AGRICULTURAL NATURE STUDY OUTLINES 
63 
2. Beneficial 
a. Attacking Insects 
1. Common red black-spotted ladybird beetle ( Hippodamia convergens). 
2. The vedalia ( Novius cardinalis). 
3. Large syrphid fly ( Syrphus pyrastri). 
4. Parasite of European Fruit Lecanium (Cornys fusca). 
5. Scutellista (Scutcllista cyanea ). 
b. Pollenizers 
1. Blastophaga (Blastopliaga psenes ). 
2. The honey bee (Apis mellifica). Also producer of a very important 
commercial product. 
III. TROUBLESOME WEEDS IN CALIFORNIA FOR STUDY 
IN THE RURAL SCHOOLS 
By PROFESSOR P. B. KENNEDY 
Morning Glory (Convolvulus arvensis). —Occurring first as patches which may 
spread eventually over entire fields if not controlled. Troublesome in 
garden, orchard, and fields. A creeping plant with pernicious underground 
stems. Eradicated by suppression of the leafage which starves the 
rootstocks. 
Johnson Grass (Andropogon halepense). —Troublesome only where winters 
are not severe as in southern California. Has large rooastocks which may 
penetrate to a depth of 4 feet in the orchards and fields. Eradicated by 
severe and continuous pasturing or by same method as morning glory. 
Dodders or Love Vines (Cuscuta sp.). —Parasite on alfalfas and clovers, suck¬ 
ing the nourishment from them for their own use and finally destroying 
and taking the place of the host plant. Remedy, sow clean seed. Eradi¬ 
cation by cutting and burning before going to seed. Reseeding with grass 
or grain or tillable crop for a period of one or two years. Then replant 
to alfalfa, using clean seed. 
Mustards (Brassica sp.).—Some produce as many as 15,000 seeds on a single 
plant. Troublesome chiefly in grains, especially in regions of continuous 
cropping. Seeds will lie dormant in the ground a long time, ten or fifteen 
years, and yet when brought near the surface will germinate. Remedy, 
clean seed and summer fallowing. Harrowing grain when young to destroy 
young and tender mustard plants. Spraying with iron-sulphate. 
Barnyard Grass or Water Grass (Echinochloa crus-galli).— Unusually trouble¬ 
some in rice fields, finally choking rice out. Sometimes three-fourths of 
the rice crop is water grass. Remedy, clean seed and pulling out and 
cutting the plants off below the crown with a hooked knife. Making clean 
and perfect seed bed so as to give the rice plants every chance. 
