For the American Iiee Journal 



My Worst Bee Enemies. 



CHAS. SONNE. 



My bees seem to have lost the swarm- 

 ing fever. During the years of 1877, 

 1878 and 1879 they have not given over 

 three or four swarms during each sea- 

 son, although I have had 100 colonies ; 

 I now have 105. This is to me very 

 agreeable as I dislike natural swarming; 

 but the fact that the honey harvest 

 commences each year at a later date is 

 not so agreeable. My observations and 

 experience on this, are as follows : 



Three years ago I observed in this 

 latitude (39°) three families of bee kill- 

 ing flies abound : Asilus Missouriensis 

 (Riley); Asilus sericeus (Say); Erax bas- 

 tardi (Macquart). 



I herewith send a number of speci- 

 mens of Asilus Missouriensis and Asilus 

 sericeus. Of Erax bastardi I could catch 

 none this month ; they having passed 



Asilus Missouriensis (Riley). 



away already. For a description of 

 these three species I refer to Prof. C. V. 

 Riley's second annual report, page 151. 

 I will only make a few remarks on their 

 effect on the bees. 



At the time when bees begin to fill 

 their hives, their combs being full of 

 brood, and they bringing in honey and 

 commencing to build queen cells, pre- 

 paratory to swarming, these three spe- 

 cies of bee-killers appear. When in the 

 morning the dew has evaporated from 

 the leaves and blossoms, if the day is 

 warm and clear and' the bees are busy 

 gathering honey, these voracious in- 

 sects commence their ravages among 

 the loaded bees. You see an Asilus or 

 Erax perched on a shaded leaf, or hang- 

 ing to a stem waiting for prey, almost 

 like a spider. Any bee coming within 

 a foot of it is lost. With lightning ra- 

 pidity, while humming much like a 

 drone when flying, they pounce upon 

 the bee, holding it with the two (often 

 four) front feet, and let themselves fall 



to some twig near the ground, where 

 I they take hold by their long hind feet. 

 I The bee evidently feels itself lost, and 

 is resigned to its fate. I have never 

 I seen one who tried to escape or defend 

 | itself. The Asilus then very quietly 

 I turns the bee between its sharp, hairy 

 I claws, so that the breast is turned to- 

 wards it, when it immediately sinks its 

 sharp, horny proboscis into the thorax 

 (never the abdomen) of the bee, sucking 

 its life-blood. This lasts about a min- 

 ute, when the bee drops dead, and the 

 fly-tiger is ready for another victim. 



Asilus Missouriensis is rather oniniv- 

 erous. It catches not only bees, but any 

 insect it can master. Butterflies, bugs, 

 beetles, hornets, and even Asilus sericeus 

 and Erax bastardi; the latter two in 

 such numbers as to justify the conclu- 

 sion that Asilus Missouriensis may be- 

 come the arch enemy and destroyer of 

 Asilus sericeus and Erax bastardi. I 

 have observed, this year, that Asilus 

 Missouriensis has out-lasted Asilus seri- 

 ceus. Asilus sericeus and Erax bastardi 

 live exclusively on bees ; I have not 

 seen one preying on any other insect. 

 My experience and observations con- 

 vince me, that these insect-tigers arc 

 the main cause of the failure of my bees 

 to swarm, or bring in any surplus honey, 

 so long as they abound. 



My bees have been in the best possi- 

 ble condition during all the summer, 

 with six, and in many hives eight combs, 

 full of brood from the middle of May 

 to this day. Where are all the bees 

 which have matured during these three 

 months V Why have they collected no 

 surplus honey, in spite of the abundance 

 of flowers around me, in the woods, on 

 the open prairie, on white clover, and 

 on my five acres of alsike clover ? Why 

 did they destroy their queen cells as 

 soon as these tiger-flies appeared ? and 

 why does my trial-hive increase in 

 weight immediately after the daily hunt 

 for them, showing conclusively that 

 they had considerably lessened ? 



From July 27th, I have had a hive 

 placed permanently on a Howe scale, so 

 that I could make close observations. 

 On every clear day, from 1 to 2% lbs. of 

 bees would by 10 or 11 in the morning 

 have left the hive. By the time that 

 darkness set in, my scale showed very 

 near the same weight as in the morning. 

 From July 27th to Any;. 15th, the trill 

 hive had lost l, 1 ^ lbs. On the latter day 

 (after a few dark days had passed) I 

 found that Asilus sericeush&d nearly dis- 

 appeared,that ■Era.r bastardi had entirely 

 vanished, and that of all the Asilus Mis- 

 souriensis caught that day, only 1 was a 

 female ; the balance (20) were males. 

 That same evening my trial hive indi- 



