256 



ELEMENTARY ENTOMOLOGY 



they are so fond. Wherever aphides which produce honey-dew 

 are abundant, the ants will be found watching over them, warding 

 off parasites and often transporting them from plant to plant when 

 food becomes scarce. Now and then an ant may be seen to tap 

 an aphis with its antennae, when a drop of the honey-dew will be 

 exuded and greedily lapped up. So well do they herd them that 

 the aphides have been aptly called the ants' little green cattle. The 

 relation of some ants to plant-lice is most remarkable, as in the 

 case of the little brown ant (Lasius nigcr americanus) which cares 



for the eggs of the corn root-aphis in its 

 ; f ; nest over winter and then carries the 



*' .' .* * 



aphides to the roots of weeds and grasses 

 and then to corn roots in the spring. It is 

 this relation of the ants to aphides which 

 makes many species of decided economic 

 importance to the farmer and necessitates 

 his destroying them as far as possible. 

 There are several families of ants, but 

 most of our common forms are included 

 in two large families. 



The typical ants (Camponotidae) have but 

 one segment to the petiole of the abdomen, 

 and have no sting. The large, black car- 

 /, Camponotidae; 2 , Poncri- penter-ant (Ccimponotns penusylvanicns), 



dac ; j, Mynnicidae ; a, tho- i i i 



rax; b, first abdominal seg- which tunnels out dead or dying trees, 

 ment ; c, second abdominal logs, an( j timbers, is a well-known example 



segment ; </, third abdominal _ . 111-1 



segment. (After Kellogg) oi one oi our larger species, and the little 



brown ants of the genus Lasins make their 



nests along roadways and in pastures and meadows, and include the 

 species which care for the corn root-aphis and other injurious 

 plant-lice. Some of the species make large mounds for their 

 homes, and others are slaveholders, capturing the ants of other 

 colonies and maintaining them in servitude. 



Stinging ants. In the Mynnicidae the petiole of the abdomen 

 is composed of two segments, and most of the females bear a sting. 

 The little red ant (Monomorium pharaonis] which often infests our 

 pantries is well known, but fortunately has no sting. The so-called 

 agricultural-ants of the southwest belong to this group. Their 



FIG. 406. Lateral aspects 

 of abdomens of three fam- 

 ilies of ants 



