. CALENDRINAE 

 (Not further treated here). 



2. Metasternum as long as 1st sternite, covered with 

 dense, varnishlike, waterproof coating of scales .... 3 



— Metasternum 1/3 length of 1st sternite; front coxae 

 narrowly separated Phycoetes LeConte 1876 



Phycoetes testaceus LeConte 1876, So. Calif. 



3. Beak very short and broad, not longer than head; tarsi 

 narrow, 3rd segment deeply emarginate 



Stenopelmus Schoenherr 1845 



Stenopelmus rufinasus Gyllenhal 1835, Florida 

 to southern California. 



— Beak cylindrical, much longer than head 4 



4. Third segment of hind tarsi emarginate or bilobed 



5 



— Third segment of hind tarsi simple; legs long and 

 slender 10 



5. Beak curved; antennal funicle of 6 segments, the 

 2nd short; 3rd segment of tarsi broad, deeply bilobed, 

 last segment short 6 



— Beak straight; 2nd segment of funicle long, as is 

 also last segment of tarsi 9 



6. Tarsi with a single claw. . . . Brachybamus Germar 1836 



Brachybamus electus Germar 1836, Massachusetts, 

 Indiana, Florida 



— Tarsi with 2 claws 7 



7. Last segment of tarsi broad, claws well separated 



8 



— Last segment of tarsi narrow, projecting beyond lobes 

 of 3rd, claws slender; eastern 



Onychylis LeConte 1876 



8. Elytra but slightly if at all wider than thorax; length 

 usually 2 mm. or more Endalus Laporte 1840 



— Elytra much wider than thorax; length less than 1.5 mm. 



Tanysphyrus Germar 18 17 



9. Front and middle tibiae serrate on inner side; 3rd 

 tarsal segment narrow, slightly emarginate; funicle 

 of 6 segments Lixellus LeConte 1876 



Lixellus filiformis LeConte 1876, Ontario, Alberta, 

 Oregon 



— Tibiae not serrate within; 3rd tarsal segment broad, 

 deeptly bilobed; funicle of 7 segments; eastern 



Anchodemus LeConte 1876 



10. Club of antennae partly smooth and shining, funicle 

 of 6 segments; prosternum not excavated 



Lissorhoptrus LeConte 1876 



Lissorhoptrus simplex (Say) 1831; eastern. 



— Club entirely pubescent and sensitive, funicle of 7 

 segments; prosternum broadly and deeply excavated 

 in front of coxae 11 



11. Pronotum feebly constricted in front (fig. 13:615) 

 Bagous Germar 18 17 



— Pronotum very strongly constricted and tubulate in 

 front (fig. 13:61a) Pnigodes LeConte 1876 



Pnigodes setosus LeConte 1876; U.S. 



Key to California Species of Endalus 

 Adults 



1. Last segment of tarsi slightly prominent, claws moder- 

 ately large, elytra wider than prothorax; U.S 



limatulus (Gyllenhal) 1836 



— Last segment of tarsi not prominent; body oval; U.S. 

 ovalis LeConte 1876 



