THE INFLUENCE OF VARIOUS APHID SPECIES AS FOOD FOR THE 

 LADY-BIRDS COCCINELLA 7-PUNCTATA L. 

 AND ADALIA BIPUNCTATA L. 



Сравнение влияния некоторых видов Twieü в качестве пищи божьих коровок 



Goccinella 7 -punctata L. и Adalia bipunctata L. 



/. HODEK 



(Entomological Laboratory of Czechoslovak Academy of Sciences, 

 Praha, Czechoslovakia) 



On the basis of numerous investigations the aphidophagous lady-birds 

 were considered polyphagous their ordinary food being not only all aphid 

 species, but also other insects. Only a fcAv allusions in the literature spoke 

 against the universal view (Johnson, 1907, Tëlenga, Bogunova, 1936, 

 Radzievskaja, 1939, George, 1957). 



As demonstrated by a series of exact long-term food experiments this con- 

 ception is liable to criticism. Aphidophagous coccinellids may be polyphagous 

 — but this quality does not exclude a kind of food specialization. This opinion 

 has been expressed by various authors as Moursi, Kamal (1946), Djadec- 

 ko (1954), Ibrahim (1955) and Putman (1955 — analogically, by the aca- 

 rophagous lady-bird). 



By means of experimental breeds of Coccinella 7 -'punctata L. it was ascertain- 

 ed the suitable prey being the aphids Aphis {Doralis) fabae Scop., Pergan- 

 cleicla medicaginis Koch, Hyalopterus pruni L., Urofnelan aeneus Hrl. The 

 aphid Aphis sambuci L. proved to be a highly detrimental food causing in- 

 variably the total extinction of larval breeds after 25 — 26 days. The daily 

 consumption of this food Avas excessively reduced compared to controls 

 and the larvae were considerably retarded in their development. The alternating 

 of suitable and unsuitable food during the larval development proved that 

 the negative effect of this aphid food affected all the larval stages. Most sensible 

 appeared to be the last stage with the greatest food consumption. 



Young newly emerged lady-birds C. 7-punctata were equally sensible 

 towards Aphis sambuci as the larvae. Imaginai breeds fed on this aphid 

 from their emergence finished again with the complete dying-out within 

 17,5 days. 



Early in spring the lady-birds С 7-punctafa having left their hibernacula 

 can be seen on the shrubs Sambucus nigra L. consuming the colonies of A. 

 sambuci. Accordingly, old imagoes could be considered more resistent against 

 the detrimental effect of A. sambuci. Experiments made in this direction 



314 



