THE MONTHLY HI LLETIN. 



Ill 



Scymnus Sordidus Born. 



Several species of the ladybirds belonging to the genus Scymnus are 

 of some importance as enemies of i he mealybugs. Perhaps the one most 

 rally found is Scymnus sordidus. Tins ladybird is a very small 

 brownish insect, about one-eighth of an inch in length. Its eggs are 

 deposited in the mealybug colonies and the larvae are covered with a 

 white cottony wax. very similar to the preceding species of ladybirds. 

 This species is sometimes very effective as an enemy of mealybugs, 

 although its small size places it at a certain disadvantage. The ladybird 

 is found generally distributed throughout the southern part of the state, 



as well as sometimes in the north, and f Is on various suit-bodied 



insects, including the aphids. 



Fig. 33. Scymnus 

 latus Lee, An im- 

 portant ladybird enemy 

 "i the in e a I y b u g s. 

 1 1 iriginal.) 



Scymnus Guttulatus !.<■■ 



Like the preceding, this tiny ladybird becomes at times of considerable 

 importance as an enemy of the citrus mealybug. We have found it 



especially abundant at Marysville, where it is abl icasionally to free 



the host plants from the pest. The adult beetle 

 is small like the preceding, general ground color 

 dark, mottled with a light brown. The larva'. 

 like other species of Scymnus. are covered with 



• cottony filaments. The species apparently 



ui-ciirs throughout the entire state, but su far 

 as my observations have gone is mosl abundant 

 in the Sacramento Valley. 



Scymnus Marginicollis Mann. 



This native species 



-urs throughout 



the entire state and 



feeds upon all kinds 



of scale insects. 



Since it is not con- 

 fined to mealybugs its in- 

 crease upon these insects is 

 not generally very rapid, 

 although in combination 

 with other predators it is 

 of considerable value. The 

 adult beetle is of a dark 

 brown or blackish color, 

 with the prothorax and 

 head brownish-red. 



Scymnus Bipunctatus 

 Kugelann. 



This ladybird was 6rs1 



introduced into California 



in 1910 by Mr. George 

 Compere, under the name of Cryptogonus orbiculus. It was found by 

 him in the Philippine Jsbmds. and later in the same place by the writer. 

 It is a most effective enemy of mealybugs in its native habitat, and this 



Fig. 35. The mar- 

 gined Scymnu s, 

 Scymnus marginicol- 

 iliim. Adult fe- 

 male enlarged ten 

 times. (After E 



I'i. 



Ujtus in tlii' acl 

 ■ I ro ii' ' mealybug. 



mill.) 



