The Role of Plesiochrysa ramburi (Shneider) (Neuroptera: Chrysopidae), to Control Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) at Cassava in West Java, Indonesia

Mealybug Phenacoccus manihoti (Hemiptera: Pseudococcidae) is new invasive pest which have been attacked cassava in Indonesia.  This pest can cause loss of yield about 80%.   At this time in Indonesia cassava increasingly developed as a food and non-food industries, the pests will reduce the production of cassava if control measures are not taken.  Biological control  is one of alternative control which have developed using natural enemies such as parasitoid and  predator.  The result of cassava survey in field was showed that there are natural enemies were dominant is Chrysopidae Plesiochrysa ramburi .  Potential experiment of P. ramburi in laboratorium was showed  that eating preferences 3rd instar larvae of P. ramburi the second instar nymphs of P. manihoti has the highest preference index is equal to 0.159.  Third instar larval stage is a phase most potential predators to control P. manihoti because it has the longest stage with an average length of instars 3-4 days.  On treatment with a single-stage feeding prey (non-choice) showed that, three larval instars highest predation predator doing an average of 439.35  prey. While on treatment provision prey with diverse prey (choice) indicates that there is the composition of the selection of prey during the larval stage of P. ramburi on P. manihoti is 303.25 (The first instar), 285.45 (second instar), 102.2 (third instar), and 66.25 (adults).  Third instar larvae functional response of P. ramburi on P. manihoti including the second type  functional response.