- The Hop Aphis (Phorodon After the Coccidae the next most important insects male; C, ovigerous wingless female; economically are r the plant lice or A phididae.
An example of the latter is seen in the hop aphis FIG.
Another aphis of importance is the woolly aphis (Schizoneura lanigera) of the apple and pear: it secretes tufts of white flocculent wool often to be seen hanging B D E humuli).
Genera: Blatta, Mantis, Gryllus, Fulgora, Cicada, Notonecta, Nepa, Cimex, Aphis, Chermes, Coccus, Thrips.
The Chinese galls of commerce (Woo-pei-tsze) are stated to be produced by Aphis Chinensis, Bell, on Rhus semialata, Murr.
Lichtenstein has established the fact that from the egg of the Aphis of Pistachio galls, Anopleura lentisci, is hatched an apterous insect (the gall-founder), which gives birth to young Aphides (emigrants), and that these, having acquired wings, fly to the roots of certain grasses (Bromus sterilis and Hordeum vulgare), and by budding underground give rise to several generations of apterous insects, whence finally comes a winged brood (the pupifera).
The " woolly aphis," " American blight," or " larch blight " (Eriosoma laricis) often attacks the trees in close valleys, but rarely spreads much unless other unhealthy conditions are present.
The aphis, or " green fly," must also be destroyed; tobacco may be used.