THE NATURAL ENEMIES OF THE CITRUS MEALY BUG 11 261 



Maxillaries inserteill under the mandibles; basal maxillary sclerite is short, 

 indefinite, and inserted on the head ; the second maxillary sclerite is flattened, 

 large, extending forward and uniting the greater part of its length with 

 the second sclerite of the labrum. The exterior lobe does not exist. The 

 interior lobe is carnose, widening, provided with an appendage of two articles, 

 slightly inclined, and situated on the apex of which are some hairs or bristles. 

 Maxillary palpi three-articled, large, strong, hard, conical, slightly bent, and 

 provided with a few bristles. The third article of the palpus is large, and 

 conical with the point obtusely rounded and provided with conical sensoria- 

 like structures. The second sclerite of the labrum is large, widening, and 

 unites on the under side with the maxillary stipe. The stipes of the diverging 

 labial palpi are united. The labial palpi are inclined slightly upward, conical, 

 strong, two-articled, the apical article is conical, largest and well-rounded at the 

 point, which is provided with numerous conical sensoria. Without ligula. 



Thorax with three distinct segments. Prothorax longer and narrower than 

 the mesothorax and metathorax which are almost equal. 



Legs consisting of coxa, trochanter, femur, tibia, and claw. Coxa short, 

 conical, length less than one-third the width of the base. Trochanters much 

 shorter and narrower than the coxs. Femur large, nearly cylindrical, curving 

 slightly inward, much longer than the coxa, where it unites with the trochan- 

 ter it is small and obliquely truncate permitting great flexibility in the joint. 

 Tibia large, nearly cylindrical, sparcely bristly on the exterior surface and 

 densely bristly on the interior; generally longer than the femur and claviform 

 in shape. Claw one on each leg, curving downward and inward and thickened 

 at the base. 



Abdomen straight, more or less flattened, wider than the thorax and 

 gradually tapering posteriorly ; with nine distinct segments. The last seg- 

 ment is generally much narrower than the other eight. Anal tube mem- 

 braneous and retractile ; can be extended and is used in locomotion. 



Habit active, and usually living upon plants infested with Aphids, Coc- 

 cids, and other small insects on which they feed. Usually diurnal. 



L,arva moult four times in development. 



For convenience the larvse of the family were placed in five groups 

 by Dimmock, as follows : 



1. Larvae with tubercles producing bristles. These larvae are great Aphid 



feeders. A few are adorned with brilliant colors. The shape is gen- 

 erally fusiform with the body flattened. The nymphs are bare. 



2. Larvas with short stout spines, some having very small spines or bristles. 



Generally flattened and fusiform ; adorned with many bright colors ; 

 great Aphid feeders; nymphs usually bare. The larvre of Exochomus 

 forms a transition from this group to the next, the larva; of which 

 are mostly Coccitl feeders and the nymphs remain in the larval skins 

 in transforming. 



2. Larve with short, stout spines, some having very small spines or bristles. 

 The nymphs remain in the skins of the larvae in changing to adult. 



