Laboratory Study of Interspecific Predation of Green Lacewing,<i> Chrysoperla carnea </i>(Steph.) and Ladybeetle, <i>Hippodamia variegata</i> (Goeze)

The interference of biological agents may cause behaviors such as interspecific predation, reducing their efficiencies. The interspecific predation of lacewing, Chrysoperla carnea (Steph.) and ladybeetle, Hippodamia variegata (Goeze) was investigated in the presence and absence of prey, Aphis gossypii Glover under laboratory conditions. In the presence and absence of prey, the larvae of lacewing fed on eggs, larvae, pupae and adults of ladybeetle and the larvae and adults of ladybeetle fed on eggs and larvae of lacewing. Presence of prey reduced the rate of feeding significantly. Feeding of lacewing larvae on ladybeetle eggs was higher than the feeding of ladybeetle larvae and adults on lacewing eggs. This is probably due to the stalk of lacewing eggs. The 1st larval instar of lacewing was dominant to that of ladybeetle, so were 2nd larval instar of lacewing to the 1st and 2nd larval instars of ladybeetle and 3rd larval instar of lacewing to all larval instars and adults of ladybeetle. Third larval instar of ladybeetle was dominant to the 1st larval instar of lacewing, and 4th larval instar and adult of ladybeetle to the 1st and 2nd larval instars of lacewing. The 2nd and 3rd larval instars of lacewing fed on pupa of ladybeetle but larval feeding of ladybeetle was not observed on lacewing pupa. This was probably related to lacewing pupa covered by a cocoon.