Hyalesthes obsoletus

Question 1

Answer 1

Hyalesthes obsoletus

Question 2

How many instars for hyalesthes obsoletus?

Answer 2

5 instars

Question 3

Life history

Answer 3

• 1 generation per year
• overwintering as 4th instar nymphs on roots of herbaceous plants

Question 4

Damage of Hyalesthes obsoletus

Answer 4

The leafhopper isnt directly harmful to the plant, but is a vector for bois noir phytoplasma

Question 5

In terms of cycles how is S. Titanus different from Hyalesthes obsoletus?

Answer 5

HO has an open cycle in that it can go to a different plant in its lifetime and then return to the grapevine, while S. Titanus stays its entire life on the grapevine

Question 6

What is Stolbur and is it rare or common?

Answer 6

Stolbur is Bois noir and it is very common on weeds

Question 7

Important consideration for the control

Answer 7

Avoid insecticide control of the vector as nymphs are in the soil and adults are polyphagous

Question 8

What is Xylella fastidiosa

Answer 8

A phytoplasma from central america, It lives in xylem vessels of the plant and can be transferred by xylem feeding insects such as Homalodisca in America

Question 9

Answer 9

Homalodisca

Question 10

Who is the main vector in Italy?

Answer 10

Philaenus spumarius

Question 11

Where is the Xylella in Philaenus?

Answer 11

It resides in the insect foregut and doesnt enter the body. Nymphs loose infectivity after molting because the foregut is also shed

Question 12

Life cycle of the Philaenus

Answer 12

Overwintering occurs in the plant collar, they look like little white bubbles. There are 5 nymphal stages and adults emerge in April

Question 13

Are they polyphagous?

Answer 13

Yes

Question 14

Vine mealy bug

Answer 14

Pseudococcus spp.

Question 15

Answer 15

Pseudococcus spp.

Question 16

Pseudococcus spp. is also known as…

Answer 16

Planococcus ficus it is a phloem feeder and prefers grape, but has a wide range of hosts

Question 17

Life cycle

Answer 17

they can be spread by wind, birds, ants, farm equipment, farm workers
3-7 generations per year
More than 500 eggs per female

Question 18

Another mealy bug is the

Answer 18

Heliococcus bohemicus

Question 19

HB is important because it is…

Answer 19

A vector for GV

Question 20

Grapevine phylloxera

Answer 20

Daktulosphaira vitifoliae

Question 21

Reproduction of phylloxera

Answer 21

An asexual fundatrix hatches from the overwintering egg and lays eggs on roots or leaves.

Question 22

Difference between feeding activities on leaves or roots

Answer 22

Feeding on leaves results in galls called gallicoles, while feeding on roots results in galls called radicoles