Pear-bedstraw aphid
Dysaphis pyri
Identification: Adult apterae of Dysaphis pyri medium to rather large globe-shaped, brownish-red to dark brown aphids. They are thickly coated with wax meal. The antennae are pale yellow near the base, but darker towards the apex.
The first 5 abdominal tergites have a double row of small dark spots. Hemispherical marginal tubercles are usually present only on abdominal tergites 1-5. The siphunculiare black and perpendicular to the body. They are 3.4-4.1 times their diameter at midpoint, and longer than the cone-shaped cauda. The adult aptera has a body length of 2.1-3.2 mm. Immature Dysaphis pyri are a pale yellowish brown, with reddish suffusion around the bases of their siphunculi.
The primary host of Dysaphis pyri is common pear (Pyrus communis). Leaves and shoots are yellowed and distorted to form a pseudogall(see second picture above). After about three generations on pear, alatae are produced which migrate to the secondary hosts. These are bedstraws, especially hedge bedstraw (Galium mollugo) and cleavers (Galium aparine) and sometimes squincywort (Asperula cynanchica).Dysaphis pyri may form colonies on the roots and prostrate stems, where it is attended by ants.







